title: Inhibition of mTOR promotes hyperthermia sensitivity in SMMC-7721 human hepatocellular carcinoma cell line.
abstract: The mammalian target of rapamycin (mTOR) is a critical mediator of the phosphoinositide 3-kinase/protein kinase B/mTOR signaling pathway, and mTOR activity is induced following heat shock. Thermotherapy is used to treat hepatocellular carcinoma (HCC). However, the role of mTOR in modulating thermosensitivity in HCC has yet to be elucidated. In the present study, the antisense plasmid pEGFP-C1-mTOR was transfected into SMMC-7721 cells, and the expression levels of mTOR were analyzed by reverse transcription-polymerase chain reaction and western blot analysis. The thermal responses of the transfected cells were also examined. The results revealed that SMMC-7721 cells were sensitive to heat treatment, and cell viability was significantly inhibited following hyperthermia treatment (P<0.01). The mRNA and protein expression levels of mTOR decreased post-transfection. Cell proliferation, colony-forming ability and motility were all significantly decreased following hyperthermia treatment in the transfected cells. Flow cytometry analysis demonstrated that apoptosis was significantly increased following treatment (P<0.01). The number of cells in S phase was increased, and the cell cycle was arrested in S phase. In conclusion, inhibition of mTOR increased the thermosensitivity of SMMC-7721 cells by increasing cellular apoptosis and inducing S phase arrest.
authors.affiliation: Department of General Surgery, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: Qing-Liang
authors.initials: QL
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: B O
authors.initials: BO
authors.lastname: Liu
authors.affiliation: Department of Laboratory Medicine, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Department of General Surgery, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: Kun-Peng
authors.initials: KP
authors.lastname: Hu
authors.affiliation: Department of General Surgery, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhao
authors.affiliation: Department of General Surgery, Ling Nan Hospital, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510530, P.R. China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Ye
keywords: apoptosis; gene expression; hepatocellular carcinoma; hyperthermia sensitivity; mammalian target of rapamycin