The Influence of STAT3 Silencing by RNA Interference on the Biological Characteristics of Eca-109 Cell Line / 中国肿瘤临床

ABSTRACT

Objective: To study the cell proliferation, cell cycle and apoptosis of esophageal carcinoma Eca-109 cells treated with RNA interference technique to silence signal transducers and activators of transcription 3 (STAT3) gene. Methods: Three pairs of DNA template coding siRNA specific for human STAT3 gene mRNA were designed and synthesized. The annealed oligonucleotide fragments were subcloned into pRNAT-U6.1/neo plasmid to construct STAT3-siRNA expression vector which was then transfected into Eca-109 cells. The expression of STAT3 mRNA and protein in cancer cells was detected by RT-PCR and Western blot, respectively. The cell proliferation, cell cycle distribution and apoptosis were examined by MTT and flow cytometry. Results: STAT3-siRNA expression vector was successfully constructed and identified by sequencing. The results of RT-PCR and Western blot demonstrated that STAT3 expression in Eca-109 cells transfected with STAT3-siRNA expression vector was significantly higher than that in the control group (P＜ 0.01). MTT showed that after transfection of the siRNA vector into Eca-109 cells, cell proliferation was obviously reduced and the cell growth inhibition ratio in the siRNA3 group was 35.68%, significantly higher than that in the control group (P＜0.01). Flow cytometry results suggested that cell cycle arrest and more apoptosis were observed in the siRNA3 group. Cell cycle was arrested at G_0/G_1 phase, and the rate of apoptosis was 13.26%, much higher than that in the control group (P＜0.01). Conclusion: Silencing STAT3 gene by RNA interference technique can effectively inhibit STAT3 expression, suppress the proliferation of Eca-109 cells, induce cell cycle arrest at G_0/G_1 phase, and promote apoptosis.