Combined effect of rapamycin and cisplatin on survival of Hep-2 cells in vitro.
The cytotoxic effects and mechanism of action of cisplatin and the mTOR inhibitor rapamycin on Hep-2 laryngeal cancer cells were investigated. Hep-2 cells were cultured in the presence of different concentrations of rapamycin, cisplatin, or the two combined. Inhibition of cell growth, apoptosis, and AKT, mTOR, S6K, and ERCC1 protein levels were assessed. All combinations of rapamycin and cisplatin resulted in synergistic inhibition of cell growth (as indicated by q values determined using Jin's formula > 1.15). Rapamycin inhibited Hep-2 cell growth, induced G1 arrest, and when combined with cisplatin, enhanced apoptosis. p-mTOR and S6K expressions were significantly downregulated by rapamycin. ERCC1 expression was significantly upregulated with cisplatin treatment. Combined cisplatin and rapamycin treatment resulted in significant downregulated p-mTOR and S6K expression, but no change in ERCC1 expression. Rapamycin and cisplatin act in a synergistic manner, increasing the cytotoxic effect on Hep-2 cells. Rapamycin may facilitate increased Hep-2 cell apoptosis with cisplatin via inhibiting downstream expression of proteins in the AKT-mTOR signaling pathway.
Lei
Wenbin
W
National Key Disciplines of Otorhinolaryngology, Otorhinolaryngology Hospital, Otorhinolaryngology Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangdong, P.R. China. leiwb2003@yahoo.com.cn
Jia
Tao
T
Su
Zhenzhong
Z
Wen
Weiping
W
Zhu
Xiaolin
X
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000032:analysis; D004357:Drug Synergism; D004720:Endonucleases / Q000032:analysis; D006801:Humans; D007822:Laryngeal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011494:Protein Kinases / Q000502:physiology; D019893:Ribosomal Protein S6 Kinases / Q000032:analysis; D020123:Sirolimus / Q000494:pharmacology*; D058570:TOR Serine-Threonine Kinases
D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D011494:Protein Kinases; C546842:MTOR protein, human; D019893:Ribosomal Protein S6 Kinases; D058570:TOR Serine-Threonine Kinases; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin; D020123:Sirolimus