Effect of antisurvivin oligodeoxynucleotides on proliferation and apoptosis in gastric cancer cell line BGC-823 and the molecular mechanism

Abstract

To explore the effects of antisense oligodeoxynucleotides (ASODN) on proliferation and apoptosis in gastric cancer cell line BGC-823 cells and the molecular mechanisms induced by ASODN. survivin ASODN-1, survivin ASODN-2 and survivin ASODN-3 were transfected into BGC-823 cells by Lipofectamine(TM) 2000 transfection reagent. The growth activity of BGC-823 cells was detected by MTT assay. Apoptosis index (AI), proliferation index (PI), cell cycle and expressions of survivin, VEGF and Smac/DIABLO proteins were detected by flow cytometry (FCM). The changes of survivin mRNA, VEGF mRNA and Smac/DIABLO mRNA were detected by RT-PCR. The expression of survivin was down-regulated by the three ASODN sequences, especially the ASODN-2 was best. At 48 hours after transfection with 600 nmol/L survivin ASODN-2, the cells in G(1)/G(0) phase were significantly increased [(72.25 ± 2.95)%], apoptotic index increased [(11.31 ± 0.38)%], proliferation index decreased [(27.77 ± 2.97)%], compared with those in the control group [(56.25 ± 0.75)%, (1.62 ± 0.36)%, (43.80 ± 0.80)%, all P < 0.05]. The survivin mRNA and protein levels (0.523 ± 0.091, 0.733 ± 0.009) were down-regulated compared with those in the control group (0.861 ± 0.047, 0.997 ± 0.233), VEGF (0.519 ± 0.076, 0.75 ± 0.006) were down-regulated compared with those in the control group (0.779 ± 0.059, 1.000 ± 0.01), while those of Smac/DIABLO(0.899 ± 0.113, 1.637 ± 0.023)were up-regulated compared with those in the control group (0.558 ± 0.041, 1.000 ± 0.049, all P < 0.05). Survivin ASODN can induce apoptosis and inhibit the proliferation of gastric cancer cell line BGC-823 cells. Those effects are induced through up-regulation of Smac/DIABLO and down-regulation of survivin and VEGF expression simultaneously.