HSD3B1 Genotype and Clinical Outcomes in Metastatic Castration-Sensitive Prostate Cancer

Current uses and resistance mechanisms of enzalutamide in prostate cancer treatment

INTRODUCTION

Prostate cancer continues to be a major cause of morbidity and mortality for men worldwide. Enzalutamide, a second-generation non-steroidal antiandrogen that blocks androgen receptor (AR) transcriptional activity, is a treatment for biochemically recurrent, metastatic, castration-sensitive, and castration-resistant tumors. Unfortunately, most patients ultimately develop resistance to enzalutamide, making long-term treatment with this agent challenging.

AREAS COVERED

We performed a literature search of PubMed without date restrictions to investigate the literature surrounding enzalutamide and discuss the current uses of enzalutamide, proposed mechanisms driving resistance, and summarize current efforts to mitigate this resistance.

EXPERT OPINION

Enzalutamide is an effective prostate cancer therapy that is currently used in biochemically recurrent and metastatic disease and for both castration-sensitive and castration-resistant tumors. Unfortunately, resistance to enzalutamide occurs in each of these scenarios. In the clinical setting, enzalutamide-resistant tumors are either AR-driven or AR-indifferent. AR-dependent resistance mechanisms include genomic or epigenomic events that result in enhanced AR signaling. Tumors that do not require AR signaling instead may depend on alternative oncogenic pathways. There are numerous strategies to mitigate enzalutamide resistance, including concurrent use of PARP inhibitors or immune therapies. Additional work is required to uncover novel approaches to treat patients in the enzalutamide-resistant setting.

Survival of men with metastatic hormone-sensitive prostate cancer and adrenal-permissive HSD3B1 inheritance

BACKGROUNDMetastatic hormone-sensitive prostate cancer (mHSPC) is androgen dependent, and its treatment includes androgen deprivation therapy (ADT) with gonadal testosterone suppression. Since 2014, overall survival (OS) has been prolonged with addition of other systemic therapies, such as adrenal androgen synthesis blockers, potent androgen receptor blockers, or docetaxel, to ADT. HSD3B1 encodes the rate-limiting enzyme for nongonadal androgen synthesis, 3β-hydroxysteroid dehydrogenase-1, and has a common adrenal-permissive missense-encoding variant that confers increased synthesis of potent androgens from nongonadal precursor steroids and poorer prostate cancer outcomes.METHODSOur prespecified hypothesis was that poor outcome associated with inheritance of the adrenal-permissive HSD3B1 allele with ADT alone is reversed in patients with low-volume (LV) mHSPC with up-front ADT plus addition of androgen receptor (AR) antagonists to inhibit the effect of adrenal androgens. HSD3B1 genotype was obtained in 287 patients with LV disease treated with ADT + AR antagonist only in the phase III Enzalutamide in First Line Androgen Deprivation Therapy for Metastatic Prostate Cancer (ENZAMET) trial and was associated with clinical outcomes.RESULTSPatients who inherited the adrenal-permissive HSD3B1 allele had more favorable 5-year clinical progression-free survival and OS when treated with ADT plus enzalutamide or ADT plus nonsteroidal antiandrogen compared with their counterparts who did not have adrenal-permissive HSD3B1 inheritance. HSD3B1 was also associated with OS after accounting for known clinical variables. Patients with both genotypes benefited from early enzalutamide.CONCLUSIONThese data demonstrated an inherited physiologic driver of prostate cancer mortality is associated with clinical outcomes and is potentially pharmacologically reversible.FUNDINGNational Cancer Institute, NIH; Department of Defense; Prostate Cancer Foundation, Australian National Health and Medical Research Council.

HSD3B1 genotype and outcomes in metastatic hormone-sensitive prostate cancer with androgen deprivation therapy and enzalutamide: ARCHES

HSD3B1 encodes 3β-hydroxysteroid dehydrogenase-1, which converts adrenal dehydroepiandrosterone to 5α-dihydrotestosterone and is inherited in adrenal-permissive (AP) or adrenal-restrictive forms. The AP allele is linked to castration resistance, mainly in low-volume tumors. Here, we investigate the association of HSD3B1 alleles with outcomes in ARCHES, a multinational, double-blind, randomized, placebo-controlled phase 3 trial that demonstrated clinical benefit with enzalutamide plus androgen deprivation therapy (ADT) in men with metastatic hormone-sensitive prostate cancer (mHSPC) compared to those treated with placebo plus ADT. There are no significant differences between genotypes for clinical efficacy endpoints. Enzalutamide significantly improves radiographic progression-free survival and overall survival vs. placebo irrespective of HSD3B1 status. Men with the AP genotype have higher post-progression mortality and treatment-emergent adverse events, including hypertension, cardiovascular events, and gynecomastia, but a lower fracture rate. Overall, enzalutamide is beneficial in men with mHSPC independent of the HSD3B1 genotype. Inherited polymorphisms of HSD3B1 may account for differential toxicities.

Reproducible preclinical models of androgen receptor driven human prostate cancer bone metastasis

BACKGROUND

Preclinical models recapitulating the metastatic phenotypes are essential for developing the next-generation therapies for metastatic prostate cancer (mPC). We aimed to establish a cohort of clinically relevant mPC models, particularly androgen receptor positive (AR+) bone metastasis models, from LuCaP patient-derived xenografts (PDX) that reflect the heterogeneity and complexity of mPC.

METHODS

PDX tumors were dissociated into single cells, modified to express luciferase, and were inoculated into NSG mice via intracardiac injection. The progression of metastases was monitored by bioluminescent imaging. Histological phenotypes of metastases were characterized by immunohistochemistry and immunofluorescence staining. Castration responses were further investigated in two AR-positive models.

RESULTS

Our PDX-derived metastasis (PDM) model collection comprises three AR+ adenocarcinomas (ARPC) and one AR- neuroendocrine carcinoma (NEPC). All ARPC models developed bone metastases with either an osteoblastic, osteolytic, or mixed phenotype, while the NEPC model mainly developed brain metastasis. Different mechanisms of castration resistance were observed in two AR+ PDM models with distinct genotypes, such as combined loss of TP53 and RB1 in one model and expression of AR splice variant 7 (AR-V7) expression in another model. Intriguingly, the castration-resistant tumors displayed inter- and intra-tumor as well as organ-specific heterogeneity in lineage specification.

CONCLUSION

Genetically diverse PDM models provide a clinically relevant system for biomarker identification and personalized medicine in metastatic castration-resistant prostate cancer.

Xenoestrogen and Its Interaction with Human Genes and Cellular Proteins: An In-Silico Study

BACKGROUND

Breast cancer represents one of the leading causes of death worldwide. Apart from genetic factors, the sex hormone estrogen plays a pivotal role in breast cancer development. We are exposed to a plethora of estrogen mimics on a daily basis via various routes. Nevertheless, how xenoestrogens, the exogenous estrogen mimics, modulate cancer-associated signaling pathways and interact with specific genes is still underexplored. Hence, this study aims to explore the direct or indirect binding partners of xenoestrogens and their expression upon exposure to these estrogenic compounds.

METHODS

The collection of genes linked to the xenoestrogens Octylphenol, Nonylphenol, Bisphenol-A, and 2,2-bis(4-hydroxyphenyl)-1,1,1-trichloroethane were gathered from the Comparative Toxicogenomics Database. Venny 2.1 was utilized to pinpoint the genes shared by these xenoestrogens. Subsequently, the shared genes underwent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis using the Database for Annotation, Visualization, and Integrated Discovery bioinformatics resource. A xenoestrogen-protein interaction network was constructed using Search Tool for Interactions of Chemicals. The expressions of common genes were studied with the microarray dataset GSE5200 from the Gene Expression Omnibus database. Also, the expression of a common gene set within different breast cancer subtypes was identified using the University of California, Santa Cruz Xena.

RESULTS

The genes linked to xenoestrogens were identified, and 13 genes were found to interact with all four xenoestrogens. Through DAVID analysis, the genes chosen are found to be enriched for various functions and pathways, including pathways in cancer, chemical carcinogenesis-receptor activation, and estrogen signaling pathways. The results of the Comparative Toxicogenomics Database and the chemical-protein interaction network derived from STITCH were similar. Microarray data analysis showed significantly high expression of all 13 genes in another study, with Bisphenol-A and Nonylphenol treated MCF-7 cells, most of the genes are expressed in luminal A or basal breast cancer subtype.

CONCLUSION

In summary, the genes associated with the four xenoestrogens were mostly linked to pathways related to tumorigenesis, and the expression of these genes was found to be higher in breast cancer.

Adrenal-Permissive Germline HSD3B1 Allele and Prostate Cancer Outcomes

Importance

The adrenal androgen-metabolizing 3β-hydroxysteroid dehydrogenase-1 enzyme, encoded by the HSD3B1 gene, catalyzes the rate-limiting step necessary for synthesizing nontesticular testosterone and dihydrotestosterone production. The common adrenal-permissive HSD3B1(1245C) allele is responsible for encoding the 3β-HSD1 protein with decreased susceptibility to degradation resulting in higher extragonadal androgen synthesis. Retrospective studies have suggested an association of the HSD3B1 adrenal-permissive homozygous genotype with androgen deprivation therapy resistance in prostate cancer.

Objective

To evaluate differences in mortality outcomes by HSD3B1 genetic status among men with prostate cancer.

Design, Setting, and Participants

This cohort study of patients with prostate cancer who were enrolled in the Million Veteran Program within the Veterans Health Administration (VHA) system between 2011 and 2023 collected genotyping and phenotyping information.

Exposure

HSD3B1 genotype status was categorized as AA (homozygous adrenal-restrictive), AC (heterozygous adrenal-restrictive), or CC (homozygous adrenal-permissive).

Main Outcomes and Measures

The primary outcome of this study was prostate cancer-specific mortality (PCSM), defined as the time from diagnosis to death from prostate cancer, censored at the date of last VHA follow-up. Secondary outcomes included incidence of metastases and PCSM in predefined subgroups.

Results

Of the 5287 participants (median [IQR] age, 69 [64-74] years), 402 (7.6%) had the CC genotype, 1970 (37.3%) had the AC genotype, and 2915 (55.1%) had the AA genotype. Overall, the primary cause of death for 91 patients (1.7%) was prostate cancer. Cumulative incidence of PCSM at 5 years after prostate cancer diagnosis was higher among men with the CC genotype (4.0%; 95% CI, 1.7%-6.2%) compared with the AC genotype (2.1%; 95% CI, 1.3%-2.8%) and AA genotype (1.9%; 95% CI, 1.3%-2.4%) (P = .02). In the 619 patients who developed metastatic disease at any time, the cumulative incidence of PCSM at 5 years was higher among patients with the CC genotype (36.0%; 95% CI, 16.7%-50.8%) compared with the AC genotype (17.9%; 95% CI, 10.5%-24.7%) and AA genotype (18.5%; 95% CI, 12.0%-24.6%) (P = .01).

Conclusions and Relevance

In this cohort study of US veterans undergoing treatment for prostate cancer at the VHA, the HSD3B1 CC genotype was associated with inferior outcomes. The HSD3B1 biomarker may help identify patients who may benefit from therapeutic targeting of 3β-hydroxysteroid dehydrogenase-1 and the androgen-signaling axis.

Evaluation of Survival Outcomes Among Black and White Patients with Metastatic Castration-resistant Prostate Cancer: A Systematic Review and Meta-analysis

Context

Data on racial disparities among patients with metastatic castration-resistant prostate cancer (mCRPC) are limited and there is no uniform conclusion on differences by race in this setting.

Objective

To provide the latest evidence on racial disparities in survival outcomes between Black and White patients receiving systemic therapies for mCRPC.

Evidence acquisition

Our study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We systematically searched the PubMed, Web of Science, and Cochrane Library databases up to September 2023 to identify potentially relevant studies. Overall survival (OS) and progression-free survival (PFS) were the outcomes of interest. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were evaluated.

Evidence synthesis

Nine studies involving 9462 patients with mCRPC (2058 Black and 7404 White men) met the eligibility criteria and were included. Pooled estimates demonstrated significantly better OS for Black than for White men (HR 0.75, 95% CI 0.70-0.80; p < 0.0001). The results were similar in a subgroup of men receiving androgen receptor-targeted therapies (HR 0.72, 95% CI 0.66-0.78; p < 0.0001) and a subgroup of men receiving other treatments (HR 0.79, 95% CI 0.71-0.88; p < 0.0001). Likewise, significantly favorable PFS was observed for Black men receiving ARTs in comparison to their White counterparts (HR 0.84, 95% CI 0.71-0.99; p = 0.0373).

Conclusions

Overall, our meta-analysis of survival outcomes for men with mCRPC stratified by race revealed a significant survival benefit for Black men in comparison to their White counterparts, regardless of systemic therapeutic agent.

Patient summary

Both biological and nonbiological factors could account for racial differences in the efficacy of systemic treatments for metastatic prostate cancer that is resistant to hormone therapy. Our review provides the latest reliable evidence showing better survival outcomes for Black than for White men. The results will be helpful in further understanding the molecular mechanisms that might explain racial differences in this disease stage and in planning treatment.

Chronic hypoxia stabilizes 3βHSD1 via autophagy suppression

Progression of prostate cancer depends on androgen receptor, which is usually activated by androgens. Therefore, a mainstay treatment is androgen deprivation therapy. Unfortunately, despite initial treatment response, resistance nearly always develops, and disease progresses to castration-resistant prostate cancer (CRPC), which remains driven by non-gonadal androgens synthesized in prostate cancer tissues. 3β-Hydroxysteroid dehydrogenase/Δ5-->4 isomerase 1 (3βHSD1) catalyzes the rate-limiting step in androgen synthesis. However, how 3βHSD1, especially the "adrenal-permissive" 3βHSD1(367T) that permits tumor synthesis of androgen from dehydroepiandrosterone (DHEA), is regulated at the protein level is not well understood. Here, we investigate how hypoxia regulates 3βHSD1(367T) protein levels. Our results show that, in vitro, hypoxia stabilizes 3βHSD1 protein by suppressing autophagy. Autophagy inhibition promotes 3βHSD1-dependent tumor progression. Hypoxia represses transcription of autophagy-related (ATG) genes by decreasing histone acetylation. Inhibiting deacetylase (HDAC) restores ATG gene transcription under hypoxia. Therefore, HDAC inhibition may be a therapeutic target for hypoxic tumor cells.

Intratumoral androgen biosynthesis associated with 3β-hydroxysteroid dehydrogenase 1 promotes resistance to radiotherapy in prostate cancer

Half of all men with advanced prostate cancer (PCa) inherit at least 1 copy of an adrenal-permissive HSD3B1 (1245C) allele, which increases levels of 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) and promotes intracellular androgen biosynthesis. Germline inheritance of the adrenally permissive allele confers worse outcomes in men with advanced PCa. We investigated whether HSD3B1 (1245C) drives resistance to combined androgen deprivation and radiotherapy. Adrenally permissive 3βHSD1 enhanced resistance to radiotherapy in PCa cell lines and xenograft models engineered to mimic the human adrenal/gonadal axis during androgen deprivation. The allele-specific effects on radiosensitivity were dependent on availability of DHEA, the substrate for 3βHSD1. In lines expressing the HSD3B1 (1245C) allele, enhanced expression of DNA damage response (DDR) genes and more rapid DNA double-strand break (DSB) resolution were observed. A correlation between androgen receptor (AR) expression and increased DDR gene expression was confirmed in 680 radical prostatectomy specimens. Treatment with the nonsteroidal antiandrogen enzalutamide reversed the resistant phenotype of HSD3B1 (1245C) PCa in vitro and in vivo. In conclusion, 3βHSD1 promotes prostate cancer resistance to combined androgen deprivation and radiotherapy by upregulating DNA DSB repair. This work supports prospective validation of early combined androgen blockade for high-risk men harboring the HSD3B1 (1245C) allele.

Analysis of genetic biomarkers, polymorphisms in ADME-related genes and their impact on pharmacotherapy for prostate cancer

Prostate cancer (PCa) is a non-cutaneous malignancy in males with wide variation in incidence rates across the globe. It is the second most reported cause of cancer death. Its etiology may have been linked to genetic polymorphisms, which are not only dominating cause of malignancy casualties but also exerts significant effects on pharmacotherapy outcomes. Although many therapeutic options are available, but suitable candidates identified by useful biomarkers can exhibit maximum therapeutic efficacy. The single-nucleotide polymorphisms (SNPs) reported in androgen receptor signaling genes influence the effectiveness of androgen receptor pathway inhibitors and androgen deprivation therapy. Furthermore, SNPs located in genes involved in transport, drug metabolism, and efflux pumps also influence the efficacy of pharmacotherapy. Hence, SNPs biomarkers provide the basis for individualized pharmacotherapy. The pharmacotherapeutic options for PCa include hormonal therapy, chemotherapy (Docetaxel, Mitoxantrone, Cabazitaxel, and Estramustine, etc.), and radiotherapy. Here, we overview the impact of SNPs reported in various genes on the pharmacotherapy for PCa and evaluate current genetic biomarkers with an emphasis on early diagnosis and individualized treatment strategy in PCa.

Genomic and Phenotypic Biomarkers for Precision Medicine Guidance in Advanced Prostate Cancer

OPINION STATEMENT

Prostate cancer (PCa) is the second most diagnosed malignant neoplasm and is one of the leading causes of cancer-related death in men worldwide. Despite significant advances in screening and treatment of PCa, given the heterogeneity of this disease, optimal personalized therapeutic strategies remain limited. However, emerging predictive and prognostic biomarkers based on individual patient profiles in combination with computer-assisted diagnostics have the potential to guide precision medicine, where patients may benefit from therapeutic approaches optimally suited to their disease. Also, the integration of genotypic and phenotypic diagnostic methods is supporting better informed treatment decisions. Focusing on advanced PCa, this review discusses polygenic risk scores for screening of PCa and common genomic aberrations in androgen receptor (AR), PTEN-PI3K-AKT, and DNA damage response (DDR) pathways, considering clinical implications for diagnosis, prognosis, and treatment prediction. Furthermore, we evaluate liquid biopsy, protein biomarkers such as serum testosterone levels, SLFN11 expression, total alkaline phosphatase (tALP), neutrophil-to-lymphocyte ratio (NLR), tissue biopsy, and advanced imaging tools, summarizing current phenotypic biomarkers and envisaging more effective utilization of diagnostic and prognostic biomarkers in advanced PCa. We conclude that prognostic and treatment predictive biomarker discovery can improve the management of patients, especially in metastatic stages of advanced PCa. This will result in decreased mortality and enhanced quality of life and help design a personalized treatment regimen.

Targeting the Androgen Signaling Axis in Prostate Cancer

Activation of the androgen receptor (AR) and AR-driven transcriptional programs is central to the pathophysiology of prostate cancer. Despite successful translational efforts in targeting AR, therapeutic resistance often occurs as a result of molecular alterations in the androgen signaling axis. The efficacy of next-generation AR-directed therapies for castration-resistant prostate cancer has provided crucial clinical validation for the continued dependence on AR signaling and introduced a range of new treatment options for men with both castration-resistant and castration-sensitive disease. Despite this, however, metastatic prostate cancer largely remains an incurable disease, highlighting the need to better understand the diverse mechanisms by which tumors thwart AR-directed therapies, which may inform new therapeutic avenues. In this review, we revisit concepts in AR signaling and current understandings of AR signaling-dependent resistance mechanisms as well as the next frontier of AR targeting in prostate cancer.

Management of patients with advanced prostate cancer-metastatic and/or castration-resistant prostate cancer: Report of the Advanced Prostate Cancer Consensus Conference (APCCC) 2022

BACKGROUND

Innovations in imaging and molecular characterisation together with novel treatment options have improved outcomes in advanced prostate cancer. However, we still lack high-level evidence in many areas relevant to making management decisions in daily clinical practise. The 2022 Advanced Prostate Cancer Consensus Conference (APCCC 2022) addressed some questions in these areas to supplement guidelines that mostly are based on level 1 evidence.

OBJECTIVE

To present the voting results of the APCCC 2022.

DESIGN, SETTING, AND PARTICIPANTS

The experts voted on controversial questions where high-level evidence is mostly lacking: locally advanced prostate cancer; biochemical recurrence after local treatment; metastatic hormone-sensitive, non-metastatic, and metastatic castration-resistant prostate cancer; oligometastatic prostate cancer; and managing side effects of hormonal therapy. A panel of 105 international prostate cancer experts voted on the consensus questions.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The panel voted on 198 pre-defined questions, which were developed by 117 voting and non-voting panel members prior to the conference following a modified Delphi process. A total of 116 questions on metastatic and/or castration-resistant prostate cancer are discussed in this manuscript. In 2022, the voting was done by a web-based survey because of COVID-19 restrictions.

RESULTS AND LIMITATIONS

The voting reflects the expert opinion of these panellists and did not incorporate a standard literature review or formal meta-analysis. The answer options for the consensus questions received varying degrees of support from panellists, as reflected in this article and the detailed voting results are reported in the supplementary material. We report here on topics in metastatic, hormone-sensitive prostate cancer (mHSPC), non-metastatic, castration-resistant prostate cancer (nmCRPC), metastatic castration-resistant prostate cancer (mCRPC), and oligometastatic and oligoprogressive prostate cancer.

CONCLUSIONS

These voting results in four specific areas from a panel of experts in advanced prostate cancer can help clinicians and patients navigate controversial areas of management for which high-level evidence is scant or conflicting and can help research funders and policy makers identify information gaps and consider what areas to explore further. However, diagnostic and treatment decisions always have to be individualised based on patient characteristics, including the extent and location of disease, prior treatment(s), co-morbidities, patient preferences, and treatment recommendations and should also incorporate current and emerging clinical evidence and logistic and economic factors. Enrolment in clinical trials is strongly encouraged. Importantly, APCCC 2022 once again identified important gaps where there is non-consensus and that merit evaluation in specifically designed trials.

PATIENT SUMMARY

The Advanced Prostate Cancer Consensus Conference (APCCC) provides a forum to discuss and debate current diagnostic and treatment options for patients with advanced prostate cancer. The conference aims to share the knowledge of international experts in prostate cancer with healthcare providers worldwide. At each APCCC, an expert panel votes on pre-defined questions that target the most clinically relevant areas of advanced prostate cancer treatment for which there are gaps in knowledge. The results of the voting provide a practical guide to help clinicians discuss therapeutic options with patients and their relatives as part of shared and multidisciplinary decision-making. This report focuses on the advanced setting, covering metastatic hormone-sensitive prostate cancer and both non-metastatic and metastatic castration-resistant prostate cancer.

TWITTER SUMMARY

Report of the results of APCCC 2022 for the following topics: mHSPC, nmCRPC, mCRPC, and oligometastatic prostate cancer.

TAKE-HOME MESSAGE

At APCCC 2022, clinically important questions in the management of advanced prostate cancer management were identified and discussed, and experts voted on pre-defined consensus questions. The report of the results for metastatic and/or castration-resistant prostate cancer is summarised here.

Approaches to assessing 3β-hydroxysteroid dehydrogenase-1

The enzyme 3β-hydroxysteroid dehydrogenase-1 (3βHSD1), encoded by the gene HSD3B1, plays an essential role in the peripheral conversion of 3β-OH, Δ5-steroids to 3-keto, Δ4-steroids. In human physiology, the adrenal produces dehydroepiandrosterone (DHEA) and DHEA-sulfate, which are major precursors for the biosynthesis of potent androgens and estrogens. DHEA is converted by 3βHSD1 and subsequently is converted by steroid-5α-reductase to potent androgens or by aromatase to estrogens. Assessment of 3βHSD1 is therefore critical under various conditions. In this chapter, we detail several approaches to assessing 3βHSD1. First, we describe a genotyping protocol for the identification of a common missense-encoding variation that regulates 3βHSD1 cellular metabolic activity. This protocol distinguishes between the HSD3B1(1245A) and the HSD3B1(1245C) allele which have lower and higher metabolic activity, respectively. Second, we detail mass spectrometry approaches to determining 3βHSD1 activity using stable isotope dilution. Third, we describe methods for using tritiated DHEA and high performance liquid chromatography coupled with a beta-RAM to also determine 3βHSD1 activity. Together, we provide multiple methods of directly assessing 3βHSD1 activity or anticipated 3βHSD1 activity.

Cancer-associated fibroblast-secreted glucosamine alters the androgen biosynthesis program in prostate cancer via HSD3B1 upregulation

After androgen deprivation, prostate cancer frequently becomes castration resistant (CRPC), with intratumoral androgen production from extragonadal precursors that activate the androgen receptor pathway. 3β-Hydroxysteroid dehydrogenase-1 (3βHSD1) is the rate-limiting enzyme for extragonadal androgen synthesis, which together lead to CRPC. Here, we show that cancer-associated fibroblasts (CAFs) increased epithelial 3βHSD1 expression, induced androgen synthesis, activated the androgen receptor, and induced CRPC. Unbiased metabolomics revealed that CAF-secreted glucosamine specifically induced 3βHSD1. CAFs induced higher GlcNAcylation in cancer cells and elevated expression of the transcription factor Elk1, which induced higher 3βHSD1 expression and activity. Elk1 genetic ablation in cancer epithelial cells suppressed CAF-induced androgen biosynthesis in vivo. In patient samples, multiplex fluorescent imaging showed that tumor cells expressed more 3βHSD1 and Elk1 in CAF-enriched areas compared with CAF-deficient areas. Our findings suggest that CAF-secreted glucosamine increases GlcNAcylation in prostate cancer cells, promoting Elk1-induced HSD3B1 transcription, which upregulates de novo intratumoral androgen synthesis to overcome castration.

Serum Androgen Metabolites Correlate with Clinical Variables in African and European American Men with Localized, Therapy Naïve Prostate Cancer

Dihydrotestosterone (DHT) and testosterone (T), which mediate androgen receptor nuclear translocation and target gene transcription, are crucial androgens and essential molecular triggers required for the proliferation and survival of prostate cancer cells. Therefore, androgen metabolism is commonly targeted in the treatment of prostate cancer. Using a high-pressure liquid chromatographic assay with tandem mass spectral detection, we determined the serum levels of metabolites produced during DHT/T biosynthesis in African American (AA) and European American (EA) men with localized, therapy naïve prostate cancer. Serum progesterone and related metabolites were significantly lower in AA men than in EA men, and these differences were associated with rapid disease progression. Multivariate analysis revealed significant differences between a subset of intermediate androgen metabolites between AA and EA men and between men with <=3 + 4 and >=4 + 3 Gleason score disease. AA men have a significantly higher frequency of single nucleotide polymorphisms in CYP11B1 and CYP11B2, enzymes that regulate corticosterone-aldosterone conversion. Finally, higher levels of T and pregnenolone were associated with a lower risk of progression-free survival only in AA men. This work provides new insight into androgen metabolism and racial disparities in prostate cancer by presenting evidence of dysregulated androgen biosynthesis in therapy naïve disease that correlates with clinical variables.

UGT2B28 accelerates prostate cancer progression through stabilization of the endocytic adaptor protein HIP1 regulating AR and EGFR pathways

The androgen inactivating UGT2B28 pathway emerges as a predictor of progression in prostate cancer (PCa). However, the clinical significance of UGT2B28 tumoral expression and its contribution to PCa progression remain unclear. Using the Canadian Prostate Cancer Biomarker Network biobank (CPCBN; n = 1512), we analyzed UGT2B28 tumor expression in relation to clinical outcomes in men with localized PCa. UGT2B28 was overexpressed in tumors compared to paired normal adjacent prostatic tissue and was associated with inferior outcomes. Functional analyses indicated that UGT2B28 promoted cell proliferation, and its expression was regulated by the androgen receptor (AR)/ARv7. Mechanistically, UGT2B28 was shown to be a protein partner of the endocytic adaptor protein huntingtin-interacting protein 1 (HIP1), increasing its stability and priming AR/epidermal growth factor receptor (EGFR) pathways, leading to ERK1/2 activation triggering cell proliferation and epithelial-to-mesenchymal transition (EMT). HIP1 knockdown in UGT2B28 positive cells, and dual pharmacological targeting of AR and EGFR pathways, abolished cell proliferative advantages conferred by UGT2B28. In conclusion, UGT2B28 is a prognosticator of progression in localized PCa, regulates both AR and EGFR oncogenic signaling pathways via HIP1, and therefore can be therapeutically targeted by using combination of existing AR/EGFR inhibitors.

BMX controls 3βHSD1 and sex steroid biosynthesis in cancer

Prostate cancer is highly dependent on androgens and the androgen receptor (AR). Hormonal therapies inhibit gonadal testosterone production, block extragonadal androgen biosynthesis, or directly antagonize AR. Resistance to medical castration occurs as castration-resistant prostate cancer (CRPC) and is driven by reactivation of the androgen-AR axis. 3β-hydroxysteroid dehydrogenase-1 (3βHSD1) serves as the rate-limiting step for potent androgen synthesis from extragonadal precursors, thereby stimulating CRPC. Genetic evidence in men demonstrates the role of 3βHSD1 in driving CRPC. In postmenopausal women, 3βHSD1 is required for synthesis of aromatase substrates and plays an essential role in breast cancer. Therefore, 3βHSD1 lies at a critical junction for the synthesis of androgens and estrogens, and this metabolic flux is regulated through germline-inherited mechanisms. We show that phosphorylation of tyrosine 344 (Y344) occurs and is required for 3βHSD1 cellular activity and generation of Δ4, 3-keto-substrates of 5α-reductase and aromatase, including in patient tissues. BMX directly interacts with 3βHSD1 and is necessary for enzyme phosphorylation and androgen biosynthesis. In vivo blockade of 3βHSD1 Y344 phosphorylation inhibits CRPC. These findings identify what we believe to be new hormonal therapy pharmacologic vulnerabilities for sex-steroid dependent cancers.

Racial Differences in Germline Genetic Testing for Prostate Cancer: A Systematic Review

PURPOSE

Testing for pathogenic variants can aid in oncologic risk stratification and identification of targeted therapies. Despite known disparities in access to prostate cancer (PCa) care, little has been written about access to germline genetic testing (GGT) for Black men and other historically marginalized populations. This systematic review sought to delineate racial/ethnic disparities in GGT for PCa.

METHODS

This systematic review identified articles published from January 1996 through May 2021 in PubMed, Web of Science, and Embase. We included studies that reported rates of GGT in men with PCa in the United States by race/ethnicity as reflective of routine clinical care or research. A narrative synthesis was performed.

RESULTS

Of 4,309 unique records, 91 studies examining 50 unique study populations met inclusion criteria. Of these, four populations included men who received GGT through routine clinical care, accounting for 4,415 men (72.6% White and 7.2% Black). The other 46 populations included men who received GGT as part of a research study, accounting for 30,824 men (64.3% White and 21.6% Black). Of these 46 research populations, 19 used targeted methods to increase recruitment from a specific demographic.

CONCLUSION

Most studies that report GGT rates by race/ethnicity are in research settings. Many of these studies used targeted recruitment methods and subsequently have a greater proportion of Black men than clinical and US population-based studies. Other historically marginalized populations are not well represented. There remains a knowledge gap regarding the extent of racial disparities in the use of GGT, particularly in the clinical setting.

Adrenal Steroids and Resistance to Hormonal Blockade of Prostate and Breast Cancer

Prostate cancer and breast cancer are sex-steroid-dependent diseases that are driven in major part by gonadal sex steroids. Testosterone (T) is converted to 5α-dihydrotestosterone, both of which stimulate the androgen receptor (AR) and prostate cancer progression. Estradiol is the major stimulus for estrogen receptor-α (ERα) and proliferation of ERα-expressing breast cancer. However, the human adrenal provides an alternative source for sex steroids. A number of different androgens are produced by the adrenals, the most abundant of which is dehydroepiandrosterone (DHEA) and DHEA sulfate. These precursor steroids are subject to metabolism by peripherally expressed enzymes that are responsible for the synthesis of potent androgens and estrogens. In the case of prostate cancer, the regulation of one of these enzymatic steps occurs at least in part by way of a germline-encoded missense in 3β-hydroxysteroid dehydrogenase-1 (3βHSD1), which regulates potent androgen biosynthesis and clinical outcomes in men with advanced prostate cancer treated with gonadal T deprivation. The sex steroids that drive prostate cancer and breast cancer require a common set of enzymes for their generation. However, the pathways diverge once 3-keto, Δ4-androgens are generated and these steroids are either turned into potent androgens by steroid-5α-reductase, or into estrogens by aromatase. Alternative steroid receptors have also emerged as disease- and treatment-resistance modifiers, including a role for AR in breast cancer and glucocorticoid receptor both in breast and prostate cancer. In this review, we integrate the commonalities of adrenal steroid physiology that regulate both prostate and breast cancer while recognizing the clear distinctions between these diseases.

Association Between Adrenal-Restrictive HSD3B1 Inheritance and Hormone-Independent Subtypes of Endometrial and Breast Cancer

BACKGROUND

The germline variant rs1047303 (HSD3B1[1245A/C]), restricting or enabling production of potent androgens and estrogens from adrenal precursors, affects outcomes of castration-resistant prostate cancer and is associated with estrogen receptor positivity in postmenopausal breast cancer. Like breast cancer, endometrial cancer is another malignancy with hormone-dependent and hormone-independent subtypes. We hypothesized that adrenal-restrictive HSD3B1 genotype would associate with hormone-independent cancer subtypes.

METHODS

We employed a previously described classification of tumors in The Cancer Genome Atlas into genomic clusters. We determined HSD3B1 genotype frequencies by endometrial cancer genomic cluster and calculated the odds per adrenal-restrictive A allele for the largely hormone-independent copy-number (CN) high subtype vs other subtypes. An equivalent analysis was performed for the genomically similar, hormone-independent basal breast cancer subtype. Last, we performed survival analyses for UK Biobank participants with endometrial cancer by HSD3B1 genotype. All statistical tests were 2-sided.

RESULTS

The adrenal-restrictive HSD3B1(1245A) allele was associated with the CN-high endometrial cancer subtype (odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.14 to 2.32; P = .007). Similarly, HSD3B1(1245A) was associated with the basal breast cancer subtype (OR = 1.54, 95% CI = 1.13 to 2.08; P = .006). In the UK Biobank, endometrial cancer patients homozygous for HSD3B1(1245A) had worse overall (hazard ratio [HR] = 1.39, 95% CI = 1.16 to 1.68; P < .001) and cancer-specific (HR = 1.39, 95% CI = 1.14 to 1.70; P = .001) survival, consistent with the A allele being enriched in the more aggressive CN-high subtype.

CONCLUSIONS

These findings suggest roles for adrenal-restrictive vs adrenal-permissive steroidogenesis, by way of rs1047303 genotype, in the development of and/or outcomes from at least 3 commonly hormone-associated types of cancer: prostate, breast, and endometrial.

Hypoxia-Reoxygenation Couples 3βHSD1 Enzyme and Cofactor Upregulation to Facilitate Androgen Biosynthesis and Hormone Therapy Resistance in Prostate Cancer

Androgen deprivation therapy suppresses tumor androgen receptor (AR) signaling by depleting circulating testosterone and is a mainstay treatment for advanced prostate cancer. Despite initial treatment response, castration-resistant prostate cancer nearly always develops and remains driven primarily by the androgen axis. Here we investigated how changes in oxygenation affect androgen synthesis. In prostate cancer cells, chronic hypoxia coupled to reoxygenation resulted in efficient metabolism of androgen precursors to produce androgens and activate AR. Hypoxia induced 3βHSD1, the rate-limiting androgen synthesis regulator, and reoxygenation replenished necessary cofactors, suggesting that hypoxia and reoxygenation both facilitate potent androgen synthesis. The EGLN1/VHL/HIF2α pathway induced 3βHSD1 expression through direct binding of HIF2α to the 5' regulatory region of HSD3B1 to promote transcription. Overexpression of HIF2α facilitated prostate cancer progression, which largely depended on 3βHSD1. Inhibition of HIF2α with the small-molecule PT2399 prevented prostate cancer cell proliferation. These results thus identify HIF2α as a regulator of androgen synthesis and potential therapeutic target in prostate cancer.

SIGNIFICANCE

Hypoxia followed by reoxygenation in prostate cancer drives androgen deprivation therapy resistance via increasing the rate-limiting enzyme and cofactors for androgen synthesis, revealing HIF2α as a therapeutic target to subvert resistance.

Inheritance of a common androgen synthesis variant allele is associated with female COVID susceptibility in UK Biobank

Context

A sex discordance in COVID exists, with males disproportionately affected. Although sex steroids may play a role in this discordance, no definitive genetic data exist to support androgen-mediated immune suppression neither for viral susceptibility nor for adrenally produced androgens.

Objective

The common adrenal-permissive missense-encoding variant HSD3B1(1245C) that enables androgen synthesis from adrenal precursors and that has been linked to suppression of inflammation in severe asthma was investigated in COVID susceptibility and outcomes reported in the UK Biobank.

Methods

The UK Biobank is a long-term study with detailed medical information and health outcomes for over 500 000 genotyped individuals. We obtained COVID test results, inpatient hospital records, and death records and tested for associations between COVID susceptibility or outcomes and HSD3B1(1245A/C) genotype. Primary analyses were performed on the UK Biobank Caucasian cohort. The outcomes were identification as a COVID case among all subjects, COVID positivity among COVID-tested subjects, and mortality among subjects identified as COVID cases.

Results

Adrenal-permissive HSD3B1(1245C) genotype was associated with identification as a COVID case (odds ratio (OR): 1.11 per C allele, 95% CI: 1.04-1.18, P = 0.0013) and COVID-test positivity (OR: 1.09, 95% CI: 1.02-1.17, P = 0.011) in older (≥70 years of age) women. In women identified as COVID cases, there was a positive linear relationship between age and 1245C allele frequency (P < 0.0001). No associations were found between genotype and mortality or between genotype and circulating sex hormone levels.

Conclusion

Our study suggests that a common androgen synthesis variant regulates immune susceptibility to COVID infection in women, with increasingly strong effects as women age.

SDR enzymes oxidize specific lipidic alkynylcarbinols into cytotoxic protein-reactive species

Hundreds of cytotoxic natural or synthetic lipidic compounds contain chiral alkynylcarbinol motifs, but the mechanism of action of those potential therapeutic agents remains unknown. Using a genetic screen in haploid human cells, we discovered that the enantiospecific cytotoxicity of numerous terminal alkynylcarbinols, including the highly cytotoxic dialkynylcarbinols, involves a bioactivation by HSD17B11, a short-chain dehydrogenase/reductase (SDR) known to oxidize the C-17 carbinol center of androstan-3-alpha,17-beta-diol to the corresponding ketone. A similar oxidation of dialkynylcarbinols generates dialkynylketones, that we characterize as highly protein-reactive electrophiles. We established that, once bioactivated in cells, the dialkynylcarbinols covalently modify several proteins involved in protein-quality control mechanisms, resulting in their lipoxidation on cysteines and lysines through Michael addition. For some proteins, this triggers their association to cellular membranes and results in endoplasmic reticulum stress, unfolded protein response activation, ubiquitin-proteasome system inhibition and cell death by apoptosis. Finally, as a proof-of-concept, we show that generic lipidic alkynylcarbinols can be devised to be bioactivated by other SDRs, including human RDH11 and HPGD/15-PGDH. Given that the SDR superfamily is one of the largest and most ubiquitous, this unique cytotoxic mechanism-of-action could be widely exploited to treat diseases, in particular cancer, through the design of tailored prodrugs.

Comparative transcriptomes of three different skin sites for the Asiatic toad (Bufo gargarizans)

Toads release toxic dry secretions from glands in their skin. Toxin possesses a wide range of biological effects, but little is known about its specific gene expression pattern and regulatory mechanisms. The Asiatic toad (Bufo gargarizans) is widely used to produce toxin. Here, we explored the gene expression of 30 tissue samples from three different skin sites (parotoid gland, dorsal skin, and abdomen skin) of B. gargarizans. After de novo assembly, 783,130 unigenes with an average length of 489 bp (N50 = 556 bp) were obtained. A total of 9,248 significant differentially expressed genes (DEGs) were detected. There were 8,819 DEGs between the parotoid gland and abdomen skin and 1,299 DEGs between the dorsal skin and abdomen skin, while only 1,283 DEGs were obtained between the parotoid gland and dorsal skin. Through enrichment analysis, it was found that the detected differential gene expressions corresponded to the different functions of different skin sites. Our key findings were the genetic expression of toxin secretion, the protection function of skin, and the related genes such as HSD3B, Cyp2c, and CAT, LGALS9. In conclusion, we provide useful transcript resources to study the gene expression and gene function of B. gargarizans and other amphibians. The detected DEGs between different sites of the skin provided better insights into the genetic mechanisms of toxin secretion and the protection function of skin for amphibians.

Seasonal shift of the gut microbiome synchronizes host peripheral circadian rhythm for physiological adaptation to a low-fat diet in the giant panda

Characteristics of the gut microbiome vary synchronously with changes in host diet. However, the underlying effects of these fluctuations remain unclear. Here, we performed fecal microbiota transplantation (FMT) of diet-specific feces from an endangered mammal (the giant panda) into a germ-free mouse model. We demonstrated that the butyrate-producing bacterium Clostridium butyricum was more abundant during shoot-eating season than during the leaf-eating season, congruent with the significant increase in host body mass. Following season-specific FMT, the microbiota of the mouse model resembled that of the donor, and mice transplanted with the microbiota from the shoot-eating season grew faster and stored more fat. Mechanistic investigations revealed that butyrate extended the upregulation of hepatic circadian gene Per2, subsequently increasing phospholipid biosynthesis. Validation experiments further confirmed this causal relationship. This study demonstrated that seasonal shifts in the gut microbiome affect growth performance, facilitating a deeper understanding of host-microbe interactions in wild mammals.

Outcomes Among African American and Non-Hispanic White Men With Metastatic Castration-Resistant Prostate Cancer With First-Line Abiraterone

IMPORTANCE

Prospective evidence suggests abiraterone is associated with superior progression-free survival for African American men compared with non-Hispanic White men with metastatic castration-resistant prostate cancer (mCRPC).

OBJECTIVE

To investigate differences in outcomes with first-line abiraterone therapy between African American and non-Hispanic White men with mCRPC in a national real-world cohort.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used a nationwide electronic health record-derived database of 3808 men receiving first-line therapy for mCRPC between January 1, 2012, and December 31, 2018. Data analysis was performed between January 1, 2020, and June 1, 2021. Median follow-up was 13 months (IQR, 7-22 months). Propensity score-based inverse probability of treatment weighting was applied to reduce imbalance in measured confounders between patients receiving first-line abiraterone vs other first-line therapies. Deidentified patient data originated from a geographically diverse set of approximately 280 cancer clinics (approximately 800 sites of care) throughout the United States. Participants had newly diagnosed mCRPC and were receiving first-line systemic therapy during the study period.

EXPOSURES

Receipt of abiraterone for first-line therapy.

MAIN OUTCOMES AND MEASURES

Overall survival from start of first-line treatment. Stratified analyses investigated overall survival within each race group, with first-line enzalutamide as the comparator.

RESULTS

Among 3808 patients with mCRPC, there were 2615 non-Hispanic White men (68.7%; mean [SD] age at diagnosis, 74 [8] years) and 404 African American men (10.6%; mean [SD] age at diagnosis, 69 [9] years), and 1729 patients (45.4%) in the cohort received first-line abiraterone. Among patients receiving first-line abiraterone, African American men had higher median overall survival than non-Hispanic White men (23 months [IQR, 10-37 months] vs 17 months [IQR, 9-32 months], respectively; inverse probability of treatment weighting hazard ratio, 0.76; 95% CI, 0.60-0.98). A race-by-treatment interaction existed for first-line abiraterone vs first-line enzalutamide (hazard ratio for abiraterone vs enzalutamide: non-Hispanic White men, 1.21 [95% CI, 1.06-1.38]; African American men, 1.05 [95% CI, 0.74-1.50]; interaction P = .02). There was no overall survival difference between first-line abiraterone and first-line enzalutamide among African American patients (24 vs 24 months, respectively; inverse probability of treatment weighting hazard ratio, 1.05; 95% CI, 0.74-1.50). First-line abiraterone was associated with decreased median overall survival relative to first-line enzalutamide among non-Hispanic White patients (17 months [IQR, 9-32 months] vs 20 months [IQR, 10-36 months], respectively; inverse probability of treatment weighting hazard ratio, 1.21; 95% CI, 1.06-1.38).

CONCLUSIONS AND RELEVANCE

In this cohort study of patients who received first-line systemic therapy for mCRPC, African American men who received abiraterone had improved overall survival compared with non-Hispanic White men. Future prospective studies should assess drivers of differential abiraterone outcomes in mCRPC between African American and non-Hispanic White men, including differences in genetic factors and socioeconomic status, to inform treatment strategies.

Regulatory genes in the androgen production, uptake and conversion (APUC) pathway in advanced prostate cancer

The androgen receptor (AR) signaling pathway regulates the progression of prostate cancer (PC). Metastatic castration-resistant prostate cancer (mCRPC) patients generally receive AR-targeted therapies (ART) or androgen-deprivation therapies (ADT) with the initial response; however, resistance is inevitably observed. Prior studies have shown activity and upregulation of a family of androgen production, uptake, and conversion - APUC genes - based on genomic analyses of patient germlines. Genetic variants of some APUC genes, such as the conversion gene, HSD3B1, predict response to second-generation androgen-targeted therapies. Studies have begun to elucidate the overall role of APUC genes, each with unique actionable enzymatic activity, in mCRPC patient outcomes. The current role and knowledge of the genetic and genomic features of APUC genes in advanced prostate cancer and beyond are discussed in this review. These studies inform of how interpreting behavior of APUC genes through genomic tools will impact the treatment of advanced prostate cancer.

Biomarkers for Treatment Response in Advanced Prostate Cancer

Simple Summary

Prostate cancer is a leading cause of cancer-related death among males. Many treatments are available to manage the disease, but despite this, ultimately advanced prostate cancer is incurable and fatal. In order to improve survival and minimize side effects from these various treatments, the treatments need to be given in an optimal sequence or combination. This optimal use of therapies must be individualized, and biomarkers can be used for these decisions. Biomarkers can be useful in predicting whether a patient will respond to a treatment option and may help avoid use of therapies that are not expected to be effective. Many biomarkers are already in clinical use while many others are currently being investigated and may become part of clinical practice in future. In this review, we discuss both established and novel biomarkers with a role in management of advanced prostate cancer.

Abstract

Multiple treatment options with different mechanisms of action are currently available for the management of metastatic prostate cancer. However, the optimal use of these therapies—specifically, the sequencing of therapies—is not well defined. In order to obtain the best clinical outcomes, patients need to be treated with the therapies that are most likely to provide benefit and avoid toxic therapies that are unlikely to be effective. Ideally, predictive biomarkers that allow for the selection of the therapies most likely to be of benefit would be employed for each treatment decision. In practice, biomarkers including tumor molecular sequencing, circulating tumor DNA, circulating tumor cell enumeration and androgen receptor characteristics, and tumor cell surface expression (PSMA), all may have a role in therapy selection. In this review, we define the established prognostic and predictive biomarkers for therapy in advanced prostate cancer and explore emerging biomarkers.

Clinical impact of HSD3B1 polymorphism by metastatic volume and somatic HSD3B1 alterations in advanced prostate cancer

This study aimed to investigate the significance of HSD3B1 gene status including germline polymorphism and somatic alterations in prostate cancer. Patients with prostate cancer treated with androgen-deprivation therapy, as well as tissues from metastatic prostate cancer, were included. Genomic DNA was extracted from cancer tissues and whole blood samples, and HSD3B1 (rs1047303, 1245C) was genotyped by Sanger sequencing. The association of HSD3B1 genotype with progression-free survival according to metastatic volume was examined. Copy number alteration and gene expression of HSD3B1 were examined in prostate cancer cells and public datasets. Among 194 patients, 121 and 73 patients were categorized into low- and high-volume diseases respectively. In multivariate analysis, the adrenal-permissive genotype (AC/CC) was significantly associated with increased risk of progression compared with the adrenal-restrictive genotype (AA) in low volume, but not high-volume diseases. Somatic mutation in HSD3B1 was detected at least in two cases of castration-resistant prostate cancer tissues. HSD3B1 amplification and overexpression were detected in castration-resistant prostate cancer cells and tissues. The current findings suggest that both germline and somatic alterations of HSD3B1 may cooperatively promote castration resistance in prostate cancer and HSD3B1 as a promising biomarker for precision medicine, warranting further investigations.

Adrenal-permissive HSD3B1 genetic inheritance and risk of estrogen-driven postmenopausal breast cancer

BACKGROUND

Genetics of estrogen synthesis and breast cancer risk has been elusive. The 1245A→C missense-encoding polymorphism in HSD3B1, which is common in White populations, is functionally adrenal permissive and increases synthesis of the aromatase substrate androstenedione. We hypothesized that homozygous inheritance of the adrenal-permissive HSD3B1(1245C) is associated with postmenopausal estrogen receptor–positive (ER-positive) breast cancer.

METHODS

A prospective study of postmenopausal ER-driven breast cancer was done for determination of HSD3B1 and circulating steroids. Validation was performed in 2 other cohorts. Adrenal-permissive genotype frequency was compared between postmenopausal ER-positive breast cancer, the general population, and postmenopausal ER-negative breast cancer.

RESULTS

Prospective and validation studies had 157 and 538 patients, respectively, for the primary analysis of genotype frequency by ER status in White female breast cancer patients who were postmenopausal at diagnosis. The adrenal-permissive genotype frequency in postmenopausal White women with estrogen-driven breast cancer in the prospective cohort was 17.5% (21/120) compared with 5.4% (2/37) for ER-negative breast cancer (P = 0.108) and 9.6% (429/4451) in the general population (P = 0.0077). Adrenal-permissive genotype frequency for estrogen-driven postmenopausal breast cancer was validated using Cambridge and The Cancer Genome Atlas data sets: 14.4% (56/389) compared with 6.0% (9/149) for ER-negative breast cancer (P = 0.007) and the general population (P = 0.005). Circulating androstenedione concentration was higher with the adrenal-permissive genotype (P = 0.03).

CONCLUSION

Adrenal-permissive genotype is associated with estrogen-driven postmenopausal breast cancer. These findings link genetic inheritance of endogenous estrogen exposure to estrogen-driven breast cancer.

FUNDING

National Cancer Institute, NIH (R01CA236780, R01CA172382, and P30-CA008748); and Prostate Cancer Foundation Challenge Award.

Three-month Prostate-specific Antigen Level After Androgen Deprivation Therapy Predicts Survival in Patients With Metastatic Castration-sensitive Prostate Cancer

BACKGROUND/AIM

Although upfront combination therapies with androgen deprivation are recommended for patients with castration-sensitive prostate cancer (CSPC), combination therapies may be excessive for some patients. The aim of this study was to identify patients with favorable outcome under androgen deprivation therapy (ADT) alone.

PATIENTS AND METHODS

This study consisted of 242 patients with CSPC who received ADT alone. The association between 3-month prostate-specific antigen (PSA) value after ADT and survival was analyzed.

RESULTS

The median overall survival for men with high-volume and/or high-risk cancer and those with low-volume low-risk cancer were 48.0 months and 103.0 months, respectively (p≤0.0001). Notably, in patients with low-volume low-risk cancer, the median overall survival for patients who achieved PSA ≤2 ng/ml at 3 months after ADT initiation was quite long at 112.0 months.

CONCLUSION

Conventional ADT may be sufficient and upfront combination therapy may be excessive for those patients with favorable outcome.

Clinical implications of genomic alterations in metastatic prostate cancer

There has been a rapid expansion in treatment options for the management of metastatic prostate cancer, but individual patient outcomes can be variable due to inter-patient tumor heterogeneity. Fortunately, the disease can be stratified on the basis of common somatic features, providing potential for the development of clinically useful prognostic and predictive biomarkers. Tissue biopsy programs and studies leveraging circulating tumor DNA (ctDNA) have revealed specific genomic alterations that are associated with aggressive disease biology. In this review, we discuss the potential for genomic subtyping to improve prognostication and to help guide treatment selection. We summarize data on associations between AR pathway alterations and patient response to AR signaling inhibitors and other standards of care. We describe the links between detection of different types of DNA damage repair defects and clinical outcomes with targeted therapies such as poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors or immune checkpoint inhibitors. PI3K signaling pathway inhibitors are also in advanced clinical development and we report upon the potential for these and other novel targeted therapies to have impact in specific molecular subsets of metastatic prostate cancer. Finally, we discuss the growing use of blood-based analytes for prognostic and predictive biomarker development, and summarize ongoing prospective biomarker-driven clinical trials.

Trilostane, a 3β-hydroxysteroid dehydrogenase inhibitor, suppresses growth of hepatocellular carcinoma and enhances anti-cancer effects of sorafenib

Background Human 3β-hydroxysteroid dehydrogenase type 1 (HSD3B1) is an enzyme associated with steroidogenesis, however its' role in hepatocellular carcinoma (HCC) biology is unknown. Trilostane is an inhibitor of HSD3B1 and has been tested as a treatment for patients with breast cancer but has not been studied in patients with HCC. Methods and Results The expression of HSD3B1 in HCC tumors in 57 patients were examined. A total of 44 out of 57 tumors (77.2%) showed increased HSD3B1 expression. The increased HSD3B1 in tumors was significantly associated with advanced HCC. In vitro, the knockdown of HSD3B1 expression in Mahlavu HCC cells by a short hairpin RNA (shRNA) led to significant decreases in colony formation and cell migration. The suppression of clonogenicity in the HSD3B1-knockdown HCC cells was reversed by testosterone and 17β-estradiol. Trilostane-mediated inhibition of HSD3B1 in different HCC cells also caused significant inhibition of clonogenicity and cell migration. In subcutaneous HCC Mahlavu xenografts, trilostane (30 or 60 mg/kg, intraperitoneal injection) significantly inhibited tumor growth in a dose-dependent manner. Furthermore, the combination of trilostane and sorafenib significantly enhanced the inhibition of clonogenicity and xenograft growth, surpassing the effects of each drug used alone, with no documented additional toxicity to animals. HSD3B1 blockade was found to suppress the phosphorylation of extracellular signal-regulated kinase (ERK). The decreased ERK phosphorylation was reversed by testosterone or 17b-estradiol. Conclusions Trilostane significantly inhibited the growth of HCC by inhibiting HSD3B1 function and augmenting the efficacy of sorafenib.

Hormonal Therapy for Prostate Cancer

Huggins and Hodges demonstrated the therapeutic effect of gonadal testosterone deprivation in the 1940s and therefore firmly established the concept that prostate cancer is a highly androgen-dependent disease. Since that time, hormonal therapy has undergone iterative advancement, from the types of gonadal testosterone deprivation to modalities that block the generation of adrenal and other extragonadal androgens, to those that directly bind and inhibit the androgen receptor (AR). The clinical states of prostate cancer are the product of a superimposition of these therapies with nonmetastatic advanced prostate cancer, as well as frankly metastatic disease. Today's standard of care for advanced prostate cancer includes gonadotropin-releasing hormone agonists (e.g., leuprolide), second-generation nonsteroidal AR antagonists (enzalutamide, apalutamide, and darolutamide) and the androgen biosynthesis inhibitor abiraterone. The purpose of this review is to provide an assessment of hormonal therapies for the various clinical states of prostate cancer. The advancement of today's standard of care will require an accounting of an individual's androgen physiology that also has recently recognized germline determinants of peripheral androgen metabolism, which include HSD3B1 inheritance.

Targeting backdoor androgen synthesis through AKR1C3 inhibition: A presurgical hormonal ablative neoadjuvant trial in high-risk localized prostate cancer

BACKGROUND

Localized prostate cancers (PCs) may resist neoadjuvant androgen receptor (AR)-targeted therapies as a result of persistent intraprostatic androgens arising through upregulation of steroidogenic enzymes. Therefore, we sought to evaluate clinical effects of neoadjuvant indomethacin (Indo), which inhibits the steroidogenic enzyme AKR1C3, in addition to combinatorial anti-androgen blockade, in men with high-risk PC undergoing radical prostatectomy (RP).

METHODS

This was an open label, single-site, Phase II neoadjuvant trial in men with high to very-high-risk PC, as defined by NCCN criteria. Patients received 12 weeks of apalutamide (Apa), abiraterone acetate plus prednisone (AAP), degarelix, and Indo followed by RP. Primary objective was to determine the pathologic complete response (pCR) rate. Secondary objectives included minimal residual disease (MRD) rate, defined as residual cancer burden (RCB) ≤ 0.25cm³ (tumor volume multiplied by tumor cellularity) and elucidation of molecular features of resistance.

RESULTS

Twenty patients were evaluable for the primary endpoint. Baseline median prostate-specific antigen (PSA) was 10.1 ng/ml, 4 (20%) patients had Gleason grade group (GG) 4 disease and 16 had GG 5 disease. At RP, 1 (5%) patient had pCR and 6 (30%) had MRD. Therapy was well tolerated. Over a median follow-up of 23.8 months, 1 of 7 (14%) men with pathologic response and 6 of 13 (46%) men without pathologic response had a PSA relapse. There was no association between prostate hormone levels or HSD3B1 genotype with pathologic response.

CONCLUSIONS

In men with high-risk PC, pCR rates remained low even with combinatorial AR-directed therapy, although rates of MRD were higher. Ongoing follow-up is needed to validate clinical outcomes of men who achieve MRD.

Epidemiology and genomics of prostate cancer in Asian men

Prostate cancer is a global health problem, but incidence varies considerably across different continents. Asia is traditionally considered a low-incidence area, but the incidence and mortality of prostate cancer have rapidly increased across the continent. Substantial differences in epidemiological features have been observed among different Asian regions, and incidence, as well as mortality-to-incidence ratio, is associated with the human development index. Prostate cancer mortality decreased in Japan and Israel from 2007 to 2016, but mortality has increased in Thailand, Kyrgyzstan and Uzbekistan over the same period. Genomic analyses have shown a low prevalence of ERG oncoprotein in the East Asian population, alongside a low rate of PTEN loss, high CHD1 enrichments and high FOXA1 alterations. Contributions from single-nucleotide polymorphisms to prostate cancer risk vary with ethnicity, but germline mutation rates of DNA damage repair genes in metastatic prostate cancer are comparable in Chinese and white patients from the USA and UK. Pharmacogenomic features of testosterone metabolism might contribute to disparities seen in the response to androgen deprivation between East Asian men and white American and European men. Overall, considerable diversity in epidemiology and genomics of prostate cancer across Asia defines disease characteristics in these populations, but studies in this area are under-represented in the literature. Taking into account this intracontinental and intercontinental heterogeneity, translational studies are required in order to develop ethnicity-specific treatment strategies.

Prostate Cancer Mortality Associated with Aggregate Polymorphisms in Androgen-Regulating Genes: The Atherosclerosis Risk in the Communities (ARIC) Study

Genetic variations in androgen metabolism may influence prostate cancer (PC) prognosis. Clinical studies consistently linked PC prognosis with four single nucleotide polymorphisms (SNPs) in the critical androgen-regulating genes: 3-beta-hydroxysteroid dehydrogenase (HSD3B1) rs1047303, 5-alpha-reductase 2 (SRD5A2) rs523349, and solute carrier organic ion (SLCO2B1) rs1789693 and rs12422149. We tested the association of four androgen-regulating SNPs, individually and combined, with PC-specific mortality in the ARIC population-based prospective cohort. Men diagnosed with PC (N = 622; 79% White, 21% Black) were followed for death (N = 350) including PC death (N = 74). Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95%CI adjusting for center, age, stage, and grade at diagnosis using separate hazards for races. A priori genetic risk score (GRS) was created as the unweighted sum of risk alleles in the four pre-selected SNPs. The gain-of-function rs1047303C allele was associated PC-specific mortality among men with metastatic PC at diagnosis (HR = 4.89 per risk allele, p = 0.01). Higher GRS was associated with PC-specific mortality (per risk allele: HR = 1.26, p = 0.03). We confirmed that the gain-of-function allele in HSD3B1 rs1047303 is associated with greater PC mortality in men with metastatic disease. Additionally, our findings suggest a cumulative effect of androgen-regulating genes on PC-specific mortality; however, further validation is required.

Genetic Polymorphisms and Pharmacotherapy for Prostate Cancer

The therapeutic landscape of pharmacotherapy for prostate cancer has dramatically evolved, and multiple therapeutic options have become available for prostate cancer patients. Therefore, useful biomarkers to identify suitable candidates for treatment are required to maximize the efficacy of pharmacotherapy. Genetic polymorphisms such as single-nucleotide polymorphisms (SNPs) and tandem repeats have been shown to influence the therapeutic effects of pharmacotherapy for prostate cancer patients. For example, genetic polymorphisms in the genes involved in androgen receptor signaling are reported to be associated with the therapeutic outcome of androgen-deprivation therapy as well as androgen receptor-pathway inhibitors. In addition, SNPs in genes involved in drug metabolism and efflux pumps are associated with therapeutic effects of taxane chemotherapy. Thus, genetic polymorphisms such as SNPs are promising biomarkers to realize personalized medicine. Here, we overview the current findings on the influence of genetic polymorphisms on the outcome of pharmacotherapy for prostate cancer and discuss current issues as well as future visions in this field.

Management of Advanced Prostate Cancer in Clinical Practice: Real-World Answers to Challenging Dilemmas

Advanced prostate cancer is a continuum of states distinguished by the presence or absence of metastasis and sensitivity or resistance to androgen deprivation therapy (ADT). Therapeutic options for this disease continue to rapidly evolve, making it a challenge to apply results of clinical trial data to daily patient management. One question relevant to providers is whether molecular biomarkers predictive of response or resistance to therapies are available to guide clinical treatment decisions. Other salient topics include the timing of therapy initiation in patients with biochemical recurrence, treatment approach in low-volume versus high-volume metastatic castrate-sensitive prostate cancer, types of agents available beyond ADT, and timing of their use in men with nonmetastatic castrate-resistant prostate cancer as well as whether sequencing of therapies in metastatic castrate-resistant prostate cancer matters. Additionally, familiarity with emerging treatment strategies is important. This review addresses the gray areas and challenging questions in advanced prostate cancer management that frequently arise in clinical practice.

Treatment and resistance mechanisms in castration-resistant prostate cancer: new implications for clinical decision making?

Introduction: The armamentarium of treatment options in metastatic and non-metastatic CRPC is rapidly evolving. However, the question of how individual treatment decisions should be balanced by available predictive clinical parameters, pharmacogenetic and drug interaction profiles, or compound-associated molecular biomarkers is a major challenge for clinical practice.Areas covered: We discuss treatment and resistance mechanisms in PC with regard to their association to drug efficacy and tolerability. Current efforts of combination treatment and putative predictive biomarkers of available and upcoming compounds are highlighted with regard to their implication on clinical decision-making.Expert opinion: Several treatment approaches are delineated, where identification of resistance mechanisms in CRPC may guide treatment selection. To date, most of these candidate biomarkers will however be found only in a small subset of patients. While current approaches of combination treatment in CRPC are proving synergistic effects on cancer biology, higher complexity with regard to biomarker analysis and interaction profiles of the respective compounds may be expected. Among other aspects of personalized treatment, consideration of drug-drug interaction and pharmacogenetics is an underrepresented issue. However, the non-metastatic castration resistant prostate cancer situation may be an example for treatment selection based on drug interaction profiles in the future.

Germline HSD3B1 Genetics and Prostate Cancer Outcomes

Dihydrotestosterone synthesis in prostate cancer from adrenal DHEA/DHEA-sulfate requires enzymatic conversion in tumor tissues. 3β-hydroxysteroid dehydrogenase-1 is an absolutely necessary enzyme for such dihydrotestosterone synthesis and is encoded by the gene HSD3B1 which comes in 2 functional inherited forms described in 2013. The adrenal-permissive HSD3B1(1245C) allele allows for rapid dihydrotestosterone synthesis. The adrenal-restrictive HSD3B1(1245A) allele limits androgen synthesis. Studies from multiple cohorts show that adrenal-permissive allele inheritance confers worse outcomes and shorter survival after castration in low-volume prostate cancer and poor outcomes after abiraterone or enzalutamide treatment for castration-resistant prostate cancer. Here, we review the clinical data and implications.

Through the Looking-Glass: Reevaluating DHEA Metabolism Through HSD3B1 Genetics

Dehydroepiandrosterone (DHEA) and DHEA sulfate together are abundant adrenal steroids whose physiological effects are mediated through their conversion to potent downstream androgens. 3β-Hydroxysteroid dehydrogenase isotype 1 (3βHSD1) facilitates the rate-limiting step of DHEA metabolism and gates the flux of substrate into the distal portion of the androgen synthesis pathway. Notably, a germline, missense-encoding change, HSD3B1(1245C), results in expression of 3βHSD1 protein that is resistant to degradation, yielding greater potent androgen production in the periphery. In contrast, HSD3B1(1245A) encodes 3βHSD1 protein that is easily degraded, limiting peripheral androgen synthesis. These adrenal-permissive (AP) and adrenal-restrictive (AR) alleles have recently been associated with divergent outcomes in androgen-sensitive disease states, underscoring the need to reevaluate DHEA metabolism using HSD3B1 genetics.

Examining HSD3B1 as a possible biomarker to detect prostate cancer patients who are likely to progress on ADT

The Chemohormonal Therapy vs Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) was a randomized phase III trial that evaluated the outcomes of men with metastatic prostate cancer who received castration with or without docetaxel. Patients from this trial were genotyped in a recent study to detect HSD3B1 variance and to determine 2-y freedom from castration-resistant prostate cancer as well as overall survival. The results of this study identified HSD3B1 as a possible biomarker that can be used to predict response to therapy in patients with metastatic disease.