[Inhibition on the proliferation of human endometrial cancer cells by RNAi inhibiting HMGB1 gene expression and its possible molecular mechanism].

ABSTRACT

OBJECTIVE: To investigate the effect of HMGB1 small interfering RNA (siRNA) on the proliferation, cell cycle and apoptosis of human endometrial cancer cell line HEC-1A, and its possible molecular mechanism. METHODS: Lentivirus vector with HMGB1 shRNA was constructed and infected the endometrial cancer cell line HEC-1A. After viral infection for 72 h, real time PCR and Western blot were performed to investigate HMGB1 mRNA and protein expression. The cell proliferation was determined with methyl thiazolyl tetrazolium (MTT) method. Flow cytometry was performed to analyze the cell cycle progression of propidium iodide (PI)-stained HEC-1A cells and the apoptotic rate of annexinV/PI-stained cells. Western blot was used to detect the protein expression of AKT, pAKT and CyclinD1. RESULTS: Lentivirus vector with HMGB1 shRNA inhibited the mRNA (P<0.05) and protein (P<0.01) expression of HMGB1 in the cell line HEC-1A. The MTT assay demonstrated that HMGB1 knockdown significantly reduced the cell proliferation. FCM results showed that HMGB1 knockdown significantly resulted in the disruption of the cell cycle at G0/G1 phase and the induction of apoptosis. The apoptotic rate was (17.89±0.23)%, (4.69±0.20)% and (4.62±0.17)% in the HMGB1 knockdown group, the blank group and the negative group respectively. There was significance difference between the 3 groups (P<0.01). The protein expressions of pAKT and cyclinD1 were down-regulated after the HMGB1 knockdown for 72 h. CONCLUSION: Knockdown of HMGB1 expression can significantly inhibit the proliferation and induce the cell cycle arrest and apoptosis in the endometrial cancer cell line HEC-1A. PI3K/ AKT pathway and down-regulation of the protein expression of cyclinD1 may be involved in its therapeutic mechanism.