Background: Phospholipase C isozymes (PLC) play a role in ligand-mediated signal transduction for cellular activity, such as proliferation and differentiation. However, the biologic significance of their molecules in carcinogenesis or tumor progression is yet to be determined.
Methods: Using PLC isozyme-specific antibodies, the relative content of PLC in human colorectal carcinomas and in normal colonic mucosa was examined.
Results: Immunoreactive analysis revealed considerably higher levels of PLC-gamma 1 protein in 15 of 17 colorectal carcinomas and little difference in PLC-beta 1 or PLC-gamma 1 content compared with normal colorectal tissues. By radioimmunoassay and Western blotting, PLC-gamma 1 showed three-fold to fourfold more expression in carcinomas than that in normal tissues.
Conclusion: Although factors that might influence the level of PLC-gamma 1 expression in colorectal carcinomas still remain obscure, the fact that most colorectal carcinomas display elevated levels of PLC-gamma 1 expression implies that PLC-gamma 1 may play an important role in proliferation of colorectal carcinoma cells.