OBJECTIVETo study cell membrane phospholipid variation and protein kinase C (PKC) isoenzyme expression and their effects on hepatic metastasis of large intestinal carcinoma.

METHODSHigh function liquid chromatography was used to separate and detect cell membrane phospholipids of phosphatidylinosital (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) in primary foci, paratumor intestine mucosa and hepatic metastasis of large intestinal carcinomas. And mRNA expression levels of PKC-alpha, -beta II, -delta, -epsilon, -lambda, -zeta isoenzymes were detected using QRT-PCR technique.

RESULTSFifty-eight cases of colorectal cancer were examined.

CONTENTSof PI, PC and PE in primary foci and hepatic metastasis were higher than those in paratumor mucosa. PE content in hepatic metastasis was much higher than that in primary foci (t = 98.88, P < 0.01). But PI and PC contents had no significant differences between primary and hepatic metastasis (t = 1.73, 1.36, P > 0.05). PKC-beta II, -delta, -epsilon, -lambda, -zeta expression were enhanced in primary foci and hepatic metastasis, but PKC-alpha level decreased in comparison with paratumor mucosa. And PKC-delta, -epsilon, -lambda, -zeta levels in hepatic metastasis were higher than those in primary foci (t = 4.31, P < 0.05). PI and PC had positive correlations with PKC-beta II expression. PE had positive correlations with PKC-delta, -epsilon, -lambda, -zeta, but a negative correlation with PKC-alpha.

CONCLUSIONSThe increases of PI and PC and PKC-alpha/PKC-beta II ratio change are related with colorectal cancer genesis. High content of PE and enhanced expression of PKC-delta, -epsilon, -lambda, -zeta isoenzymes and decreased PKC-alpha level improved hepatic metastasis of large intestinal carcinoma.