The inhibitory effects of siRNA expression vector on STAT3 expression of human pancreatic cancer

Objective To construct signal transduction and activators of transcription 3 (STAT3)small interference RNA(siRNA) expression vector and to investigate its inhibitory effect on STAT3 expression of human pancreatic cancer. Methods Three pairs of hairpin-like oligonucleotide sequences specific for human STAT3 gene were designed and synthesized. The annealed oligonucleotide fragments were subcloned into pRNAT-U6. 1/Neo plasmid. The STAT3 siRNA expressing vectors were confirmed by PCR and sequencing. Transfection of STAT3 siRNA expressing vectors into SW1990 cells was performed using liposome transfection reagents. STAT3 mRNA and protein expression were examined using real-time reverse transcription polymerase chain reaction (real-time RT-PCR) and Western blotting, respectively. Results PCR and DNA sequencing showed that the oligonucleotide fragments were correctly inserted into pRNAT U6. 1/Neo plasmid. STAT3 expression in the cells transfected by three STAT3 siRNA expressing vectors was inhibited significantly at both mRNA and protein level. STAT3 mRNA and protein expression were decreased 63% and 60% compared with pRNAT-U6. 1/Neo group, respectively. Conclusions The STAT3 siRNA expression vector can effectively inhibit the expression of STAT3 in transfected SW1990 cells.