Abstract

P-glycoprotein, livin, and survivin are apoptosis inhibitory proteins. This study was to clarify the correlation between expression of P-glycoprotein, livin, survivin, and drug resistance in the human gastric cancer resistant cell line OCUM-2MD3/oxaliplatin. The highly invasive metastatic gastric cancer cell line OCUM- 2MD3 was utilized as experimental material. The oxaliplatin-resistant cell line, OCUM-2MD3/oxaliplatin, was established by inducing OCUM-2MD3 cells with oxaliplatin. Flow cytometry was employed to analyze the cell cycle and apoptosis of OCUM-2MD3/oxaliplatin cells. The sensitivity of OCUM-2MD3/oxaliplatin cells to drugs was determined using cell counting kit-8 assay. Real-time quantitative polymerase chain reaction and Western blot analysis were performed to determine the gene and protein expression levels of P-glycoprotein, livin, and survivin in OCUM-2MD3 and OCUM-2MD3/oxaliplatin cells, establishing the association between expression of these genes and proteins and drug resistance of OCUM-2MD3/oxaliplatin cells. Gene and protein expression levels of P-glycoprotein, livin, and survivin were markedly upregulated in OCUM-2MD3/ oxaliplatin cells relative to OCUM-2MD3 cells. P-glycoprotein and livin expression exhibited a positive correlation with cisplatin resistance in OCUM-2MD3/oxaliplatin cells, whereas survivin expression showed a negative correlation with resistance. The expression levels of P-glycoprotein, livin, and survivin are closely associated with drug resistance in the human gastric cancer resistant cell line OCUM-2MD3/oxaliplatin. A theoretical basis was provided for development of novel therapeutic strategies targeting these molecules and contributes to enhancing clinical efficacy in gastric cancer patients.