title: Hypoxia- and radiation-induced overexpression of Smac by an adenoviral vector and its effects on cell cycle and apoptosis in MDA-MB-231 human breast cancer cells.
abstract: A conditionally replicative adenoviral (CRAd) vector, designated as CRAd.pEgr-1-Smac, that promotes the overexpression of second mitochondria-derived activator of caspase (Smac) when stimulated by hypoxia and radiation was constructed. MDA-MB-231 cells were transfected with CRAd.pEgr-1-Smac and treated with 4-Gy X-rays. The hypoxic status in cancer cells was mimicked with the chemical reagent CoCl2. Smac protein expression was measured by a western blotting assay and cell proliferation was detected with the MTT assay. The cell cycle progression and apoptotic percentage were measured by flow cytometry with PI and Annexin V-FITC staining kits, respectively, following the irradiation of the transfected cells with 4-Gy X-rays. The results showed that CRAd.pEgr-1-Smac was able to increase the Smac protein expression induced by hypoxia and radiation, inhibit cell proliferation and promote apoptosis. Therefore, this method of gene-radiotherapy is indicated to be an ideal strategy for the treatment of breast cancer.
authors.affiliation: Key Laboratory of Radiobiology, Ministry of Health, School of Public Health, Jilin University, Changchun, Jilin 130021, P.R. China ; Department of Radiology, Second Hospital, Jilin University, Changchun, Jilin 130041, P.R. China.
authors.forename: Wei-Wu
authors.initials: WW
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Shuo
authors.initials: S
authors.lastname: Liang
authors.forename: Jia-Hui
authors.initials: JH
authors.lastname: Wu
authors.forename: Zhi-Cheng
authors.initials: ZC
authors.lastname: Wang
authors.forename: Shou-Liang
authors.initials: SL
authors.lastname: Gong
keywords: apoptosis; breast cancer; hypoxia; radiation; second mitochondria-derived activator of caspase