Synergistic anti-tumor effect of obatoclax and MG-132 in esophageal cancer cell line CaES-17.
- Author:
Xu-Yan ZHAO
1
;
Qing-Huan LIN
;
Fu-Chang QUE
;
Chun-Ping GU
;
Le YU
;
Shu-Wen LIU
Author Information
- Publication Type:Journal Article
- MeSH: Apoptosis; Caspase 9; metabolism; Cell Cycle Checkpoints; Cell Line, Tumor; drug effects; Esophageal Neoplasms; pathology; Histones; metabolism; Humans; Leupeptins; pharmacology; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; metabolism; Pyrroles; pharmacology
- From: Journal of Southern Medical University 2016;36(4):506-513
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore whether MG-132 could enhance the anti-tumor activity of obatoclax against esophageal cancer cell line CaES-17.
METHODSMTT assay was used to determine the cytotoxicity of obatoclax and MG-132 in CaES-17 cells. The IC(50) of obatoclax and MG-132 were used to determine the molar ratio (1:2.4) of the two drugs for combined treatment of the cells. The concentrations of obatoclax and MG-132 ranged from 1/8 IC(50) to 4 IC(50) after serial dilution, and their combination index (CI) was calculated using CompuSyn software. The expression of ubiquitin and the cleavage of PARP, caspase-9, phospho-histone H3 and phospho-aurora A/B/C in the exposed cells were examined with Western blotting; the cell apoptosis was measured by flow cytometry with Annexin V staining, and the percentage of cells in each cell cycle phase was also determined by flow cytometry.
RESULTSThe CI of obatoclax and MG-132 was 0.296 for a 50% inhibition of Caes-17 cells and was 0.104 for a 95% inhibition. The cells treated with obatoclax or MG-132 alone showed increased expression of ubiquitin and cleavage of PARP and caspase-9. Compared with the cells treated with obatoclax or MG-132 alone, the cells with a combined treatment exhibited significantly increased expression of ubiquitin, cleavage of PARP and caspase-9, and expression of phospho-Histone H3 (P<0.05). The combined treatment of the cells also resulted in significantly increased expression of phospho-Aurora A/B/C compared with obatoclax treatment alone. The cells with the combined treatment showed significantly higher percentages of apoptotic cells and cells in sub-G(1) and G(2)/M phases compared with the cells treated with either of the drugs (P<0.05).
CONCLUSIONObatoclax combined with MG-132 shows a significant synergistic anti-tumor effect against esophageal cancer CaES-17 cells by inducing apoptosis and cell cycle arrest.