title: Transglutaminase 2 Inhibitor KCC009 Induces p53-Independent Radiosensitization in Lung Adenocarcinoma Cells.
abstract: BACKGROUND The expression of transglutaminase 2 (TG2) is correlated to DNA damage repair and apoptosis through the p53 pathway. The present study aimed to investigate the potential radiosensitization effect and possible mechanisms of the TG2 inhibitor KCC009 in lung cancer in vitro. MATERIAL AND METHODS A single hit multi-target model was used to plot survival curves and to calculate the sensitizing enhancement ratios in lung cancer wild-type or mutant p53 of H1299 cells. We performed analyses for changes of cell cycling and apoptotic responses of cells; Western blot analysis and real-time SYBR Green PCR assay were used to determine the changes of mRNA/protein expressions; ELISA assay was used for examination of cytochrome c release in cytoplasm. RESULTS Our results showed that KCC009 induced radiosensitization in both H1299/WT-p53 and H1299/M175H-p53 cells. KCC009+IR induced G0/G1 arrest in H1299/WT cells and G2/M arrest in H1299/M175H-p53 cells. KCC009+IR also induced apoptosis in both cell lines. In addition, KCC009+IR decreased the TG2 expression, and increased the p53 expression in H1299/WT cells but not in H1299/M175H-p53 cells. KCC009+IR also increased the expression of p21, Bax, p-caspase-3, and decreased Bcl-2 and CyclinD expression in H1299/WT cells. While KCC009+IR induced phosphorylation of caspase-3 and increase Cyt-C level in the cytoplasm of, and decreased CyclinB, Bcl-2 expression in H1299/M175H-p53 cells, we noticed that Cyt-C level in the nucleus decreased in the H1299/WT cells. CONCLUSIONS KCC009, a TG2 inhibitor, exhibits potent radiosensitization effects in human lung cancer cells expressing wild-type or mutant p53 with different mechanisms.
authors.affiliation: Department of Thoracic Oncology, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).
authors.forename: Sheng
authors.initials: S
authors.lastname: Huaying
authors.affiliation: Cancer Research Institute, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).
authors.forename: Yao
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Cancer Research Institute, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).
authors.forename: Zhu
authors.initials: Z
authors.lastname: Chihong
authors.affiliation: Cancer Research Institute, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).
authors.forename: Qian
authors.initials: Q
authors.lastname: Xiaoqian
authors.affiliation: Cancer Research Institute, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).
authors.forename: Wan
authors.initials: W
authors.lastname: Danying
authors.affiliation: Cancer Research Institute, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, China (mainland).|Key Laboratory Diagnosis and Treatment Technology on Thoracic Oncology, Hangzhou, Zhejiang, China (mainland).
authors.forename: Feng
authors.initials: F
authors.lastname: Jianguo
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002999:Clone Cells; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D007555:Isoxazoles / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011839:Radiation, Ionizing; D011838:Radiation-Sensitizing Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D011503:Transglutaminases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D007555:Isoxazoles; C510621:KCC 009; D011838:Radiation-Sensitizing Agents; D016159:Tumor Suppressor Protein p53; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins