Previous studies have shown the presence of dilated neoplastic glands with cellular gaps called glandular pores (GPs) and
laminin 5gamma2 expression at the invading edge of colonic
carcinomas. We now extended our studies to explore a possible association between GP formation and
laminin 5gamma2 expression at the invading edge of colonic
carcinomas. Immunostain was performed on sections of five consecutive neoplastic glands with and without GPs from 86 colonic
adenocarcinomas to assess the expression of
laminin 5gamma2. Neoplastic glands with GPs were observed in 85% (73/86) of the
tumors.
Laminin 5gamma2 was expressed in 92% (335/365) of the neoplastic glands with GPs but only in 17% (63/365) of the neoplastic glands without GPs (p<0.05).
Laminin 5gamma2 was overexpressed in the cells at the free ends of the pores in 88% of the neoplastic glands with GPs, but only in 14% of those without pores (p<0.05). Hence, at the growing edge of colonic
carcinomas,
laminin 5gamma2 was frequently expressed in neoplastic glands having GPs. Remarkably, the
tumor cells at the free ends of the GPs overexpressed
laminin 5gamma2, indicating increased production of this adhesion-migration macromolecule. The results suggest a close interaction between this adhesion-migration macromolecule, PG formation and the local progression of colonic
carcinomas.