Effect of silencing Bmi-1 expression in reversing cisplatin resistance in lung cancer cells and its mechanism
10.3969/j.issn.1673-4254.2014.07.17
- VernacularTitle:沉默Bmi-1表达可逆转肺癌细胞对顺铂的耐药性
- Author:
Nan MAO
1
;
Guansheng HE
;
Jinjun RAO
;
Lin LÜ
Author Information
1. 南方医科大学药学院
- Keywords:
lung neoplasm;
cisplatin;
drug-resistance;
Bmi-1;
cell senescence;
cell cycle
- From:
Journal of Southern Medical University
2014;(7):1000-1004
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of silencing Bmi-1 expression in reversing cisplatin resistance in human lung cancer cells and explore the possible mechanisms. Methods Cisplatin-resistant A549/DDP cells with small interference RNA (siRNA)-mediated Bmi-1 expression silencing were examined for cisplatin sensitivity using MTT assay and alterations in cell cycle distribution and apoptosis with flow cytometry, and the changes in cell senescence was assessed using β-galactosidase staining. The protein expressions of Bmi-1, P14ARF, P16INK4a, P53, P21, Rb and ubi-H2AK119 in the cells were determined with Western blotting. Results A549/DDP cells showed significantly higher Bmi-1 expression than A549 cells. After siRNA-mediated Bmi-1 silencing, A549/DDP cells showed significantly enhanced cisplatin sensitivity with an increased IC50 from 40.3± 4.1μmol/L to 18.3 ± 2.8μmol/L (P<0.01) and increased cell percentage in G0/G1 phase from (48.9 ± 2.3)%to (78.7 ± 7.6)%(P<0.01). Silencing Bmi-1 did not cause significant changes in the cell apoptosis rate but induced obvious senescence phenotype in A549/DDP cells with down-regulated expression of ubi-H2AK119 and up-regulated expressions of P14ARF, P16INK4a, P53,P21 and Rb. Conclusion Silencing Bmi-1 by RNA interference can induce cell senescence and resensitize A549/DDP cells to cisplatin possibly by regulating INK4a/ARF/Rb senescence pathway.
