[3-bromopyruvate enhances cisplatin sensitivity of hepatocellular carcinoma cells in vitro].
OBJECTIVE
To investigate the effect of 3-bromopyruvate (3-BP) in sensitizing hepatocellular carcinoma cells to cisplatin-induced apoptosis and its possible mechanism.


METHODS
The growth inhibition of HepG2 and SMMC7721 cells following exposures to different concentrations of 3-BP and cisplatin was measured by MTT assay. The apoptosis of cells treated with 100 µmol/L 3-BP with or without 8 µmol/L cisplatin was assessed using flow cytometry with PI staining, and the activity of caspase-3 and intracellular ATP level were detected using commercial detection kits; the expression of XIAP and PARP was analyzed using Western blotting.


RESULTS
3-BP produced obvious inhibitory effects on HepG2 and SMMC7721 cells at the concentrations of 50-400 µmol/L with IC50 values of 238.9∓13.9 µmol/L and 278.7∓11.7 µmol/L for a 48-h treatment, respectively. Cisplatin also inhibited the growth of HepG2 and SMMC7721 cells at the concentrations of 2-32 µmol/L, with IC50 values of 16.4∓0.9 µmol/L and 20.9∓1.8 µmol/L after a 48-h treatment, respectively. Treatment with 100 µmol/L 3-BP combined with 8 µmol/L cisplatin for 48 h resulted in a growth inhibition rate of (60.6∓2.2)% in HepG2 cells and (56.8∓2.3)% in SMMC7721 cells, which were significantly higher than those in cells treated with 3-BP or cisplatin alone. The combined treatment for 48 h induced an apoptotic rate of (51.1∓4.3)% in HepG2 cells and (46.5∓3.9)% in SMMC7721 cells, which were also markedly higher than those in cells with 3-BP or cisplatin treatment alone.


CONCLUSIONS
3-BP can sensitize HepG2 and SMMC7721 cells to cisplatin-induced apoptosis possibly by causing intracellular ATP deficiency, down-regulating XIAP, and increasing caspase-3 activity.
Faculty of Pharmacy, Bengbu Medical College/Anhui Engineering Technology Research Center of Biochemical Pharmaceuticals, Bengbu 233030, China. E-mail: zhsurong@aliyun.com.
Surong
S
Zhao
Yuanyuan
Y
Zhang
Chengzhu
C
Wu
Hongmei
H
Li
Chenchen
C
Jiang
Zhiwen
Z
Jiang
Hao
H
Liu
D000255:Adenosine Triphosphate / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D002945:Cisplatin / Q000494:pharmacology*; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology; D011773:Pyruvates / Q000494:pharmacology*; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism
D000970:Antineoplastic Agents; D011773:Pyruvates; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; C017092:bromopyruvate; D000255:Adenosine Triphosphate; C505407:CASP3 protein, human; D053148:Caspase 3; D002945:Cisplatin