Combination of androgen receptor inhibitor and cisplatin, an effective treatment strategy for urothelial carcinoma of the bladder

Inhibition of aldo-keto reductase 1C3 overcomes gemcitabine/cisplatin resistance in bladder cancer

Systemic chemotherapy with gemcitabine and cisplatin (GC) has been used for the treatment of bladder cancer in which androgen receptor (AR) signaling is suggested to play a critical role. However, its efficacy is often limited, and the prognosis of patients who develop resistance is extremely poor. Aldo-keto reductase 1C3 (AKR1C3), which is responsible for the production of a potent androgen, 5α-dihydrotestosterone (DHT), by the reduction of 5α-androstane-3α,17β-dione (5α-Adione), has been attracting attention as a therapeutic target for prostate cancer that shows androgen-dependent growth. By contrast, the role of AKR1C3 in bladder cancer remains unclear. In this study, we examined the effect of an AKR1C3 inhibitor on androgen-dependent proliferation and GC sensitivity in bladder cancer cells. 5α-Adione treatment induced the expression of AR and its downstream factor ETS-domain transcription factor (ELK1) in both T24 cells and newly established GC-resistant T24GC cells, while it did not alter AKR1C3 expression. AKR1C3 inhibitor 2j significantly suppressed 5α-Adione-induced AR and ELK1 upregulation, as did an AR antagonist apalutamide. Moreover, the combination of GC and 2j in T24GC significantly induced apoptotic cell death, suggesting that 2j could enhance GC sensitivity. Immunohistochemical staining in surgical specimens further revealed that strong expression of AKR1C3 was associated with significantly higher risks of tumor progression and cancer-specific mortality in patients with muscle-invasive bladder cancer. These results suggest that AKR1C3 inhibitors as adjunctive agents enhance the efficacy of GC therapy for bladder cancer.

GABBR2 as a Downstream Effector of the Androgen Receptor Induces Cisplatin Resistance in Bladder Cancer

The precise molecular mechanisms responsible for resistance to cisplatin-based chemotherapy in patients with bladder cancer remain elusive, while we have indicated that androgen receptor (AR) activity in urothelial cancer is associated with its sensitivity. Our DNA microarray analysis in control vs. AR-knockdown bladder cancer sublines suggested that the expression of a GABA B receptor GABBR2 and AR was correlated. The present study aimed to determine the functional role of GABBR2 in modulating cisplatin sensitivity in bladder cancer. AR knockdown and dihydrotestosterone treatment considerably reduced and induced, respectively, GABBR2 expression, and the effect of dihydrotestosterone was at least partially restored by an antiandrogen hydroxyflutamide. A chromatin immunoprecipitation assay further revealed the binding of AR to the promoter region of GABBR2 in bladder cancer cells. Meanwhile, GABBR2 expression was significantly elevated in a cisplatin-resistant bladder cancer subline, compared with control cells. In AR-positive bladder cancer cells, knockdown of GABBR2 or treatment with a selective GABA B receptor antagonist, CGP46381, considerably enhanced the cytotoxic activity of cisplatin. However, no additional effect of CGP46381 on cisplatin-induced growth suppression was seen in GABBR2-knockdown cells. Moreover, in the absence of cisplatin, CGP46381 treatment and GABBR2 knockdown showed no significant changes in cell proliferation or migration. These findings suggest that GABBR2 represents a key downstream effector of AR signaling in inducing resistance to cisplatin treatment. Accordingly, inhibition of GABBR2 has the potential of being a means of chemosensitization, especially in patients with AR/GABBR2-positive bladder cancer.

The androgen receptor in bladder cancer

Bladder cancer is the ninth most common cancer worldwide with a striking sex-based difference in incidence. Emerging evidence indicates that the androgen receptor (AR) might promote the development, progression and recurrence of bladder cancer, contributing to the observed sex differences. Targeting androgen-AR signalling has promise as potential therapy for bladder cancer and helps to suppress progression of this disease. In addition, the identification of a new membrane AR and AR-regulated non-coding RNAs has important implications for bladder cancer treatment. The success of human clinical trials of targeted-AR therapies will help in the development of improved treatments for patients with bladder cancer.

Relationship between testosterone and male bladder cancer

Researches had proven that the occurrence of bladder cancer (BC) is much higher in men than those in women, which induced us to explore whether androgen plays a role in BC. A total of 147 patients who were diagnosed with primary BC by histopathological biopsy were included. Meanwhile 154 non-tumor patients were matched as the control group. The continuous variables were expressed as median (interquartile range, IQR) and compared by Mann-Whitney U test, for the reason that the data were not matched the requirementsthe of normal test. A Chi-square test was used to compare the categorical variables, which were expressed as frequency (percentage). Meanwhile univariate and multivariate logistic regression was done to further evaluating the potential independent factor of BC. P < 0.05 was considered statistically significant. Univariate multivariate analyse showed significant difference between two groups in hemoglobin (OR 0.979, 95% CI 0.968-0.991, P < 0.001), hypertension (OR 3.026, 95% CI 1.731-5.288, P < 0.001), diabetes (OR 4.294, 95% CI 1.887-9.771, P = 0.001) and smoking (OR 1.729, 95% CI 1.096-2.729, P = 0.019). Furthermore, multivariate logistic regression analysis was conducted to eliminate the interference of confounding factors, which showed that testosterone seems to be great correlated with the BC (OR 1.002, 95% CI 1.000-1.003, P = 0.017). Similar results were also found in hemoglobin (OR 0.981, 95% CI 0.968-0.993, P = 0.002), hypertension (OR 2.780, 95% CI 1.509-5.120, P = 0.001), diabetes (OR 3.313 95% CI 1.373-7.991, P = 0.008) and smoking (OR 1.938, 95% CI 1.184-3.174, P = 0.009). As a conclusion, our study showed that there was significant correlation between serum total testosterone levels and the occurrence of BC, similar results were shown in hemoglobin, hypertension, diabetes and smoking.

Stranger Things: New Roles and Opportunities for Androgen Receptor in Oncology Beyond Prostate Cancer

The androgen receptor (AR) is one of the oldest therapeutic targets in oncology and continues to dominate the treatment landscape for advanced prostate cancer, where nearly all treatment regimens include some form of AR modulation. In this regard, AR remains the central driver of prostate cancer cell biology. Emerging preclinical and clinical data implicate key roles for AR in additional cancer types, thereby expanding the importance of this drug target beyond prostate cancer. In this mini-review, new roles for AR in other cancer types are discussed as well as their potential for treatment with AR-targeted agents. Our understanding of these additional functions for AR in oncology expand this receptor's potential as a therapeutic target and will help guide the development of new treatment approaches.

Impact of Finasteride on survival in bladder cancer: A retrospective multi-institutional database analysis

INTRODUCTION

Androgen suppression therapy has been associated with a lower incidence of bladder cancer (BCa) or improved overall/cancer-specific survival. Results are ofent conflicting; therefore, we aim to assess the impact of use of finasteride on overall survival (OS) for BCa using multi-institutional database.

METHODS

The South Texas Veterans Healthcare System from 5 medical centers was queried for patients with BCa with or without use of finasteride after diagnosis of BCa. The primary outcome was the impact of finasteride use after diagnosis on the OS in BCa and in the high-risk Non-muscle invasive BCa (NMIBC) cohort.

RESULTS

A total of 1890 patients were included, amongst which 619 (32.8%) men were classified as finasteride users and 1271 (67.2%) men as controls. At a median (IQR) follow up of 53.8 (27.4, 90.9) months, death due to any cause was noted in 272 (43.9%) finasteride-treated, and 672 (49.3%) control groups (P = .028). The patients in the finasteride group had significantly better OS in overall cohort (112.1 months vs. 84.8 months, P < .001) as well as in the NMIBC cohort (129.3months vs. 103.2 months, P = .0046). The use of finasteride was independently associated with improved OS in both, overall cohort (HR 0.74, 95% CI 0.63-0.86; P < .001) and in the NMIBC cohort (HR = 0.71, 95% CI 0.55-0.93; P = .011).

CONCLUSION

Finasteride use is associated with the improved overall survival in patients with BCa, specifically in patients with NMIBC. We, further, propose a randomized clinical trial to investigate the use of finasteride in BCa patients.

Hypogonadism and urologic surgeries: a narrative review

Background and Objective

Previous studies indicated that the treatment of male hypogonadism can be beneficial for intraoperative and postsurgical outcomes. In this study, we aimed to determine the impact of male hypogonadism on urologic surgeries. We provided an overview of the key studies in the field with the focus on the outcomes of urologic surgeries in hypogonadal men with/without testosterone replacement therapy (TRT).

Methods

We performed a literature review in PubMed and Google Scholar databases for the most relevant articles pertaining to the outlined topics without placing any limitations on publication years or study designs. We included full-text English articles published in peer reviewed journals between January 1970 and March 2022.

Key Content and Findings

Androgen deficiency is a common finding after major urologic surgeries. Although guidelines recommend against TRT in men with prostate carcinoma, recent investigations showed no association between TRT and disease progression and recurrence. Indeed, recent evidence suggested that low androgen levels could be related to high grade prostate carcinoma and increased risk of upgrading from low to high grade disease. Investigations on the application of TRT in benign prostatic hyperplasia (BPH) patients also revealed contrasting results. While some studies suggested higher rates of prostate-related events in men who received TRT, others showed that TRT could alleviate urinary symptoms in hypogonadal men with BPH. Decreased testosterone level is commonly seen in bladder cancer patients. The treatment of perioperative androgen deficiency can reduce postoperative morbidities and lower the risk of recurrence in these patients. Low testosterone levels are observed in approximately half of the men who undergo artificial urinary sphincter (AUS) placement and can increase the risk of complications.

Conclusions

The role of testosterone treatment in patients with urologic diseases such as prostate carcinoma and BPH is controversial. Further investigations are needed to determine the impact of hypogonadism and TRT on the outcomes of urologic surgeries in patients with androgen deficiency.

Synergistic Inhibitory Effects of 5-Aza-2'-Deoxycytidine and Cisplatin on Urothelial Carcinoma Growth via Suppressing TGFBI-MAPK Signaling Pathways

This study is to reveal the gene transcriptional alteration, possible molecular mechanism, and pathways involved in the synergy of 5-aza-2'-deoxycytidine (DAC) and CDDP in UC. Two UC cell lines, 5637 and T24, were used in the study. A cDNA microarray was carried out to identify critical genes in the synergistic mechanism of both agents against UC cells. The results showed that several key regulatory genes, such as interleukin 24(IL24), fibroblast growth factor 1(FGF1), and transforming growth factor beta-induced (TGFBI), were identified and may play critical roles in the synergy of DAC and CDDP in UC. Pathway enrichment suggested that many carcinogenesis-related pathways, such as ECM-receptor interaction and MAPK signaling pathways, may participate in the synergy of both agents. Our results suggested that TGF-β1 stimulates the phosphorylation levels of ERK1/2 and p38 via increasing TGFBI expression, TGFBI-MAPK signaling pathway plays an important role in the synergy of DAC and CDDP against UC. Therefore, we revealed the synergistic mechanism of DAC and CDDP in UC, several key regulatory genes play critical roles in the synergy of combined treatment, and TGFBI-MAPK signaling pathway may be an important potential target of these two agents.

Gender Differences in Urothelial Bladder Cancer: Effects of Natural Killer Lymphocyte Immunity

Men are more likely to develop cancer than women. In fact, male predominance is one of the most consistent cancer epidemiology findings. Additionally, men have a poorer prognosis and an increased risk of secondary malignancies compared to women. These differences have been investigated in order to better understand cancer and to better treat both men and women. In this review, we discuss factors that may cause this gender difference, focusing on urothelial bladder cancer (UBC) pathogenesis. We consider physiological factors that may cause higher male cancer rates, including differences in X chromosome gene expression. We discuss how androgens may promote bladder cancer development directly by stimulating bladder urothelium and indirectly by suppressing immunity. We are particularly interested in the role of natural killer (NK) cells in anti-cancer immunity.

Androgen Receptor Signaling Induces Cisplatin Resistance via Down-Regulating GULP1 Expression in Bladder Cancer

The underlying molecular mechanisms of resistance to cisplatin-based systemic chemotherapy in bladder cancer patients remain to be elucidated, while the link between androgen receptor (AR) activity and chemosensitivity in urothelial cancer has been implicated. Our DNA microarray analysis in control vs. AR knockdown bladder cancer lines identified GULP1 as a potential target of AR signaling. We herein determined the relationship between AR activity and GULP1 expression in bladder cancer cells and then assessed the functional role of GULP1 in cisplatin sensitivity. Androgen treatment in AR-positive cells or AR overexpression in AR-negative cells considerably reduced the levels of GULP1 expression. Chromatin immunoprecipitation further showed direct interaction of AR with the promoter region of GULP1. Meanwhile, GULP1 knockdown sublines were significantly more resistant to cisplatin treatment compared with respective controls. GULP1 knockdown also resulted in a significant decrease in apoptosis, as well as a significant increase in G2/M phases, when treated with cisplatin. In addition, GULP1 was immunoreactive in 74% of muscle-invasive bladder cancers from patients who had subsequently undergone neoadjuvant chemotherapy, including 53% of responders showing moderate (2+)/strong (3+) expression vs. 23% of non-responders showing 2+/3+ expression (P = 0.044). These findings indicate that GULP1 represents a key downstream effector of AR signaling in enhancing sensitivity to cisplatin treatment.

Sex Hormone Receptor Signaling in Bladder Cancer: A Potential Target for Enhancing the Efficacy of Conventional Non-Surgical Therapy

There have been critical problems in the non-surgical treatment for bladder cancer, especially residence to intravesical pharmacotherapy, including BCG immunotherapy, cisplatin-based chemotherapy, and radiotherapy. Recent preclinical and clinical evidence has suggested a vital role of sex steroid hormone-mediated signaling in the progression of urothelial cancer. Moreover, activation of the androgen receptor and estrogen receptor pathways has been implicated in modulating sensitivity to conventional non-surgical therapy for bladder cancer. This may indicate the possibility of anti-androgenic and anti-estrogenic drugs, apart from their direct anti-tumor activity, to function as sensitizers of such conventional treatment. This article summarizes available data suggesting the involvement of sex hormone receptors, such as androgen receptor, estrogen receptor-α, and estrogen receptor-β, in the progression of urothelial cancer, focusing on their modulation for the efficacy of conventional therapy, and discusses their potential of overcoming therapeutic resistance.

Identification of BXDC2 as a Key Downstream Effector of the Androgen Receptor in Modulating Cisplatin Sensitivity in Bladder Cancer

Simple Summary

It remains unclear why chemotherapy is often ineffective in patients with bladder cancer. Meanwhile, we previously reported that male sex hormones (i.e., androgens) could considerably reduce the efficacy of cisplatin, an anti-cancer drug used as the first-line treatment against advanced bladder cancer. The present study aimed to investigate how androgen receptor signaling, which is activated by binding of androgenic hormones, modulates sensitivity to cisplatin treatment in bladder cancer, using cell line models and surgical specimens. We found that the expression levels of the androgen receptor and a molecule (BXDC2) were inversely correlated and that loss of BXDC2 was associated with cisplatin resistance. We thus provide evidence to suggest an underlying molecular mechanism responsible for androgen receptor-induced chemoresistance in bladder cancer.

Abstract

Underlying mechanisms for resistance to cisplatin-based chemotherapy in bladder cancer patients are largely unknown, although androgen receptor (AR) activity, as well as extracellular signal-regulated kinase (ERK) signaling, has been indicated to correlate with chemosensitivity. We also previously showed ERK activation by androgen treatment in AR-positive bladder cancer cells. Because our DNA microarray analysis in control vs. AR-knockdown bladder cancer lines identified BXDC2 as a potential downstream target of AR, we herein assessed its functional role in cisplatin sensitivity, using bladder cancer lines and surgical specimens. BXDC2 protein expression was considerably downregulated in AR-positive or cisplatin-resistant cells. BXDC2-knockdown sublines were significantly more resistant to cisplatin, compared with respective controls. Without cisplatin treatment, BXDC2-knockdown resulted in significant increases/decreases in cell proliferation/apoptosis, respectively. An ERK activator was also found to reduce BXDC2 expression. Immunohistochemistry showed downregulation of BXDC2 expression in tumor (vs. non-neoplastic urothelium), higher grade/stage tumor (vs. lower grade/stage), and AR-positive tumor (vs. AR-negative). Patients with BXDC2-positive/AR-negative muscle-invasive bladder cancer had a significantly lower risk of disease-specific mortality, compared to those with a BXDC2-negative/AR-positive tumor. Additionally, in those undergoing cisplatin-based chemotherapy, BXDC2 positivity alone (p = 0.083) or together with AR negativity (p = 0.047) was associated with favorable response. We identified BXDC2 as a key molecule in enhancing cisplatin sensitivity. AR-ERK activation may thus be associated with chemoresistance via downregulating BXDC2 expression in bladder cancer.

Depletion of androgen receptor low molecular weight isoform reduces bladder tumor cell viability and induces apoptosis

Bladder cancer (BlCa) exhibits a gender disparity where men are three times more likely to develop the malignancy than women suggesting a role for the androgen receptor (AR). Here we report that BlCa cells express low molecular weight (LMW) AR isoforms that are missing the ligand binding domain (LBD). Isoform expression was detected in most BlCa cells, while a few express the full-length AR. Immunofluorescence studies detect AR in the nucleus and cytoplasm, and localization is cell dependent. Cells with nuclear AR expression exhibit reduced viability and increased apoptosis on total AR depletion. A novel AR-LMW variant, AR-v19, that is missing the LBD and contains 15 additional amino acids encoded by intron 3 sequences was detected in most BlCa malignancies. AR-v19 localizes to the nucleus and can transactivate AR-dependent transcription in a dose dependent manner. AR-v19 depletion impairs cell viability and promotes apoptosis in cells that express this variant. Thus, AR splice variant expression is common in BlCa and instrumental in ensuring cell survival. This suggests that targeting AR or AR downstream effectors may be a therapeutic strategy for the treatment of this malignancy.

Novel Combination Therapies for the Treatment of Bladder Cancer

Bladder cancer is the ninth most frequently diagnosed cancer world-wide and ranks 13th in cancer-related deaths. Two tremendous breakthroughs in bladder cancer therapy over the last decades are the approval of immune checkpoint inhibitors(ICIs)and the fibroblast growth factor receptor tyrosine kinase inhibitor (FGFR-TKI) erdafitinib for treating this deadly disease. Despite the beneficial effects of these approaches, the low response rate and the potential resistance of the cancer are major concerns. Hence, novel combination therapies to overcome these limitations have been investigated. In this context, combining immunotherapy with targeted drugs is an appealing therapeutic option to improve response and reduce the emergence of resistance in the management of bladder cancer. In this review, the rationale of using different therapeutic combinations is discussed according to the mechanistic differences, emphasizing the efficacy and safety based on evidence collected from preclinical and clinical studies. Finally, we highlight the limitations of these combinations and provide suggestions for further efforts in this challenging field.

ASR490, a Small Molecule, Overrides Aberrant Expression of Notch1 in Colorectal Cancer

Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

Platinum(IV)-Estramustine Multiaction Prodrugs Are Effective Antiproliferative Agents against Prostate Cancer Cells

Herein, we describe the synthesis, characterization, and biological properties of Pt(IV) derivatives of cisplatin with estramustine at the first axial position, which is known to disrupt the microtubule assembly and act as an androgen antagonist, and varying the second axial position using an innocent ligand (acetate or hydroxyl) to prepare dual-action and triple-action prodrugs with known inhibitors of histone deacetylase, cyclooxygenase, and pyruvate dehydrogenase kinase. We demonstrate superior antiproliferative activity at submicromolar concentrations of the prodrugs against a panel of cancer cell lines, particularly against prostate cancer cell lines. The results obtained in this study exemplify the complex mode of action of "multiaction" Pt(IV) prodrugs. Interestingly, changing the second axial ligand in the Pt-estramustine complex has a significant effect on the mode of action, suggesting that all three components of the Pt(IV) prodrugs (platinum moiety and axial ligands) contribute to the killing of cells and not just one dominant component.

Switching Cancers: A Systematic Review Assessing the Role of Androgen Suppressive Therapy in Bladder Cancer

CONTEXT

Bladder cancer demonstrates striking gender-based differences in incidence, with a role for androgens possibly implicated in the development and progression of the disease. Emerging preclinical and clinical evidence suggests that there may be a role for antiandrogen therapy in bladder cancer.

OBJECTIVE

This systematic review assessed the current clinical evidence evaluating androgen suppressive therapy (AST) for the treatment or prevention of bladder cancer.

EVIDENCE ACQUISITION

Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, MEDLINE was searched for full-text articles detailing clinical outcomes or incidence of bladder cancer among patients who received AST, defined as gonadotropin-releasing hormone agonists or equivalent, androgen receptor antagonists, or 5-alpha reductase inhibitors.

EVIDENCE SYNTHESIS

A total of 12 studies were included. Five studies focused on prostate cancer patients, with one study in men with lower urinary tract symptoms. Among these studies, a lower incidence of bladder cancer was observed in five, with adjusted risk reduction estimates ranging from 7% to 47%. Six studies evaluating 11 820 bladder cancer patients investigated clinical outcomes among men who received a form of AST. Three out of four studies evaluating recurrence-free survival found a benefit for AST, with adjusted hazard ratios for recurrence of non-muscle-invasive cancer ranging from 0.29 to 0.53. Limitations included large variability in data sources and methodologies, as well as no data on tolerability.

CONCLUSIONS

Current evidence indicates that antiandrogen therapies exert a favorable influence on bladder tumors. Further prospective studies are needed to assess their therapeutic potential.

PATIENT SUMMARY

Androgen suppressive therapy is commonly prescribed for the treatment of prostate-related problems. Prior research indicates that there may be a role for these treatments in patients with bladder cancer. In this review, we evaluate the current evidence that strongly suggests that these agents may be effective against bladder cancer.

Integrated immunohistochemical and molecular analysis improves diagnosis of high-grade carcinoma in the urinary bladder of patients with prior radiation therapy for prostate cancer

Prostatic adenocarcinoma and urothelial carcinoma typically demonstrate distinct morphologic and immunohistochemical features. However, high-grade prostate and urothelial carcinomas sometimes show significant morphologic and immunohistochemical overlap, which can result in misdiagnosis and mistreatment. This diagnostic dilemma is particularly acute in patients previously treated with radiation and/or hormone therapy for prostate cancer, who later present with high-grade carcinoma in the urinary bladder. To address the diagnostic utility of integrated immunohistochemical and molecular analysis in this setting, we evaluated 25 high-grade carcinomas of the bladder for which morphologic features were deemed indeterminate. Our analysis included immunohistochemistry for urothelial markers (GATA3, p63, uroplakin II), prostate markers (NKX3.1, prostate specific antigen, P501S), androgen receptor (AR) and ERG, along with molecular characterization using capture-based next generation DNA sequencing. Immunohistochemical findings were concordant with the final integrated diagnosis in 21 (84%) cases. However, in three (12%) cases, immunohistochemistry supported a diagnosis of urothelial carcinoma, but molecular analysis identified the correct diagnosis of prostate cancer based on the presence of a TMPRSS2-ERG fusion. One case remained unclassifiable even after this integrated analysis. Notably, in 1 of 21 cases, the presence of a TERT promoter mutation and the absence of a TMPRSS2-ERG fusion would typically favor a diagnosis of urothelial carcinoma, but the aggregate immunohistochemical and molecular findings instead supported a diagnosis of microsatellite unstable prostatic adenocarcinoma with deep deletion of MSH2 and MSH6. Our findings highlight the importance of considering prostatic origin in high-grade carcinoma of the urinary bladder of patients with a history of treated prostate cancer, even when the immunohistochemical findings favor urothelial carcinoma. In a subset of cases, an approach that integrates immunophenotypic and molecular data may help correctly assign site of origin and prevent misdiagnosis that can result from overreliance on any individual immunohistochemical or molecular result.

Androgen receptor and immune cell PD-L1 expression in bladder tumors predicts disease recurrence and survival

PURPOSE

The impact of sex hormones on cancer immunotherapy remains controversial. Androgens, via the androgen receptor (AR), may impact the success of immune checkpoint blockade. This study characterizes AR and programmed death ligand-1 (PD-L1) expression in bladder tumors with long clinical follow-up.

METHODS

AR and PD-L1 expression was analyzed using immunohistochemistry on 143 transurethral resection (TUR) and 203 radical cystectomy (RC) specimens. Descriptive statistics and survival analyses assessed the relationship of AR and PD-L1 staining with clinical outcomes of tumor recurrence, progression, and overall survival.

RESULTS

AR expression was observed in a higher proportion of TUR than RC specimens (59% vs 35%, p < 0.001). High immune cell (IC) PD-L1 expression was associated with higher stage and grade. Patients with the combination of an absence of AR expression and the highest (> 10%) IC PD-L1 expression in TUR tumors had an increased risk of recurrence and progression. In RC specimens, the expression of AR increased the risk of local recurrence (adjusted hazard ratio (HR) 2.09, 95% CI 0.98-4.45), which was even higher among patients who also had IC PD-L1 expression (HR 4.16, 95% CI 1.28-13.52). For 28 paired metastatic lymph nodes among RC patients, tumor cell PD-L1 expression was significantly correlated (r = 0.48, p = 0.01), while no relationship with IC PD-L1 expression was observed.

CONCLUSIONS

The expression of AR and its relationship to clinical outcomes appears to vary between non-muscle invasive and muscle-invasive bladder cancer. Our results support the role of IC PD-L1 expression as an independent risk factor for bladder cancer outcomes.

ASR488, a novel small molecule, activates an mRNA binding protein, CPEB1, and inhibits the growth of bladder cancer

Due to a lack of mechanistic insights, muscle-invasive bladder cancer (MIBC) remains incurable and is one of the most lethal types of cancer in the United States. The present study investigated changes in the molecular signatures of MIBC cells (TCCSUP and HT1376) after treatment with a novel small molecule, ASR488, to gain knowledge of the mechanisms that inhibited MIBC cell growth. ASR488 treatment initiated apoptotic signaling in MIBC cells. Pathway enrichment analysis was used to analyze the changes in function of differentially expressed genes. Gene Ontology analysis, as well as Kyoto Encyclopedia of Genes and Genomes analysis, was also performed. These analyses along with reactome pathway enrichment analyses indicated that the genes upregulated in the ASR488-treated cells are involved in focal adhesion, neurotrophin signaling, p53 signaling, endoplasmic reticulum functioning in terms of protein processing, and pathways related to bladder cancer. The genes downregulated in ASR488-treated MIBC cells were mainly involved in DNA replication, mismatch repair, RNA degradation, nucleotide excision repair and TGFβ signaling (P<0.05). Furthermore, reverse transcription-quantitative PCR analysis revealed an increase in transcripts of the most upregulated genes in ASR 488-treated MIBC cells: CPEB1 (36-fold), IL11 (30-fold), SFN (20.12-fold) and CYP4F11 (15.8-fold). In conclusion, the analysis of biological functions of the most differentially expressed genes revealed possible mechanisms that may be associated with the aggressiveness of MIBC.

Androgen receptor in bladder cancer: A promising therapeutic target

There has been a significant progress in the treatment of metastatic urothelial carcinoma in the last few years with the advent of immunotherapy after a long gap of no drug approvals for over 4 decades. While immunotherapy with checkpoint inhibitors has revolutionized the treatment of urothelial carcinoma, unfortunately, only a minority of patients respond to immunotherapy. Treatment options for patients who do not respond and/or progress on immunotherapy are very limited and overall prognosis remains dismal in metastatic urothelial carcinoma. The first targeted therapy targeting the fibroblast growth factor receptor (FGFR) was recently approved for bladder cancer, but it is effective only in select patients harboring the FGFR2 and FGFR 3 mutations. Antibody drug conjugates like enfortumab vedotin have shown promising activity in clinical trials. Development of novel targeted therapies remains an area of investigation and an unmet need in bladder cancer. Exploitation of androgen receptor (AR) is a potential strategy for targeted drug development in bladder cancer. A significant proportion of urothelial carcinoma patients express AR irrespective of gender. AR signaling in urothelial carcinoma has been linked to progression through multiple mechanisms, including activation of human epidermal growth factor receptor-2 (EGFR or HER-2) signaling and epithelial to mesenchymal transition (EMT). Furthermore, AR is enriched in the luminal papillary mRNA subtype of urothelial carcinoma and also mediates resistance to cisplatin-based chemotherapy. Preclinical evidence suggests that AR inhibition can successfully inhibit urothelial carcinoma growth as monotherapy and is synergistic with cisplatin-based chemotherapy. We review the preclinical and clinical evidence supporting the putative role of AR signaling in urothelial carcinoma pathogenesis, progression and its role as a novel therapeutic target and future directions.

Chronic exposure to cadmium induces a malignant transformation of benign prostate epithelial cells

Epidemiological evidence suggests that cadmium (Cd) is one of the causative factors of prostate cancer, but the effect of Cd on benign prostatic hyperplasia (BPH) remains unclear. This study aimed to determine whether Cd exposure could malignantly transform BPH1 cells and, if so, to dissect the mechanism of action. We deciphered the molecular signaling responsible for BPH1 transformation via RNA-sequencing and determined that Cd induced the expression of zinc finger of the cerebellum 2 (ZIC2) in BPH1 cells. We noted Cd exposure increased ZIC2 expression in the Cd-transformed BPH1 cells that in turn promoted anchorage-independent spheroids and increased expression of stem cell drivers, indicating their role in stem cell renewal. Subsequent silencing of ZIC2 expression in transformed cells inhibited spheroid formation, stem cell marker expression, and tumor growth in nude mice. At the molecular level, ZIC2 interacts with the glioma-associated oncogene family (GLI) zinc finger 1 (GLI1), which activates prosurvival factors (nuclear factor NFκB, B-cell lymphoma-2 (Bcl2), as well as an X-linked inhibitor of apoptosis protein (XIAP)) signaling in Cd-exposed BPH1 cells. Conversely, overexpression of ZIC2 in BPH1 cells caused spheroid formation confirming the oncogenic function of ZIC2. ZIC2 activation and GLI1 signaling induction by Cd exposure in primary BPH cells confirmed the clinical significance of this oncogenic function. Finally, human BPH specimens had increased ZIC2 versus adjacent healthy tissues. Thus, we report direct evidence that Cd exposure induces malignant transformation of BPH via activation of ZIC2 and GLI1 signaling.