The Effect Of Human Gastric Cancer Cell Proliferation By Conjugated Linoleic Acid And Its Molecular Mechanism

Objective: To investigate the effect of human gastric cancer cell line MGC-803 by conjugated linoleic acid (CLA) in vitro and to explore its molecular mechanism. Methods: Human gastric cancer cell line MGC-803 was cultured in vitro and used to perform experiments. The effect of CLA was examined 3-[4,5-dimedthylthiazol -2-yl]5-diphenyl tetrazolium bromid(MTT) assay in vitro. The influences of CLA on MGC-803 cell growth were measured by counting cell numbers. The influence of CLA on apoptosis and cell cycle were also detected in MGC-803 cells using flow cytometry(FCM). Immunocytochemical staining were designed to detect the expression of Bax, Bcl-2, CyclinD₁ COX-2. Western Blot was used to analyze the expression of ERK and p-ERK. All of these were to elucidate the possible mechanism of apoptosis induced by CLA in MGC-803 cells.Results:1.CLA of 12.5,25.0,50.0,100.0,200.0μmol/L inhibited the growth of MGC-803 cells in a concentration dependent manner.2. The cell counting revealed the inhibition ratio range from 21% to 51% on 24h and from 43% to 94 on 120h.3.The dye HE and Geimsa revealed that human gastric cancer cell line MGC-803 processed by CLA displayed some distinctive characteristic with apoptosis.4.Immunocytochemical staining and morphometric quantitative analysis indicated that down-regulation in expression of Bcl-2, CyclinDl protein and COX-2 (P<0.05 or P<0.01), while up-regulation in expression of Bax protein(P<0.01).5.Flow cytometry analysis revealed that CLA arrest cell cycle in G1 phase and induced apoptosis in MGC-803 cells.