[The role of caspase-3 in rapamycin-induced apoptosis of hepatocellular carcinoma BEL-7402 cells].
OBJECTIVE
Rapamycin, isolated from Streptomyces hygroscopicus, is recently reported to have immunosuppressive and antitumor effects on a large variety of cancers. This study was to investigate the role of Caspase-3 in rapamycin-induced apoptosis of hepatocellular carcinoma BEL-7402 cells.


METHODS
BEL-7402 cells were treated with different concentrations (5, 10, 20, 30, 40, 50 nmol/L) of rapamycin. Cell viability was detected by MTT assay; cell apoptosis was observed by flow cytometry (FCM) and Hoechst 33258 staining. The activity of Caspase-3 was determined by Caspase colorimetric assay kit and Western blot.


RESULTS
Rapamycin inhibited the growth of BEL-7402 cells and induced apoptosis significantly in time- and dose-dependent manners. Marked morphologic changes of cell apoptosis, such as chromatin condensation and nuclear fragmentation, were observed clearly at 48 h after exposion to rapamycin; Caspase-3 was activated by the loss of Caspase-3 proenzyme (32-ku) and its 20-ku subunit appeared at 24 h after incubation. Caspase-3 inhibitor z-DEVD-FMK could block the apoptosis induced by rapamycin.


CONCLUSIONS
Rapamycin can inhibit growth and induce apoptosis of BEL-7402 cells. The activation of Caspase-3 may play an important role in cell apoptosis.
Zhang
Jun-Feng
JF
Department of Liver Transplantation, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510630, P. R. China.
Lu
Min-Qiang
MQ
Cai
Chang-Jie
CJ
Yang
Yang
Y
Li
Hua
H
Yi
Hui-Min
HM
Chen
Gui-Hua
GH
D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism*; D061945:Caspase Inhibitors; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009842:Oligopeptides / Q000494:pharmacology; D020123:Sirolimus / Q000008:administration & dosage / Q000494:pharmacology*
D000903:Antibiotics, Antineoplastic; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; D053148:Caspase 3; D020123:Sirolimus