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

N6-methyladenosine-modified SRD5A3, identified by IGF2BP3, sustains cisplatin resistance in bladder cancer

Resistance to cisplatin-based chemotherapy limits the clinical benefit to some bladder cancer patients, and understanding the epigenetic regulation mechanism of cisplatin (CDDP) resistance in bladder cancer from the perspective of N6-methyladenosine (m6A) modification may optimize CDDP-based treatments. The study identified SRD5A3 as an oncogene for bladder cancer and stabilized by a m6A reader, IGF2BP3, to sustain CDDP resistance. Our results revealed that the expression of SRD5A3 was elevated in human bladder cancer tissues and cell lines, and this elevation was more evident in CDDP-resistant T24 and 5637 cells. Results of CCK-8 assay, colony formation assay, EdU staining, and flow cytometric analysis revealed that SRD5A3 knockdown and IGF2BP3 knockdown reduced cell proliferation and prevented chemoresistance in CDDP-resistant T24 and 5637 cells. Results of methylated RNA immunoprecipitation-PCR, RNA immunoprecipitation assay, and luciferase reporter assay showed IGF2BP3 recognized the SRD5A3 m6A modification and stabilized its mRNA. Nude mice implanted subcutaneously with CDDP-resistant T24 cells were injected intraperitoneally with CDDP (2 mg/kg) every 3 days for 35 days and the results demonstrated that SRD5A3 knockdown and IGF2BP3 knockdown effectively inhibited the tumor growth in subcutaneous implantation model. Collectively, the study unveils that IGF2BP3-mediated SRD5A3 m6A modification facilitates bladder cancer progression and induces CDDP resistance, providing rational therapeutic targets for bladder cancer patients.

GULP1 as a Downstream Effector of the Estrogen Receptor-β Modulates Cisplatin Sensitivity in Bladder Cancer

BACKGROUND/AIM

Precise molecular mechanisms underlying resistance to cisplatin-based chemotherapy remain unclear, while the activity of estrogen receptor-β (ERβ) has been suggested to be associated with chemosensitivity in urothelial cancer. We aimed to determine if GULP1, an adapter protein known to facilitate phagocytosis, could represent a downstream effector of ERβ and thereby modulate cisplatin sensitivity in bladder cancer.

MATERIALS AND METHODS

GULP1 expression and cisplatin cytotoxicity were compared in bladder cancer lines. Immunohistochemistry was used to determine the expression of GULP1 and ERβ in two sets of tissue microarray (TMA) consisting of transurethral resection specimens.

RESULTS

The levels of GULP1 expression were considerably higher in ERβ-knockdown sublines than in the respective control ERβ-positive sublines. Estradiol treatment reduced GULP1 expression in ERα-negative/ERβ-positive lines, which was restored by the anti-estrogen tamoxifen. Chromatin immunoprecipitation assay revealed the binding of ERβ to the GULP1 promoter in bladder cancer cells. Moreover, GULP1 knockdown sublines were significantly more resistant to cisplatin treatment, but not to other chemotherapeutic agents, including gemcitabine, methotrexate, vinblastine, and doxorubicin. In the first set of TMA (n=129), the expression of ERβ and GULP1 was inversely correlated (p=0.023), and ERβ(-)/GULP1(+) in 51 muscle-invasive tumors was associated with significantly lower risk of disease progression and cancer-specific mortality. Similarly, in the second set (n=43), patients with ERβ(-)/GULP1(+) muscle-invasive disease were significantly (p=0.021) more likely to be responders to cisplatin-based neoadjuvant chemotherapy before radical cystectomy.

CONCLUSION

ERβ activation was found to reduce the expression of GULP1 as a direct downstream target in bladder cancer cells, resulting in the induction of cisplatin resistance.

Human-specific protein-coding and lncRNA genes cast sex-biased genes in the brain and their relationships with brain diseases

BACKGROUND

Gene expression shows sex bias in the brain as it does in other organs. Since female and male humans exhibit noticeable differences in emotions, logical thinking, movement, spatial orientation, and even the incidence of neurological disorders, sex biases in the brain are especially interesting, but how they are determined, whether they are conserved or lineage specific, and what the consequences of the biases are, remain poorly explored and understood.

METHODS

Based on RNA-seq datasets from 16  and 14 brain regions in humans and macaques across developmental periods and from patients with brain diseases, we used linear mixed models (LMMs) to differentiate variations in gene expression caused by factors of interest and confounding factors and identify four types of sex-biased genes. Effect size and confidence in each effect were measured upon the local false sign rate (LFSR). We utilized the biomaRt R package to acquire orthologous genes in humans and macaques from the BioMart Ensembl website. Transcriptional regulation of sex-biased genes by sex hormones and lncRNAs were analyzed using the CellOracle, GENIE3, and Longtarget programs. Sex-biased genes' functions were revealed by gene set enrichment analysis using multiple methods.

RESULTS

Lineage-specific sex-biased genes greatly determine the distinct sex biases in human and macaque brains. In humans, those encoding proteins contribute directly to immune-related functions, and those encoding lncRNAs intensively regulate the expression of other sex-biased genes, especially genes with immune-related functions. The identified sex-specific differentially expressed genes (ssDEGs) upon gene expression in disease and normal samples also indicate that protein-coding ssDEGs are conserved in humans and macaques but that lncRNA ssDEGs are not conserved. The results answer the above questions, reveal an intrinsic relationship between sex biases in the brain and sex-biased susceptibility to brain diseases, and will help researchers investigate human- and sex-specific ncRNA targets for brain diseases.

CONCLUSIONS

Human-specific genes greatly cast sex-biased genes in the brain and their relationships with brain diseases, with protein-coding genes contributing to immune response related functions and lncRNA genes critically regulating sex-biased genes. The high proportions of lineage-specific lncRNAs in mammalian genomes indicate that sex biases may have evolved rapidly in not only the brain but also other organs.

Latrophilin-3 as a downstream effector of the androgen receptor induces bladder cancer progression

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer and its outgrowth. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptors to which a spider venom latrotoxin (LTX) is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in the progression of bladder cancer. In AR-positive bladder cancer lines, dihydrotestosterone considerably increased the expression levels of ADGRL3 and LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. Treatment with LPHN3 ligands (e.g. α-LTX, FLRT3) resulted in the induction of ADGRL3 expression, as well as cell viability, in bladder cancer lines. By contrast, LPHN3 knockdown via shRNA virus infection significantly reduced the viability and migration of these cells. Immunohistochemistry in transurethral resection specimens further showed a strong correlation between LPHN3 and AR expression. Moreover, LPHN3 positivity in muscle-invasive bladder tumors, as an independent prognosticator, was associated with a significantly higher risk of disease progression and disease-specific mortality following radical cystectomy. These findings suggest that LPHN3 functions as a downstream effector of AR and promotes the growth of bladder cancer.

CYP19A1 polymorphisms and bladder cancer risk in the Chinese Han population

BACKGROUND

The expression of CYP19A1 has implications for the prognosis of female bladder cancer. However, this study aimed to explore the association between single nucleotide polymorphisms (SNPs) in CYP19A1 and bladder cancer risk, as no prior research has addressed this association.

RESEARCH DESIGN AND METHODS

We selected and genotyped five CYP19A1 SNPs (rs4646, rs6493487, rs1062033, rs17601876, and rs3751599) in 217 patients and 550 controls using the Agena MassARRAY system. Logistic regression analysis was employed to calculate the odds ratio (OR) and 95% confidence intervals (CIs). Bioinformatics predicted SNP functions and CYP19A1 involving pathways.

RESULTS

Our study revealed a significant association between bladder cancer risk and four SNPs (rs4646 (AC vs. CC: OR = 1.71, FDR-p = 0.005), rs6493487 (G vs. A: OR = 0.68, FDR-p = 0.011), rs1062033 (G vs. C: OR = 0.36, FDR-p < 0.001), and rs17601876 (GA vs. GG: OR = 1.66, FDR-p = 0.008)) in CYP19A1. The three SNPs (rs4646, rs1062033, and rs17601876) were significantly correlated with CYP19A1 expression levels in normal whole blood (p < 0.05). Moreover, CYP19A1 was found to primarily participate in the steroid hormone biosynthesis and metabolic pathways.

CONCLUSIONS

Consequently, CYP19A1 gene polymorphisms may play a crucial role in the genetic susceptibility to bladder cancer.

Glucose oxidase and ruthenium nanorods-embedded self-healing polyvinyl alcohol/polyethylene imine hydrogel for simultaneous photothermal/photodynamic/starvation therapy and skin reconstruction

Tumor recurrence and wound healing represent significant burdens for tumor patients after the surgical removal of melanomas. Wound dressings with wound healing and anticancer therapeutic abilities could help to solve these issues. Thus, a hybrid hydrogel made of polyvinyl alcohol (PVA) and polyethylene imine (PEI) was prepared by cross-linking imine bond and boronic acid bond. This hydrogel was loaded with ruthenium nanorods (Ru NRs) and glucose oxidase (GOx) and named as nanocomposite hydrogel (Ru/GOx@Hydrogel), exhibiting remarkable photothermal/photodynamic/starvation antitumor therapy and wound repair abilities. Ru NRs are bifunctional phototherapeutic agents that simultaneously exhibit intrinsic photothermal and photodynamic functions. Three-dimensional composite hydrogel loaded with GOx can also consume glucose in the presence of O2 during tumor starvation therapy. Near-infrared (NIR) light-triggered hyperthermia can not only promote the consumption of glucose, but also facilitate the ablation of residual cancer cells. The antitumor effect of the Ru/GOx@Hydrogel resulted in significant improvements, compared to those observed with either phototherapy or starvation therapy alone. Additionally, the postoperative wound was substantially healed after treatment with Ru/GOx@Hydrogel and NIR irradiation. Therefore, the Ru/GOx@Hydrogel can be used as a multi-stimulus-responsive nanoplatform that could facilitate on-demand controlled drug release, and be used as a promising postoperative adjuvant in combination therapy.

Single-cell profiling of murine bladder cancer identifies sex-specific transcriptional signatures with prognostic relevance

Bladder cancer (BLCA) is more common in men but more aggressive in women. Sex-based differences in cancer biology are commonly studied using a murine model with BLCA generated by N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). While tumors in the BBN model have been profiled, these profiles provide limited information on the tumor microenvironment. Here, we applied single-cell RNA sequencing to characterize cell-type specific transcriptional differences between male and female BBN-induced tumors. We found proportional and gene expression differences in epithelial and non-epithelial subpopulations between male and female tumors. Expression of several genes predicted sex-specific survival in several human BLCA datasets. We identified novel and clinically relevant sex-specific transcriptional signatures including immune cells in the tumor microenvironment and it validated the relevance of the BBN model for studying sex differences in human BLCA. This work highlights the importance of considering sex as a biological variable in the development of new and accurate cancer markers.

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.

Recent advances in the understanding of urothelial tumorigenesis

INTRODUCTION

Patients with non-muscle-invasive bladder tumor suffer from disease recurrence following transurethral surgery even with intravesical pharmacotherapy, while muscle-invasive disease is often deadly. It is therefore critical to elucidate the underlying molecular mechanisms responsible for not only bladder tumor progression but also its tumorigenesis. Indeed, various molecules and/or signaling pathways have been suggested to contribute to the pathogenesis of bladder cancer.

AREAS COVERED

We summarize the progress during the last few years on the initiation or development, but not progression, of urothelial cancer. The clinical implications of these available data, including prognostic significance and possible application for the prevention of the recurrence of non-muscle-invasive bladder tumors, are also discussed.

EXPERT OPINION

Bladder cancer is a heterogeneous group of neoplasms. The establishment of personalized therapeutic options based on the molecular profile in each case should thus be considered. On that account, further accumulation of data on urothelial tumorigenesis is warranted to identify promising targets for the prevention of postoperative tumor recurrence or tumor development in otherwise high-risk patients.

Androgen receptor transcriptionally inhibits programmed death ligand-1 (PD-L1) expression and influences immune escape in bladder cancer

In multiple clinical trials, immune checkpoint blockade-based immunotherapy has shown significant therapeutic efficacy in bladder cancer (BCa). Sex is closely related to the incidence rate and prognosis of BCa. As one of the sex hormone receptors, the androgen receptor (AR) is a well-known key regulator that promotes the progression of BCa. However, the regulatory mechanism of AR in the immune response of BCa is still unclear. In this study, the expression of AR and programmed cell death-ligand 1 (PD-L1) was negatively correlated in BCa cells, clinical tissues, and tumor data extracted from The Cancer Genome Atlas Bladder Urothelial Carcinoma (TCGA-BLCA) cohort. A human BCa cell line was transfected to alter expression of AR. The results show that AR negatively regulated PD-L1 expression by directly binding to AR response elements (AREs) on the PD-L1 promoter region. In addition, AR overexpression in BCa cells significantly enhanced the antitumor activity of co-cultured CD8+ T cells. Injection of anti-PD-L1 monoclonal antibodies into C3H/HeN mice significantly suppressed tumor growth, and stable expression of AR dramatically enhanced the antitumor activity in vivo. In conclusion, this study describes a novel role of AR in regulating the immune response to BCa by targeting PD-L1, thus providing potential therapeutic strategies for immunotherapy in BCa.

Synthesis and evaluation of radioiodinated estrogens for diagnosis and therapy of male urogenital tumours

The preparation of 24 estrogens, their estrogen receptor (ER) affinity and studies of radioiodinated estrogen binding to ER-positive male bladder tumor cells (HTB9) are described. The estrogens with the highest affinity were selected using fluorescence anisotropy assays. A 2,2,2-trifluoroethyl group at the 11β-position caused particularly promising affinity. (Radio)iodination was performed on the 17α-vinyl group. Binding studies on HTB9 cells revealed picomolar affinities of radioconjugates 19 and 31, indicating promising ability for targeting of urogenital tumors.

Function of Foxl2 and Dmrt1 proteins during gonadal differentiation in the olive flounder Paralichthys olivaceus

Study on fish sex differentiation is important both from academic and practical aspects. Foxl2 and Dmrt1 are important transcription factors that should be involved in fish gonadal differentiation, but there is still no direct evidence to clarify their protein functions. Olive flounder Paralichthys olivaceus, an important mariculture fish in China, Japan, and Korea, shows sex-dimorphic growth. In this study, the Foxl2 and Dmrt1 proteins were detected in granulosa cells of the ovary and Sertoli cells of the testis, respectively, showing significant sex-dimorphic expression patterns. Then, bioactive high-purity Foxl2 and Dmrt1 recombinant proteins were obtained in vitro. Furthermore, effects of the recombinant Foxl2 and Dmrt1 during gonadal differentiation period were evaluated by intraperitoneal injection in juvenile fish. Compared with the control group, the male rate in the Dmrt1 group increased from 0 % to 82 %, showing for the first time in fish that the recombinant Dmrt1 could alter the sex phenotype. In addition, transcription levels of cyp19a and its transcription factors also changed after the recombinant Foxl2 and Dmrt1 injection. These findings reveal that Foxl2 and Dmrt1 are vital regulators for fish gonadal differentiation by regulating cyp19a expression, and also provide a new approach for sex control in fish aquaculture.

Multiple endocrine disorders manifested as gynecomastia in a patient with renal pelvis cancer

A 95-year-old man was diagnosed with left renal pelvis cancer which presented with rapid tumor growth, multiple metastases, and bilateral tender gynecomastia. Elevated serum human chorionic gonadotropin (hCG), prolactin, estradiol, and progesterone were detected. The patient's condition rapidly deteriorated, and he passed away.

The impact of biological sex on diseases of the urinary tract

Biological sex, being female or male, broadly influences diverse immune phenotypes, including immune responses to diseases at mucosal surfaces. Sex hormones, sex chromosomes, sexual dimorphism, and gender differences all contribute to how an organism will respond to diseases of the urinary tract, such as bladder infection or cancer. Although the incidence of urinary tract infection is strongly sex biased, rates of infection change over a lifetime in women and men, suggesting that accompanying changes in the levels of sex hormones may play a role in the response to infection. Bladder cancer is also sex biased in that 75% of newly diagnosed patients are men. Bladder cancer development is shaped by contributions from both sex hormones and sex chromosomes, demonstrating that the influence of sex on disease can be complex. With a better understanding of how sex influences disease and immunity, we can envision sex-specific therapies to better treat diseases of the urinary tract and potentially diseases of other mucosal tissues.

Impact of Androgen Suppression Therapy on the Risk and Prognosis of Bladder Cancer: A Systematic Review and Meta-Analysis

Purpose

The purpose of this study was to summarize the existing evidence and develop a comprehensive systematic review of the impact of androgen suppression therapy (AST) on the incidence or clinical outcomes of bladder cancer.

Methods

We systematically searched the PubMed and Embase databases from inception to June 20, 2021 to identify all observational studies examining the incidence or clinical outcomes of bladder cancer in patients who received AST. AST is defined as the use of 5-alpha reductase inhibitors (5-ARIs) or androgen deprivation therapy (ADT).

Results

A total of 18 observational studies were included. Our results showed that AST was not significantly associated with a reduced risk of BCa incidence (OR: 0.92, 95% CI: 0.68–1.24) compared with the lack of AST. The subgroup analysis revealed that finasteride use was significantly associated with a reduction in the risk of BCa incidence (OR: 0.75, 95% CI: 0.64–0.88). Recurrence-free survival (RFS) was improved among AST users compared with nonusers (HR: 0.68, 95% CI: 0.48–0.95), while no significant difference between AST users versus nonusers was identified for cancer-specific survival (CSS), overall survival (OS) or progression-free survival (PFS).

Conclusion

Current evidence indicates that therapy with finasteride may represent a potential strategy aimed at reducing BCa incidence. Moreover, AST has a beneficial effect on the recurrence of bladder cancer. Further well-designed randomized trials or cohort studies with better characterized study populations are needed to validate our preliminary findings.

Systematic Review Registration

International Prospective Register of Systematic Reviews database [https://www.crd.york.ac.uk/PROSPERO/], identifier CRD42021261685.

Bridging Radiotherapy to Immunotherapy: The IFN-JAK-STAT Axis

The unprecedented successes of immunotherapies (IOs) including immune checkpoint blockers (ICBs) and adoptive T-cell therapy (ACT) in patients with late-stage cancer provide proof-of-principle evidence that harnessing the immune system, in particular T cells, can be an effective approach to eradicate cancer. This instills strong interests in understanding the immunomodulatory effects of radiotherapy (RT), an area that was actually investigated more than a century ago but had been largely ignored for many decades. With the "newly" discovered immunogenic responses from RT, numerous endeavors have been undertaken to combine RT with IOs, in order to bolster anti-tumor immunity. However, the underlying mechanisms are not well defined, which is a subject of much investigation. We therefore conducted a systematic literature search on the molecular underpinnings of RT-induced immunomodulation and IOs, which identified the IFN-JAK-STAT pathway as a major regulator. Our further analysis of relevant studies revealed that the signaling strength and duration of this pathway in response to RT and IOs may determine eventual immunological outcomes. We propose that strategic targeting of this axis can boost the immunostimulatory effects of RT and radiosensitizing effects of IOs, thereby promoting the efficacy of combination therapy of RT and IOs.

Development of Mitomycin C-Loaded Nanoparticles Prepared Using the Micellar Assembly Driven by the Combined Effect of Hydrogen Bonding and π-π Stacking and Its Therapeutic Application in Bladder Cancer

Micelle is mainly used for drug delivery and is prepared from amphiphilic block copolymers. It can be formed into an obvious core-shell structure that can incorporate liposoluble drugs. However, micelles are not suitable for the encapsulation of water-soluble drugs, and it is also difficult to maintain stability in the systemic circulation. To solve these problems, a type of polymer material, Fmoc-Lys-PEG and Fmoc-Lys-PEG-RGD, was designed and synthesized. These copolymers could self-assemble into micelles driven by π-π stacking and the hydrophobic interaction of 9-fluorenylmethoxycarbony (Fmoc) and, at the same time, form a framework for a hydrogen-bonding environment in the core. Mitomycin C (MMC), as a water-soluble drug, can be encapsulated into micelles by hydrogen-bonding interactions. The interaction force between MMC and the polymers was analyzed by molecular docking simulation and Fourier transform infrared (FTIR). It was concluded that the optimal binding conformation can be obtained, and that the main force between the MMC and polymers is hydrogen bonding. Different types of MMC nanoparticles (NPs) were prepared and the physicochemical properties of them were systematically evaluated. The pharmacodynamics of the MMC NPs in vitro and in vivo were also studied. The results show that MMC NPs had a high uptake efficiency, could promote cell apoptosis, and had a strong inhibitory effect on cell proliferation. More importantly, the as-prepared NPs could effectively induce tumor cell apoptosis and inhibit tumor growth and metastasis in vivo.

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.