The role of the androgen receptor in the development and progression of bladder cancer.
ABSTRACT Men are at a higher risk of developing bladder cancer than women. Since bladder cancer cell lines and tissues were found to express the androgen receptor, efforts have been made to inspect whether androgen-mediated androgen receptor signals are implicated in bladder carcinogenesis as well as cancer progression. Mounting evidence supports the view that bladder cancer is a member of the endocrine-related tumors and may clearly explain the gender-specific difference in the incidence. However, the underlying mechanisms of how androgen receptor signals regulate bladder cancer growth are still far from fully characterized. Moreover, it remains controversial whether the androgen receptor pathway always plays a dominant role in bladder cancer progression. In this review, we summarize the available data on the involvement of androgen receptor signaling in bladder cancer. In particular, current evidence demonstrating the stimulatory effects of androgens on tumor progression or, more convincingly, tumorigenesis via the androgen receptor pathway may offer great potential for androgen deprivation as a therapeutic or chemopreventive option in patients with bladder cancer.
SourceAvailable from: Kotaro Hirai[Show abstract] [Hide abstract]
ABSTRACT: Although accumulating preclinical evidence indicates the involvement of androgen receptor signals in bladder cancer (BC) development, its clinical relevance remains unclear. We aimed to evaluate the predictive role of androgen deprivation therapy (ADT) in BC recurrence in prostate cancer (PC) patients. We retrospectively reviewed 20,328 patients with PC diagnosed during 1991–2013 and identified 239 (1.2%) men having primary BC. After excluding ineligible patients, 162 patients made up a final cohort. With a median follow-up of 62 months, 38 (50%) of 76 control patients without ADT experienced BC recurrence, while 19 (22%) of 86 did in ADT group. Thus, patients having received ADT for their PC showed a significantly lower risk of BC recurrence (5-year actuarial recurrence-free survival: 76% v 40%; P < 0.001) and also had a significantly smaller number of recurrence episodes (5-year cumulative recurrence: 0.44 v 1.54; P < 0.001), compared to the control patients. A multivariable analysis revealed ADT as an independent prognosticator (hazard ratio, 0.29; 95% confidence interval, 0.17–0.49) for BC recurrence. This is the first clinical study showing that ADT significantly reduces the risk of BC recurrence.Oncotarget 12/2014; 5(24). · 6.63 Impact Factor
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ABSTRACT: The functional role of nuclear factor of activated T-cells (NFAT), a key regulator of the immune response, in bladder cancer progression remains uncertain. In this study, we assessed biological significance of NFAT in human bladder cancer. Immunohistochemistry detected nuclear/cytoplasmic NFATc1 signals in 14 (21.5%)/34 (52.3%), respectively, of 65 muscle-invasive bladder carcinomas and showed that patients with nuclear NFATc1-positive tumor had a significantly higher risk of disease progression (P = 0.006). In bladder cancer cell lines, cyclosporine A (CsA) and tacrolimus (FK506), immunosuppressant drugs/non-selective NFAT inhibitors, attenuated NFATc1 expression and its nuclear translocation, NFAT transcriptional activity, and the expression of cyclooxygenase-2 and c-myc, downstream targets of NFATc1. NFAT inhibition via NFATc1-small interfering RNA (siRNA) or treatment with these NFAT inhibitors resulted in decreases in cell viability/colony formation, cell migration/invasion, and the expression/activity of MMP-2 and MMP-9, as well as an increase in apoptosis, in the parental/control lines. No significant additional inhibition in the viability and invasion of NFATc1-siRNA cells was seen. In xenograft-bearing mice, CsA and FK506 significantly retarded tumor growth. These results suggest that NFATc1 plays an important role in bladder cancer outgrowth. Thus, NFATc1 inactivation, especially using CsA and FK506, has the potential of being a therapeutic approach for bladder cancer.Oncotarget 01/2015; · 6.63 Impact Factor
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ABSTRACT: Cripto-1 is an important embryonic gene that involved in self-renewal and maintenance of pluripotency of stem cells. Overexpression of Cripto-1 has been found to be correlated with tumorigenesis and may affect tumor recurrence and metastasis. The previous studies indicate that Cripto-1 might be a potential prognostic biomarker for several malignancies. The aim of this study is to examine Cripto-1 expression pattern and clinicopathological significance in human bladder cancer patients. We investigated Cripto-1 expression in 30 paired bladder cancer tissues and corresponding noncancerous bladder tissues using real-time quantitative RT-PCR (qRT-PCR). Moreover, Cripto-1 expression in 130 bladder cancer specimens and bladder cancer T24 and 5637 cells were analyzed using immunohistochemistry and immunofluorescence assays. The recurrence/metastasis-free survival was assessed by Kaplan-Meier method and log-rank test. Cox regression was also used for univariate and multivariate analyses of prognostic factors. The results showed that Cripto-1 expression is increased in bladder cancer tissues and is significantly associated with tumor size (P = 0.005) and tumor grade (P = 0.035). In addition, the expression level of Cripto-1 in bladder cancer was also found to be significantly associated with SRY-related HMG-box gene 2 expression (P = 0.003) and Ki-67 (P = 0.001). Compared with the patients with low Cripto-1 expression, the patients with high Cripto-1 expression had significantly poorer recurrence/metastasis-free survival (P = 0.011). Cox regression showed that Cripto-1 might be an independent prognostic factor for recurrence/metastasis-free survival (P = 0.036). Our findings suggest that high Cripto-1 expression might be involved in the development of bladder cancer and a potentially effective prognostic marker in bladder cancer patients.Tumor Biology 10/2014; DOI:10.1007/s13277-014-2695-1 · 2.84 Impact Factor