Reversal effects of desipramine on resistance of U251/TR cells to temozolomide
10.3867/j.issn.1000-3002.2016.06.002
- VernacularTitle:地昔帕明逆转人脑胶质瘤耐药细胞U251/TR对替莫唑胺的耐药作用
- Author:
Jian MA
;
Yanru YANG
;
Jingjing LIU
;
Fangfang LI
;
Meihua CHEN
;
Hao WANG
;
Lei WANG
;
Lili SUN
;
Fengze WANG
;
Decai WANG
;
Zhang HANTING
- Publication Type:Journal Article
- Keywords:
glioma;
desipramine;
temozolomide;
drug resistance;
C/EBP homologous protein
- From:
Chinese Journal of Pharmacology and Toxicology
2016;30(6):620-626
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To examine the reversal effect of desipramine (DMI) on resistance to temozolomide(TMZ) in U251/TR cells and explore its mechanism. METHODS U251/TR cells were exposed to DMI (20-80μmol · L-1) or TMZ (0.5-10 mmol · L-1) for 24 h, cell viability was determined by cell counting kit-8 assay with IC50 calculated. The cytotoxicity of U251/TR cells treated with TMZ (1 or 2 mmol·L-1) in combination with DMI (20, 30 or 40 μmol · L-1) for 24 h was detected using CCK-8 assay. Synergism between DMI and TMZ was analyzed by the JIN Zheng-jun method. Apoptosis of U251/TR cells induced by TMZ 1 mmol · L-1, DMI 30 μmol · L-1,or their combination was examined by Hoechst33258 stains and caspase 3 activity was detected by luminescence analysis. Expression of C/EBP homologous protein (CHOP) was measured using quantitative real-time PCR and Western blotting. The survival rate of U251/TR cells treated with TMZ 1 mmol·L-1 and/or DMI 30μmol·L-1 was also assessed after silencing CHOP expression by small interference RNA (siRNA). RESULTS DMI or TMZ alone inhibited the growth of U251/TR cells significantly in a concentration-dependent manner (r 2=0.983,0.982,P<0.05), with the IC50 (33.6 ± 0.5)μmol · L-1 and (2.5 ± 0.6)mmol · L-1, respectively. The cell viability inhibitory rate of U251/TR cells by TMZ (1 or 2 mmol · L-1) combined with DMI (20, 30, or 40μmol · L-1) was greater than that by TMZ or DMI alone (P<0.05). The JIN Zheng-jun analysis revealed that combination of DMI and TMZ produced synergistic cytotoxicity (Q>1.15), ie, compared with TMZ alone, TMZ (1 mmol·L-1) com?bined with DMI (30 μmol · L-1) produced significant nuclear fragmentation and condensation (P< 0.05). In addition, DMI and TMZ in combination activated caspase 3 activity in U251/TR cells (P<0.05). Knock?down of CHOP by specific siRNA attenuated the synergistic effect of DMI in the presence of TMZ, the survival rate of the combined drug group raised from 51.8%to 62.2%(P<0.05). CONCLUSION The results suggest that DMI reverse resistance of U251/TR cells to TMZ through activation of the CHOP-depend?ently apoptosis pathway.
