text: [Interference of survivin in pancreatic cancer Bx-PC3 cell line with Smac sensitizing its response to cisplatin].
  To investigate the downregulation of survivin, an inhibitor of apoptosis protein with Smac and further analyze the sensitization to cisplatin chemotherapy in survivin-overexpressing pancreatic cancer BX-PC3 cell line with Smac transfection. Stably passaged Bx-PC3 cell line was established to express survivin uniformly. Smac-GFP recombinant plasmid was constructed and transfected into BX-PC3 cells, in which survivin was semiquantitatively analyzed by Western blot. Cells were incubated with 10 mg/L cisplatin for 48 h and 72 h, whose rate of inhibition (%) was determined with MTT assay. Bx-PC3 cells presented mild positive transfection (green GFP fluorescence positive) at 24 h post transfection, which became substantial at 48 h and reach its peak at 72 h. Western blot assay showed that survivin in transfected cells was equal to 28.6% of that in control cells (P<0.01). Moreover, with the prolongation of cisplatin treatment, both control and transfected cells showed a rising trend in their rates of inhibition (48 h vs 72 h, P<0.05) and meanwhile the former was always below the latter at both time points (P<0.01) as confirmed by MTT assay. Survivin played an important role in regulation of proliferation in pancreatic cancer and is also closely correlated to its chemotherapeutic resistance. Antagonism with Smac could downregulate the protein expression of survivin and sensitize the response of pancreatic cancer to chemotherapeutic agents, which emerged as a potential and effective therapeutic strategy for pancreatic cancer.