The cAMP responsive element binding protein 1 transactivates epithelial membrane protein 2, a potential tumor suppressor in the urinary bladder urothelial carcinoma.
In this study, we report that EMP2 plays a tumor suppressor role by inducing G2/M cell cycle arrest, suppressing cell viability, proliferation, colony formation/anchorage-independent cell growth via regulation of G2/M checkpoints in distinct urinary bladder urothelial carcinoma (UBUC)-derived cell lines. Genistein treatment or exogenous expression of the cAMP responsive element binding protein 1 (CREB1) gene in different UBUC-derived cell lines induced EMP2 transcription and subsequent translation. Mutagenesis on either or both cAMP-responsive element(s) dramatically decreased the EMP2 promoter activity with, without genistein treatment or exogenous CREB1 expression, respectively. Significantly correlation between the EMP2 immunointensity and primary tumor, nodal status, histological grade, vascular invasion and mitotic activity was identified. Multivariate analysis further demonstrated that low EMP2 immunoexpression is an independent prognostic factor for poor disease-specific survival. Genistein treatments, knockdown of EMP2 gene and double knockdown of CREB1 and EMP2 genes significantly inhibited tumor growth and notably downregulated CREB1 and EMP2 protein levels in the mice xenograft models. Therefore, genistein induced CREB1 transcription, translation and upregulated pCREB1(S133) protein level. Afterward, pCREB1(S133) transactivated the tumor suppressor gene, EMP2, in vitro and in vivo. Our study identified a novel transcriptional target, which plays a tumor suppressor role, of CREB1.
Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan.|National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan.|Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
Chien-Feng
CF
Li
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.
Wen-Jeng
WJ
Wu
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
Wen-Ren
WR
Wu
Division of Physiology, Livestock Research Institute, Tainan, Taiwan.
Yu-Jing
YJ
Liao
Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.|Division of Physiology, Livestock Research Institute, Tainan, Taiwan.
Lih-Ren
LR
Chen
Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.|Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
Chun-Nung
CN
Huang
Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan.
Ching-Chia
CC
Li
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.|Department of Urology, Ministry of Health and Welfare Pingtung Hospital, Pingtung, Taiwan.
Wei-Ming
WM
Li
Department of Pathology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Hsuan-Ying
HY
Huang
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
Yi-Ling
YL
Chen
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.|Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.
Shih-Shin
SS
Liang
Department of Pathology, National Cheng Kung University Hospital, Tainan, Taiwan.|Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Nan-Haw
NH
Chow
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.|Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.|Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan.
Yow-Ling
YL
Shiue
D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D002470:Cell Survival; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D059565:G2 Phase Cell Cycle Checkpoints / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008875:Middle Aged; D009368:Neoplasm Transplantation; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering; D015533:Transcriptional Activation / Q000235:genetics*; D014183:Transplantation, Heterologous; D001743:Urinary Bladder / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000401:mortality / Q000473:pathology*
C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; C486403:EMP2 protein, human; D008562:Membrane Glycoproteins; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D019833:Genistein
CREB1; EMP2; tumor suppressor; urinary bladder urothelial carcinoma