[Effect of human telomerase reverse transcriptase gene antisense oligonucleotide on sensitivity of gemcitabine in pancreatic cancer cell].

OBJECTIVE: To evaluate whether antisense oligonucleotides (ASODN) targeting hTERT mRNA could sensitize human pancreatic cancer cell to gemcitabine in vitro. METHODS: hTERT mRNA expression was measured by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) assay. Telomerase activity was examined by TRAP, polyacrylamide gel electrophoresis and silver staining. The proliferation capacity and the apoptosis of cancer cells were evaluated by MTT assay and double staining with both Annexin V-FITC and PI. RESULTS: Transient transfection in human pancreatic cancer cell with hTERT ASODN diminished the abundance of hTERT mRNA in a concentration-dependent fashion. And 0.2 micromol/L ASODN decreased the telomerase activity by 0.47-fold in cancer cell. The IC(50) value of gemcitabine in ASODN-transfected cell was (0.8 +/- 0.2) micromol/L while that in oligofectamine-transfected control cell (7.3 +/- 0.9) micromol/L with a statistically significant difference. hTERT ASODN significantlly increased the gemcitabine-induced apoptosis rate in pancreatic cancer cell. The gemcitabine-induced apoptosis rate in ASODN-transfected cell was 60.28% while that in oligofectamine-transfected control cell 17.34%. CONCLUSION: hTERT antisense oligodeoxynucleotide can increase the sensitivity of pancreatic cancer cell to gemcitabine. The mechanism may be due to the down-regulated expression of hTERT mRNA and telomerase activity.