Effect of inhibiting STAT3 gene on growth of human pancreatic cancer cells in vitro

Objective To investigate the effect and mechanism of RNA interference ( RNAi)-mediated signal transducer and activators of transcription 3 ( STAT3 ) gene inhibition on growth of human pancreatic cancer cells in vitro. Methods STAT3 short hairpin RNA (shRNA) expression vector was stably transfected into SW1990 cells. STAT3 mRNA was examined by using reverse transcription-polymerase chain reaction (RT-PCR). Methyl thiazol tetrazolium (MTT) assay and flow cytometry were performed to detect the cell proliferation, and apoptosis, respectively. RT-PCR was performed to detect the mRNA expression of Cyclin D1 and bcl-xL. Results The mRNA expression of STAT3 was decreased by 95% after stable transfection of STAT3 shRNA expressing vectors. Inhibition of STAT3 with RNAi significantly inhibited the growth and proliferation of pancreatic cancer cells, and induced apoptosis in pancreatic cancer cells. The percentage of early apoptotic cells and the late apoptotic cells in SW1990-RNAi cells was increased to (20. 97 ± 1.85)% and (23. 16 ± 1.94)%, respectively. Moreover, the relative Cyclin D1 and bcl-xL mRNA expression in SW1990-RNAi cells was reduced by 48% and 61% as compared with that of the parental SW1990 cells, respectively. Conclusion Inhibition of STAT3 with RNAi can significantly inhibit the growth ability of pancreatic cancer cells through down-regulating bcl-xL and Cyclin D1. Key words: Pancreatic carcinoma;  RNA interference;  STAT3;  Growth