Abstract: Objective To investigate the effect of polyenephosphatidylcholine（PPC） combined with oxaliplatin（L-OHP） on proliferation of gastric cancer cell lines. Methods After different concentrations of PPC and L-OHP treated on SGC7901 gastric cancer cells for 24，48，72 hours， MTT assay was used to examine the proliferation ability of each group. The MTT assay was used to calculate the proliferation ability of L-OHP at the concentration lower than the halfinhibitory concentration （IC₅₀） combined with different concentrations of PPC acting on SGC7901 gastric cancer cells for 48 hours. Flow cytometry was used to evaluate the apoptosis rate and analyze cell cycle of combined group. Western blotting was used to measure the expression levels of cytochrome c， Bcl-2， Bax， caspase-9， caspase-3, Cyclin D1 and Cyclin E.
Results L-OHP could significantly inhibit the proliferation of SGC-7901 cells in a dose and time-dependent manner（P＜0.05）. The effect of PPC on the proliferation of SGC7901 cells was dose-related（P＜0.05）， but not time-related（P＞0.05）. The antiproliferation effect of PPC combined with L-OHP on SGC-7901 cells was synergistic， which had statistical significance compared with L-OHP alone（P＜0.05）. PPC greatly promoted cell apoptosis and G0／G1 phase arrest induced by L-OHP. But the promotive effect was not related with the dose of PPC（P＞0.05）. PPC and L-OHP could upregulate the expression of cytochrome c and activate the following downstream protein including Bcl-2, Bax, caspase-9 and caspase-3， downregulate Cyclin D1 and Cyclin E expression. Conclusion PPC combined with L-OHP can inhibit the proliferation， induce the apoptosis of SGC-7901 cell lines， and block the cells at G0／G1 phase， which shows a synergistic anti-tumor effect on gastric cancer cells.