title: Downregulation of glutathione S-transferase M1 protein in N-butyl-N-(4-hydroxybutyl)nitrosamine-induced mouse bladder carcinogenesis.
abstract: Bladder cancer is highly recurrent following specific transurethral resection and intravesical chemotherapy, which has prompted continuing efforts to develop novel therapeutic agents and early-stage diagnostic tools. Specific changes in protein expression can provide a diagnostic marker. In our present study, we investigated changes in protein expression during urothelial carcinogenesis. The carcinogen BBN was used to induce mouse bladder tumor formation. Mouse bladder mucosa proteins were collected and analyzed by 2D electrophoresis from 6 to 20 weeks after commencing continuous BBN treatment. By histological examination, the connective layer of the submucosa showed gradual thickening and the number of submucosal capillaries gradually increased after BBN treatment. At 12-weeks after the start of BBN treatment, the urothelia became moderately dysplastic and tumors arose after 20-weeks of treatment. These induced bladder lesions included carcinoma in situ and connective tissue invasive cancer. In protein 2D analysis, the sequentially downregulated proteins from 6 to 20 weeks included GSTM1, L-lactate dehydrogenase B chain, keratin 8, keratin 18 and major urinary proteins 2 and 11/8. In contrast, the sequentially upregulated proteins identified were GSTO1, keratin 15 and myosin light polypeptide 6. Western blotting confirmed that GSTM1 and NQO-1 were decreased, while GSTO1 and Sp1 were increased, after BBN treatment. In human bladder cancer cells, 5-aza-2'-deoxycytidine increased the GSTM1 mRNA and protein expression. These data suggest that the downregulation of GSTM1 in the urothelia is a biomarker of bladder carcinogenesis and that this may be mediated by DNA CpG methylation.
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Chuang
authors.affiliation: Department of Pathology, Chiayi Christian Hospital, Chiayi, Taiwan.
authors.forename: Yuan-Chang
authors.initials: YC
authors.lastname: Dai
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan.
authors.forename: Yung-Lun
authors.initials: YL
authors.lastname: Lin
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan.
authors.forename: Yang-Yi
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan.
authors.forename: Wei-Han
authors.initials: WH
authors.lastname: Lin
authors.affiliation: Institute of Bioinformatics and Structural Biology & Department of Medical Sciences, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Hong-Lin
authors.initials: HL
authors.lastname: Chan
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan. Electronic address: ywlss@mail.ncyu.edu.tw.
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Liu
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D002085:Butylhydroxybutylnitrosamine / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D045744:Cell Line, Tumor; D004396:Coloring Agents; D000077209:Decitabine; D015536:Down-Regulation / Q000187:drug effects; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005982:Glutathione Transferase / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009092:Mucous Membrane / Q000187:drug effects / Q000648:ultrastructure; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D060888:Real-Time Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D001743:Urinary Bladder / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced* / Q000235:genetics* / Q000473:pathology
chemical_list: D000964:Antimetabolites, Antineoplastic; D001374:Azacitidine; D002085:Butylhydroxybutylnitrosamine; D002273:Carcinogens; D004396:Coloring Agents; D000077209:Decitabine; D005982:Glutathione Transferase; D012333:RNA, Messenger
keywords: Biomarker; Bladder cancer; DNA CpG methylation; Glutathione S-transferase; Nitrosamines; Protein 2D electrophoresis