Type IV collagen α chains in colon cancer

Recently, differences in histological diagnosis of colonic neoplasms between Japan and Western countries have been noted. We examined the relationship between the histopathology and immunohistochemical localization of six genetically distinct type IV collagen α chains, the major component of basement membrane (BM), in normal and neoplastic colonic tissues. α1/α2(IV) and α5/α6(IV) chains were observed in normal mucosa and tubular adenomas with mild/moderate atypia. In non-invasive cancers, both α1/α2(IV) chains were linearly stained in the BM of cancer cell nests, while the assembly of α5/α6(IV) chains into the BM was inhibited in a discontinuous or negatively stained pattern. The differential expressions of the type IV collagen α5/α6 chains could be one of the diagnostic markers of the invasiveness of colon cancer. [Copyright &y& Elsevier]