Effect of silencing Bmi-1 expression in reversing cisplatin resistance in lung cancer cells and its mechanism.
- Author:
Nan MAO
1
;
Guansheng HE
;
Jinjun RAO
;
Lin LV
Author Information
- Publication Type:Journal Article
- MeSH: Antineoplastic Agents; pharmacology; Apoptosis; Cell Cycle; Cell Line, Tumor; Cisplatin; pharmacology; Drug Resistance, Neoplasm; Gene Silencing; Humans; Lung Neoplasms; genetics; Polycomb Repressive Complex 1; genetics; RNA, Small Interfering
- From: Journal of Southern Medical University 2014;34(7):1000-1004
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo investigate the effect of silencing Bmi-1 expression in reversing cisplatin resistance in human lung cancer cells and explore the possible mechanisms.
METHODSCisplatin-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, P14(ARF), P16(INK4a), P53, P21, Rb and ubi-H2AK119 in the cells were determined with Western blotting.
RESULTSA549/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±4.1 µmol/L to 18.3±2.8 µmol/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 P14(ARF), P16(INK4a), P53, P21 and Rb.
CONCLUSIONSilencing Bmi-1 by RNA interference can induce cell senescence and resensitize A549/DDP cells to cisplatin possibly by regulating INK4a/ARF/Rb senescence pathway.
