Inhibition of cell growth by rapamycin through targeting mammalian target of rapamycin signaling pathway in nasopharyngeal carcinoma

Objective To study the effects of rapamycin on cell growth and cell cycle in CNE-1 and CNE-2 cells. Methods Growth inhibition effect of rapamycin on CNE-1 and CNE-2 cells were assessed by cell counting kit-8 （CCK-8） assay. Morphological alterations of the cells were observed by microscope. Cell cycle and cell apoptosis were analyzed by FCM. The expression of mammalian target of rapamycin （mTOR）was analyzed by reverse transcription-polymerase chain reaction（RT-PCR）. Results The growth of CNE-1and CNE-2 cells was inhibited significantly by rapamycin dose-dependently. FCM showed that CNE-1 and CNE-2 cells at 48 hours after rapamycin （ 150 nmoL/L） treatment were arrested in the G0/G1 phase of cell cycle. However rapamycin treatment did not significantly induce apoptosis of CNE-1 and CNE-2 cells （P >0. 05）. RT-PCR showed that rapamycin significantly inhibited mRNA expression of mTOR in CNE-2 cells （t = 10. 625 ,P < 0. 01 ）. Conclusions Rapamycin inhibits the growth of CNE-1 and CNE-2 cells by inhibiting the progression of cell cycle, which could be achieved through decreaseing the expression of mTOR. Key words: Nasopharyngeal neoplasms; Sirolimus; Cell line, tumor