Knockdown of hTERT by SiRNA suppresses growth of Capan-2 human pancreatic cancer cell via the inhibition of expressions of Bcl-2 and COX-2.

OBJECTIVE: To investigate the effects of human telomerase reverse transcriptase (hTERT) on the growth of Capan-2 human pancreatic cancer cell and apoptosis. METHODS: Cell proliferation, apoptosis and cell cycle were analyzed by cell counting and flow cytometry. mRNA and protein expressions of hTERT, Bcl-2 and cyclooxygenase (COX)-2 were assessed by real time PCR and Western blot. RESULTS: Cell growth was significantly inhibited by 26.39 percent 24 h after hTERT-small interference RNA (siRNA) transfection (50 nmol/L) with a 100 percent silencing efficiency (P < 0.05). The inhibition rates of cell proliferation were 46.77 percent, 70.61 percent, 84.71 percent and 85.99 percent at 2, 3, 5 and 7 days after transfection, respectively (P < 0.001). Early and late apoptotic cells increased significantly (especially 24 h after transfection) (P < 0.001). The cell cycle was suppressed significantly as manifested by the increase of cells in the G0/G1 phase and the decrease of cells in the S phase and G2/M phase (P < 0.01). The expressions of Bcl-2 mRNA and COX-2 mRNA were inhibited significantly 48 h after transfection: the inhibition rates were 86.86 percent and 100 percent, respectively (P < 0.001). Levels of Bcl-2 protein were downregulated by 58.54 percent and 63.44 percent and the levels of COX-2 protein were downregulated by 50.06 percent and 82.77 percent at 48 h and 72 h after transfection, respectively. CONCLUSION: Knockdown of hTERT by siRNA can inhibit the growth of Capan-2 cell. The inhibitory effect is associated with the downregulation of Bcl-2 and COX-2.