ERCC1-shRNA inhibits the proliferation and promotes the apoptosis of lung cancer A549/DDP cells / 医学研究生学报

ABSTRACT

Objective Studies show that the ERCC1 gene may be involved in secondary cisplatin resistance.This article aims to investigate the effects of shRNA targeting silencing excision repair cross-complementation group 1 (ERCC1-shRNA) on the proliferation and apoptosis of lung cancer A549/DDP cells treated with different concentrations of cisplatin.Methods Lung cancer A549/DDP cells were divided into a negative control, a blank control, an ERCC1-shRNA1, and an ERCC1-shRNA2 group.Human interfering RNA (RNAi) targeting the human ERCC1 gene was constructed and transfected into the A549/DDP cells using Lipofectamine 2000.The mRNA and protein expressions of ERCC1 in the A549/DDP cells were detected by real-time PCR and Western blot respectively, the proliferation-inhibition rate was assessed by MTT, and their cell cycle and apoptosis were determined by flow cytometry.Results ERCC1-shRNA was successfully constructed and transfected into the A549/DDP cells.Both the mRNA and protein expressions of ERCC1 were significantly lower in the ERCC1-shRNA1 (0.20±0.04 and 0.24±0.10) and ERCC1-shRNA2 (0.47±0.28 and 0.37±0.11) than in the negative control (0.96±0.12 and 1.32±0.13) and blank control groups (0.84±0.07 and 1.45±0.23) (P<0.01).Compared with the negative and blank control groups, the ERCC1-shRNA1 group showed a significantly decreased IC50 value (16.71±2.33 and 16.69±1.69 vs 7.78±0.54, P<0.01) and an increased proportion of G0/G1 phase cells ([72.87±3.23] and [71.75±4.56] vs [82.99±4.23]%, P<0.05), with the cell cycle arrested in the G0/G1 phase.The apoptosis rate of the cells in the ERCC1-shRNA1 group was remarkably lower after treated with cisplatin at the concentrations of 6.25 and 12.5 μg/mL than at 0 μg/mL ([8.17±0.65] and [11.91±1.41] vs [29.97±3.14]%, P<0.05).Conclusion ERCC1-shRNA can inhibit the proliferation and enhance the apoptosis of A549/DDP cells by silencing the expression of the ERCC1 gene.