Anticancer effect and apoptosis induction of gambogic acid in human gastric cancer line BGC-823.
OBJECTIVE
To investigate the anticancer effect of a traditional Chinese medicine gambogic acid (GA) in human gastric cancer line BGC-823 and further study the mechanism of apoptosis induction of GA.


METHODS
Low differential human gastric cancer line BGC-823 were treated with GA at different doses and different times, the inhibitory rates were detected by MTT assay. Apoptosis induced by GA in BGC-823 cells was observed by Annexin-V/PI doubling staining flow cytometry assay. And T/C (%) was chosen to detect the inhibition of GA on human gastric adenocarcinoma BGC-823 nude mice xenografts. Apoptosis on nude mice xenografts was observed by Annexin-V/PI doubling staining flow cytometry assay and DNA fragmentation assay. To further determine the molecular mechanism of apoptosis induced by GA, the changes on the expression of bcl-2 and bax genes were detected by RT-PCR.


RESULTS
After incubation with GA, low differential human gastric cancer line BGC-823 was dramatically inhibited in a dose-dependent manner. After these cells was exposed to GA for 24, 48 and 72 h, the IC(50) value were 1.02+/-0.05, 1.41+/-0.20 and 1.14+/-0.19 micromol/L, respectively. Apoptosis in BGC-823 cells induced by GA was observed by Annexin-V/PI doubling staining flow cytometry assay. The apoptotic population of BGC-823 cells was about 12.96% and 24.58%, respectively, when cells were incubated with 1.2 micromol/L GA for 48 and 72 h. T/C (%) of human gastric carcinoma adenocarcinoma BGC-823 nude mice xenografts was 44.3, when the nude mice were treated with GA (8 mg/kg). Meanwhile, apoptosis induced by GA was observed in human gastric carcinoma adenocarcinoma BGC-823 nude mice xenografts. The increase of bax gene and the decrease of bc1-2 gene expressions were found by RT-PCR.


CONCLUSIONS
The inhibition of GA on human gastric cancer line BGC-823 was confirmed. This effect connects with the inducing apoptosis in BGC-823 cells and the molecular mechanism might be related to the reduction of expression of apoptosis-regulated gene bcl-2, and the improvement of the expression of apoptosis-regulated gene bax. The result was also confirmed in vivo.
Liu
Wei
W
Department of Physiology, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, China.
Guo
Qing-Long
QL
You
Qi-Dong
QD
Zhao
Li
L
Gu
Hong-Yan
HY
Yuan
Sheng-Tao
ST
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D006801:Humans; D008516:Medicine, Chinese Traditional; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology; D044004:Xanthones / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays
D000970:Antineoplastic Agents; D044004:Xanthones; C052659:gambogic acid