Distribution of laminin and collagen type IV in rat colon tumors induced by 1,2-dimethylhydrazine.

Immunofluorescent distribution of basement membrane components laminin and collagen type IV was studied in 51 rat colon tumors induced by 1, 2-dimethylhydrazine. In normal colonic mucosa, adenomas and carcinomas in situ continuous basement membranes were present, while in adenocarcinomas they were altered to different extents. An uncoordinated loss, or dissociation, of the two markers studied was found: the degree of collagen type IV loss was often much higher than that of laminin in the same tumor. These data suggest that a reliable determination of cancer invasion by monitoring basement membrane alteration requires the use of several basement membrane markers.