Influence of checkpoint kinase 1 small interfering RNA on EC9706 cell proliferation inhibition and apoptosis induction by cisplatin

Objective To construct recombinant vector pSilencer 3.1-checkpoint kinase 1 (Chk1) small interfering RNA (siRNA) and study the effect of Chk1 siRNA interference expression vector on EC9706 esophageal cancer cell proliferation inhibition and apoptosis induction by cisplatin.Methods Three pairs of anti-sense oligonucleotide fragments and a pair of non-sense sequence were designed and annealed,introduced into RNA interfering expression vector pSilencer 3.1,and the recombinant expression vector pSilencer 3.1-Chk1 siRNA was successfully constructed.The.expression of ChK1 mANA and protein in the cells was detected by using real-time quantitative polymerase chain reaction (Real-time PCR) and Western blotting respectively.The pSilencer 3.1-Chk1 siRNA with strongest inhibitory effect on Chk1 expression was transfected into EC9706 cells,and 24 h later,EC9706 cells were treated with cisplatin (10 μmol/L) for 12 h.Methyl thiazol tetrazolium (MTT) assay was used to measure the cell proliferation,and TdT-mediated dUTP nick end labeling (TUNEL) and flow cytometry were used to examine apoptosis.Results When the pSilencer 3.1-Chk1 siRNA was transfected into EC9706 cells,the expression of Chk1 mRNA and protein in EC9706 cells were significantly inhibited,and cell proliferation inhibition and induction of apoptosis by cisplatin on EC9706 cells were enhanced (P ＜ 0.05).Conclusion The PSilencer 3.1-Chk1 siRNA recombinant vector had been constructed successfully,which can inhibit the gene expression of Chk1,and enhance the sensitivity of tumor cells to cisplatin. Key words: Esophageal squamous carcinoma;  Checkpoint kinases 1;  RNA interference; Cisplatin;  Proliferation