RLN2 and its role in cancer

 

Jordan M Willcox and Alastair JS Summerlee

Department of Biomedical Science,
Ontario Veterinary College, University of Guelph,
Guelph, Ontario N1G 2W1, Canada

 

July 2009

 

 

* To whom correspondence should be addressed. Email: jwillcox@uoguelph.ca


Key words:
Relaxin, cancer, metastasis, tumour invasion, angiogenesis



Abstract
There is clear evidence that relaxin (RLN2 9p24) is involved in tumorigenesis. Relaxin, and a family of related peptides, has significant actions on connective tissue, cell growth and death and vascularization. Originally identified and named for its action on relaxing the ligaments of the pelvic girdle, over the last thirty years a picture has emerged that relaxin is involved in a number of critical tissue and cellular functions which are important attributes of cancer development and growth. This review provides an overview of the relaxin superfamily and focuses attention on evidence that relaxin is involved in different aspects of tumorigenesis.

I. Introduction
In 1926, F.L. Hisaw reported that injection of serum from pregnant guinea pigs or rabbits into virgin guinea pigs resulted in relaxation of the pubic ligament (Hisaw, 1926) and, shortly after in 1930, was able to develop an aqueous extract of this relaxative agent (Fevold et al., 1930). The hormone was named "relaxin" - it was one of earlier peptide hormones to be discovered and its method of discovery and its name have left an indelible impression that it is a hormone of pregnancy. But almost one hundred years on, the hormone is now known as one of a family of related peptides with putative and accepted roles in a variety of tissues and organs throughout the body and across many animal species from paramecium to humans.
Despite its relatively early discovery, relaxin research was hampered by technological barriers - primarily the lack of an ability to isolate pure extracts of relaxin. However, in 1974 techniques were developed to isolate and produce large quantities of purified hormone spawning a renewed interest in relaxin research (Sherwood and O’Byrne, 1974). Relaxin was isolated from a number of species and purified forms were used to determine its primary structure, develop a radioimmunoassay, identify actions in a number of tissues, and develop monoclonal antibodies and knock-out mice to elucidate its action (Bathgate et al., 2006a). But almost all the reports focused on its role in the female (Sherwood, 1994). Although there were reports of its presence in males or in non-reproductive tissue, the predominant focus of relaxin research was in its role as a hormone of pregnancy.
The first substantive observation that relaxin might have actions outside of the reproductive system was published by Summerlee and co-workers in 1984 who showed that relaxin affected the release of other peptide hormones from the brain. Since this discovery, many other actions of relaxin have been identified in tissues ranging from the heart and vascular system (Han et al., 1994), kidney (Novak et al., 2001), and neoplastic tissue (Silvertown et al., 2003). It is now clear that relaxin acts on a multiplicity of tissues in males and females (Bathgate et al., 2006a).
The advent of molecular techniques paved the way to cloning the first relaxin gene: cloning the rat (Hudson et al., 1981) and porcine (Haley et al., 1982) relaxin genes confirmed previous work that relaxin is structurally similar to insulin and is synthesized as a prohormone with three distinct regions or chains designed A, B and C. The A and B chains, with a characteristic signature of disulphide bridges cementing the tertiary structure, form the mature hormone but as relaxin was cloned from different species a remarkable lack of sequence homology between species was confirmed. Two human relaxin genes were cloned - RLN1 (Hudson et al., 1983) and RLN2 (Hudson et al., 1984). We now know that the second of these genes RLN2 is the gene encoding the relaxin peptide produced in the corpus luteum and released in the circulation in women. It is the ortholog of circulating relaxins in other species and is known as H2 relaxin and has more recently been named systematically as RLX2 (Bathgate et al., 2006b).
The availability of recombinant H2 relaxin and the availability of genome databases rapidly led to the discovery that there were five novel genes with high homology to relaxin: four of these were named insulin-like peptides (INSL) - designated 3-6 (Adham et al., 1993; Chassin et al., 1996; Conklin et al., 1999; Hsu, 1999; Kasik et al., 2000; Lok et al., 2000). The insulin-like peptides do not share the relaxin-binding motif and are unable to mimic the actions of relaxin. Interestingly, in 2002 Bathgate and co-workers reported on a new relaxin gene with almost exclusive expression in the brain; termed RLN3 this discovery also provided researchers with new avenues for study with respect to the central actions of relaxin (Bathgate et al., 2002). Further studies investigating the sequence of RLN3 provide evidence that this peptide is indeed the ancestral form of all relaxins, insulin-like peptides, and insulin itself leading researchers to classify this group of peptides as a family of hormones (Hsu, 2003; Wilkinson et al., 2005; Bathgate et al., 2006b).
Concurrent with the rapid expansion in our knowledge of relaxin genes, there has been a substantial growth in our knowledge of the potentially physiological actions of relaxin; indeed there may be instances where relaxin has pathological actions (e.g. cancer). The hormone acts on a variety of tissues including connective tissue (Unemori and Amento, 1990), blood vessels (Bani, 1997) and neurons (Geddes and Summerlee, 1995) and on a number of organs including the brain (Geddes and Summerlee, 1995), heart (Han et al., 1994), and on the male and female productive reproductive tracts (Sherwood, 2004). And most recently has been implicated in tumour biology (Silvertown et al., 2003a) with a number of putative roles including modulation of tumour growth, neovascularization, migration and tumour progression (Silvertown et al., 2003a; ; Silvertown et al., 2006, Silvertown et al.,2007). The purpose of the current review is to focus on the potential role of relaxin in facilitating and supporting tumour development and metastasis and spread but before highlighting some of the key actions of relaxin in cancer, it is important to highlight one other fascinating feature of this unique, pleiomorphic hormone - the nature of its receptors.
Once again, the story of the discovery of "the" relaxin receptor is remarkable - remarkable for three reasons: (1) it took almost eighty years from the discovery of the hormone to the first receptor was identified (Hsu et al., 2002); (2) despite the structural similarities and in some cases sequence homology with insulin, relaxin appears to use a completely different family of receptors (Hsu et al., 2002; Kumagi et al., 2002; Liu et al., 2003a, Liu et al., 2003b; Liu et al., 2005) from insulin; and (3) there are several receptors and specific ligand-receptor pairings and even some specific peptide and species specific interactions between ligands and receptors (Bathgate et al., 2006b) that may complicate our understanding of the way these hormones may bring about their effects at the cellular level.
With all these complexities, it is important to understand and situate the biology of RLN2 9p24 within the framework of the family of peptides and to appreciate that the observations about the potential role of relaxin in cancer biology in one species may not necessarily be extrapolated to another species. There have been a number of critically important reviews of the actions of relaxin published over the years which provide a more detailed account of the history, chemistry and biology of relaxin (Sherwood, 1994; Schwabe and Büllesbach, 1994; Goldsmith et al., 1995; Bani, 1997; Ivell and Einspanier, 2002; Bathgate et al., 2003; Dschietzig and Stangl, 2003; Samuel et al., 2003; Silvertown et al., 2003b) and conference proceedings from meetings in 2000 (Tregear et al., 2001), 2004 (Sherwood et al., 2005) and 2008 (Bryant-Greenwood et al., 2009a). However, the current review is focused on the role of relaxin in cancer. It therefore outlines the isolation and cloning of relaxin and the relationship between the relaxin family of genes using RLN2 as the principal reference point. We then provide information on identification of the binding sites and receptors for relaxin and the actions of relaxin, primarily in non-reproductive tissues, that might underlie roles of relaxin in cancer biology. Finally, we review the evidence that supports the contention that relaxin has a role in the development and maintenance of cancer and in metastasis. We conclude with some remarks about the opportunities and challenges for further work in this field.

II. Isolation and purification of relaxin
The initial work isolating and purifying relaxin was published by Fevold et al., (1930) who reported that relaxin was probably a peptide as it was soluble in water, amphoteric and could be readily digested by trypsin (Fevold et al., 1930; Fevold et al., 1932). However, the early studies were limited by the lack of techniques for isolating and purifying proteins and by the lack of an ability to determine the purity of a substance. A significant break-through was achieved by Sherwood and O’Byrne (1974) who described a procedure for isolating the peptide in high yields from pig ovaries in kilogram quantities. For the first time it was possible to sequence the hormone and show the similarity between relaxin and insulin (Figure 1).

Figure 1: The structure of porcine relaxin (equivalent to H2 relaxin) and porcine insulin to illustrate the similarities and differences between the two peptides. The residues are numbered according to the insulin sequence to facilitate comparison. There are minor differences between three forms of porcine relaxin reported (CMB, Cma and Cma') which are shown on the B Chain of porcine relaxin. There are minor differences in the lengths of the B Chain between residues 25 and 26, 26 and 27 and 28 and 29 respectively. The amino acids which are identical in the two hormones are circled and those which contribute to the hydrophobic core of insulin and the comparable positions in relaxin are underlined.

Much of the work done on the structure of relaxin has been focused on the isolation and purification in three species - the pig (Sherwood and O'Byrne, 1974); the rat (Sherwood, 1979) and the horse (Stewart and Papkoff, 1986). The comparisons between these three types of relaxin underscore that despite the overall framework of two peptide chains held together in a characteristic tertiary conformation with an approximate molecular weight of roughly 6000 Da, there is considerable heterogeneity. Despite the notion that sequence homology is not highly conserved between species, three invariant structural characteristics are highly conserved: (1) the overall two-chain structure designated A and B; (2) the location of the disulfide bridges yielding the tertiary structure of the peptide; and (3) because the tertiary structure is highly conserved, the distinctive binding motif (R-x-x-x-R-x-x-I/V) is exposed and confers biological activity of the peptide.
Isolation of human relaxin did not occur until the late 1980s and early nineties because the hormone is present in lower concentrations in human tissues and initial attempts to isolate the hormone were confounded by lack of purity of the isolate but eventually sufficient hormone was extracted and purified for amino acid sequence analysis from human relaxin corpora lutea (Winslow et al., 1989) and later Winslow et al., (1992) were also able to extract relaxin from seminal plasma and show that the luteal and seminal relaxin were identical.
The heterogeneity of relaxin between species is remarkable with differences in lengths of the chains - particularly the B chain and considerable differences and differences within the chains. In some animals, the B chain is particularly long, for example, the domestic dog (Canis familiaris) (Stewart et al., 1992) and the skate (Raja erinacea) has the longest B chain (Büllesbach et al., 1987): in some species not only is hormone different but its biological activity is considerably different - for example, shark relaxin shows very poor bioactivity in the mouse interpubic ligament bioassay (Büllesbach et al., 1986, Reinig et al., 1981); whilst in some species there is an astonishing conservation of amino acid sequence - for example, there is virtually no difference between porcine (Sus scrofa) relaxin and relaxin obtained from a mike whale (Blaenoptera acutorostrata) (Schwabe et al., 1989) or the porpoise (Phocaena phcaena) (Woods et al., 1991).

III. Cloning of relaxin
Work began on the cloning of relaxin genes with the activities of Niall and colleagues (Hudson et al., 1981; Haley et al., 1982) who determined the complete amino acid sequences of porcine (Haley et al., 1982) and rat (Hudson et al., 1981) preprorelaxin by cloning of relaxin cDNA. They confirmed that relaxin is synthesized as one single chain peptide with a signal tail connected to the B chain, a connecting peptide and the A chain in that order. Since then, first porcine (Haley et al., 1987) and then rat (Soloff et al., 2003) relaxin genes were cloned from genomic libraries. The sequences are identical in both circumstances with the potential of a single allelic variation in the porcine sequence (Haley et al., 1987) and the structure conforms to the gene structure for all relaxin genes.
There has now been analysis of the genomic DNA from humans, primates, pigs, rats and mice and their general structure is similar. There is a consistent view that an intron interrupts the coding region at the Glu in position 46 of the C peptide (Hudson et al., 1983; Haley et al., 1987; Crawford et al., 1989; Evans et al., 1993; Soloff et al., 2003) and the position of this intron matches that of one of the two introns found in insulin genes (Bell et al., 1980). Although there is no evidence of the second intron seen in insulin (Bell et al., 1980).

Figure 2: Schematic representation of the transcription of the human RLN2 gene. Adapted from Bathgate et al. 2006a (with permission). The gene is located with the RLN1, INSL4 and INSL6 genes on chromosome 9 at 9p24. The RLN2 gene consists of two exons and is transcribed to give preprorelaxin-2 mRNA. Exon I encodes for the signal peptide, the B Chain and part of the C Chain, and Exon II encodes for the remainder of the C Chain and the A chain of H2 relaxin. The arrows on the diagrams indicate the orientation of the genes. Although insulin and H2 relaxin are similar, there is no report that the insulin gene posses an intron.

IV. Relaxin-family of related peptides
The first hint that there might be other members of the relaxin family came in the early 1990s when two groups independently identified a new cDNA clone that was differentially expressed in porcine (Adham et al., 1993) and mouse (Pusch et al., 1996) testis. The newly identified clone encoded for a protein that was structurally similar to insulin and relaxin. In both cases the cDNA was highly expressed in the Leydig cells and initially known as Leydig cell insulin-like peptide (Adham et al., 1993) and relaxin-like factor (Büllesbach and Schwabe, 1995) which provides some confusion in the early literature. Subsequently, the gene for this peptide was cloned from human, porcine, mouse and rat (Burkhardt et al., 1994; Koskimies et al., 1997; Zimmerman et al., 1997; Spiess et al., 1999) and showed to be a single-copy gene similar to the relaxin gene - two exons and a single intron in the middle of the coding for the C-peptide - remarkably similar to relaxin. (See Figure 2). The name of this new member of the relaxin family was rationalized to insulin-like peptides and the peptide produce from this particular gene designated INSL3 because it was the third insulin-like gene to be discovered.
Although the gene for INSL3 was discovered in the early 1990s, it was not until 2002 that the structure of INSL3 synthesized in vivo was identified (Büllesbach and Schwabe, 2002). Comparing the predicted and the actual sequence of the peptide revealed another surprise about these relaxin-like peptides: the A chain of bovine INSL3 was exactly as predicted but the B chain is longer by 8-9 amino acids - paradoxically the longer, naturally-produced INLS3 is less bioactive than an artificially synthesized version with a shorter B chain (Büllesbach and Schwabe, 2002). This implies that there may be mechanisms for processing relaxins once it is released or at the target tissue. Although this observation has only been specifically verified for INSL3, there are reports that transfected cells in vitro and in vivo with a cDNA for prorelaxin (H2 relaxin) will produce a peptide that appears to be prorelaxin which is as biologically active as relaxin. Such a possibility raises more questions about the possibility to there could be local control at the site of action for relaxin and members of the relaxin family of peptides that might be critical in cancer or in mitigation of the effects of relaxin in cancer.

V. The Evolving Story of the Relaxin Family of Peptides
In total, six human relaxin-like genes have been discovered. These are shown in Table I along with their specific chromosomal location. The key facet that links these genes and their products is the greater similar to relaxin (H2) than to either insulin or the insulin-like growth factors although there are clearly similarities across these three groups (Hsu, 2003). Phylogenetic analysis has revealed that there is a common ancestor (Hsu, 2003) and this is most likely to be the third relaxin gene that was identified most recently (RLN3) and is located predominantly in the brain (Bathgate et al., 2002).
The similarities and differences among the relaxins, insulin and insulin-like growth factors are highlighted by their clustering on different chromosomes. These are illustrated in Figure 3. The focus of the remainder of the review will concentrate on RLN2 which is located on chromosome 9p24 closely associated with RLN1, INSL4 and INSL6 on the same chromosome.

Figure 3: Schema showing the human chromosomal locations of the 10 members of the relaxin and insulin-like family of peptides genes. The relaxin peptide family genes are in different locations from the insulin and IGF-1 genes. The human RLN1 and RLN2 genes map in a tight cluster with INSL4 and INSL6 genes on chromosome 9 at 9p24. The RLN3 gene is located on chromosome 19 at 19p13.3 in close proximity to INSL3 at 19p13.2. In contrast, the INSL5 gene is located in chromosome 1 at 1p31.1 and is not closely associated with the other relaxin-like genes.

Peptide name
Abbreviations
Gene name
Insulin INS INS
Insulin-like growth factor-1 IGF-1 IGF1
Insulin-like growth factor-2 IGF-2 IGF2
Relaxin-1 RLX1 (human H1) RLN1
Relaxin-2 RLX2 (human H2) RLN2
Relaxin-3 RLX3 or INSL7 RLN3
Insulin-like peptide 3
Leydig-insulin-like peptide
Relaxin-like factor
INSL3
Ley-I-L
RLF
INSL3
Placentin
Early placental insulin-like factor
INSL4
EPIL
INSL4
Insulin-like peptide 5
Relaxin-insulin-like factor 2
INSL5
RIF2
INSL5
Insulin-like peptide 6
Relaxin-insulin-like factor 1
INSL6
RIF1
INSL6
Table I
Members of the relaxin and insulin-like peptide family of genes.

VI. Binding sites and receptors for relaxin
Relaxin binding sites were identified in reproductive and non-reproductive tissue before the discovery of the relaxin receptor. The principal challenge was labeling pure hormone in a way that the labeled relaxin retained its biological activity. The early studies used two different techniques to label porcine relaxin: (1) iodination of tyrosine residues added to the N terminus producing a polytyrosyl-relaxin (Sherwood et al., 1975) or (2) incorporation of a 125I group directly into the N terminus of porcine relaxin (McMurtry et al., 1978). Both methods produced labeled hormone that was biologically active and binding sites were demonstrated in reproductive tissues such as uterus (McMurtry et al., 1978; Mercado-Simmen et al., 1980; Mercado-Simmen et al., 1982; Weiss and Bryant-Greenwood, 1982) and placental membranes (Koay et al., 1986). Binding sites were also reported in fibroblasts in human skin (McMurtry et al., 1980). Although neither approach yielded completely pure iodinated forms, binding of the radioactive labeled hormone could not be displaced by insulin, IGF-1 or IGF-2.
More recently, relaxin binding studies were expanded using a 32P (Osheroff et al., 1990) or 33P (Tan et al., 1989) labeled relaxin. Specific binding with the 32P labeled relaxin was confirmed in the uterus and cervix but also extended to the brain (Osheroff et al., 1990; Osheroff and Phillips, 1991; Osheroff and Ho, 1993). Interestingly, latter studies demonstrated binding in the rat heart atrium (Osheroff et al., 1992) and rat atrial cardiomyocytes (Osheroff and King, 1995).
In 1990, Büllesbach and Schwabe reported that the relaxin molecule could be biotinylated yet preserve its biological activity. Binding sites have subsequently been confirmed in the rat cervix, mammary gland and nipple (Kuenzi and Sherwood, 1995), cervix, mammary gland, nipple, small intestine, skin, ovary and testis of pigs (Min and Sherwood, 1998); the reproductive tract and breast tissue of women (Kohsaka et al., 1998); and prostate (Hornsby et al., 2001).
As a result of the chemical structure of members of the relaxin and insulin families of peptides and the evidence for the coevolution of the two peptide families and probably their receptors, it was assumed that receptors for relaxin and the INSLs 3-7 would be related to the known insulin receptors with tyrosine kinase activity. Indeed some of the initial work suggested that stimulation with relaxin resulted in tyrosine phosphorylation (Büllesbach and Schwabe, 2000). But the relaxin receptor remained illusive and attempts to purify the receptors were confounded by high levels of non-specific binding of tracer and apparently low levels of binding sites in target tissues.
At the turn of the twenty first century, there was a significant break through in relaxin receptor biology. Investigating the phenotypes of mice deficient in INSL3 (Nef and Parada, 1999; Zimmerman et al., 1999) two groups of researchers reported that bilateral cryptorcidism was a consistent feature of the INSL3 knock-out mouse and it was suggested that a leucine-rich glycoprotein receptor might be the receptor for relaxin (Hsu et al., 2002). It was shown that porcine relaxin stimulates both LGR7 and LGR8 receptors and results in increased cAMP (Hsu et al., 2002). Subsequent work has shown that LGR7 transcripts are located in a number of reproductive and non-reproductive tissues throughout the body. Although there is some evidence that relaxin activates both LGR7 and LGR8 there are clearly species differences in both the ability of relaxin to bind to LGR8 and the sensitivity of that binding (Bathgate et al., 2006b).
The complexity of the receptor-ligand story for relaxin was further compounded by the discovery that RLX3 has a relatively low affinity for LGR7 (Bathgate et al., 2002; Sudo et al., 2003). It now appears as if RLX3, which is located specifically within the brain, is a ligand to two orphan receptors GPCR135 (also known as somatostatin and angiotensin-like peptide receptor [SALPR]) and GPCR142 (Liu et al., 2003a; Liu et al., 2003b). There close links between the sites of concentration of these GPCR receptors and binding sites for relaxin and for relaxin-3 message (Osheroff and Phillips, 1991; Bathgate et al., 2006b) but low levels of GPCR142 message have also been reported in a variety of non-neural tissues throughout the body (Liu et al., 2003b).
Identification of receptors for relaxin created the possibility of confirming the intricate signaling cascade in normal and neoplastic tissues (Hsu et al., 2002; Kumagi et al., 2002; Sudo et al., 2003).

VII. Signaling pathways
Relaxin enacts its many physiological actions through a number of distinct signaling pathways that ultimately upregulate cAMP (Braddon, 1978; Sanborn et al., 1980; Sanborn and Sherwood, 1981; Hsu et al., 1985). Interaction of relaxin and its cognate GPCR stimulates cAMP production in a bi-phasic manner through GS to enhance the activity of adenylate cyclase (Halls et al., 2006). Relaxin has also been reported to act through Gbetagamma thereby activating PI3K and further increasing cAMP production (Nguyen et al., 2003; Nguyen and Dessauer 2005). Downstream signaling of PI3K has also indicated that relaxin stimulates PKCzeta to stimulate cAMP (Nguyen and Dessauer, 2005). PKA has also been implicated in the signaling cascade initiated by relaxin. Inhibition of PKA has been reported to reduce contractility of heart cells (inotropy) (Han et al., 1994) and also has been demonstrated to be involved in affecting contractility of the myometrium by modulating potassium channels (Meera et al., 1995). Taken together it is clear that relaxin stimulates profound changes in cAMP levels in many cell types and tissues in order to bring about diverse physiological actions.
Relaxin has also been demonstrated to affect expression of NOS expression both acutely and chronically (Nistri and Bani, 2003). Modulation of NOS expression has been reported in endothelial cells (Failli et al., 2001) and vascular smooth muscle cells (Bani et al., 1998). It appears that two NOS isoforms are implicated: NOSII (iNOS) is likely affected by chronic administration of relaxin (Quattrone et al., 2004) while shorter term NO production is likely through NOSIII (eNOS) (Willcox et al., 2009).
The intracellular signaling pathways affected by relaxin have a number of implications in cancer and may explain the invasive, growth promoting, and angiogenic phenotypes promoted by relaxin in tumours. Relaxin has been reported to increase cAMP levels in a number of tumour cell lines including MCF-7 breast cancer cells (Bigazzi et al., 1992), PC-3 prostate cancer cells (Silvertown et al., 2007), and MDA-MB-231 human breast cancer cells (Radestock et al., 2008). Liu and colleagues (2008) also reported an involvement of the PI3K/PKB (Akt) pathway in a LNCaP prostate cancer cell model. Taken together these studies indicate that congruent to physiological actions, relaxin retains a diverse signaling profile and an ability to activate multiple signaling pathways in order to promote tumour growth and invasion characteristics. Whether or not these pathways are working in parallel or converge remains to be elucidated and requires further study in order to further understand relaxin's action in these cancers and develop potential therapeutic targets to treat this disease.
Relaxin has also been reported to increase NO production through increased iNOS activity in MCF-7 breast cancer cells (Bani et al., 1995). In spite of this observation, whether or not this is a positive effect of relaxin remains to be determined. It is possible that this phenotype contributes to the inhibition of tumour cell growth by the inhibition of DNA synthesis and mitochondrial respiration (Silvertown et al., 2003) however conversely increased NO may also induce cellular resistance to apoptotic events thereby contributing to cellular growth of the tumour. However other studies investigating the effect of NO on tumour development clearly report on the increased tumour cell migration (Jadeski et al., 2003) and tumour cell growth and angiogenesis (Jadeski et al., 2000). Furthermore, relaxin-induced expression of NO may affect the blood supply of the tumour contributing to the increased blood supply required by tumours to promote their own growth. In a number of vascular beds, relaxin has been noted to increase NO and therefore induce vasodilation in tissues ranging from the heart (Fisher et al., 2002) to skeletal muscle (Willcox et al., 2009). Given that NO is a potent vasodilator and has been reported to increase blood flow (Di Bellow et al., 1995) and angiogenesis in mammary cancer (Jadeski et al., 2000) the fact that relaxin-induced NO signaling may play a role in the development of tumours presents opportunities for further and intruiging studies.

VIII. Biological actions of relaxin that might underlie a role in cancer biology
A number of actions of relaxin at the tissue and cellular level are also important components of tumour growth, development, and metastasis and present the possibility that relaxin is involved the progression of cancer. Its action modulating connective tissue, inducing angiogenesis and affecting cell growth and apoptosis are critical in tumorigenesis and metastasis.

Evidence that relaxin affects tumour growth and development
Relaxin, acting in concert with estrogen and progesterone plays a critical role in mammary gland development (Min and Sherwood, 1996; Winn et al., 1994). In the mouse, the hormone induces mammary growth and differentiation (Bani and Bigazzi, 1984). Conversely, mammary development is retarded and nipple development impaired in the relaxin-deficient mouse (Zhao et al., 1999). Although lactational changes do occur in the mammary tissue in the knock-out mice, the young are unable to suck milk and starve to death which confirms the essential role that relaxin plays in remodeling connective and epithelial tissue and development of the nipples. Similarly, both H1 and H2 relaxin are present in human breast and have been linked to normal development. They have also been implicated in neoplastic growth of the breast (Tashima et al., 1994; Mazoujian and Bryant-Greenwood, 1990; Bryant-Greenwood et al., 1994). Moveover, Tashima et al., (1994) reported the presence of relaxin (H2) transcripts were identified in 100% of neoplastic mammary tissue (benign and malignant) with relatively low proportions in non-neoplastic tissue. LGR7 receptors are present in both malignant human breast cancer tissues and in human mammary tumour cell lines (Silvertown et al., 2003a) suggesting that the neoplastic tissue is not only producing relaxin but is also a target for the hormone. The possible extracellular roles of relaxin in tumour growth, development and metastasis are discussed later in the review. Low concentrations of relaxin over short periods of time appear to promote the growth of breast adenocarcinoma cells in vitro (Sacchi et al., 1994; Bani et al., 1999) and Binder et al., (2004) reported that there are elevated circulating levels of relaxin in women with breast cancer - particularly those with metastatic disease. Relaxin stimulates invasiveness and migration of breast tissue, thyroid, and endometrial carcinoma cells in vitro and is accompanied by up-regulation of matrix metalloproteinase activity and expression of vascular endothelial growth factors (VEGF) (Binder et al., 2002; Kamat et al., 2006; Hombach-Klonisch et al., 2006). Prorelaxin 2 (the precursor of relaxin) also stimulates the invasiveness of canine mammary carcinoma cells (Silvertown et al., 2003b).
Similar to reports of the presence and action of relaxin in normal development of human breast tissue, relaxin is present in prostatic tissue (Ivell et al., 1989; Sokol et al., 1989; Hansell et al., 1991) and has been implicated in development and maturation of prostatic tissue in rats (Hornsby et al., 2001; Feng et al., 2007). The prostate gland undergoes a number of structural changes during life and prostatic hypertrophy and tumour are condition of men over 45 years of age (Carter and Coffey, 1990) with similar age-related changes reported in other species (Gann et al., 1996). Much of the work on the etiology of both prostatic hyperplasia and carcinoma and adenocarcinoma has focused on the role of steroid hormones (Montie and Pienta, 1994; Barret-Connor et al., 1990; Normura et al., 1988) but the findings are not entirely consistent and there is a persistent view that peptides may also be involved in the disease. There is a clear progression of the disease from hypertrophy to cancer which is characterized by an unresponsive switch to a differentiated state and uncontrollable proliferation of cells (Hanahan and Weinberg, 2000) reported in both men and male dogs (Nomura et al., 1988). The hyperplastic state is associated with a change in the connective tissue framework of the gland and a marked angiogenesis (Lissbrant et al., 1997): changes which are further exaggerated in the neoplastic state - both of these changes are hallmarks of the action of relaxin (Bathgate et al., 2006a; Bathgate et al., 2006b). Gunnerson et al. (1995) reported that the human prostate adenocarcinoma cell line LNCaP. FGC expresses high levels of relaxin transcripts which implies a link with prostatic cancer. Lentiviral-mediated delivery of relaxin into PC-3 prostate cancer cells increases growth of prostate tumour xenografts (Silvertown et al., 2006) and it has been shown that relaxin is a direct downstream target of R273H p53 mutation in prostate carcinoma cells (Vinall et al., 2006). Moreover, relaxin expression appears to be up-regulated by androgen withdrawal both in vivo and in vitro (Thompson et al., 2006). Finally, Feng and colleagues (Feng et al., 2007) reported that there is a strong correlation between significantly higher levels of relaxin message and message for its receptor LGR7 in recurrent prostate cancer samples from human patients and congruent with reports in breast tissue, relaxin stimulates cell proliferation, invasiveness and adhesion in vitro (Feng et al., 2007). Interfering with the production of relaxin and its receptor in vitro on prostate adenocarcinoma cells decreased cell invasiveness and growth and increased cell death in vitro (Feng et al., 2007). Finally, experiments conducted by Feng and colleagues, (2007) in vivo using a transgenic mouse with overexpression of RLN1 demonstrated a shorter survival time for mice with excess relaxin in the presence of prostate adenocarcinoma compared with controls. Further evidence that relaxin modulated tumour growth and progression was provided by Silvertown et al., (2007) when this group reported that an analog of relaxin which appears to be a relaxin anatgonist impairs prostate tumour growth in vivo both reducing the growth of a prostate cell line xenograft and reducing the incidence of metastasis. This was the first study to indicate the possible use of a relaxin antagonist to both investigate the progression and course of tumourigenesis as well as it suggest a possible therapeutic agent for use in the treatment of prostate cancer.
Relaxin-like peptides and INSL3 have been associated with a number of other tumours (Klonisch et al., 2005) including malignancies in the gastrointestinal tract (Stemmermann et al., 1994) thyroid gland (Homach-Klonisch et al., 2006), colorectum (Alfonso et al., 2005), and the male and female reproductive tracts (Silvertown et al., 2003a) in addition to the report above on relaxin and tumour development in breast and prostate. Although the data are not as fulsome for these other cancers, common themes emerge: there are higher levels of expression of transcripts for relaxin and its receptor in malignant cell forms, and in some cases correlations reported between increased relaxin expression, circulating levels of hormone, tendency to malignancy and incidence of metastasis (Homach-Klonisch et al., 2006). Studies in vitro suggest that relaxin promotes proliferation, invasion and metastasis of tumour cells. There is some evidence that levels of circulating hormone can be linked to survival times. Taken together, evidence is accumulating to suggest that relaxin signaling plays a significant role in tumour development and progression.

Relaxin and cell growth
Relaxin affects cancer cell differentiation and growth. Relaxin induced a transient growth followed by a reduction in growth of mammary tumours induced by estrogen and radiation in rats (Segaloff, 1983). Human breast cancer MCF-7 cells show marked proliferation and differentiation to relatively low levels of relaxin. However at higher doses relaxin seems to suppress proliferation although differentiation is still observed both in coculture (Bani et al., 1994) and in an in vivo preparation in nude mice (Bani et al., 1999). This raises intriguing questions about the possible role of relaxin in cancer suppression that need to be answered but at the same time Zhang and colleagues demonstrated that relaxin caused cellular proliferation by increasing MAPK and MEK protein expression in a variety of cells including normal human endometrial stromal cells, THP-1 myelomonocytic leukemia cells, and coronary and pulmonary artery smooth muscle cells (Zhang et al., 2002). Insulin, IGF-1 and platelet derived growth factor (PDGF) activate proliferative, apoptotic and metabolic signals via both MAPK and P13-Kinase/Akt. Although relaxin appears to stimulate P13-Kinase in blood vessels (Willcox et al., 2009) it appears that its action in human endometrial stromal cells stimulates the transcription factor CREB but does not involve Akt or Jun N-terminal kinase (JNK) (Zhang et al., 2002).
One of the principal intracellular pathways activated by relaxin is the nitric oxide (NO) cascade (see previous section). Activation of NO results in cytoskeletal and organellular changes and, depending on conditions be involved in antiapoptosis or cytostasis (Rivoltini et al., 2002): suppression of NO synthesis in human melanoma results in induction of the intrinsic apoptosis pathway. Cell survival is thereby promoted against chemotherapeutic drugs, mediating hypoxia induced drug resistance in human and murine tumours and assisting neoplastic cells to avoid immune destruction. Nitric oxide also induces a cytostatic state by inhibiting DNA synthesis, mitochondrial respiration and cytochroms P-450 activity (Bani et al., 1995; Bani et al., 1998; Bogdan, 2001). There is either spontaneous or induced expression of NO-synthase (iNOS) in both mouse mammary and melanoma cell lines (Lala and Orucevic, 1998; Xie and Fidler, 1998; Li et al., 1991). This results in increased NO which inhibits DNA synthesis and this is inversely correlated with metastasis. Bani and colleagues (Bani et al., 1995) reported that MCF-7 cells incubated with porcine relaxin showed an increased expression of two isoforms of NOS. They reported a dose dependent, bi-phasic increase in Ca2+/calmodulin dependent NOS (cNOS) and a graduate increase in iNOS activity. This implies that relaxin may indirectly attenuate tumour growth by activating the NO pathway to inhibit DNA synthesis that results in cytostasis and/or relaxin may facilitate tumorigenesis by assisting cells to avoid apoptosis.
Relaxin has been shown to activate protein kinase A (PKA) in a number of cells including the human tumour cell lines MCF-7 and THP-1 (Parsell et al., 1996; Fei et al., 1990; Hsu et al., 2000; Failli et al., 2002) and evidence in most cells confirms that the PKA pathway not PKC mediates the actions of the LGR7 and 8 receptors (Hsu et al., 2000; Hsu et al., 2002; Willcox et al., 2009) but there is one exception. It appears as if the action of relaxin in cardiac myocytes is mediated through PKC (Shaw et al., 2009). Through a complex cascade (Xi et al., 1994): increased PKAc activity results in enhanced phosphorylation of the NFkappaB p65 subunit and an increase in transcriptional activity of NFkappaB. This change in transcription has been suggested to promote tumour growth (Zhong et al., 1997).

Relaxin and cell invasion
Remodeling of connective tissue is a hallmark action of relaxin (Bathgate et al., 2006a) and the hormone has been implicated in anti-fibrotic action (Casten and Boucek, 1958). Relaxin acts directly on transforming growth factor-beta-stimulated human dermal fibroblasts (Unemori and Amento, 1990), lung fibroblasts (Unemori et al., 1996) and cardiac fibroblasts (Samuel et al., 2004) to promote both a decrease in type I and type II collagen synthesis and an increase in MMP expression and activation (Samuel et al., 2004). As a result, relaxin has actually been used in a number of animal models to alleviate fibrosis where it has been used to remodel the extracellular matrix including in the skin (Kibblewhite et al., 1992; Unemori et al., 1993), lung (Unemori et al., 1996); liver (Williams et al., 2001), liver (Bennett et al., 2003; Bennett et al., 2007; Bennett et al., 2009) and kidney (Garber et al., 2001; Garber et al., 2003). However, apart from the original report of clinical trials with porcine relaxin in humans by Casten and Boucek, (1958), a more rigorous clinical trial with genetically engineered relaxin was not successful in demonstrating an effective anti-fibrotic therapeutic action for relaxin in the human disease scleroderma (Seibold et al., 2000; Khanna et al., 2009). Nevertheless, relaxin has been reported to improve wound healing (Casten et al., 1960) although the prime site of action may not be on the connective tissue but on blood supply (see later) and in serving as a cardioprotective agent to experimentally produced ischemia (Masini et al., 1997; Bani et al., 1998).
It has been strongly suggested that loosening connective tissue may assist in tumour migration as a result of the actions of relaxin, mediated through the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMP) (Silvertown et al., 2003a). In tumour biology, MMP/TIMP has been implicated in degradation of the extracellular matrix to facilitate cell migration, alteration in the cellular environment that fosters cell migration, and the activation of tissue specific molecules that modulate TIMPs (Vu and Werb, 2000). MMPs are also involved in angiogenesis, invasion and metastasis (Duffy et al., 2000; Hiraoka et al., 1998) and they affect tumour suppressing growth factor (TGF-beta) (Yu and Stamenkovic, 2000), heparin-binding epidermal growth factor (HBEGF) (Pierce et al., 2001; Prenzel, 1999) various binding proteins (Fowlkes et al., 1994a; Fowlkes et al., 1994b); and proteases (Polette and Birembaut, 1998; Ugwu et al., 1998). These data clearly lead to the conclusion that by activating MMPs and TIMP, relaxin could support and enhance tumour invasion. However, at the same time there is evidence that MMPs can induce programmed cell death in anchorage-dependent cells and might defy tumour progression (Li et al., 1999: Will et al., 2000).
In a similar vein, the effects of relaxin on the MMP/TIMP system appear to be cell-type dependent: relaxin is reported to stimulate MMPs in cervical fibroblasts (Palejwala et al., 2001) but reduces pro-MMP-1 in endometrial cells (Palejwala et al., 2002). There is certainly evidence that relaxin can stimulate MMP release: Binder et al., (2002) showed that relaxin upregulated the expression of mRNA of MMP-2, -9 and -14 in MCF-7 and SK-BR3 cell lines and increased cellular migration; and Silvertown et al., (Silvertown et al., 2001; Silvertown et al., 2003a) showed that human relaxin could stimulate the migration of L6 cells and the movement of canine mammary tumour cells (CF33.Mt) respectively, through a porous membrane. Again, suggesting perhaps that the response is cell-type specific, Silvertown and colleagues, (2003a) reported that human relaxin resulted in a decreased migration of the human mammary cancer cell line MDA-MB-435.
Binder and colleagues, (2001) reported that patients with active metastatic breast cancer have elevated circulating levels of relaxin in the serum. In an interesting study on the incidence of breast cancer in the early nineties, Lambe et al., (1994) had postulated that one pregnancy increased the risk of breast cancer but multiple pregnancies decreased the risk which was confounding. Silvertown and colleagues (2003a) suggested that perhaps the short- and long-term risks of breast cancer and pregnancy might be related to the differential action of relaxin but this remains to be explored.

Relaxin and angiogenesis
Tumour growth depends on blood supply and there is critical point in the growth phase when a switch towards an angiogenic phenotype is absolutely critical (Ellis et al., 1996; Hanahan and Folkman, 1996; Tonini et al., 2003; Kerbel, 2008). The modelling and remodeling of vascular supply depends on a balance of proangiogenic and antiangiogenic factors that are produced by neoplastic tissue or induced in the surrounding cells (Tonini et al., 2003). Proangiogenic factors include vascular endothelial growth factor (VEGF), angiopoietins and ephrins, and a variety of other molecules and transcriptional factors. A number of these have been implicated as a possible product of relaxin stimulation. Reports and claims that relaxin stimulates these angiogenic substances are provided in Table II. In contrast, although there is a wide cadre of potential antiangiogenic factors known, only a limited number have been reported to be stimulated by relaxin.

Known Angiogenic Factor
Relaxin stimulates production
Adenosine Chen et al. 1988
Angiogenin Unemori et al. 1999
Angiopoetin-1 (Ang-1) Hewitson and Samuel 2009
Collagen Unemori et al. 1993
Epidermal growth factor Steinetz et al. 2009
Ephrins Davison et al. 2004
Fibroblast growth factors (a and b) Taylor and Clark 1992
Fibronectin McDonald et al. 2003
Follistatin Petraglia et al. 1994
Granulocyte colony-stimulating factor Moore et al. 2007
Heparin Masini et al. 1994
Interleukin 8 (IL-8) Bryant-Greenwood et al. (2009a)
Leptin Steinetz et al. (2009)
Midkine Sacchi et al. (1994)
Nicotinamide Berne 2002
Proliferin Conrad et al. 2004
Table II
Known angiogenic factors which have been linked with or claimed to be linked with relaxin.

Originally identified as a single compound, it is now known that VEGF is one of the most potent angiogenic cytokines and comprises a family of related molecules VEGF A-D and placental growth factor (Ogawa, 1998; Meyer et al., 1999; Neufeld et al., 1999; Ferrar, 2002; Hicklin and Ellis, 2005; Kerbel, 2008). The critical importance of VEGF to the integrity of the vascular system is supported by knockout studies: disruption of one VEGF allele in mice results in lethal abnormalities and removal of both alleles results in a virtually complete absence of vasculature in embryos (Cameliet et al., 1996; Ferrara et al., 1996; Carmeliet, 2000). All the members of the VEGF family have overlapping abilities to interact with the different receptors expressed primarily in the vascular endothelium (Eriksson and Alitalo, 1999). The vital importance of angiogenesis in tumour growth and development and the major role of VEGF has led to a great deal of basic and clinical research directed towards the VEGF family and the receptor tyrosine kinases that mediate their proangiogenic effects (Ferrara, 2002; Hicklin and Ellis, 2005). Relaxin has been shown to upregulate VEGF in stromal and glandular epithelial cells of the endometrium in wound healing (Palejwala et al., 2002; Unemori et al., 1999; Unemori et al., 2000), and in the myelomoncytic leukemia cell line THP-1 (Parsell et al., 1996). The THP-1 cells also exhibit relaxin receptors (Unemori et al., 1999; Unemori et al., 2000) which implies there may be some autocrine function of relaxin that may be related to angiogenesis in tumour development (Silvertown et al., 2003a; Kerbel, 2008). But again, the action of relaxin may be dependent on cell type and by inference on tumour cell type - Zhang and colleagues (2002) report that human endometrial stromal cells incubated with relaxin showed a reduced level of VEGF transcription.
The major mediator of tumour angiogenesis appears to be VEGF-A (Kerbel, 2008) which acts preferentially through the VEGF receptor 2. This is highly expressed by endothelial cells engaged in angiogenesis and by circulating bone marrow-derived endothelial precursor cells (Shibuya and Claesson-Welsh, 2006). There is also a VEGF receptor 1 which has a ten-fold higher affinity with VEGF-A but its signal transducing properties are extremely weak (Shibuya and Claesson-Welsh, 2006). Consequently, the role of VEGF receptor-1 remains unknown (Kerbel, 2008).
Most types of human cells have been shown to express high levels of VEGF and it appears as if hypoxia, which is a characteristic of solid tumours (Semenza, 2003) is important for inducing VEGF release. There are no data to date that indicate the hypoxia results in relaxin release but this is an intriguing possibility, especially as the appears to be conductance phenomena among branches of the microcirculation which might explain both an increased blood flow (Willcox et al., 2010) and angiogenic effect of relaxin.
It is assumed that VEGF has paracrine effects as tumour cells produce VEGF but lack cell-surface receptors for VEGF whereas endothelial cells express the receptors but produce relatively little VEGF. It has been suggested that VEGF originates from host cells in the body such as platelets and muscle cells (Kut et al., 2007) and tumour-associated tumour cells (Fukumura et al., 1998; Liang et al., 2006).
As mentioned earlier, relaxin upregulates NO through NOS in both vascular cells (Willcox et al., 2009) and neoplastic cells (Parsell et al., 1996; Fei et al., 1990; Hsu et al., 2000; Failli et al., 2002; Davel et al., 2002). Furthermore, tumour-associated angiogenic activity in vivo has been linked with increased levels of iNOS (Jadeski and Lala, 1999) and endothelial cells NOS (eNOS) (Jadeski et al., 2000) and inhibition of NOS with N-nitro-L-arginine methyl esther (L-NAME) results in a marked reduction in angiogenesis (Jadeski and Lala, 1999; Jadeski et al., 2000). Relaxin has been shown to increase microvascular arterial diameter in vitro (Bani et al., 1998) and in vivo (Willcox et al., 2009; Willcox et al., 2010). Arteriolar dilation decreases leukocyte-endothelial adhesive properties and increases vascular permeability (Fukumura and Jain, 1998). Bearing in mind that microvessel density, in both mammary and prostate tumours, is positively correlated with tumour cell survival and negatively correlated with longevity of the patient (Lissbrandt et al., 1997), Silvertown and colleagues suggested that high circulating and/or local levels of relaxin might upregulate VEGF and NO to increase blood flow to the region and stimulate an active angiogenesis to support tumour growth (Silvertown et al., 2006).

Other possible pathways for relaxin-involvement in angiogenesis
There is a body of literature supporting a pivotal new signaling pathways in angiogenesis related to tumorigenesis: notch delta-like ligand (DII) (Sainson and Harris, 2007; Noguera-Troise et al., 2006; Lobov et al., 2007; Ridgway et al., 2006; Gale et al., 2004). Notch cell-surface receptors are expressed by various cell types and generally involved in cell differentiation, proliferation and apoptosis. These receptors interact with transmembrane ligands on adjacent cells and may be involved in vital angiogenic activity which implies a possible role in vascular growth in tumorigenesis (Gale et al., 2004; Carmeliet et al., 1996; Ferrara et al., 1996). Although there are no reports to date of the possible role for relaxin in stimulating pathways that might interact with the Notch cell-surface receptors, this remains a possibility that deserves further investigation.
Finally, it is known that a number of cell types can be mobilized from bone marrow that may be important in new blood vessel formation (Betolini et al., 2006). These include various monocytic and myeloid cells that express endothelial cells markers such as VE-Cadherin, VEGF-1 and VEGF-2 (Okazaki et al., 2006; Conejo-Carcia et al., 2005; Grunewald et al., 2006). As relaxin has been reported to upregulate VEGF and bFGF in the myelomonocytic leukemia THP-1 cells (Parsell et al., 1996) this raises the interesting spectre that relaxin could also affect the responses of circulating bone-marrow derived cells in promoting angiogenesis.

IX. The next steps
The evidence that RLN2 9p24 and other members of the relaxin superfamily of peptides are involved in tumorigenesis is now unequivocal. There are data suggesting that relaxin is upregulated in tumour tissue, that receptors are present and that the hormone appears to be involved in the growth, vascularization and spread of cancer. There is a picture emerging of the signaling events induced by relaxin. Under specific conditions, relaxin appears to facilitate growth, limit apoptosis, induced angiogenesis and facilitate connective tissue remodeling that would support local and metastatic spread. This raises the spectre that inhibitors of inhibitors of relaxin could be part of the arsenal of weapons to be used in the fight against cancer. Recently, Silvertown and colleagues (Silvertown et al., 2006) showed that transfecting tumour xenografts implanted in mice with a modified relaxin cDNA not only reduced tumour size and vascularization but also reduced the incidence of metastasis raising the exciting possibility that anti-relaxin agents might suppress tumour development.

Bibliography

Experimental relaxation of the pubic ligament of the guinea pig.
Hisaw FL.
Proc Soc Exp Biol Med. 1926;23:661-663.
 
The relaxative hormone of the corpus luteum: its purification and concentration.
Fevold H, Hisaw FL, Meyer RK.
J Am Chem Soc. 1930;52:3340-3348.
 
Use of relaxin in the treatment of scleroderma.
Casten GG, Boucek RJ.
J Am Med Assoc. 1958 Jan 25;166(4):319-24.
PMID 13491339
 
A new approach to the management of obliterative peripheral arterial disease.
Casten GG, Gilmore HR, Houghton FE, Samuels SS.
Angiology. 1960 Oct;11:408-14.
PMID 13691417
 
The detection of relaxin in porcine, ovine and human plasma by radioimmunoassay.
Bryant GD.
Endocrinology. 1972 Oct;91(4):1113-7.
PMID 5065809
 
Purification and characterization of porcine relaxin.
Sherwood CD, O'Byrne EM.
Arch Biochem Biophys. 1974 Jan;160(1):185-96.
PMID 4828522
 
Development of a radioimmunoassay for porcine relaxin using 125I-labeled polytyrosyl-relaxin.
Sherwood OD, Rosentreter KR, Birkhimer ML.
Endocrinology. 1975 May;96(5):1106-13.
PMID 1122877
 
Relaxin-dependent adenosine 6',5'-monophosphate concentration changes in the mouse pubic symphysis.
Braddon SA.
Endocrinology. 1978 Apr;102(4):1292-9.
PMID 217619
 
Target tissues for relaxin identified in vitro with 125I-labelled porcine relaxin.
McMurtry JP, Kwok SC, Bryant-Greenwood GD.
J Reprod Fertil. 1978 Jul;53(2):209-16.
PMID 211231
 
Purification and characterization of rat relaxin.
Sherwood OD.
Endocrinology. 1979 Apr;104(4):886-92.
PMID 436762
 
Sequence of the human insulin gene.
Bell GI, Pictet RL, Rutter WJ, Cordell B, Tischer E, Goodman HM.
Nature. 1980 Mar 6;284(5751):26-32.
PMID 6243748
 
Characterization of the binding of 125I-labelled succinylated porcine relaxin to human and mouse fibroblasts.
McMurtry JP, Floersheim GL, Bryant-Greenwood GD.
J Reprod Fertil. 1980 Jan;58(1):43-9.
PMID 7359488
 
Characterization of the binding of 125I-relaxin to rat uterus.
Mercado-Simmen RC, Bryant-Greenwood GD, Greenwood FC.
J Biol Chem. 1980 Apr 25;255(8):3617-23.
PMID 6245087
 
The interaction of relaxin with the rat uterus. I. Effect on cyclic nucleotide levels and spontaneous contractile activity.
Sanborn BM, Kuo HS, Weisbrodt NW, Sherwood OD.
Endocrinology. 1980 Apr;106(4):1210-5.
PMID 6244146
 
Molecular cloning and characterization of cDNA sequences coding for rat relaxin.
Hudson P, Haley J, Cronk M, Shine J, Niall H.
Nature. 1981 May 14;291(5811):127-31.
PMID 7231533
 
Isolation and characterization of relaxin from the sand tiger shark (Odontaspis taurus).
Reinig JW, Daniel LN, Schwabe C, Gowan LK, Steinetz BG, O'Byrne EM.
Endocrinology. 1981 Aug;109(2):537-43.
PMID 7250055
 
Effect of relaxin on bound cAMP in rat uterus.
Sanborn BM, Sherwood OD.
Endocr Res Commun. 1981;8(3):179-92.
PMID 6174316
 
Porcine relaxin: molecular cloning and cDNA structure.
Haley J, Hudson P, Scanlon D, John M, Cronk M, Shine J, Tregear G, Niall H.
DNA. 1982;1(2):155-62.
PMID 6897721
 
Relaxin receptors in the myometrium and cervix of the pig.
Mercado-Simmen RC, Goodwin B, Ueno MS, Yamamoto SY, Bryant-Greenwood GD.
Biol Reprod. 1982 Feb;26(1):120-8.
PMID 6279186
 
Localization of relaxin binding sites in the rat uterus and cervix by autoradiography.
Weiss TJ, Bryant-Greenwood GD.
Biol Reprod. 1982 Oct;27(3):673-9.
PMID 6291650
 
Structure of a genomic clone encoding biologically active human relaxin.
Hudson P, Haley J, John M, Cronk M, Crawford R, Haralambidis J, Tregear G, Shine J, Niall H.
Nature. 1983 Feb 17-23;301(5901):628-31.
PMID 6298628
 
The role of the ovary in the synergism between radiation and estrogen in the production of mammary cancer in the rat.
Segaloff A.
Biology of Relaxin and its role in the human. Eds: M Bigazzi, FC Greenwood, F Gaspari. Excerpta Medica Amsterdam. 1983;410-416.
 
Morphological changes induced in mouse mammary gland by porcine and human relaxin.
Bani G, Bigazzi M.
Acta Anat (Basel). 1984;119(3):149-54.
PMID 6464647
 
Relaxin gene expression in human ovaries and the predicted structure of a human preprorelaxin by analysis of cDNA clones.
Hudson P, John M, Crawford R, Haralambidis J, Scanlon D, Gorman J, Tregear G, Shine J, Niall H.
EMBO J. 1984 Oct;3(10):2333-9.
PMID 6548702
 
Relaxin affects the central control of oxytocin release.
Summerlee AJ, O'Byrne KT, Paisley AC, Breeze MF, Porter DG.
Nature. 1984 May 24-30;309(5966):372-4.
PMID 6727991
 
Naturally occurring porcine relaxins and large-scale preparation of the B29 hormone.
Bullesbach EE, Schwabe C.
Biochemistry. 1985 Dec 17;24(26):7717-22.
PMID 4092034
 
The effect of relaxin on cyclic adenosine 3',5'-monophosphate concentrations in rat myometrial cells in culture.
Hsu CJ, McCormack SM, Sanborn BM.
Endocrinology. 1985 May;116(5):2029-35.
PMID 2985368
 
Isolation, purification, and the sequence of relaxin from spiny dogfish (Squalus acanthias).
Bullesbach EE, Gowan LK, Schwabe C, Steinetz BG, O'Byrne E, Callard IP.
Eur J Biochem. 1986 Dec 1;161(2):335-41.
PMID 3780747
 
The human fetal membranes: a target tissue for relaxin.
Koay ES, Bryant-Greenwood GD, Yamamoto SY, Greenwood FC.
J Clin Endocrinol Metab. 1986 Mar;62(3):513-21.
PMID 3003143
 
Purification and characterization of equine relaxin.
Stewart DR, Papkoff H.
Endocrinology. 1986 Sep;119(3):1093-9.
PMID 3732157
 
Relaxin from an oviparous species, the skate (Raja erinacea).
Bullesbach EE, Schwabe C, Callard IP.
Biochem Biophys Res Commun. 1987 Feb 27;143(1):273-80.
PMID 3827922
 
Porcine relaxin. Gene structure and expression.
Haley J, Crawford R, Hudson P, Scanlon D, Tregear G, Shine J, Niall H.
J Biol Chem. 1987 Sep 5;262(25):11940-6.
PMID 2442155
 
The effect of relaxin on cyclic adenosine 3',5'-monophosphate concentrations in human endometrial glandular epithelial cells.
Chen GA, Huang JR, Tseng L.
Biol Reprod. 1988 Oct;39(3):519-25.
PMID 2848594
 
Prediagnostic serum hormones and the risk of prostate cancer.
Nomura A, Heilbrun LK, Stemmermann GN, Judd HL.
Cancer Res. 1988 Jun 15;48(12):3515-7.
PMID 3370644
 
Structure of rhesus monkey relaxin predicted by analysis of the single-copy rhesus monkey relaxin gene.
Crawford RJ, Hammond VE, Roche PJ, Johnston PD, Tregear GW.
J Mol Endocrinol. 1989 Nov;3(3):169-74.
PMID 2590381
 
Induction of angiogenesis during the transition from hyperplasia to neoplasia.
Folkman J, Watson K, Ingber D, Hanahan D.
Nature. 1989 May 4;339(6219):58-61.
PMID 2469964
 
Expression of the human relaxin gene in the corpus luteum of the menstrual cycle and in the prostate.
Ivell R, Hunt N, Khan-Dawood F, Dawood MY.
Mol Cell Endocrinol. 1989 Oct;66(2):251-5.
PMID 2612734
 
Cetacean relaxin. Isolation and sequence of relaxins from Balaenoptera acutorostrata and Balaenoptera edeni.
Schwabe C, Büllesbach EE, Heyn H, Yoshioka M.
J Biol Chem. 1989 Jan 15;264(2):940-3.
PMID 2910872
 
Immunohistochemical localization of relaxin in human prostate.
Sokol RZ, Wang XS, Lechago J, Johnston PD, Swerdloff RS.
J Histochem Cytochem. 1989 Aug;37(8):1253-5.
PMID 2666509
 
Purification and structure of human pregnancy relaxin from corpora lutea, serum and plasma.
Winslow JW, Shih A, Laramee G, Bourell J, Stults J, Johnston P.
Program of the 71st Annual Meeting of the Endocrine Society. 1989;p245 (Abstract).
 
A prospective, population-based study of androstenedione, estrogens, and prostatic cancer.
Barrett-Connor E, Garland C, McPhillips JB, Khaw KT, Wingard DL.
Cancer Res. 1990 Jan 1;50(1):169-73.
PMID 2293551
 
Monobiotinylated relaxins. Preparation and chemical properties of the mono(biotinyl-epsilon-aminohexanoyl) porcine relaxin.
Bullesbach EE, Schwabe C.
Int J Pept Protein Res. 1990 May;35(5):416-23.
PMID 2376467
 
The prostate: an increasing medical problem.
Carter HB, Coffey DS.
Prostate. 1990;16(1):39-48.
PMID 1689482
 
A method to establish pure fibroblast and endothelial cell colony cultures from murine bone marrow.
Fei RG, Penn PE, Wolf NS.
Exp Hematol. 1990 Sep;18(8):953-7.
PMID 2201558
 
Relaxin in breast tissue.
Mazoujian G, Bryant-Greenwood GD.
Lancet. 1990 Feb 3;335(8684):298-9.
PMID 1967759
 
Preparation of biologically active 32P-labeled human relaxin. Displaceable binding to rat uterus, cervix, and brain.
Osheroff PL, Ling VT, Vandlen RL, Cronin MJ, Lofgren JA.
J Biol Chem. 1990 Jun 5;265(16):9396-401.
PMID 2160976
 
Relaxin modulates synthesis and secretion of procollagenase and collagen by human dermal fibroblasts.
Unemori EN, Amento EP.
J Biol Chem. 1990 Jun 25;265(18):10681-5.
PMID 2162358
 
Expression of the human relaxin H1 gene in the decidua, trophoblast, and prostate.
Hansell DJ, Bryant-Greenwood GD, Greenwood FC.
J Clin Endocrinol Metab. 1991 Apr;72(4):899-904.
PMID 2005217
 
Role of nitric oxide in lysis of tumor cells by cytokine-activated endothelial cells.
Li LM, Kilbourn RG, Adams J, Fidler IJ.
Cancer Res. 1991 May 15;51(10):2531-5.
PMID 1902393
 
Autoradiographic localization of relaxin binding sites in rat brain.
Osheroff PL, Phillips HS.
Proc Natl Acad Sci U S A. 1991 Aug 1;88(15):6413-7.
PMID 1650466
 
Enzymatic digestion on the sample foil as a method for sequence determination by plasma desorption mass spectrometry: the primary structure of porpoise relaxin.
Woods AS, Cotter RJ, Yoshioka M, Büllesbach EE, Schwabe C.
Int J Mass Spectrom Ion Processes. 1991;111:77-88.
 
The effect of relaxin on tissue expansion.
Kibblewhite D, Larrabee WF Jr, Sutton D.
Arch Otolaryngol Head Neck Surg. 1992 Feb;118(2):153-6.
PMID 1540345
 
Relaxin binding in the rat heart atrium.
Osheroff PL, Cronin MJ, Lofgren JA.
Proc Natl Acad Sci U S A. 1992 Mar 15;89(6):2384-8.
PMID 1312720
 
Purification and sequence determination of canine relaxin.
Stewart DR, Henzel WJ, Vandlen R.
J Protein Chem. 1992 Jun;11(3):247-53.
PMID 1388669
 
Basic fibroblast growth factor inhibits basal and stimulated relaxin secretion by cultured porcine luteal cells: analysis by reverse hemolytic plaque assay.
Taylor MJ, Clark CL.
Endocrinology. 1992 Apr;130(4):1951-6.
PMID 1547722
 
Human seminal relaxin is a product of the same gene as human luteal relaxin.
Winslow JW, Shih A, Bourell JH, Weiss G, Reed B, Stults JT, Goldsmith LT.
Endocrinology. 1992 May;130(5):2660-8.
PMID 1572287
 
Cloning of a cDNA for a novel insulin-like peptide of the testicular Leydig cells.
Adham IM, Burkhardt E, Benahmed M, Engel W.
J Biol Chem. 1993 Dec 15;268(35):26668-72.
PMID 8253799
 
Expression of relaxin mRNA and relaxin receptors in postnatal and adult rat brains and hearts. Localization and developmental patterns.
Osheroff PL, Ho WH.
J Biol Chem. 1993 Jul 15;268(20):15193-9.
PMID 8392068
 
Human relaxin decreases collagen accumulation in vivo in two rodent models of fibrosis.
Unemori EN, Beck LS, Lee WP, Xu Y, Siegel M, Keller G, Liggitt HD, Bauer EA, Amento EP.
J Invest Dermatol. 1993 Sep;101(3):280-5.
PMID 8370965
 
Differentiation of breast cancer cells in vitro is promoted by the concurrent influence of myoepithelial cells and relaxin.
Bani D, Riva A, Bigazzi M, Bani Sacchi T.
Br J Cancer. 1994 Nov;70(5):900-4.
PMID 7947095
 
The human relaxin genes and peptides.
Bryant-Greenwood GD, Mandel M, Tashima L, Bogic L, Garibay-Tupas JL, Greenwood FC.
Progress in Relaxin Research. Eds. A MacLennon, G Tregear, G Bryant-Greewood. Global Publication Services USA. 1994;75-84.
 
Structural organization of the porcine and human genes coding for a Leydig cell-specific insulin-like peptide (LEY I-L) and chromosomal localization of the human gene (INSL3).
Burkhardt E, Adham IM, Brosig B, Gastmann A, Mattei MG, Engel W.
Genomics. 1994 Mar 1;20(1):13-9.
PMID 8020942
 
Characterization of two relaxin genes in the chimpanzee.
Evans BA, Fu P, Tregear GW.
J Endocrinol. 1994 Mar;140(3):385-92.
PMID 8182365
 
Matrix metalloproteinases degrade insulin-like growth factor-binding protein-3 in dermal fibroblast cultures.
Fowlkes JL, Enghild JJ, Suzuki K, Nagase H.
J Biol Chem. 1994a Oct 14;269(41):25742-6.
PMID 7523391
 
Proteolysis of insulin-like growth factor binding protein-3 during rat pregnancy: a role for matrix metalloproteinases.
Fowlkes JL, Suzuki K, Nagase H, Thrailkill KM.
Endocrinology. 1994b Dec;135(6):2810-3.
PMID 7527335
 
Transient increase in the risk of breast cancer after giving birth.
Lambe M, Hsieh C, Trichopoulos D, Ekbom A, Pavia M, Adami HO.
N Engl J Med. 1994 Jul 7;331(1):5-9.
PMID 8202106
 
Effects of relaxin on mast cells. In vitro and in vivo studies in rats and guinea pigs.
Masini E, Bani D, Bigazzi M, Mannaioni PF, Bani-Sacchi T.
J Clin Invest. 1994 Nov;94(5):1974-80.
PMID 7525651
 
Review of the role of androgenic hormones in the epidemiology of benign prostatic hyperplasia and prostate cancer.
Montie JE, Pienta KJ.
Urology. 1994 Jun;43(6):892-9.
PMID 7515207
 
Local production and action of follistatin in human placenta.
Petraglia F, Gallinelli A, Grande A, Florio P, Ferrari S, Genazzani AR, Ling N, DePaolo LV.
J Clin Endocrinol Metab. 1994 Jan;78(1):205-10.
PMID 8288705
 
Relaxin influences growth, differentiation and cell-cell adhesion of human breast-cancer cells in culture.
Sacchi TB, Bani D, Brandi ML, Falchetti A, Bigazzi M.
Int J Cancer. 1994 Apr 1;57(1):129-34.
PMID 8150531
 
Relaxin: structures, functions, promises, and nonevolution.
Schwabe C, Bullesbach EE.
FASEB J. 1994 Nov;8(14):1152-60.
PMID 7958621
 
Relaxin.
Sherwood OD.
The Physiology of Reproduction. Eds. E Knobil and JD Neill Raven Press New York. 1994;861-1010.
 
Immunocytochemical identification of a relaxin-like protein in gastrointestinal epithelium and carcinoma: a preliminary report.
Stemmermann GN, Mesiona W, Greenwood FC, Bryant-Greenwood GD.
J Endocrinol. 1994 Feb;140(2):321-5.
PMID 8169564
 
Human relaxins in normal, benign and neoplastic breast tissue.
Tashima LS, Mazoujian G, Bryant-Greenwood GD.
J Mol Endocrinol. 1994 Jun;12(3):351-64.
PMID 7916973
 
Individual and combined effects of relaxin, estrogen, and progesterone in ovariectomized gilts. II. Effects on mammary development.
Winn RJ, Baker MD, Merle CA, Sherwood OD.
Endocrinology. 1994 Sep;135(3):1250-5.
PMID 8070370
 
Role of transcription factor NF-kappa B/Rel in induction of nitric oxide synthase.
Xie QW, Kashiwabara Y, Nathan C.
J Biol Chem. 1994 Feb 18;269(7):4705-8.
PMID 7508926
 
Relaxin activates the L-arginine-nitric oxide pathway in human breast cancer cells.
Bani D, Masini E, Bello MG, Bigazzi M, Sacchi TB.
Cancer Res. 1995 Nov 15;55(22):5272-5.
PMID 7585587
 
Cloning of a new member of the insulin gene superfamily (INSL4) expressed in human placenta.
Chassin D, Laurent A, Janneau JL, Berger R, Bellet D.
Genomics. 1995 Sep 20;29(2):465-70.
PMID 8666396
 
The emerging concept of relaxin as a centrally acting peptide hormone with hemodynamic actions.
Geddes BJ, Summerlee AJ.
J Neuroendocrinol. 1995 Jun;7(6):411-7.
PMID 7550288
 
Relaxin and its role in pregnancy.
Goldschmidt LT, Weiss G, Steinetz BG.
Endocrinol Metab Clin North Am. 1995;24:171-186.
 
Characterization of human relaxin gene regulation in the relaxin-expressing human prostate adenocarcinoma cell line LNCaP.FGC.
Gunnersen JM, Roche PJ, Tregear GW, Crawford RJ.
J Mol Endocrinol. 1995 Oct;15(2):153-66.
PMID 8800640
 
Immunohistochemical localization of specific relaxin-binding cells in the cervix, mammary glands, and nipples of pregnant rats.
Kuenzi MJ, Sherwood OD.
Endocrinology. 1995 Apr;136(4):1367-73.
PMID 7895647
 
Binding and cross-linking of 32P-labeled human relaxin to human uterine cells and primary rat atrial cardiomyocytes.
Osheroff PL, King KL.
Endocrinology. 1995 Oct;136(10):4377-81.
PMID 7664657
 
Expression of vascular endothelial growth factor and its receptor, KDR, correlates with vascularity, metastasis, and proliferation of human colon cancer.
Takahashi Y, Kitadai Y, Bucana CD, Cleary KR, Ellis LM.
Cancer Res. 1995 Sep 15;55(18):3964-8.
PMID 7664263
 
Abnormal blood vessel development and lethality in embryos lacking a single VEGF allele.
Carmeliet P, Ferreira V, Breier G, Pollefeyt S, Kieckens L, Gertsenstein M, Fahrig M, Vandenhoeck A, Harpal K, Eberhardt C, Declercq C, Pawling J, Moons L, Collen D, Risau W, Nagy A.
Nature. 1996 Apr 4;380(6573):435-9.
PMID 8602241
 
Down-regulation of vascular endothelial growth factor in human colon carcinoma cell lines by antisense transfection decreases endothelial cell proliferation.
Ellis LM, Liu W, Wilson M.
Surgery. 1996 Nov;120(5):871-8.
PMID 8909524
 
Heterozygous embryonic lethality induced by targeted inactivation of the VEGF gene.
Ferrara N, Carver-Moore K, Chen H, Dowd M, Lu L, O'Shea KS, Powell-Braxton L, Hillan KJ, Moore MW.
Nature. 1996 Apr 4;380(6573):439-42.
PMID 8602242
 
Membrane-type matrix metalloproteinase expression and matrix metalloproteinase-2 activation in primary human ovarian epithelial carcinoma cells.
Fishman DA, Bafetti LM, Stack MS.
Invasion Metastasis. 1996;16(3):150-9.
PMID 9186550
 
Prospective study of sex hormone levels and risk of prostate cancer.
Gann PH, Hennekens CH, Ma J, Longcope C, Stampfer MJ.
J Natl Cancer Inst. 1996 Aug 21;88(16):1118-26.
PMID 8757191
 
Patterns and emerging mechanisms of the angiogenic switch during tumorigenesis.
Hanahan D, Folkman J.
Cell. 1996 Aug 9;86(3):353-64.
PMID 8756718
 
Identification of specific relaxin-binding cells in the cervix, mammary glands, nipples, small intestine, and skin of pregnant pigs.
Min G, Sherwood OD.
Biol Reprod. 1996 Dec;55(6):1243-52.
PMID 8949880
 
Relaxin binds to and elicits a response from cells of the human monocytic cell line, THP-1.
Parsell DA, Mak JY, Amento EP, Unemori EN.
J Biol Chem. 1996 Nov 1;271(44):27936-41.
PMID 8910395
 
Molecular cloning and expression of the relaxin-like factor from the mouse testis.
Pusch W, Balvers M, Ivell R.
Endocrinology. 1996 Jul;137(7):3009-13.
PMID 8770925
 
Relaxin induces an extracellular matrix-degrading phenotype in human lung fibroblasts in vitro and inhibits lung fibrosis in a murine model in vivo.
Unemori EN, Pickford LB, Salles AL, Piercy CE, Grove BH, Erikson ME, Amento EP.
J Clin Invest. 1996 Dec 15;98(12):2739-45.
PMID 8981919
 
Relaxin: a pleiotropic hormone.
Bani D.
Gen Pharmacol. 1997 Jan;28(1):13-22.
PMID 9112071
 
The mouse relaxin-like factor gene and its promoter are located within the 3' region of the JAK3 genomic sequence.
Koskimies P, Spiess AN, Lahti P, Huhtaniemi I, Ivell R.
FEBS Lett. 1997 Dec 15;419(2-3):186-90.
PMID 9428631
 
Vascular density is a predictor of cancer-specific survival in prostatic carcinoma.
Lissbrant IF, Stattin P, Damber JE, Bergh A.
Prostate. 1997 Sep 15;33(1):38-45.
PMID 9294625
 
Relaxin counteracts myocardial damage induced by ischemia-reperfusion in isolated guinea pig hearts: evidence for an involvement of nitric oxide.
Masini E, Bani D, Bello MG, Bigazzi M, Mannaioni PF, Sacchi TB.
Endocrinology. 1997 Nov;138(11):4713-20.
PMID 9348198
 
Mouse Leydig insulin-like (Ley I-L) gene: structure and expression during testis and ovary development.
Zimmermann S, Schottler P, Engel W, Adham IM.
Mol Reprod Dev. 1997 May;47(1):30-8.
PMID 9110312
 
The transcriptional activity of NF-kappaB is regulated by the IkappaB-associated PKAc subunit through a cyclic AMP-independent mechanism.
Zhong H, SuYang H, Erdjument-Bromage H, Tempst P, Ghosh S.
Cell. 1997 May 2;89(3):413-24.
PMID 9150141
 
Relaxin activates the L-arginine-nitric oxide pathway in vascular smooth muscle cells in culture.
Bani D, Failli P, Bello MG, Thiemermann C, Bani Sacchi T, Bigazzi M, Masini E.
Hypertension. 1998 Jun;31(6):1240-7.
PMID 9622136
 
Role of nitric oxide in angiogenesis and microcirculation in tumors.
Fukumura D, Jain RK.
Cancer Metastasis Rev. 1998 Mar;17(1):77-89.
PMID 9544424
 
Tumor induction of VEGF promoter activity in stromal cells.
Fukumura D, Xavier R, Sugiura T, Chen Y, Park EC, Lu N, Selig M, Nielsen G, Taksir T, Jain RK, Seed B.
Cell. 1998 Sep 18;94(6):715-25.
PMID 9753319
 
Matrix metalloproteinases regulate neovascularization by acting as pericellular fibrinolysins.
Hiraoka N, Allen E, Apel IJ, Gyetko MR, Weiss SJ.
Cell. 1998 Oct 30;95(3):365-77.
PMID 9814707
 
Identification of specific relaxin-binding cells in the human female.
Kohsaka T, Min G, Lukas G, Trupin S, Campbell ET, Sherwood OD.
Biol Reprod. 1998 Oct;59(4):991-9.
PMID 9746753
 
Role of nitric oxide in tumor progression: lessons from experimental tumors.
Lala PK, Orucevic A.
Cancer Metastasis Rev. 1998 Mar;17(1):91-106.
PMID 9544425
 
Localization of specific relaxin-binding cells in the ovary and testis of pigs.
Min G, Sherwood OD.
Biol Reprod. 1998 Aug;59(2):401-8.
PMID 9687314
 
A novel type of vascular endothelial growth factor, VEGF-E (NZ-7 VEGF), preferentially utilizes KDR/Flk-1 receptor and carries a potent mitotic activity without heparin-binding domain.
Ogawa S, Oku A, Sawano A, Yamaguchi S, Yazaki Y, Shibuya M.
J Biol Chem. 1998 Nov 20;273(47):31273-82.
PMID 9813035
 
Membrane-type metalloproteinases in tumor invasion.
Polette M, Birembaut P.
Int J Biochem Cell Biol. 1998 Nov;30(11):1195-202. (REVIEW)
PMID 9839445
 
Proteolytic cleavage of urokinase-type plasminogen activator by stromelysin-1 (MMP-3).
Ugwu F, Van Hoef B, Bini A, Collen D, Lijnen HR.
Biochemistry. 1998 May 19;37(20):7231-6.
PMID 9585535
 
Therapy of cancer metastasis by activation of the inducible nitric oxide synthase.
Xie K, Fidler IJ.
Cancer Metastasis Rev. 1998 Mar;17(1):55-75.
PMID 9544423
 
Relaxin promotes differentiation of human breast cancer cells MCF-7 transplanted into nude mice.
Bani D, Flagiello D, Poupon MF, Nistri S, Poirson-Bichat F, Bigazzi M, Bani Sacchi T.
Virchows Arch. 1999 Nov;435(5):509-19.
PMID 10592055
 
Specific, high affinity relaxin-like factor receptors.
Bullesbach EE, Schwabe C.
J Biol Chem. 1999 Aug 6;274(32):22354-8.
PMID 10428805
 
Identification of INSL5, a new member of the insulin superfamily.
Conklin D, Lofton-Day CE, Haldeman BA, Ching A, Whitmore TE, Lok S, Jaspers S.
Genomics. 1999 Aug 15;60(1):50-6.
PMID 10458910
 
Structure, expression and receptor-binding properties of novel vascular endothelial growth factors.
Eriksson U, Alitalo K.
Curr Top Microbiol Immunol. 1999;237:41-57.
PMID 9893345
 
Nitric oxide synthase inhibition by N(G)-nitro-L-arginine methyl ester inhibits tumor-induced angiogenesis in mammary tumors.
Jadeski LC, Lala PK.
Am J Pathol. 1999 Oct;155(4):1381-90.
PMID 10514420
 
Tissue inhibitor of metalloproteinase-1 inhibits apoptosis of human breast epithelial cells.
Li G, Fridman R, Kim HR.
Cancer Res. 1999 Dec 15;59(24):6267-75.
PMID 10626822
 
A novel vascular endothelial growth factor encoded by Orf virus, VEGF-E, mediates angiogenesis via signalling through VEGFR-2 (KDR) but not VEGFR-1 (Flt-1) receptor tyrosine kinases.
Meyer M, Clauss M, Lepple-Wienhues A, Waltenberger J, Augustin HG, Ziche M, Lanz C, Büttner M, Rziha HJ, Dehio C.
EMBO J. 1999 Jan 15;18(2):363-74.
PMID 9889193
 
Cryptorchidism in mice mutant for Insl3.
Nef S, Parada LF.
Nat Genet. 1999 Jul;22(3):295-9.
PMID 10391220
 
Inhibition of nitric-oxide synthase 2 by aminoguanidine provides neuroprotection of retinal ganglion cells in a rat model of chronic glaucoma.
Neufeld AH, Sawada A, Becker B.
Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9944-8.
PMID 10449799
 
EGF receptor transactivation by G-protein-coupled receptors requires metalloproteinase cleavage of proHB-EGF.
Prenzel N, Zwick E, Daub H, Leserer M, Abraham R, Wallasch C, Ullrich A.
Nature. 1999 Dec 23-30;402(6764):884-8.
PMID 10622253
 
Structure and expression of the rat relaxin-like factor (RLF) gene.
Spiess AN, Balvers M, Tena-Sempere M, Huhtaniemi I, Parry L, Ivell R.
Mol Reprod Dev. 1999 Dec;54(4):319-25.
PMID 10542371
 
Quantitative autoradiographic studies of relaxin binding in rat atria, uterus and cerebral cortex: characterization and effects of oestrogen treatment.
Tan YY, Wade JD, Tregear GW, Summers RJ.
Br J Pharmacol. 1999 May;127(1):91-8.
PMID 10369460
 
Relaxin stimulates expression of vascular endothelial growth factor in normal human endometrial cells in vitro and is associated with menometrorrhagia in women.
Unemori EN, Erikson ME, Rocco SE, Sutherland KM, Parsell DA, Mak J, Grove BH.
Hum Reprod. 1999 Mar;14(3):800-6.
PMID 10221717
 
Mice without a functional relaxin gene are unable to deliver milk to their pups.
Zhao L, Roche PJ, Gunnersen JM, Hammond VE, Tregear GW, Wintour EM, Beck F.
Endocrinology. 1999 Jan;140(1):445-53.
PMID 9886856
 
Targeted disruption of the Insl3 gene causes bilateral cryptorchidism.
Zimmermann S, Steding G, Emmen JM, Brinkmann AO, Nayernia K, Holstein AF, Engel W, Adham IM.
Mol Endocrinol. 1999 May;13(5):681-91.
PMID 10319319
 
The relaxin receptor-binding site geometry suggests a novel gripping mode of interaction.
Bullesbach EE, Schwabe C.
J Biol Chem. 2000 Nov 10;275(45):35276-80.
PMID 10956652
 
VEGF gene therapy: stimulating angiogenesis or angioma-genesis?
Carmeliet P.
Nat Med. 2000 Oct;6(10):1102-3.
PMID 11017137
 
Metalloproteinases: role in breast carcinogenesis, invasion and metastasis.
Duffy MJ, Maguire TM, Hill A, McDermott E, O'Higgins N.
Breast Cancer Res. 2000;2(4):252-7. Epub 2000 Jun 7.
PMID 11250717
 
The hallmarks of cancer.
Hanahan D, Weinberg RA.
Cell. 2000 Jan 7;100(1):57-70.
PMID 10647931
 
Nitric oxide promotes murine mammary tumour growth and metastasis by stimulating tumour cell migration, invasiveness and angiogenesis.
Jadeski LC, Hum KO, Chakraborty C, Lala PK.
Int J Cancer. 2000 Apr 1;86(1):30-9.
PMID 10728591
 
Identification, chromosomal mapping, and partial characterization of mouse InsI6: a new member of the insulin family.
Kasik J, Muglia L, Stephan DA, Menon RK.
Endocrinology. 2000 Jan;141(1):458-61.
PMID 10614671
 
Identification of INSL6, a new member of the insulin family that is expressed in the testis of the human and rat.
Lok S, Johnston DS, Conklin D, Lofton-Day CE, Adams RL, Jelmberg AC, Whitmore TE, Schrader S, Griswold MD, Jaspers SR.
Biol Reprod. 2000 Jun;62(6):1593-9.
PMID 10819760
 
Recombinant human relaxin in the treatment of scleroderma. A randomized, double-blind, placebo-controlled trial.
Seibold JR, Korn JH, Simms R, Clements PJ, Moreland LW, Mayes MD, Furst DE, Rothfield N, Steen V, Weisman M, Collier D, Wigley FM, Merkel PA, Csuka ME, Hsu V, Rocco S, Erikson M, Hannigan J, Harkonen WS, Sanders ME.
Ann Intern Med. 2000 Jun 6;132(11):871-9.
PMID 10836913
 
Relaxin induces vascular endothelial growth factor expression and angiogenesis selectively at wound sites.
Unemori EN, Lewis M, Constant J, Arnold G, Grove BH, Normand J, Deshpande U, Salles A, Pickford LB, Erikson ME, Hunt TK, Huang X.
Wound Repair Regen. 2000 Sep-Oct;8(5):361-70.
PMID 11186125
 
Matrix metalloproteinases: effectors of development and normal physiology.
Vu TH, Werb Z.
Genes Dev. 2000 Sep 1;14(17):2123-33.
PMID 10970876
 
Estimates of the lifetime costs of breast cancer treatment in Canada.
Will BP, Berthelot JM, Le Petit C, Tomiak EM, Verma S, Evans WK.
Eur J Cancer. 2000 Apr;36(6):724-35.
PMID 10762744
 
Cell surface-localized matrix metalloproteinase-9 proteolytically activates TGF-beta and promotes tumor invasion and angiogenesis.
Yu Q, Stamenkovic I.
Genes Dev. 2000 Jan 15;14(2):163-76.
PMID 10652271
 
The vasorelaxant hormone relaxin induces changes in liver sinusoid microcirculation: a morphologic study in the rat.
Bani D, Nistri S, Quattrone S, Bigazzi M, Bani Sacchi T.
J Endocrinol. 2001 Dec;171(3):541-9.
PMID 11739020
 
High serum concentrations of relaxin correlate with dissemination of breast cancer.
Binder C, Binder L, Gurlit L, Einspanier A.
Relaxin 2000. Eds: GW Tregear, R Ivell, RA Bathgate, JD Wade. Kluwer Academic Publishers, Netherlands. 2001;429-435.
 
Nitric oxide and the immune response.
Bogdan C.
Nat Immunol. 2001 Oct;2(10):907-16.
PMID 11577346
 
Relaxin decreases renal interstitial fibrosis and slows progression of renal disease.
Garber SL, Mirochnik Y, Brecklin CS, Unemori EN, Singh AK, Slobodskoy L, Grove BH, Arruda JA, Dunea G.
Kidney Int. 2001 Mar;59(3):876-82.
PMID 11231342
 
Relaxin expression and binding the rat prostate.
Hornsby DJ, Poterski RS, Summerlee AJS.
Relaxin 2000: Proceedings of the Third International Conference on Relaxin and Related Peptides. Ed., G Tregear, R Ivell, R Bathgate, J Wade. Kluwer Academic Publishers, Dordrecht, NL. 2001;225-227.
 
Relaxin positively regulates matrix metalloproteinase expression in human lower uterine segment fibroblasts using a tyrosine kinase signaling pathway.
Palejwala S, Stein DE, Weiss G, Monia BP, Tortoriello D, Goldsmith LT.
Endocrinology. 2001 Aug;142(8):3405-13.
PMID 11459784
 
Epidermal growth factor (EGF) receptor-dependent ERK activation by G protein-coupled receptors: a co-culture system for identifying intermediates upstream and downstream of heparin-binding EGF shedding.
Pierce KL, Tohgo A, Ahn S, Field ME, Luttrell LM, Lefkowitz RJ.
J Biol Chem. 2001 Jun 22;276(25):23155-60. Epub 2001 Apr 4.
PMID 11290747
 
Recombinant human relaxin increases migration of rat myoblasts.
Silvertown JD, Poterski RS, Summerlee AJS.
Biol Reprod. 2001;64:211.
 
Relaxin inhibits effective collagen deposition by cultured hepatic stellate cells and decreases rat liver fibrosis in vivo.
Williams EJ, Benyon RC, Trim N, Hadwin R, Grove BH, Arthur MJ, Unemori EN, Iredale JP.
Gut. 2001 Oct;49(4):577-83.
PMID 11559657
 
Human relaxin gene 3 (H3) and the equivalent mouse relaxin (M3) gene. Novel members of the relaxin peptide family.
Bathgate RA, Samuel CS, Burazin TC, Layfield S, Claasz AA, Reytomas IG, Dawson NF, Zhao C, Bond C, Summers RJ, Parry LJ, Wade JD, Tregear GW.
J Biol Chem. 2002 Jan 11;277(2):1148-57. Epub 2001 Oct 31.
PMID 11689565
 
Endocrine and Neuroendocrine Abnormalities.
Berne K.
Chronic Fatigue Syndrom, fibromyalgia and other invisible illnesses. Hunter House Publisher, Alameda CA USA. 2002;p157.
 
Relaxin enhances in-vitro invasiveness of breast cancer cell lines by up-regulation of matrix metalloproteases.
Binder C, Hagemann T, Husen B, Schulz M, Einspanier A.
Mol Hum Reprod. 2002 Sep;8(9):789-96.
PMID 12200455
 
The primary structure and the disulfide links of the bovine relaxin-like factor (RLF).
Bullesbach EE, Schwabe C.
Biochemistry. 2002 Jan 8;41(1):274-81.
PMID 11772026
 
Arginine metabolic pathways involved in the modulation of tumor-induced angiogenesis by macrophages.
Davel LE, Jasnis MA, de la Torre E, Gotoh T, Diament M, Magenta G, Sacerdote de Lustig E, Sales ME.
FEBS Lett. 2002 Dec 4;532(1-2):216-20.
PMID 12459493
 
Relaxin up-regulates inducible nitric oxide synthase expression and nitric oxide generation in rat coronary endothelial cells.
Failli P, Nistri S, Quattrone S, Mazzetti L, Bigazzi M, Sacchi TB, Bani D.
FASEB J. 2002 Feb;16(2):252-4. Epub 2001 Dec 14.
PMID 11744624
 
VEGF and the quest for tumour angiogenesis factors.
Ferrara N.
Nat Rev Cancer. 2002 Oct;2(10):795-803.
PMID 12360282
 
Activation of orphan receptors by the hormone relaxin.
Hsu SY, Nakabayashi K, Nishi S, Kumagai J, Kudo M, Sherwood OD, Hsueh AJ.
Science. 2002 Jan 25;295(5555):671-4.
PMID 11809971
 
Relaxin peptides are new global players.
Ivell R, Einspanier A.
Trends Endocrinol Metab. 2002 Oct;13(8):343-8.
PMID 12217491
 
Clinical translation of angiogenesis inhibitors.
Kerbel R, Folkman J.
Nat Rev Cancer. 2002 Oct;2(10):727-39.
PMID 12360276
 
INSL3/Leydig insulin-like peptide activates the LGR8 receptor important in testis descent.
Kumagai J, Hsu SY, Matsumi H, Roh JS, Fu P, Wade JD, Bathgate RA, Hsueh AJ.
J Biol Chem. 2002 Aug 30;277(35):31283-6. Epub 2002 Jul 11.
PMID 12114498
 
Relaxin gene and protein expression and its regulation of procollagenase and vascular endothelial growth factor in human endometrial cells.
Palejwala S, Tseng L, Wojtczuk A, Weiss G, Goldsmith LT.
Biol Reprod. 2002 Jun;66(6):1743-8.
PMID 12021056
 
Immunity to cancer: attack and escape in T lymphocyte-tumor cell interaction.
Rivoltini L, Carrabba M, Huber V, Castelli C, Novellino L, Dalerba P, Mortarini R, Arancia G, Anichini A, Fais S, Parmiani G.
Immunol Rev. 2002 Oct;188:97-113.
PMID 12445284
 
Relaxin activates the MAP kinase pathway in human endometrial stromal cells.
Zhang Q, Liu SH, Erikson M, Lewis M, Unemori E.
J Cell Biochem. 2002;85(3):536-44.
PMID 11967993
 
Relaxin: new peptides, receptors and novel actions.
Bathgate RA, Samuel CS, Burazin TC, Gundlach AL, Tregear GW.
Trends Endocrinol Metab. 2003 Jul;14(5):207-13.
PMID 12826326
 
Inhibition of markers of hepatic stellate cell activation by the hormone relaxin.
Bennett RG, Kharbanda KK, Tuma DJ.
Biochem Pharmacol. 2003 Sep 1;66(5):867-74.
PMID 12948868
 
Relaxin: a pregnancy hormone as central player of body fluid and circulation homeostasis.
Dschietzig T, Stangl K.
Cell Mol Life Sci. 2003 Apr;60(4):688-700.
PMID 12785716
 
Effect of relaxin in two models of renal mass reduction.
Garber SL, Mirochnik Y, Brecklin C, Slobodskoy L, Arruda JA, Dunea G.
Am J Nephrol. 2003 Jan-Feb;23(1):8-12.
PMID 12373075
 
New insights into the evolution of the relaxin-LGR signaling system.
Hsu SY.
Trends Endocrinol Metab. 2003 Sep;14(7):303-9.
PMID 12946872
 
Nitric oxide-mediated promotion of mammary tumour cell migration requires sequential activation of nitric oxide synthase, guanylate cyclase and mitogen-activated protein kinase.
Jadeski LC, Chakraborty C, Lala PK.
Int J Cancer. 2003 Sep 10;106(4):496-504.
PMID 12845643
 
Identification of relaxin-3/INSL7 as a ligand for GPCR142.
Liu C, Chen J, Sutton S, Roland B, Kuei C, Farmer N, Sillard R, Lovenberg TW.
J Biol Chem. 2003b Dec 12;278(50):50765-70. Epub 2003 Sep 30.
PMID 14522967
 
Identification of relaxin-3/INSL7 as an endogenous ligand for the orphan G-protein-coupled receptor GPCR135.
Liu C, Eriste E, Sutton S, Chen J, Roland B, Kuei C, Farmer N, Jörnvall H, Sillard R, Lovenberg TW.
J Biol Chem. 2003a Dec 12;278(50):50754-64. Epub 2003 Sep 30.
PMID 14522968
 
Relaxin increases ubiquitin-dependent degradation of fibronectin in vitro and ameliorates renal fibrosis in vivo.
McDonald GA, Sarkar P, Rennke H, Unemori E, Kalluri R, Sukhatme VP.
Am J Physiol Renal Physiol. 2003 Jul;285(1):F59-67.
PMID 12820641
 
Physiological or pathological--a role for relaxin in the cardiovascular system?
Samuel CS, Parry LJ, Summers RJ.
Curr Opin Pharmacol. 2003 Apr;3(2):152-8.
PMID 12681237
 
Targeting HIF-1 for cancer therapy.
Semenza GL.
Nat Rev Cancer. 2003 Oct;3(10):721-32.
PMID 13130303
 
Adenovirus-mediated expression of human prorelaxin promotes the invasive potential of canine mammary cancer cells.
Silvertown JD, Geddes BJ, Summerlee AJ.
Endocrinology. 2003a Aug;144(8):3683-91.
PMID 12865351
 
Relaxin-like peptides in cancer.
Silvertown JD, Summerlee AJ, Klonisch T.
Int J Cancer. 2003b Nov 20;107(4):513-9.
PMID 14520686
 
Cloning, characterization, and expression of the rat relaxin gene.
Soloff MS, Gal S, Hoare S, Peters CA, Hunzicker-Dunn M, Anderson GD, Wood TG.
Gene. 2003 Dec 24;323:149-55.
PMID 14659888
 
H3 relaxin is a specific ligand for LGR7 and activates the receptor by interacting with both the ectodomain and the exoloop 2.
Sudo S, Kumagai J, Nishi S, Layfield S, Ferraro T, Bathgate RA, Hsueh AJ.
J Biol Chem. 2003 Mar 7;278(10):7855-62. Epub 2002 Dec 27.
PMID 12506116
 
Molecular basis of angiogenesis and cancer.
Tonini T, Rossi F, Claudio PP.
Oncogene. 2003 Sep 29;22(42):6549-56.
PMID 14528279
 
Homeobox HOXA10 gene analysis in cryptorchidism.
Bertini V, Bertelloni S, Valetto A, Lala R, Foresta C, Simi P.
J Pediatr Endocrinol Metab. 2004 Jan;17(1):41-5.
PMID 14960020
 
Elevated concentrations of serum relaxin are associated with metastatic disease in breast cancer patients.
Binder C, Simon A, Binder L, Hagemann T, Schulz M, Emons G, Trümper L, Einspanier A.
Breast Cancer Res Treat. 2004 Sep;87(2):157-66.
PMID 15377840
 
Use of relaxin treat diseases related to vasoconstriction.
Conrad KP, Lewis M, Unemori EN, Huang X, Tozzi CA.
US Patent 6723702. 2004.
 
New aspects in the pathophysiology of preeclampsia.
Davison JM, Homuth V, Jeyabalan A, Conrad KP, Karumanchi SA, Quaggin S, Dechend R, Luft FC.
J Am Soc Nephrol. 2004 Sep;15(9):2440-8.
PMID 15339993
 
Haploinsufficiency of delta-like 4 ligand results in embryonic lethality due to major defects in arterial and vascular development.
Gale NW, Dominguez MG, Noguera I, Pan L, Hughes V, Valenzuela DM, Murphy AJ, Adams NC, Lin HC, Holash J, Thurston G, Yancopoulos GD.
Proc Natl Acad Sci U S A. 2004 Nov 9;101(45):15949-54. Epub 2004 Nov 1.
PMID 15520367
 
Relaxin modulates cardiac fibroblast proliferation, differentiation, and collagen production and reverses cardiac fibrosis in vivo.
Samuel CS, Unemori EN, Mookerjee I, Bathgate RA, Layfield SL, Mak J, Tregear GW, Du XJ.
Endocrinology. 2004 Sep;145(9):4125-33. Epub 2004 May 20.
PMID 15155573
 
Relaxin 2004: Proceedings of the Fourth International Conference on Relaxin and Related Peptides.
Sherwood OD, Steinetz B, Fields PA.
New York Academy of Sciences, New York. 2004.
 
Proteomic expression analysis of colorectal cancer by two-dimensional differential gel electrophoresis.
Alfonso P, Nunez A, Madoz-Gurpide J, Lombardia L, Sanchez L, Casal JI.
Proteomics. 2005 Jul;5(10):2602-11.
PMID 15924290
 
Vascular leukocytes contribute to tumor vascularization.
Conejo-Garcia JR, Buckanovich RJ, Benencia F, Courreges MC, Rubin SC, Carroll RG, Coukos G.
Blood. 2005 Jan 15;105(2):679-81. Epub 2004 Sep 9.
PMID 15358628
 
Role of the vascular endothelial growth factor pathway in tumor growth and angiogenesis.
Hicklin DJ, Ellis LM.
J Clin Oncol. 2005 Feb 10;23(5):1011-27. Epub 2004 Dec 7.
PMID 15585754
 
Relaxin-like peptides in neoplastic lesions.
Klonisch T, Hoang-Vu C, Homach-Klonisch S.
Curr Med Chem-Immunology, Endocrine and Metabolic Agents. 2005;5:431-437.
 
INSL5 is a high affinity specific agonist for GPCR142 (GPR100).
Liu C, Kuei C, Sutton S, Chen J, Bonaventure P, Wu J, Nepomuceno D, Kamme F, Tran DT, Zhu J, Wilkinson T, Bathgate R, Eriste E, Sillard R, Lovenberg TW.
J Biol Chem. 2005 Jan 7;280(1):292-300. Epub 2004 Nov 2.
PMID 15525639
 
Central effects of long-term relaxin expression in the rat.
Silvertown JD, Fraser R, Poterski RS, Geddes B, Summerlee AJ.
Ann N Y Acad Sci. 2005 May;1041:216-22.
PMID 15956711
 
Evolution of the relaxin-like peptide family.
Wilkinson TN, Speed TP, Tregear GW, Bathgate RA.
BMC Evol Biol. 2005 Feb 12;5(1):14.
PMID 15707501
 
Physiology and molecular biology of the relaxin peptide family.
Bathgate RAD, Hsueh AJW, Sherwood OD.
Knobil and Neilès Physiology of Reproduction. Third Edition. Ed: JD Neill, Elsevier Holland. 2006a;679-768.
 
International Union of Pharmacology LVII: recommendations for the nomenclature of receptors for relaxin family peptides.
Bathgate RA, Ivell R, Sanborn BM, Sherwood OD, Summers RJ.
Pharmacol Rev. 2006b Mar;58(1):7-31.
PMID 16507880
 
The multifaceted circulating endothelial cell in cancer: towards marker and target identification.
Bertolini F, Shaked Y, Mancuso P, Kerbel RS.
Nat Rev Cancer. 2006 Nov;6(11):835-45. Epub 2006 Oct 5. (REVIEW)
PMID 17036040
 
VEGF-induced adult neovascularization: recruitment, retention, and role of accessory cells.
Grunewald M, Avraham I, Dor Y, Bachar-Lustig E, Itin A, Jung S, Chimenti S, Landsman L, Abramovitch R, Keshet E.
Cell. 2006 Jan 13;124(1):175-89.
PMID 16413490
 
Relaxin family peptide receptors RXFP1 and RXFP2 modulate cAMP signaling by distinct mechanisms.
Halls ML, Bathgate RA, Summers RJ.
Mol Pharmacol. 2006 Jul;70(1):214-26. Epub 2006 Mar 28.
PMID 16569707
 
Relaxin enhances the oncogenic potential of human thyroid carcinoma cells.
Hombach-Klonisch S, Bialek J, Trojanowicz B, Weber E, Holzhausen HJ, Silvertown JD, Summerlee AJ, Dralle H, Hoang-Vu C, Klonisch T.
Am J Pathol. 2006 Aug;169(2):617-32.
PMID 16877360
 
The role of relaxin in endometrial cancer.
Kamat AA, Feng S, Agoulnik IU, Kheradmand F, Bogatcheva NV, Coffey D, Sood AK, Agoulnik AI.
Cancer Biol Ther. 2006 Jan;5(1):71-7. Epub 2006 Jan 31.
PMID 16322684
 
Cross-species vascular endothelial growth factor (VEGF)-blocking antibodies completely inhibit the growth of human tumor xenografts and measure the contribution of stromal VEGF.
Liang WC, Wu X, Peale FV, Lee CV, Meng YG, Gutierrez J, Fu L, Malik AK, Gerber HP, Ferrara N, Fuh G.
J Biol Chem. 2006 Jan 13;281(2):951-61. Epub 2005 Nov 7.
PMID 16278208
 
Blockade of Dll4 inhibits tumour growth by promoting non-productive angiogenesis.
Noguera-Troise I, Daly C, Papadopoulos NJ, Coetzee S, Boland P, Gale NW, Lin HC, Yancopoulos GD, Thurston G.
Nature. 2006 Dec 21;444(7122):1032-7.
PMID 17183313
 
Granulocyte colony-stimulating factor promotes tumor angiogenesis via increasing circulating endothelial progenitor cells and Gr1+CD11b+ cells in cancer animal models.
Okazaki T, Ebihara S, Asada M, Kanda A, Sasaki H, Yamaya M.
Int Immunol. 2006 Jan;18(1):1-9. Epub 2005 Dec 13.
PMID 16352631
 
Inhibition of Dll4 signalling inhibits tumour growth by deregulating angiogenesis.
Ridgway J, Zhang G, Wu Y, Stawicki S, Liang WC, Chanthery Y, Kowalski J, Watts RJ, Callahan C, Kasman I, Singh M, Chien M, Tan C, Hongo JA, de Sauvage F, Plowman G, Yan M.
Nature. 2006 Dec 21;444(7122):1083-7.
PMID 17183323
 
Signal transduction by VEGF receptors in regulation of angiogenesis and lymphangiogenesis.
Shibuya M, Claesson-Welsh L.
Exp Cell Res. 2006 Mar 10;312(5):549-60. Epub 2005 Dec 5.
PMID 16336962
 
H2 relaxin overexpression increases in vivo prostate xenograft tumor growth and angiogenesis.
Silvertown JD, Ng J, Sato T, Summerlee AJ, Medin JA.
Int J Cancer. 2006 Jan 1;118(1):62-73.
PMID 16049981
 
Relaxin becomes upregulated during prostate cancer progression to androgen independence and is negatively regulated by androgens.
Thompson VC, Morris TG, Cochrane DR, Cavanagh J, Wafa LA, Hamilton T, Wang S, Fazli L, Gleave ME, Nelson CC.
Prostate. 2006 Dec 1;66(16):1698-709.
PMID 16998820
 
The R273H p53 mutation can facilitate the androgen-independent growth of LNCaP by a mechanism that involves H2 relaxin and its cognate receptor LGR7.
Vinall RL, Tepper CG, Shi XB, Xue LA, Gandour-Edwards R, de Vere White RW.
Oncogene. 2006 Mar 30;25(14):2082-93.
PMID 16434975
 
Relaxin receptors in hepatic stellate cells and cirrhotic liver.
Bennett RG, Dalton SR, Mahan KJ, Gentry-Nielsen MJ, Hamel FG, Tuma DJ.
Biochem Pharmacol. 2007 Apr 1;73(7):1033-40. Epub 2006 Dec 10.
PMID 17214975
 
Relaxin promotes prostate cancer progression.
Feng S, Agoulnik IU, Bogatcheva NV, Kamat AA, Kwabi-Addo B, Li R, Ayala G, Ittmann MM, Agoulnik AI.
Clin Cancer Res. 2007 Mar 15;13(6):1695-702.
PMID 17363522
 
Relaxin-like ligand-receptor systems are autocrine/paracrine effectors in tumor cells and modulate cancer progression and tissue invasiveness.
Klonisch T, Bialek J, Radestock Y, Hoang-Vu C, Hombach-Klonisch S.
Adv Exp Med Biol. 2007;612:104-18.
PMID 18161484
 
Where is VEGF in the body? A meta-analysis of VEGF distribution in cancer.
Kut C, Mac Gabhann F, Popel AS.
Br J Cancer. 2007 Oct 8;97(7):978-85. Epub 2007 Oct 2.
PMID 17912242
 
Delta-like ligand 4 (Dll4) is induced by VEGF as a negative regulator of angiogenic sprouting.
Lobov IB, Renard RA, Papadopoulos N, Gale NW, Thurston G, Yancopoulos GD, Wiegand SJ.
Proc Natl Acad Sci U S A. 2007 Feb 27;104(9):3219-24. Epub 2007 Feb 12.
PMID 17296940
 
Relaxin antagonizes hypertrophy and apoptosis in neonatal rat cardiomyocytes.
Moore XL, Tan SL, Lo CY, Fang L, Su YD, Gao XM, Woodcock EA, Summers RJ, Tregear GW, Bathgate RA, Du XJ.
Endocrinology. 2007 Apr;148(4):1582-9. Epub 2007 Jan 4.
PMID 17204550
 
Anti-Dll4 therapy: can we block tumour growth by increasing angiogenesis?
Sainson RC, Harris AL.
Trends Mol Med. 2007 Sep;13(9):389-95. Epub 2007 Sep 6.
PMID 17822956
 
Analog of H2 relaxin exhibits antagonistic properties and impairs prostate tumor growth.
Silvertown JD, Symes JC, Neschadim A, Nonaka T, Kao JC, Summerlee AJ, Medin JA.
FASEB J. 2007 Mar;21(3):754-65. Epub 2006 Dec 28.
PMID 17197386
 
Tumor angiogenesis.
Kerbel RS.
N Engl J Med. 2008 May 8;358(19):2039-49.
PMID 18463380
 
Relaxin reduces fibrosis in models of progressive and established hepatic fibrosis.
Bennett RG, Heimann DG, Tuma DJ.
Ann N Y Acad Sci. 2009 Apr;1160:348-9.
PMID 19416217
 
Relaxin 2008. Proceedings of the Relaxin and Related Peptides 5th International Conference, May 18-23, 2008, Maui, Hawaii, USA.
Bryant-Greenwood GD.
Ann N Y Acad Sci. 2009 Apr;1160:1-392.
PMID 19462471
 
Relaxin stimulates interleukin-6 and interleukin-8 secretion from the extraplacental chorionic cytotrophoblast.
Bryant-Greenwood GD, Yamamoto SY, Sadowsky DW, Gravett MG, Novy MJ.
Placenta. 2009 Jul;30(7):599-606. Epub 2009 May 20.
PMID 19467703
 
Relaxin activates multiple cAMP signaling pathway profiles in different target cells.
Halls ML, Hewitson TD, Moore XL, Du XJ, Bathgate RA, Summers RJ.
Ann N Y Acad Sci. 2009 Apr;1160:108-11.
PMID 19416169
 
Relaxin: an endogenous renoprotective factor?
Hewitson TD, Samuel CS.
Ann N Y Acad Sci. 2009 Apr;1160:289-93.
PMID 19416206
 
Recombinant human relaxin in the treatment of systemic sclerosis with diffuse cutaneous involvement: a randomized, double-blind, placebo-controlled trial.
Khanna D, Clements PJ, Furst DE, Korn JH, Ellman M, Rothfield N, Wigley FM, Moreland LW, Silver R, Kim YH, Steen VD, Firestein GS, Kavanaugh AF, Weisman M, Mayes MD, Collier D, Csuka ME, Simms R, Merkel PA, Medsger TA Jr, Sanders ME, Maranian P, Seibold JR; Relaxin Investigators and the Scleroderma Clinical Trials Consortium.
Arthritis Rheum. 2009 Apr;60(4):1102-11.
PMID 19333948
 
Relaxin alters cardiac myofilament function through a PKC-dependent pathway.
Shaw EE, Wood P, Kulpa J, Yang FH, Summerlee AJ, Pyle WG.
Am J Physiol Heart Circ Physiol. 2009 Jul;297(1):H29-36. Epub 2009 May 8.
PMID 19429819
 
The source and secretion of immunoactive relaxin in rat milk.
Steinetz BG, Horton L, Lasano S.
Exp Biol Med (Maywood). 2009 May;234(5):562-5. Epub 2009 Feb 20.
PMID 19234058
 
Relaxin induces vasodilation in skeletal muscle arterioles through nitric oxide and potassium channel dependent pathways.
Willcox JM, Summerlee AJS, Murrant CL.
Endocrinology (in press). 2009.
 
Conductance of a relaxin-induced vasodilation in skeletal muscle arterioles.
Willcox JM, Murrant CL, Summerlee AJS.
Endocrinology (in preparation). 2010.
 
Written2009-07Jordan M Willcox, Alastair JS Summerlee
of Biomedical Science, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada

Citation

This paper should be referenced as such :
Willcox, JM ; Summerlee, AJS
RLN2, its role in cancer
Atlas Genet Cytogenet Oncol Haematol. 2010;14(6):609-626.
Free journal version : [ pdf ]   [ DOI ]
On line version : http://AtlasGeneticsOncology.org/Deep/RLN2inCancerID20079.htm

Citation

Atlas of Genetics and Cytogenetics in Oncology and Haematology

RLN2 and its role in cancer

Online version: http://atlasgeneticsoncology.org/deep-insight/20079/rln2-and-its-role-in-cancer