title: Radiosensitization by inhibiting survivin in human hepatoma HepG2 cells to high-LET radiation.
abstract: In this study, whether survivin plays a direct role in mediating high-LET radiation resistance in human hepatoma cells was investigated. Small interfering RNA (siRNA) targeting survivin mRNA was designed and transfected into human hepatoma HepG2 cells. Real-time PCR and western blotting analyses revealed that survivin expression in HepG2 cells decreased at both transcriptional and post-transcriptional levels after treatment with survivin-specific siRNA. Caspase-3 activity was determined with a microplate reader assay as well. Following exposure to high-LET carbon ions, a reduced clonogenic survival effect, increased apoptotic rates and caspase-3 activity were observed in the cells treated with the siRNA compared to those untreated with the siRNA. The cells with transfection of the survivin-specific siRNA also increased the level of G₂/M arrest. These results suggest that survivin definitely plays a role in mediating the resistance of HepG2 cells to high-LET radiation and depressing survivin expression might be useful to improve the therapeutic efficacy of heavy ions for radioresistant solid tumors.
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Jin
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Qingfeng
authors.initials: Q
authors.lastname: Wu
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Furusawa
authors.forename: Li
authors.initials: L
authors.lastname: Gong
authors.forename: Jifang
authors.initials: J
authors.lastname: Hao
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Dai
mesh_terms: D002470:Cell Survival / Q000187:drug effects*; D056945:Hep G2 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D018499:Linear Energy Transfer / Q000502:physiology*; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology* / Q000528:radiation effects*; D000077022:Survivin
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D000077022:Survivin