Effect of octreotide combined with oxaliplatin on proliferation and apoptosis of human colon carcinoma cell line SW480 cells

Abstract

Objective To investigate the effect of octreotide combined with oxaliplatin on proliferation and apoptosis of human colon carcinoma cell line SW480 cells and the possible mechanism.Methods SW480 cells cultured in vitro,and treated with different concentrations of octreotide (6.25,12.50,25.00,50.00,100.00 μg/L) and oxaliplatin (12.5,25.0,50.0,100.0,200.0 mg/L) alone or combined (oetreotide 25.00 μg/L + oxaliplatin 12.5 mg/L).The growth inhibition ratio was determined by methyl thiazol tetrazolium (MTT) assay.The apoptosis rate was analyzed by flow cytometry (FCM).The mRNA expression of bax,fas,and bcl-2 in tumor cells was detected by using reverse transcription-polymerase chain reaction (RT-PCR).Results The MTT results showed that the different concentrations of octreotide or oxaliplatin alone exhibited inhibitory effects on proliferation of SW480 cells (P ＜ 0.01) in a dose-dependent fashion.Inhibition ratio of the cell proliferation was observed under the treatment of octreotide combined with oxaliplatin [(74.5600 ± 0.0072) ％],which was significantly increased as compared with the treatment of octreotide [(44.7200 ± 0.0216)％] or oxaliplatin [(34.5100 ± 0.0053)％]alone.Apoptosis rate in the combination group was (15.45 ±0.41)％,significantly higher than in oxaliplatin alone group [(10.07 ± 0.53) ％] or octreotide alone group [(10.63 ± 0.14) ％] (P ＜ 0.05).RTPCR analysis revealed that the bax and fas mRNA levels were higher,and the bcl-2 mRNA level in the combination group was lower than those in the control group,octreotide alone group and oxaliplatin alone group(P ＜0.01).Conclusion Octreotide combined with Oxaliplatin could obviously inhibit proliferation and induce apoptosis of SW480 cells and exert the synergistic effect probably by increasing bax and fas mRNA expression,and reducing bcl-2 mRNA expression. Key words: Octreotide ; Oxaliplatin ; Colon carcinoma; Proliferation; Apoptosis