Emerging evidence has suggested that androgen receptor signaling plays an important role in ovarian cancer outgrowth. Specifically, androgen receptor activation appears to be associated with increased risks of developing ovarian cancer and inducing tumor progression. However, conflicting findings have also been reported. This review summarizes and discusses the available data indicating the involvement of androgens as well as androgen receptor and related signals in ovarian carcinogenesis and cancer growth. Although the underlying molecular mechanisms for androgen receptor functions in ovarian cancer remain far from being fully understood, current observations may offer effective chemopreventive and therapeutic approaches, via modulation of androgen receptor activity, against ovarian cancer. Indeed, several clinical trials have been conducted to determine the efficacy of androgen deprivation therapy in patients with ovarian cancer.

To assess the expression status of steroid hormone receptors in upper urinary tract urothelial carcinoma (UUTUC), we immunohistochemically stained for androgen receptor (AR), estrogen receptor-α (ERα), ERβ, glucocorticoid receptor (GR), and progesterone receptor (PR) in 99 UUTUC specimens and paired non-neoplastic urothelial tissues. AR/ERα/ERβ/GR/PR was positive in 20%/18%/62%/63%/16% of tumors, which was significantly lower (except PR) than in benign urothelial tissues [57% (P < 0.001)/40% (P = 0.001)/85% (P = 0.001)/84% (P = 0.002)/13% (P = 0.489)]. There were no significant associations between each receptor expression pattern and histopathological characteristic of the tumors including tumor grade/stage. Kaplan-Meier and log-rank tests revealed no significant prognostic value of each receptor expression in these 99 patients. However, patients with UUTUC positive for either ERα or PR had a significantly higher risk of disease-specific mortality (P = 0.025), compared with those with UUTUC negative for both. PR positivity alone in pT3 or pT4 tumors was also strongly associated with the risk of disease-specific mortality (P = 0.040). Multivariate analysis further identified the expression of ERα and/or PR as a strong predictor for disease-specific mortality in the entire cohort of the patients (hazard ratio, 2.434; P = 0.037). Thus, in accordance with previous observations in bladder specimens, significant decreases in the expression of AR/ERα/ERβ/GR in UUTUC, compared with that in non-neoplastic urothelium, were observed. Meanwhile, the negativity of both ERα and PR in UUTUC as well as the negativity of PR alone in deeply invasive tumor was suggested to serve as a prognosticator.

ZKSCAN3 promotes bladder cancer cell proliferation, migration, and invasion ZKSCAN3 promotes bladder cancer cell proliferation, migration, and invasion

Although intravesical bacillus Calmette-Guérin (BCG) immunotherapy has been the gold standard for nonsurgical management of non–muscle-invasive bladder cancer, a considerable number of patients exhibit resistance to the adjuvant treatment with unexplained mechanisms. This study aimed to investigate whether and how androgen receptor (AR) signals modulate BCG cytotoxicity in bladder cancer. AR knockdown or overexpression in bladder cancer lines resulted in induction or reduction, respectively, in intracellular BCG quantity and its cytotoxic activity. Microarray screening identified Rab27b, a small GTPase known to mediate bacterial exocytosis, which was upregulated in BCG-resistant cells and downregulated in AR-shRNA cells. Knockdown of Rab27b, or its effector SYTL3, or overexpression of Rab27b also induced or reduced, respectively, BCG quantity and cytotoxicity. In addition, treatment with GW4869, which was previously shown to inhibit Rab27b-dependent secretion, induced them and reduced Rab27b expression in bladder cancer cells. Meanwhile, AR expression was upregulated in BCG-resistant lines, compared with respective controls. In a mouse orthotopic xenograft model, Rab27b/SYTL3 knockdown or GW4869 treatment enhanced the amount of BCG within tumors and its suppressive effect on tumor growth. Moreover, in non–muscle-invasive bladder cancer specimens from patients subsequently undergoing BCG therapy, positivity of AR/Rab27b expression was associated with significantly higher risks of tumor recurrence. AR activation thus correlates with resistance to BCG treatment, presumably via upregulating Rab27b expression. Mechanistically, it is suggested that BCG elimination from urothelial cells is induced by Rab27b/SYTL3-mediated exocytosis. Accordingly, Rab27b inactivation, potentially via antiandrogenic drugs and/or exocytosis inhibition are anticipated to sensitize the efficacy of BCG therapy, especially in patients with BCG-refractory AR/Rab27b-positive bladder cancer.

Introduction: Patients with non-muscle-invasive or muscle-invasive bladder cancer undergoing surgery and currently available conventional therapy remain having a high risk of tumor recurrence or progression, respectively. Novel targeted molecular therapy is therefore expected to improve patient outcomes. Meanwhile, substantially higher incidence of bladder cancer in men has prompted research on androgen-mediated androgen receptor (AR) signaling in this malignancy. Indeed, preclinical evidence has suggested that AR signaling plays an important role in urothelial carcinogenesis and tumor outgrowth as well as resistance to some of the currently available conventional non-surgical therapies. Areas covered: We summarize and discuss available data suggesting the involvement of AR and its potential downstream targets in the development and progression of bladder cancer. Associations between AR signaling and sensitivity to cisplatin/doxorubicin or bacillus Calmette-Guérin treatment are also reviewed. Expert opinion: AR activation is likely to correlate with the promotion of urothelial carcinogenesis and cancer outgrowth as well as resistance to conventional therapies. Molecular therapy targeting the AR may thus provide effective chemopreventive and therapeutic approaches for urothelial cancer. Accordingly, bladder cancer can now be considered as an endocrine-related neoplasm. Clinical application of various anti-AR therapies available for AR-dependent prostate cancer to bladder cancer patients is anticipated.