18q21.1

JV18,JV18-1,MADH2,MADR2,hMAD-2,hSMAD2

Colorectal cancers

Smad2 was proposed to be a tumor suppressor gene that may function to disrupt TGF-beta signaling. Inactivating mutations in Smad2 have been found in various cancer including colorectal carcinomas. The majority of tumor-derived mutations cluster in the carboxy-terminal MH2 domain, and some of these have been shown to disrupt TGF-beta signaling by blocking receptor-dependent phosphorylation or by preventing heterodimeric interactions between Smads. A mutation at position 133 in the amino-terminal MH1 domain has also been associated with colorectal carcinoma. Nevertheless, loss of Smad2 activation and/or expression was related to occur in less than 10% of colorectal cancers.