Wei-Cheng Tseng1, Cheng-Wei Chuang2, Muh-Hwa Yang3, Chin-Chen Pan4, Der-Cherng Tarng5. 1. Division of Nephrology, Department of Medicine, Taipei City Hospital Heping-Fuyou Branch, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan. 2. Department and Institute of Physiology, National Yang-Ming University, Taipei, Taiwan. 3. Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan. 4. Department of Pathology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan. 5. Department and Institute of Physiology, National Yang-Ming University, Taipei, Taiwan; Immunology Center, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: dctarng@vghtpe.gov.tw.
Abstract
BACKGROUND: Krüppel-like factor 4 (KLF4) exerts tumor suppressive or oncogenic functions in a cell-type-dependent manner, but its prognostic role in urothelial carcinoma of bladder (UCB) remains unclear. We aimed to determine how KLF4 regulates epithelial-mesenchymal transition (EMT) and predicts patient survival in UCB. PATIENTS AND METHODS: The roles of KLF4 and other EMT regulators in cancer progression were studied in UCB specimens of 398 patients, UCB cell lines. The results were validated by open-access The Cancer Genome Atlas dataset. RESULTS: Over a median follow-up of 46.5 months, tissue microarray demonstrated that strong KLF4 expression was associated with higher risk toward metastasis and death (P<0.001). KLF4 expression positively correlated with TWIST1 and vimentin, and inversely correlated with E-cadherin expression. Metastasis-free survival was poorest in KLF4/TWIST1 coexpression group, followed by KLF4 or TWIST1 expression-alone group, and no-expression group (P<0.001). Multivariate analysis substantiated that KLF4/TWIST1 coexpression independently predicted overall mortality and metastasis risk with hazard ratios of 2.43 (95% CI: 1.65-3.64) and 7.54 (CI: 4.03-12.10). The Cancer Genome Atlas dataset of bladder cancer also revealed a trend toward decreased overall survival in the high KLF4 expression group as compared to the low KLF4 group. In vitro, KLF4 is accompanied with decreased E-cadherin and β-catenin expressions, increased vimentin and fibronectin expressions, and enhanced migration/invasion. KLF4 knockdown suppressed TWIST1 expression and inhibited EMT, migration and invasion, whereas enforced KLF4 overexpression activated TWIST1 expression and restored EMT and metastatic phenotype. Furthermore, TWIST1 knockdown abolished KLF4-faciliated EMT and metastatic feature without affecting KLF4 expression. CONCLUSIONS: KLF4 promotes TWIST1-mediated EMT and may represent a novel prognostic predictor in UCB.
BACKGROUND: Krüppel-like factor 4 (KLF4) exerts tumor suppressive or oncogenic functions in a cell-type-dependent manner, but its prognostic role in urothelial carcinoma of bladder (UCB) remains unclear. We aimed to determine how KLF4 regulates epithelial-mesenchymal transition (EMT) and predicts patient survival in UCB. PATIENTS AND METHODS: The roles of KLF4 and other EMT regulators in cancer progression were studied in UCB specimens of 398 patients, UCB cell lines. The results were validated by open-access The Cancer Genome Atlas dataset. RESULTS: Over a median follow-up of 46.5 months, tissue microarray demonstrated that strong KLF4 expression was associated with higher risk toward metastasis and death (P<0.001). KLF4 expression positively correlated with TWIST1 and vimentin, and inversely correlated with E-cadherin expression. Metastasis-free survival was poorest in KLF4/TWIST1 coexpression group, followed by KLF4 or TWIST1 expression-alone group, and no-expression group (P<0.001). Multivariate analysis substantiated that KLF4/TWIST1 coexpression independently predicted overall mortality and metastasis risk with hazard ratios of 2.43 (95% CI: 1.65-3.64) and 7.54 (CI: 4.03-12.10). The Cancer Genome Atlas dataset of bladder cancer also revealed a trend toward decreased overall survival in the high KLF4 expression group as compared to the low KLF4 group. In vitro, KLF4 is accompanied with decreased E-cadherin and β-catenin expressions, increased vimentin and fibronectin expressions, and enhanced migration/invasion. KLF4 knockdown suppressed TWIST1 expression and inhibited EMT, migration and invasion, whereas enforced KLF4 overexpression activated TWIST1 expression and restored EMT and metastatic phenotype. Furthermore, TWIST1 knockdown abolished KLF4-faciliated EMT and metastatic feature without affecting KLF4 expression. CONCLUSIONS:KLF4 promotes TWIST1-mediated EMT and may represent a novel prognostic predictor in UCB.