title: Transglutaminase-2 is Involved in Cell Apoptosis of Osteosarcoma Cell Line U2OS Under Hypoxia Condition.
abstract: Osteosarcoma is the most common type of solid bone cancer, which is the second leading cause of cancer-related death. Hypoxia is an ordinary phenomenon in solid tumor tissues and can induce cell apoptosis but the specific molecular mechanism remains unclear. In this study, we explored the effect and the molecular mechanism of Transglutaminase 2 (TG2) on cell apoptosis in osteosarcoma U2OS cells under hypoxia. We found the enzymatic activity of TG2 is significantly increased and the expression of TG2 is remarkably up-regulated under hypoxia condition. Cell apoptotic rate is markedly increased upon knockdown of TG2 by siRNA under hypoxia. We further investigated the mechanism of cell apoptosis and found Bax protein is significantly increased after depletion of TG2 under hypoxia. Moreover, our data also show that cytochrome C (Cyt C) is significantly increased in cytoplasm and markedly decreased in mitochondria of U2OS cells after depletion of TG2 under hypoxia. Our results suggest that TG2 can inhibit tumor cell apoptosis through down-regulation of Bax and prevention of release Cyt C from mitochondria into cytoplasm.
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Xiang-Zhen
authors.initials: XZ
authors.lastname: Han
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Fan-Bin
authors.initials: FB
authors.lastname: Meng
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Zhen-Xing
authors.initials: ZX
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Linyi People's Hospital Affiliated to Shandong University, Linyi, 276000, Shandong, People's Republic of China.
authors.forename: Yong-Qing
authors.initials: YQ
authors.lastname: Zhai
authors.affiliation: Department of Orthopedics, Shandong Provincial Hospital Affiliated to Shandong University, 324 Jing-Wu Road, Jinan, 250021, Shandong, People's Republic of China. zhoudongsheng09@sina.cn.
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Zhou
mesh_terms: D017209:Apoptosis; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005434:Flow Cytometry; D019204:GTP-Binding Proteins / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D012516:Osteosarcoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D034741:RNA, Small Interfering / Q000378:metabolism; D011503:Transglutaminases / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; D034741:RNA, Small Interfering; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins
keywords: Bax; Cell apoptosis; Cytochrome C; Osteosarcoma; Transglutaminase-2