Androgen Response Research Articles

Spatial Transcriptomic Profiling to Characterize the Nature of Peripheral- Versus Transition-zone Prostate Cancer

Background and objectiveProstate cancer (PC) in the transition zone (TZ) has better prognosis than peripheral-zone (PZ) PC despite higher prostate-specific antigen (PSA) in patients with TZ tumors. Our aim was to characterize molecular differences between TZ and PZ tumors and their clinical implications. MethodsWe performed spatial whole-transcriptome analyses of 50 regions of interest (ROIs) from three patients with PZ and/or TZ PC. ROIs were selected on the basis of SYTO13, pan-cytokeratin, smooth muscle actin, and CD45 markers. Downstream analyses of the transcriptomics data included differential gene expression and Molecular Signatures Database cancer hallmark analysis for pathway enrichment. Survival analyses were performed in The Cancer Genome Atlas (TCGA) prostate data set. Key findings and limitationsWe analyzed Gleason grade 4 (10 ROIs) and grade 5 (10 ROIs) tumors from the PZ, and grade 3 (10 ROIs), grade 4 (11 ROIs), and grade 5 (1 ROI) tumors from the TZ. We observed distinct gene expression profiles between PZ (n = 20) and TZ (n = 22) tumors. TZ ROIs exhibited enrichment of androgen response signaling (ARS; false discovery rate <5%) and a higher androgen subscore of the genomic prostate score (p < 0.001), regardless of grade and the epithelial, stromal, or immune component of the region. Genes underexpressed in PZ tumors, including ARS genes, were associated with poorer progression-free survival in the TCGA data set (n = 451; p < 0.05). Conclusions and clinical implicationsOur results demonstrate higher ARS in TZ tumors than in PZ tumors, explaining the higher PSA and better prognosis for TZ tumors. Further studies are needed to integrate zonal location in diagnostic and treatment algorithms for PC. Patient summaryWe looked at the biological explanation for higher PSA (prostate-specific antigen) levels in blood for cancers found in different zones of the prostate. We found that genes involved in androgen response signaling may explain the higher PSA often seen for tumors in the transition zone than for tumors in the peripheral zone of the prostate. These findings may inform how we diagnose and treat prostate cancer.

In-vitro Androgenic Responses in Tropical Genotypes of Maize (Zea mays L.)

In-vitro Androgenic Responses in Tropical Genotypes of Maize (Zea mays L.)

EAF2: a tumor suppressor gene with multi-aspect functions.

Since ELL-associated factor 2 (EAF2) was identified in 1997 as an androgen response gene, it has been of medical and scientific interest. Early studies demonstrated the tumor-suppressing function of EAF2 in the prostate. Sequencing studies indicated an association between EAF2 and several other malignant diseases and multiple physiological processes, such as transcription, apoptosis, embryogenesis, and DNA repair. Further understanding of EAF2 will provide new opportunities and therapeutic approaches for cancers, especially prostate cancer. This narrative review summarizes the existing knowledge of EAF2 and outlines its potential significance. To our knowledge, this is the first review of the role of this novel tumor suppressor gene and its possible functions.

Profiling of urinary extracellular vesicle protein signatures from patients with cribriform and intraductal prostate carcinoma in a cross-sectional study

Prognostic tests and treatment approaches for optimized clinical care of prostatic neoplasms are an unmet need. Prostate cancer (PCa) and derived extracellular vesicles (EVs) proteome changes occur during initiation and progression of the disease. PCa tissue proteome has been previously characterized, but screening of tissue samples constitutes an invasive procedure. Consequently, we focused this study on liquid biopsies, such as urine samples. More specifically, urinary small extracellular vesicle and particles proteome profiles of 100 subjects were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC–MS/MS). We identified 171 proteins that were differentially expressed between intraductal prostate cancer/cribriform (IDC/Crib) and non-IDC/non-Crib after correction for multiple testing. However, the strong correlation between IDC/Crib and Gleason Grade complicates the disentanglement of the underlying factors driving this association. Nevertheless, even after accounting for multiple testing and adjusting for ISUP (International Society of Urological Pathology) grading, two proteins continued to exhibit significant differential expression between IDC/Crib and non-IDC/non-Crib. Functional enrichment analysis based on cancer hallmark proteins disclosed a clear pattern of androgen response down-regulation in urinary EVs from IDC/Crib compared to non-IDC/non-Crib. Interestingly, proteome differences between IDC and cribriform were more subtle, suggesting high proteome heterogeneity. Overall, the urinary EV proteome reflected partly the prostate pathology.

5-hydroxymethylcytosine sequencing in plasma cell-free DNA identifies unique epigenomic features in prostate cancer patients resistant to androgen deprivation therapies.

Currently, no biomarkers are available to identify resistance to androgen-deprivation therapies (ADT) in men with hormone-naive prostate cancer. Since 5-hydroxymethylcytosines (5hmC) in gene body are associated with gene activation, in this study, we evaluated whether 5hmC signatures in cell-free DNA (cfDNA) predicts early resistance to ADT. We collected a total of 139 serial plasma samples from 55 prostate cancer patients receiving ADT at three time points including baseline (prior to initiating ADT, N=55), 3-month (after initiating ADT, N=55), and disease progression (N=15) within 24 months or 24-month if no progression was detected (N=14). To quantify 5hmC abundance across the genome, we used selective chemical labeling sequencing and mapped sequence reads to individual genes. Differential methylation analysis in baseline samples identified significant 5hmC difference in 1,642 of 23,433 genes between patients with and without progression (false discovery rate, FDR<0.1). Patients with disease progression showed significant 5hmC enrichments in multiple hallmark gene sets with androgen responses as top enriched gene set (FDR=1.19E-13). Interestingly, this enrichment was driven by a subgroup of patients featuring a significant 5hmC hypermethylation in the gene sets involving AR , FOXA1 and GRHL2 . To quantify overall activities of these gene sets, we developed a gene set activity scoring algorithm and observed significant association of high activity scores with poor progression-free survival (P<0.05). Longitudinal analysis showed that the high activity scores were significantly reduced after 3-months of initiating ADT (P<0.0001) but returned to higher levels when the disease was progressed (P<0.05). This study demonstrates that 5hmC-based activity scores from gene sets involved in AR , FOXA1 and GRHL2 may be used as biomarkers to determine early treatment resistance, monitor disease progression, and potentially identify patients who would benefit from upfront treatment intensification.

Decoding androgen receptor signalling: Genomic vs. non-genomic roles in prostate cancer

The Androgen receptor (AR) is known to manifest the biological actions of male sex hormones. Androgens are now known to exert a multitude of responses, sometimes contrasting, in physiological and pathological conditions. Several groups have attempted to explain the underlying mechanisms of these varying androgen responses, including the non-genomic actions of androgens. These actions lead to increased activity of pro-proliferative signal transduction pathways, resulting in rapid molecular effects that cannot be explained by the conventional model in which AR functions as a transcription factor to modulate target gene expression [1,2].This spotlight article examines Safi et al.'s research on the androgen receptor (AR) in prostate cancer, revealing that low androgen levels drive proliferation via non-genomic mechanisms involving AR monomers, while high levels suppress growth through genomic actions with AR dimers. These findings challenge current paradigms and suggest novel therapeutic strategies targeting both AR forms, particularly focusing on the role of AR monomers in cancer progression and treatment resistance.

Sexual Dimorphism in Sex Hormone Metabolism in Human Skeletal Muscle Cells in Response to Different Testosterone Exposure.

Muscle tissue is an important target of sex steroids, and particularly, testosterone plays essential roles in muscle cell metabolism. Wide ranges of studies have reported sex differences in basal muscle steroidogenesis, and recently several genes have been identified to be regulated by androgen response elements that show innate sex differences in muscle. However, studies accounting for and demonstrating cell sexual dimorphism in vitro are still scarce and not well characterized. Here, we demonstrated the ability of 46XX and 46XY human primary skeletal muscle cells to differently activate steroidogenesis in vitro, likely related to sex-chromosome onset, and to differently induce hormone release after increasing doses of testosterone exposure. Cells were treated with testosterone at concentrations of 0.5, 2, 5, 10, 32, and 100 nmol/L for 24 h. Variations in 17β-HSD, 5α-R2, CYP-19 expression, DHT, estradiol, and androstenedione release, as well as IL6 and IL8 release, were analyzed, respectively, by RT-PCR, ELISA, and luminex-assay. Following testosterone treatments, and potentially at any concentration level, an increase in the expression of 17β-HSD, 5α-R2, and CYP-19 was observed in 46XY cells, accompanied by elevated levels of DHT, androstenedione, and IL6/IL8 release. Following the same treatment, 46XX cells exhibited an increase in 5α-R2 and CYP-19 expression, a conversion of androgens to estrogens, and a reduction in IL6 and IL8 release. In conclusion, this study demonstrated that sex-chromosome differences may influence in vitro muscle cell steroidogenesis and hormone homeostasis, which are pivotal for skeletal muscle metabolism.

Effects of 5α-reductase inhibition by dutasteride on reproductive gene expression and hormonal responses in zebrafish embryos

Steroid 5α-reductase (SRD5A) is a crucial enzyme involved in steroid metabolism, primarily converting testosterone to dihydrotestosterone (DHT). Dutasteride, an inhibitor of SRD5A types 1 and 2, is widely used for treating benign prostatic hyperplasia. An adverse outcome pathway (AOP) has been documented wherein SRD5A inhibition decreases DHT synthesis, leading to reduced levels of 17β-estradiol (E2) and vitellogenin (VTG), subsequently impairing fecundity in fish (AOP 289). However, the molecular and cellular mechanisms underlying these effects remain poorly understood. In this study, we assessed the impact of SRD5A inhibition on zebrafish embryos (Danio rerio). Exposure to dutasteride resulted in decreased DHT, E2, and VTG levels, showing a positive correlation. Dutasteride also downregulated the expression of reproduction-related genes (srd5a2, cyp19a1, esr1, esr2a, esr2b, and vtg), with interrelated reductions observed across these levels. Docking studies suggested that dutasteride's effects may operate independently of androgen receptor (AR) and estrogen receptor (ER) interactions. Furthermore, co-exposure of dutasteride (0.5 or 2 μM) with 0.5 μM DHT revealed gene expression levels comparable to the control group. These findings underscore DHT's pivotal role in modulating estrogenic function and the interplay between estrogenic and androgenic responses in vertebrates. Our proposed AOP model offers insights into mechanistic gaps, thereby enhancing current understanding and bridging knowledge disparities.

Relationship of proteins and subclinical cardiovascular traits in the population-based LIFE-Adult study

Background and aimsUnderstanding molecular processes of the early phase of atherosclerotic cardiovascular disease conditions is of utmost importance for early prediction and intervention measures. MethodsWe measured 92 cardiovascular-disease-related proteins (Olink, Cardiovascular III) in 2024 elderly participants of the population-based LIFE-Adult study. We analysed the impact of 27 covariables on these proteins including blood counts, cardiovascular risk factors and life-style-related parameters. We also analysed protein associations with 13 subclinical cardiovascular traits comprising carotid intima media thickness, plaque burden, three modes of Vicorder-based pulse-wave velocities, ankle-brachial index and ECLIA-based N-terminal prohormone of brain natriuretic peptide (NT-proBNP). ResultsEstimated glomerular filtration rate, triglycerides and sex where the most relevant covariables explaining more than 1 % variance of 49, 22 and 20 proteins, respectively. A total of 43 proteins were significantly associated with at least one of the analysed subclinical cardiovascular traits. NT-pro-BNP, brachial-ankle pulse-wave velocity (baPWV) and parameters of carotid plaque burden accounted for the largest number of associations. Association overlaps were relatively sparse. Only growth/differentiation factor 15, low density lipoprotein receptor and interleukin-1 receptor type 2 are associated with these three different cardiovascular traits. We confirmed several literature findings and found yet unreported associations for carotid plaque presence (von-Willebrand factor, galectin 4), carotid intima-media thickness (carboxypeptidase A1 andB1), baPWV (cathepsin D) and NT-proBNP (cathepsin Z, low density lipoprotein receptor, neurogenic locus homolog protein 3, trem-like transcript 2). Sex-interaction effects were observed, e.g. for spondin-1 and growth/differentiation factor 15 likely regulated by androgen response elements. ConclusionsWe extend the catalogue of proteome biomarkers possibly involved in early stages of cardiovascular disease pathologies providing targets for early risk prediction or intervention strategies.

Targeting proliferating cell nuclear antigen enhances ionizing radiation-induced cytotoxicity in prostate cancer cells.

Proliferating cell nuclear antigen (PCNA) is essential for DNA replication and repair, cell growth, and survival. PCNA also enhances androgen receptor (AR) signaling in prostate cancer (PC) cells. We identified a PCNA interaction protein (PIP) box at the N-terminal domain of AR and developed a small peptide PCNA inhibitor R9-AR-PIP containing AR PIP-box. We also identified a series of small molecule PCNA inhibitors (PCNA-Is) that bind directly to PCNA and interrupt PCNA functions. The present study investigated the effects of the PCNA inhibitors on the sensitivity of PC cells to X-ray radiation. The effects of targeting PCNA on radio sensitivity of PC cells were investigated in four lines of castration-resistant PC (CRPC) cells with different AR expression statuses. The cells were treated with the PCNA inhibitors and X-ray radiation alone or in combination. The effects of the treatment on expression of AR target genes, DNA damage response, DNA damage, homologous recombination repair (HRR), and cytotoxicity were evaluated. We found that the androgen response element (ARE) occupancy of the DNA damage response gene PARP1 by AR is significantly attenuated by PCNA-I1S or R9-AR-PIP combined with X-ray radiation, while X-ray radiation alone does not enhance the ARE occupancy. PCNA-I1S or R9-AR-PIP alone significantly inhibits occupancy of the AR-occupied regions (AROR) in PRKDC and XRCC2 genes. R9-AR-PIP and PCNA-I1S inhibit expression of AR-Vs target gene cyclin A2 and show the additive effects with radiation in AR-positive CRPC cells. Targeting PCNA by PCNA-I1S and R9-AR-PIP downregulates expression of DNA damage response genes EXO1, Rad54L, Rad51, and/or PARP1 and shows the additive effects with radiation as compared with their respective controls in AR-positive CRPC LNCaP-AI, 22Rv1, and R1-D567 cells, but not in AR-negative PC-3 cells. R9-AR-PIP and PCNA-I1S elevate the levels of phospho-DNA-PKcs(S2056) and γH2AX, indicating DNA damage in response to radiation in AR-positive cells. The HRR is significantly attenuated by PCNA inhibitors PCNA-I1S, R9-AR-PIP, and T2AA in all four CRPC cells examined, and inhibited by Enzalutamide (Enz) only in 22RV1 cells. The cytotoxicity induced by X-ray radiation in androgen-dependent LNCaP cells is enhanced by Enz and a lower concentration of R9-AR-PIP in the colony formation assay. R9-AR-PIP at higher concentration reduces the colony formation and has an additive effect with X-ray radiation in all AR expressing cells, regardless of AR-FL and AR-Vs, but does not significantly alter the colony formation in AR-negative PC-3 cells. PCNA-I1S attenuates colony formation and has an additive effect with ionizing radiation in all four CRPC cells, regardless of AR expression status. These data provide a strong rationale for the therapy studies using PCNA-I1S or R9-AR-PIP in combination with X-ray radiation against CRPC tumors in preclinical models.

Psoriatic skin transcript phenotype: androgen/estrogen and cortisone/cortisol imbalance with increasing DNA damage response.

Patients prone to psoriasis suffer after a breakdown of the epidermal barrier and develop poorly healing lesions with abnormal proliferation of keratinocytes. Strong inflammatory reactions with genotoxicity (short telomeres) suggest impaired immune defenses with DNA damage repair response (DDR) in patients with psoriasis. Recent evidence indicates the existence of crosstalk mechanisms linking the DDR machinery and hormonal signaling pathways that cooperate to influence both progressions of many diseases and responses to treatment. The aim of this study was to clarify whether steroid biosynthesis and genomic stability markers are altered in parallel during the formation of psoriatic skin. Understanding the interaction of the steroid pathway and DNA damage response is crucial to addressing underlying fundamental issues and managing resulting epidermal barrier disruption in psoriasis. Skin (Lesional, non-lesional) and blood samples from twenty psoriasis patients and fifteen healthy volunteers were collected. Real-Time-PCR study was performed to assess levels of known transcripts such as: estrogen (ESR1, ESR2), androgen (AR), glucocorticoid/mineralocorticoid receptors (NR3C1, NR3C2), HSD11B1/HSD11B2, and DNA damage sensors (SMC1A, TREX1, TREX2, SSBP3, RAD1, RAD18, EXO1, POLH, HUS1). We found that ESR1, ESR2, HSD11B1, NR3C1, NR3C2, POLH, and SMC1A transcripts were significantly decreased and AR, TREX1, RAD1, and SSBP3 transcripts were increased dramatically in the lesional skin compared to skin samples of controls. We found that the regulation of the steroidogenic pathway was disrupted in the lesional tissue of psoriasis patients and that a sufficient glucocorticoid and mineralocorticoid response did not form and the estrogen/androgen balance was altered in favour of androgens. We suggest that an increased androgen response in the presence of DDR increases the risk of developing psoriasis. Although this situation may be the cause or the consequence of a disruption of the epidermal barrier, our data suggest developing new therapeutic strategies.

Central role of SUMOylation in the regulation of chromatin interactions and transcriptional outputs of the androgen receptor in prostate cancer cells.

The androgen receptor (AR) is pivotal in prostate cancer (PCa) progression and represents a critical therapeutic target. AR-mediated gene regulation involves intricate interactions with nuclear proteins, with many mediating and undergoing post-translational modifications that present alternative therapeutic avenues. Through chromatin proteomics in PCa cells, we identified SUMO ligases together with nuclear receptor coregulators and pioneer transcription factors within the AR's protein network. Intriguingly, this network displayed a significant association with SUMO2/3. To elucidate the influence of SUMOylation on AR chromatin interactions and subsequent gene regulation, we inhibited SUMOylation using ML-792 (SUMOi). While androgens generally facilitated the co-occupancy of SUMO2/3 and AR on chromatin, SUMOi induced divergent effects dependent on the type of AR-binding site (ARB). SUMOi augmented AR's pioneer-like binding on inaccessible chromatin regions abundant in androgen response elements (AREs) and diminished its interaction with accessible chromatin regions sparse in AREs yet rich in pioneer transcription factor motifs. The SUMOi-impacted ARBs divergently influenced AR-regulated genes; those associated with AR-mediated activation played roles in negative regulation of cell proliferation, while those with AR-mediated repression were involved in pattern formation. In conclusion, our findings underscore the pervasive influence of SUMOylation in shaping AR's role in PCa cells, potentially unveiling new therapeutic strategies.

Testosterone Inhibits Lipid Accumulation in Porcine Preadipocytes by Regulating ELOVL3.

Castration is commonly used to reduce stink during boar production. In porcine adipose tissue, castration reduces androgen levels resulting in metabolic disorders and excessive fat deposition. However, the underlying detailed mechanism remains unclear. In this study, we constructed porcine preadipocyte models with and without androgen by adding testosterone exogenously. The fluorescence intensity of lipid droplet (LD) staining and the fatty acid synthetase (FASN) mRNA levels were lower in the testosterone-treated cells than in the untreated control cells. In contrast, the mRNA levels of adipose triglycerides lipase (ATGL) and androgen receptor (AR) were higher than in the testosterone-treated cells than in the control cells. Subsequently, transcriptomic sequencing of porcine preadipocytes incubated with and without testosterone showed that the mRNA expression levels of very long-chain fatty acid elongase 3 (ELOVL3), a key enzyme involved in fatty acids synthesis and metabolism, were high in control cells. The siRNA-mediated knockdown of ELOVL3 reduced LD accumulation and the mRNA levels of FASN and increased the mRNA levels of ATGL. Next, we conducted dual-luciferase reporter assays using wild-type and mutant ELOVL3 promoter reporters, which showed that the ELOVL3 promoter contained an androgen response element (ARE); furthermore, its transcription was negatively regulated by AR overexpression. In conclusion, our study reveals that testosterone inhibits fat deposition in porcine preadipocytes by suppressing ELOVL3 expression. Moreover, our study provides a theoretical basis for further studies on the mechanisms of fat deposition caused by castration.

Mutant androgen receptor induces neurite loss and senescence independently of ARE binding in a neuronal model of SBMA

Spinal and bulbar muscular atrophy (SBMA) is a slowly progressing neuromuscular disease caused by a polyglutamine (polyQ)-encoding CAG trinucleotide repeat expansion in the androgen receptor (AR) gene, leading to AR aggregation, lower motor neuron death, and muscle atrophy. AR is a ligand-activated transcription factor that regulates neuronal architecture and promotes axon regeneration; however, whether AR transcriptional functions contribute to disease pathogenesis is not fully understood. Using a differentiated PC12 cell model of SBMA, we identified dysfunction of polyQ-expanded AR in its regulation of neurite growth and maintenance. Specifically, we found that in the presence of androgens, polyQ-expanded AR inhibited neurite outgrowth, induced neurite retraction, and inhibited neurite regrowth. This dysfunction was independent of polyQ-expanded AR transcriptional activity at androgen response elements (ARE). We further showed that the formation of polyQ-expanded AR intranuclear inclusions promoted neurite retraction, which coincided with reduced expression of the neuronal differentiation marker β-III-Tubulin. Finally, we revealed that cell death is not the primary outcome for cells undergoing neurite retraction; rather, these cells become senescent. Our findings reveal that mechanisms independent of AR canonical transcriptional activity underly neurite defects in a cell model of SBMA and identify senescence as a pathway implicated in this pathology. These findings suggest that in the absence of a role for AR canonical transcriptional activity in the SBMA pathologies described here, the development of SBMA therapeutics that preserve this activity may be desirable. This approach may be broadly applicable to other polyglutamine diseases such as Huntington's disease and spinocerebellar ataxias.

Confirmation of the steroid hormone receptor-mediated endocrine disrupting potential of fenvalerate following the Organization for Economic Cooperation and Development test guidelines, and its estrogen receptor α-dependent effects on lipid accumulation

In this study, we focused on confirming the steroid hormone receptor-mediated endocrine-disrupting potential of the pyrethroid insecticide fenvalerate and unraveling the underlying mechanisms. Therefore, we assessed estrogen receptor-α (ERα)- and androgen receptor (AR)-mediated responses in vitro using a hormone response element-dependent transcription activation assay with a luciferase reporter following the Organization for Economic Cooperation and Development (OECD) test guidelines. We observed that fenvalerate acted as estrogen by inducing the translocation of cytosolic ERα to the nucleus via ERα dimerization, whereas it exhibited no AR-mediated androgen response element-dependent luciferase activity. Furthermore, we confirmed that fenvalerate-induced activation of ERα caused lipid accumulation, promoted in a fenvalerate-dependent manner in 3 T3-L1 adipocytes. Moreover, fenvalerate-induced lipid accumulation was inhibited in the presence of an ERα-selective antagonist, whereas it remained unaffected in the presence of a glucocorticoid receptor (GR)-specific inhibitor. In addition, fenvalerate was found to stimulate the expression of transcription factors that promote lipid accumulation in 3 T1-L1 adipocytes, and co-treatment with an ERα-selective antagonist suppressed adipogenic/ lipogenic transcription factors at both mRNA and protein levels. These findings suggest that fenvalerate exposure may lead to lipid accumulation by interfering with ERα activation-dependent processes, thus causing an ERα-mediated endocrine-disrupting effect.

Differential Tumor Gene Expression Profiling of Patients With Prostate Adenocarcinoma on the Basis of BMI.

An increased BMI is linked to increased prostate adenocarcinoma incidence and mortality. Baseline tumor gene expression profiling (GEP) can provide a comprehensive picture of the biological processes related to treatment response and disease progression. We interrogate and validate the underlying differences in tumor GEP on the basis of BMI in patients with prostate adenocarcinoma. The inclusion criteria consisted of histologically confirmed prostate adenocarcinoma and the availability of RNA sequencing data obtained from treatment-naïve primary prostate tissue. RNA sequencing was performed by a Clinical Laboratory Improvement Amendments-certified laboratory (Tempus or Caris Life Sciences). The Tempus cohort was used for interrogation and the Caris cohort for validation. Patients were stratified on the basis of BMI at the time of prostate cancer diagnosis: BMI-high (BMIH; BMI ≥30) and BMI-low (BMIL; BMI <30). Differential gene expression analysis between the two cohorts was conducted using the DEseq2 pipeline. The resulting GEPs were further analyzed using Gene Set Enrichment software to identify pathways that exhibited enrichment in each cohort. Overall, 102 patients were eligible, with 60 patients in the Tempus cohort (BMIL = 38, BMIH = 22) and 42 patients in the Caris cohort (BMIL = 24, BMIH = 18). Tumor tissues obtained from patients in the BMIL group exhibited higher expression of genes associated with inflammation pathways. BMIH displayed increased expression of genes involved in pathways such as heme metabolism and androgen response. Our study shows the upregulation of distinct genomic pathways in BMIL compared with BMIH patients with prostate cancer. These hypothesis-generating data could explain different survival outcomes in both groups and guide personalized therapy for men with prostate cancer.

Abstract LB335: Steroid receptor cross-talk in breast cancer

Abstract Breast cancer is the most frequently diagnosed cancer in women worldwide. Oestrogen Receptor-α (ERα), is expressed in two thirds of human breast cancers, and the majority of patients are sensitive to endocrine therapy, i.e. anti-oestrogens or aromatase inhibitors that aim to block oestrogen signalling. In addition to ERα, the other members of the steroid receptor family (androgen, AR; progesterone, PR; glucocorticoid, GR; mineralocorticoid receptors, MR) also appear to play an important role in tumour development and recurrence, but the role of this signalling in cancer progression has not been fully characterised. Therefore, this study aims to address the role of the steroid receptor family members in breast cancer and to assess the effect of downstream signalling upon prognosis. Investigation of receptor signalling cross-talk using reporter, proliferation and migration assays, demonstrated that ERα and the other steroid receptors inhibit each other’s activity in endocrine responsive breast cancer cell lines, MCF7 and T47D. Furthermore, treatment with antioestrogen reversed the suppressive effects of ER𝛼;;; on the activity of the androgen, glucocorticoid progesterone receptors. To characterize receptor crosstalk on a global scale, RNA-seq and ChIP-seq datasets were analysed. Analysis of the ChIP-seq data demonstrated that the PR, GR and AR reprogramming of ERα results in the loss of ERα canonical binding sites and the gain of novel response elements/binding sites. Motif enrichment analysis of the novel ERα binding sites suggested that the altered binding in response to AR, GR and PR signalling, promotes the recruitment of ERα to androgen, glucocorticoid and progesterone response elements, respectively. Gene ontology analysis also revealed that this change in ERα binding sites is correlated with alterations in genes linked to cell proliferation and growth. Moreover, transcriptome studies showed that cotreatment of cells with estradiol and glucocorticoid or mineralocorticoid resulted in the upregulation of apoptotic signalling pathways. These findings may provide an explanation for the observed downregulation of GR and MR expression in ERα positive breast cancer. Patient datasets were used to investigate the prognostic significance of the steroid receptor target genes of interest, more specifically, those deregulated as a result of cross-talk. Considering overall survival and disease specific survival, univariate and multivariate Cox models with Lasso Regression were used to identify prognostic gene signatures using RNA_seq datasets. Kaplan-Meier (KM) and ROC analyses were applied to evaluate risk models. Established genetic markers associated with MR, AR, GR and PR was used to stratify BC patients into low and high risk groups. Patients survival was found to be positively correlated with these signatures, demonstrates that these gene sets have prognostic value. Further studies are required to validate these preliminary results to understand the role of steroid receptor crosstalk in breast cancer formation, progression, and survival. Citation Format: Aygun Azadova, Greg Brooke, Antonio Marco. Steroid receptor cross-talk in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB335.

Abstract CT085: Targeting androgen signaling in urothelial carcinoma

Abstract Background: Men are 3-4 times more likely to develop urothelial carcinoma (UC) than women, even after accounting for differences in smoking and occupational exposures. A potential cause for this difference may be androgen signaling. Testosterone receptors are present in up to 53% of UC in men and women. Androgen signaling promotes proliferation and chemotherapy resistance, while blocking androgen has been shown to sensitize UC to chemotherapy. When exposed to a chemical carcinogen, castrated male mice and androgen receptor (AR) knockout mice are less likely to develop UC. Additionally, men taking testosterone lowering agents for prostate cancer, who are concurrently treated for UC, have a 50% lower UC recurrence rate than men with normal testosterone signaling. In a study of 9 men and 1 woman with metastatic UC, all patients were treated with gemcitabine/cisplatin and concurrent enzalutamide. Patients’ testosterone levels were not medically lowered. Importantly, dihydrotestosterone, the native ligand for the AR, has higher affinity for the AR than enzalutamide. Interestingly, the only woman in the study (with presumably low dihydrotestosterone levels) had a complete response to therapy. No other complete responses were observed. The standard therapy for non-metastatic muscle invasive UC is chemotherapy followed by cystectomy. Currently this results in about a 35% pathologic complete response (pCR) rate. pCR is associated with improved overall survival. In our study (TASUC; NCT05839119), we add degarelix to standard neoadjuvant chemotherapy to treat men and women who have AR positive UC. Methods: The main eligibility criteria are: (1) Muscle-invasive urothelial carcinoma of the bladder (2) AR positive disease by nuclear staining on immunohistochemistry (3) pT2 - T4, N0 - N1, M0 (Stage II or IIIA disease) (4) Eligible for cisplatin-based chemotherapy (5) Eligible for cystectomy In this single-arm study, all patients receive standard of care gemcitabine/cisplatin neoadjuvant chemotherapy (4 cycles) with the addition of monthly degarelix during chemotherapy. The primary outcome is pCR rate at cystectomy. We are employing a Simon 2-stage minmax design. In stage I we will enroll 20 patients. If there are at least 7 pCRs (35%) we will enroll an additional 12 patients in stage II, for a total of 32 patients. This design will provide 80% statistical power to detect a change in pCR rate from 35% to 50% with a significance level of less than 0.20. If we observe at least 14 pCRs (of 32 patients) the study will be considered positive and we will plan a follow-up randomized, controlled phase II (or phase III) study. Exploratory outcomes include correlation of AR positivity with proliferation at diagnosis, identification of oncogenic androgen response elements from matched pre- and post- treatment tissue, and identification of gene signatures associated with pCR. We will also measure 2- and 5-year disease free survival. TASUC opened to accrual on October 2, 2023 and is actively recruiting. Citation Format: Mojisola Araoye, Anthony Mega, Galina G. Lagos, Benedito Carneiro, Sari Khaleel, Dragan Golijanin, SHELDON L. HOLDER. Targeting androgen signaling in urothelial carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT085.

Abstract NG02: Distinct genomic and immunologic tumor evolution in germline TP53-driven breast cancers

Abstract NG02: Distinct genomic and immunologic tumor evolution in germline TP53-driven breast cancers

Abstract CT231: Identification of a novel agnostic predictive multiomic signature via Elastic Net/Machine Learning in TALAPRO-2 (TP-2), a phase 3 study of talazoparib (TALA) + enzalutamide (ENZA) vs placebo (PBO) + ENZA as first-line (1L) treatment in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

Abstract Background: TP-2 (NCT03395197) demonstrated significantly improved radiologic progression-free survival (rPFS) regardless of homologous recombination repair (HRR) gene alteration status for pts with mCRPC who received 1L TALA + ENZA (n=402) vs PBO + ENZA (n=403; Agarwal et al. Lancet. 2023. PMID: 37285865). We explore potential associations of ctDNA genomics and tumor gene expression with efficacy in TP-2. Methods: The analysis was based on the safety population (n=799). Two data sets were used: a FoundationOne®Liquid CDx data set (Azad et al. ASCO 2023, #5056) of prospectively collected/retrospectively analyzed plasma samples (n=681); and a tumor transcriptomic data set generated via HTG’s Oncology Biomarker Panel (with 10 additional genes implicated in PARP inhibitor sensitivity; n=304). Correlations between baseline molecular biomarkers and rPFS were assessed via a Cox proportional hazards model. Multivariate elastic net regression analysis incorporated 151 pts in the TALA + ENZA arm with 2,868 molecular features (ctDNA: 309 genes [only short variant alterations incorporated]; HTG: 2,559 tumor transcripts). Results: Positively predictive candidate tumor biomarkers for TALA + ENZA included androgen response signature and individual androgen receptor (AR) target genes such as PSA, ALDH1A3, and CAMKK2. These expression signatures/transcripts had no/minimal predictive value for PBO + ENZA. A 33-feature (3 genes, 30 transcripts) elastic net signature was identified that was predictive of rPFS with TALA + ENZA: TP53 and AR short variant alteration status were each prognostic and associated with worse rPFS. Expression of multiple AR target genes, including ALDH1A3 (top selected feature) and CAMKK2, was positively associated with rPFS. For TALA + ENZA, this multiomic signature was predictive of rPFS in pts regardless of HRR gene alteration status, and to a lesser extent for PBO + ENZA. None of the 12 HRR genes used for stratification in TP-2 were included in the signature. Conclusions: Our exploratory analysis identified candidate gene expression signatures, including AR pathway elements, potentially associated with differential benefit from TALA + ENZA, reinforcing the potential for exploitable crosstalk between AR and DNA repair pathways. Though validation is necessary, a predictive multiomic signature for benefit from TALA + ENZA regardless of HRR alteration status was identified that included alterations in genes previously implicated in prognosis and expression of multiple AR target transcripts. Strikingly, it did not include any of the 12 HRR genes used in prospective stratification for TP-2, reinforcing the potential benefit for TALA + ENZA beyond HRR-deficient tumors. Citation Format: Glenn Liu, Xinmeng Jasmine Mu, Karim Fizazi, A. Douglas Laird, Nobuaki Matsubara, Steven M. Yip, Jie Pu, Joan Carles, Andre P. Fay, Robert J. Jones, Stefanie Zschäbitz, Josep M. Piulats, Jae Young Joung, Whijae Roh, Jijumon Chelliserry, Nicola Di Santo, Michelle Saul, Arun A. Azad, Neeraj Agarwal. Identification of a novel agnostic predictive multiomic signature via Elastic Net/Machine Learning in TALAPRO-2 (TP-2), a phase 3 study of talazoparib (TALA) + enzalutamide (ENZA) vs placebo (PBO) + ENZA as first-line (1L) treatment in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT231.