Abstract：Objective To study the effect of UHRF1 expression inhibition by RNA interference on the radiosensitivity of esophageal cancer cell line TE-1 and its mechanism. Methods Short hairpin RNA (shRNA) targeting UHRF1 gene was introduced into TE-1 cells by lentivector-mediated transfer. The cells were divided into three groups:non-transfected group, negative control (NC)-shRNA-transfected group, and UHRF1-shRNA-transfected group. The mRNA and protein expression levels of UHRF1 in TE-1 cells were measured by RT-PCR and Western blot before and after transfection. After transfection and X-ray radiation, the radiosensitivity of TE-1 cells was evaluated by colony formation assay;the cell cycle and cell apoptosis were determined by flow cytometry;the γ-H2AX (as a marker of DNA damage) level was measured by Western blot. Results After transfection with UHRF1-shRNA, the mRNA and protein expression levels of UHRF1 were significantly decreased in TE-1 cells, as compared with those in the NC-shRNA-transfected group and non-transfected group (0.11 vs 0.96 and 0.98, F=124.21, P=0.000;0.10 vs 0.89 and 0.94, F=125.25, P=0.000). The UHRF1-shRNA-transfected group had sensitization enhancement ratios of 1.53(D0 ratio) and 1.95(Dq ratio). X-ray radiation could cause G2/M arrest and increase apoptotic rate and γ-H2AX expression in TE-1 cells. Compared with the two control groups, the UHRF1-shRNA-transfected group showed significantly less G2/M arrest (F=500.15, P=0.000), a significantly higher apoptotic rate (F=100.10,P=0.000), and significantly higher residual γ-H2AX expression (F=61.00,P=0.000) at 24 hours after X-ray radiation. Conclusions RNA interference can effectively inhibit the UHRF1 expression and enhance the radiosensitivity of TE-1 cells. The mechanism may be related to cell cycle regulation, cell apoptosis, and DNA damage repair.
YANG Cong-rong,WANG Ya-di,LI Cheng-lin et al. UHRF1 expression inhibition by RNA interference enhances the radiosensitivity of esophageal cancer cells[J]. Chinese Journal of Radiation Oncology, 2013, 22(4): 326-328.
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