The UGT2B28 Sex-steroid Inactivation Pathway Is a Regulator of Steroidogenesis and Modifies the Risk of Prostate Cancer Progression

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.

The Uridine diphosphate (UDP)-glycosyltransferases (UGTs) superfamily: the role in tumor cell metabolism

UDP-glycosyltransferases (UGTs), important enzymes in biotransformation, control the levels and distribution of numerous endogenous signaling molecules and the metabolism of a wide range of endogenous and exogenous chemicals. The UGT superfamily in mammals consists of the UGT1, UGT2, UGT3, and UGT8 families. UGTs are rate-limiting enzymes in the glucuronate pathway, and in tumors, they are either overexpressed or underexpressed. Alterations in their metabolism can affect gluconeogenesis and lipid metabolism pathways, leading to alterations in tumor cell metabolism, which affect cancer development and prognosis. Glucuronidation is the most common mammalian conjugation pathway. Most of its reactions are mainly catalyzed by UGT1A, UGT2A and UGT2B. The body excretes UGT-bound small lipophilic molecules through the bile, urine, or feces. UGTs conjugate a variety of tiny lipophilic molecules to sugars, such as galactose, xylose, acetylglucosamine, glucuronic acid, and glucose, thereby inactivating and making water-soluble substrates, such as carcinogens, medicines, steroids, lipids, fatty acids, and bile acids. This review summarizes the roles of members of the four UGT enzyme families in tumor function, metabolism, and multiple regulatory mechanisms, and its Inhibitors and inducers. The function of UGTs in lipid metabolism, drug metabolism, and hormone metabolism in tumor cells are among the most important topics covered.

Extensive metabolic consequences of human glycosyltransferase gene knockouts in prostate cancer

BACKGROUND

Naturally occurring germline gene deletions (KO) represent a unique setting to interrogate gene functions. Complete deletions and differential expression of the human glycosyltransferase UGT2B17 and UGT2B28 genes are linked to prostate cancer (PCa) risk and progression, leukaemia, autoimmune and other diseases.

METHODS

The systemic metabolic consequences of UGT deficiencies were examined using untargeted and targeted mass spectrometry-based metabolomics profiling of carefully matched, treatment-naive PCa cases.

RESULTS

Each UGT KO differentially affected over 5% of the 1545 measured metabolites, with divergent metabolic perturbations influencing the same pathways. Several of the perturbed metabolites are known to promote PCa growth, invasion and metastasis, including steroids, ceramides and kynurenine. In UGT2B17 KO, reduced levels of inactive steroid-glucuronides were compensated by sulfated derivatives that constitute circulating steroid reservoirs. UGT2B28 KO presented remarkably lower levels of oxylipins paralleled by reduced inflammatory mediators, but higher ceramides unveiled as substrates of the enzyme in PCa cells.

CONCLUSION

The distinctive and broad metabolic rewiring caused by UGT KO reinforces the need to examine their unique and divergent functions in PCa biology.

The Glycosyltransferase Pathway: An Integrated Analysis of the Cell Metabolome

Nucleotide sugar-dependent glycosyltransferases (UGTs) are critical to the homeostasis of endogenous metabolites and the detoxification of xenobiotics. Their impact on the cell metabolome remains unknown. Cellular metabolic changes resulting from human UGT expression were profiled by untargeted metabolomics. The abundant UGT1A1 and UGT2B7 were studied as UGT prototypes along with their alternative (alt.) splicing-derived isoforms displaying structural differences. Nineteen biochemical routes were modified, beyond known UGT substrates. Significant variations in glycolysis and pyrimidine pathways, and precursors of the co-substrate UDP-glucuronic acid were observed. Bioactive lipids such as arachidonic acid and endocannabinoids were highly enriched by up to 13.3-fold (p < 0.01) in cells expressing the canonical enzymes. Alt. UGT2B7 induced drastic and unique metabolic perturbations, including higher glucose (18-fold) levels and tricarboxylic acid cycle (TCA) cycle metabolites and abrogated the effects of the UGT2B7 canonical enzyme when co-expressed. UGT1A1 proteins promoted the accumulation of branched-chain amino acids (BCAA) and TCA metabolites upstream of the mitochondrial oxoglutarate dehydrogenase complex (OGDC). Alt. UGT1A1 exacerbated these changes, likely through its interaction with the OGDC component oxoglutarate dehydrogenase-like (OGDHL). This study expands the breadth of biochemical pathways associated with UGT expression and establishes extensive connectivity between UGT enzymes, alt. proteins and other metabolic processes.

Uridine Diphosphate Glucuronosyl Transferase 2B28 (UGT2B28) Promotes Tumor Progression and Is Elevated in African American Prostate Cancer Patients

Prostate cancer (PCa) is the second most diagnosed cancer in the United States and is associated with metabolic reprogramming and significant disparities in clinical outcomes among African American (AA) men. While the cause is likely multi-factorial, the precise reasons for this are unknown. Here, we identified a higher expression of the metabolic enzyme UGT2B28 in localized PCa and metastatic disease compared to benign adjacent tissue, in AA PCa compared to benign adjacent tissue, and in AA PCa compared to European American (EA) PCa. UGT2B28 was found to be regulated by both full-length androgen receptor (AR) and its splice variant, AR-v7. Genetic knockdown of UGT2B28 across multiple PCa cell lines (LNCaP, LAPC-4, and VCaP), both in androgen-replete and androgen-depleted states resulted in impaired 3D organoid formation and a significant delay in tumor take and growth rate of xenograft tumors, all of which were rescued by re-expression of UGT2B28. Taken together, our findings demonstrate a key role for the UGT2B28 gene in promoting prostate tumor growth.

The Expression Profiles and Deregulation of UDP-Glycosyltransferase (UGT) Genes in Human Cancers and Their Association with Clinical Outcomes

The human UDP-glycosyltransferase (UGTs) superfamily has 22 functional enzymes that play a critical role in the metabolism of small lipophilic compounds, including carcinogens, drugs, steroids, lipids, fatty acids, and bile acids. The expression profiles of UGT genes in human cancers and their impact on cancer patient survival remains to be systematically investigated. In the present study, a comprehensive analysis of the RNAseq and clinical datasets of 9514 patients from 33 different TCGA (the Genome Cancer Atlas) cancers demonstrated cancer-specific UGT expression profiles with high interindividual variability among and within individual cancers. Notably, cancers derived from drug metabolizing tissues (liver, kidney, gut, pancreas) expressed the largest number of UGT genes (COAD, KIRC, KIRP, LIHC, PAAD); six UGT genes (1A6, 1A9, 1A10, 2A3, 2B7, UGT8) showed high expression in five or more different cancers. Kaplan-Meier plots and logrank tests revealed that six UGT genes were significantly associated with increased overall survival (OS) rates [UGT1A1 (LUSC), UGT1A6 (ACC), UGT1A7 (ACC), UGT2A3 (KIRC), UGT2B15 (BLCA, SKCM)] or decreased OS rates [UGT2B15 (LGG), UGT8 (UVM)] in specific cancers. Finally, differential expression analysis of 611 patients from 12 TCGA cancers identified 16 UGT genes (1A1, 1A3, 1A6, 1A7, 1A8, 1A9, 1A10, 2A1, 2A3, 2B4, 2B7, 2B11, 2B15, 3A1, 3A2, UGT8) that were up/downregulated in at least one cancer relative to normal tissues. In conclusion, our data show widespread expression of UGT genes in cancers, highlighting the capacity for intratumoural drug metabolism through the UGT conjugation pathway. The data also suggests the potentials for specific UGT genes to serve as prognostic biomarkers or therapeutic targets in cancers.

Alternative promoters control UGT2B17-dependent androgen catabolism in prostate cancer and its influence on progression

BACKGROUND

Perturbation of the major UGT2B17-dependent androgen catabolism pathway has the potential to affect prostate cancer (PCa) progression. The objective was to evaluate UGT2B17 protein expression in primary tumours in relation to hormone levels, disease characteristics and cancer evolution.

METHODS

We conducted an analysis of a high-density prostate tumour tissue microarray consisting of 239 localised PCa cases treated by radical prostatectomy (RP). Cox proportional hazard ratio analysis was used to evaluate biochemical recurrence (BCR), and a linear regression model evaluated variations in circulating hormone levels measured by mass spectrometry. The transcriptome of UGT2B17 in PCa was established by using RNA-sequencing data.

RESULTS

UGT2B17 expression in primary tumours was associated with node-positive disease at RP and linked to circulating levels of 3α-diol-17 glucuronide, a major circulating DHT metabolite produced by the UGT2B17 pathway. UGT2B17 was an independent prognostic factor linked to BCR after RP, and its overexpression was associated with development of metastasis. Finally, we demonstrated that distinctive alternative promoters dictate UGT2B17-dependent androgen catabolism in localised and metastatic PCa.

CONCLUSIONS

The androgen-inactivating gene UGT2B17 is controlled by overlooked regulatory regions in PCa. UGT2B17 expression in primary tumours influences the steroidome, and is associated with relevant clinical outcomes, such as BCR and metastasis.

Emerging roles for UDP-glucuronosyltransferases in drug resistance and cancer progression

The best-known role of UDP-glucuronosyltransferase enzymes (UGTs) in cancer is the metabolic inactivation of drug therapies. By conjugating glucuronic acid to lipophilic drugs, UGTs impair the biological activity and enhance the water solubility of these agents, driving their elimination. Multiple clinical observations support an expanding role for UGTs as modulators of the drug response and in mediating drug resistance in numerous cancer types. However, accumulating evidence also suggests an influence of the UGT pathway on cancer progression. Dysregulation of the expression and activity of UGTs has been associated with the progression of several cancers, arguing for UGTs as possible mediators of oncogenic pathways and/or disease accelerators in a drug-naive context. The consequences of altered UGT activity on tumour biology are incompletely understood. They might be associated with perturbed levels of bioactive endogenous metabolites such as steroids and bioactive lipids that are inactivated by UGTs or through non-enzymatic mechanisms, thereby eliciting oncogenic signalling cascades. This review highlights the evidence supporting dual roles for the UGT pathway, affecting cancer progression and drug resistance. Pharmacogenomic testing of UGT profiles in patients and the development of therapeutic options that impair UGT actions could provide useful prognostic and predictive biomarkers and enhance the efficacy of anti-cancer drugs.

Revealing Metabolic Liabilities of Ralaniten To Enhance Novel Androgen Receptor Targeted Therapies

Inhibition of the androgen receptor (AR) is the mainstay treatment for advanced prostate cancer. Ralaniten (formally EPI-002) prevents AR transcriptional activity by binding to its N-terminal domain (NTD) which is essential for transcriptional activity. Ralaniten acetate (EPI-506) the triacetate pro-drug of ralaniten, remains the only AR-NTD inhibitor to have entered clinical trials (NCT02606123). While well tolerated, the trial was ultimately terminated due to poor pharmacokinetic properties and resulting pill burden. Here we discovered that ralaniten was glucuronidated which resulted in decreased potency. Long-term treatment of prostate cancer cells with ralaniten results in upregulation of UGT2B enzymes with concomitant loss of potency. This has proven to be a useful model with which to facilitate the development of more potent second-generation AR-NTD inhibitors. Glucuronidated metabolites of ralaniten were also detected in the serum of patients in Phase 1 clinical trials. Therefore, we tested an analogue of ralaniten (EPI-045) which was resistant to glucuronidation and demonstrated superiority to ralaniten in our resistant model. These data support that analogues of ralaniten designed to mitigate glucuronidation may optimize clinical responses to AR-NTD inhibitors.

Ages of hepatocellular carcinoma occurrence and life expectancy are associated with a UGT2B28 genomic variation

Background

Hepatocellular carcinoma (HCC) is an aggressive solid tumor. HCC occurred at younger and elder ages were considered driven by different oncogenic mechanisms, and they demonstrated distinct clinical courses.

Methods

A total of 382 HCC patients treated by surgical resections was analyzed.

Results

A univariate-multivariate analysis showed that viral etiology (chronic hepatitis B, C) and the UDP glucuronosyltransferase family 2 member B28 (UGT2B28) genomic variant rs2132039 were independently associated with the age at presentation of HCC (all adjusted P < 0.05). An extensive evaluations of clinicalpathological factors showed that the age (Odds ratio [OR], 1.016; 95% confidence interval [CI], 1.001–1.032; adjusted P = 0.037) and ascites (OR, 3.505; CI, 1.358–9.048; adjusted P = 0.010) were two independent factors associated with this genomic variant. The age was 54.1 ± 14.6 years for patients with the “TT” variant type, and 58.2 ± 13.7 years for those with the “Non-TT” variant type. The age disparity was most prominent in alcoholic patients (OR, 1.079; CI, 1.035–1.125; P < 0.001, age of “TT”, 49.6 ± 12.2; age of “non-TT”, 59.3 ± 10.7). This genomic variant was also associated with age of recurrence (P = 0.025), distant metastasis (P = 0.024) and HCC-related death (P = 0.008) in non-censored patients.

Conclusions

An UGT2B28 genomic variant was indicative of the age of HCC presentation, recurrence, distant metastasis and death.

JAB1/COPS5 is a putative oncogene that controls critical oncoproteins deregulated in prostate cancer

Recent evidence support that the c-Jun activation domain-binding protein 1 (JAB1)/COPS5 has an oncogenic function in various tissues. We show that JAB1 amplification in human prostate cancer (PCa) correlates with reduced overall survival and disease-free progression. Immunohistochemical staining shows enhanced expression of JAB1 in the cytoplasmic compartment of PCa cells compared to the normal prostate epithelium, indicating the activity/function of JAB1 is altered in PCa. To test the function of JAB1 in PCa, we efficiently silenced JAB1 expression using four unique shRNAs in three PCa cell lines (LNCaP, C4-2, and PC-3) and an immortalized prostate epithelial cell line, RWPE-1. Our data clearly show that silencing JAB1 robustly suppresses the growth of PCa cells, but not RWPE-1 cells, suggesting that PCa cells become addicted to JAB1. To study the potential mechanism by which JAB1 controls PCa growth, we profiled gene expression changes by whole transcriptome microarray analysis of C4-2 cells silenced for JAB1 using a pool of 3 shRNAs compared to scrambled shRNA control. We identified 1268 gene changes ≥1.5 fold by silencing JAB1 in C4-2. Western blot confirmation and bioinformatics pathway analyses support that PCa cells become addicted to JAB1 through controlling the following signaling pathways: cell cycle, p53 signaling, DNA replication, TGF-β/BMP, MAPK, TNF, and steroid hormone biosynthesis. We propose that UGT2B28, UGT2B10, UGT2B11, Skp2, EZH2, MDM2, BIRC5 (Survivin), UBE2C, and Smads 1/5/8, which are all associated with the abovementioned key oncogenic pathways, may play critical roles in the putative oncogenic function of JAB1 in PCa.

Factors Affecting Interindividual Variability of Hepatic UGT2B17 Protein Expression Examined Using a Novel Specific Monoclonal Antibody

Accurate quantification of the metabolic enzyme uridine diphospho-glucuronosyltransferase (UGT) UGT2B17 has been hampered by the high sequence identity with other UGT2B enzymes (as high as 94%) and by the lack of a specific antibody. Knowing the significance of the UGT2B17 pathway in drug and hormone metabolism and cancer, we developed a specific monoclonal antibody (EL-2B17mAb), initially validated by the lack of detection in liver microsomes of an individual carrying no UGT2B17 gene copy and in supersomes expressing UGT2B enzymes. Immunohistochemical detection in livers revealed strong labeling of bile ducts and variable labeling of hepatocytes. Expression levels assessed by immunoblotting were highly correlated to mass spectrometry-based quantification (r = 0.93), and three major expression patterns (absent, low, or high) were evidenced. Livers with very low expression were carriers of the functional rs59678213 G variant, located in the binding site for the transcription factor forkhead box A1 (FOXA1) of the UGT2B17 promoter. The highest level of expression was observed for individuals carrying at least one rs59678213 A allele. Multiple regression analysis indicated that the number of gene copies explained only 8% of UGT2B17 protein expression, 49% when adding rs59678213, reaching 54% when including sex. The novel EL-2B17mAb antibody allowed specific UGT2B17 quantification and exposed different patterns of hepatic expression. It further suggests that FOXA1 is a key driver of UGT2B17 expression in the liver. The availability of this molecular tool will help characterize the UGT2B17 level in various disease states and establish more precisely the contribution of the UGT2B17 enzyme to drug and hormone metabolism.

The UDP-Glycosyltransferase (UGT) Superfamily: New Members, New Functions, and Novel Paradigms

UDP-glycosyltransferases (UGTs) catalyze the covalent addition of sugars to a broad range of lipophilic molecules. This biotransformation plays a critical role in elimination of a broad range of exogenous chemicals and by-products of endogenous metabolism, and also controls the levels and distribution of many endogenous signaling molecules. In mammals, the superfamily comprises four families: UGT1, UGT2, UGT3, and UGT8. UGT1 and UGT2 enzymes have important roles in pharmacology and toxicology including contributing to interindividual differences in drug disposition as well as to cancer risk. These UGTs are highly expressed in organs of detoxification (e.g., liver, kidney, intestine) and can be induced by pathways that sense demand for detoxification and for modulation of endobiotic signaling molecules. The functions of the UGT3 and UGT8 family enzymes have only been characterized relatively recently; these enzymes show different UDP-sugar preferences to that of UGT1 and UGT2 enzymes, and to date, their contributions to drug metabolism appear to be relatively minor. This review summarizes and provides critical analysis of the current state of research into all four families of UGT enzymes. Key areas discussed include the roles of UGTs in drug metabolism, cancer risk, and regulation of signaling, as well as the transcriptional and posttranscriptional control of UGT expression and function. The latter part of this review provides an in-depth analysis of the known and predicted functions of UGT3 and UGT8 enzymes, focused on their likely roles in modulation of levels of endogenous signaling pathways.

GLI1-Inducible Glucuronidation Targets a Broad Spectrum of Drugs

Cancer therapies are plagued by resistance. Previously, we discovered a novel form of cancer drug resistance where the Glioma-associated protein 1 (GLI1) elevates UGT1A glucuronidation enzymes, thereby glucuronidating cytarabine and ribavirin, leading to resistance in leukemia patients. Here, we demonstrate that GLI1 imparts resistance to ∼40 compounds, including FDA-approved drugs with disparate chemotypes ( e.g., methotrexate and venetoclax). GLI1 indirectly elevates UGT1As via the chaperone calreticulin, which is required for resistance. Further, we demonstrate that resistant cells are more sensitive to ATP inhibitors, suggesting an Achilles' heel, which could be exploited in the future. In all, we identify GLI1-inducible glucuronidation as a broad-spectrum multidrug resistance pathway.

A Comprehensive Analysis of Steroid Hormones and Progression of Localized High-Risk Prostate Cancer

BACKGROUND

In men with localized prostate cancer who are undergoing radical prostatectomy (RP), it is uncertain whether their systemic hormonal environment is associated with outcomes. The objective of the study was to examine the association between the circulating steroid metabolome with prognostic factors and progression.

METHODS

The prospective PROCURE cohort was recruited from 2007 to 2012, and comprises 1,766 patients with localized prostate cancer who provided blood samples prior to RP. The levels of 15 steroids were measured in plasma using mass spectrometry, and their association with prognostic factors and disease-free survival (DFS) was established with logistic regression and multivariable Cox proportional hazard models.

RESULTS

The median follow-up time after surgery was 73.2 months. Overall, 524 patients experienced biochemical failure and 75 developed metastatic disease. Testosterone and androsterone levels were higher in low-risk disease. Associations were observed between adrenal precursors and risk of cancer progression. In high-risk patients, a one-unit increment in log-transformed androstenediol (A5diol) and dehydroepiandrosterone-sulfate (DHEA-S) levels were linked to DFS with HR of 1.47 (P = 0.0017; q = 0.026) and 1.24 (P = 0.043; q = 0.323), respectively. Although the number of metastatic events was limited, trends with metastasis-free survival were observed for A5diol (HR = 1.51; P = 0.057) and DHEA-S levels (HR = 1.43; P = 0.054).

CONCLUSIONS

In men with localized prostate cancer, our data suggest that the preoperative steroid metabolome is associated with the risk of recurrence of high-risk disease.

IMPACT

The associations of adrenal androgens with progression of localized high-risk disease could help refine hormonal strategies for these patients.

Whole exome sequencing identifies hemizygous deletions in the UGT2B28 and USP17L2 genes in a three‑generation family with endometriosis

Endometriosis is an enigmatic condition with an unknown etiology and a poorly understood pathogenesis. It is considered to appear from the interplay of many genetic and environmental factors, affecting up to 10% of women and represents a major cause of pain and infertility. The familial association of endometriosis, as demonstrated through monozygotic twin and family studies suggests a genetic contribution to the disease, with further case-control and genome-wide association studies (GWAS) detecting various endometriosis risk factors. In a recent study, we described a unique, three-generation family of Cretan origin (Greece) with 7 females with surgically confirmed endometriosis (grandmother, 3 daughters and 3 granddaughters). All the affected members of this family displayed a variety of clinical manifestations and complications. In the present study, to further analyze the genetic variants conferring the risk of developing endometriosis, whole exome sequencing (WES) was performed, using the AmpliSeq technology on the Ion Proton platform. An initial analysis of 64 variants that were detected across the 14 genes previously confirmed to be associated with endometriosis, did not identify any deleterious exonic variants in these genes. However, further analysis revealed 2 hemizygous deletions in the grandmother that segregate in several of her affected offspring. The first deletion was found in the UGT2B28 locus, spanning 7 informative sequence variants across at least 14 kb. The second deletion, located in USP17L2, spans 3 informative variants across at least 2 kb. On the whole, the findings of the presents study implicate 2 additional genes in the pathogenesis of endometriosis, apart from those already identified by GWAS.

A Multi-Institutional Validation of Gleason Score Derived from Tissue Microarray Cores

To test the agreement between high-grade PCa at RP and TMA, and the ability of TMA to predict BCR. Validation of concordance between tissue microarray (TMA) and radical prostatectomy (RP) high-grade prostate cancer (PCa) is crucial because latter determines the treated natural history of PCa. We hypothesized that TMA Gleason score is in agreement with RP pathology and capable of accurately predicting biochemical recurrence (BCR). Data were provided from a multi-institutional Canadian sample of 1333 TMA and RP specimens with complete clinicopathological data. First, rate of agreement between TMA and high-grade Gleason at RP or biopsy and RP was tested. Second, ability of RP, TMA and biopsy to predict BCR was compared. Multivariable (MVA) Cox regression models were fitted and BCR rates were illustrated with Kaplan-Meier plots. Agreement between RP and TMA and between RP and biopsy was 72.6% (95% CI:69.7-75.5) and 60.4% (95% CI:57.2-63.6), respectively. In MVA predicting BCR, the accuracy for RP, TMA and biopsy was 0.73, 0.72 and 0.68, respectively. TMA added discriminatory ability among exclusively low-grade Gleason RP patients (p = 0.02), but did not improve BCR discrimination in exclusive high-grade PCa RP patients (p = 0.8). TMA Gleason grade accurately reflects presence of high-grade Gleason in RP specimen, accurately predicts BCR rates after RP and improves prediction of BCR in low-grade Gleason patients at RP.

Serum Steroid Ratio Profiles in Prostate Cancer: A New Diagnostic Tool Toward a Personalized Medicine Approach

BACKGROUND

Serum steroids are crucial molecules altered in prostate cancer (PCa). Mass spectrometry (MS) is currently the elected technology for the analysis of steroids in diverse biological samples. Steroids have complex biological pathways and stoichiometry and it is important to evaluate their quantitative ratio. MS applications to patient hormone profiling could lead to a diagnostic approach.

METHODS

Here, we employed the Surface Activated Chemical Ionization-Electrospray-NIST (SANIST) developed in our laboratories, to obtain quantitative serum steroid ratio relationship profiles with a machine learning Bayesian model to discriminate patients with PCa. The approach is focused on steroid relationship profiles and disease association.

RESULTS

A pilot study on patients affected by PCa, benign prostate hypertrophy (BPH), and control subjects [prostate-specific antigen (PSA) lower than 2.5 ng/mL] was done in order to investigate the classification performance of the SANIST platform. The steroid profiles of 71 serum samples (31 controls, 20 patients with PCa and 20 subjects with benign prostate hyperplasia) were evaluated. The levels of 10 steroids were quantitated on the SANIST platform: Aldosterone, Corticosterone, Cortisol, 11-deoxycortisol, Androstenedione, Testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), 17-OH-Progesterone and Progesterone. We performed both traditional and a machine learning analysis.

CONCLUSION

We show that the machine learning approach based on the steroid relationships developed here was much more accurate than the PSA, DHEAS, and direct absolute value match method in separating the PCa, BPH and control subjects, increasing the sensitivity to 90% and specificity to 84%. This technology, if applied in the future to a larger number of samples will be able to detect the individual enzymatic disequilibrium associated with the steroid ratio and correlate it with the disease. This learning machine approach could be valid in a personalized medicine setting.

Identification of SPOP related metabolic pathways in prostate cancer

Speckle-type POZ protein (SPOP), as a cullin-based E3 ubiquitin ligase, has been identified as one of the most frequently mutated genes in prostate cancer (PCa). However, whether SPOP mutations contribute to metabolic reprogramming in PCa remains unknown. Here, integrated studies of transcriptomics and metabolomics as well as lipidomics were performed in matched PCa tumor (PCT) and adjacent non-tumor (ANT) tissues, followed by correlation analysis of SPOP mutations with altered metabolic pathways in SPOP-mutated PCa patients. Interestingly, transcriptomics profiling showed that all SPOP mutations (with 16.7% frequency, 11/66) occurred at the conserved residues in the substrate binding domain of meprin and TRAF homology (MATH). The results of integrated analysis indicated that three metabolic pathways, including tricarboxylic acid (TCA) cycle, fatty acid metabolism and glycerophospholipid metabolism, exhibited obvious upregulation in SPOP-mutated PCT tissues. Furthermore, both correlation analyses based on integrated data and cBioportal revealed that FH, ELOVL2 and ACADL genes might be involved in SPOP-mutation-related upregulation of these metabolic pathways. Taken together, our study provided new insights in understanding the relationship between metabolic pathways and SPOP mutations in PCa.

Genetic variations in UGT2B28, UGT2B17, UGT2B15 genes and the risk of prostate cancer: A case-control study

Glucuronidation is a major pathway for elimination of exogenous and endogenous compounds such as environmental carcinogens and androgens from the body. This biochemical pathway is mediated by enzymes called uridine diphosphoglucuronosyltransferases (UGTs). Null (del/del) genes polymorphisms in UGT2B17, and UGT2B28 and D85Y single-nucleotide polymorphism (SNP) of UGT2B15 have been reported to increase the risk of prostate cancer. The goal of this study was to determine the association of mentioned genetic variants with the risk of prostate cancer. We investigated the copy number variations (CNVs) of UGT2B17 and UGT2B28 loci and the association between rs1902023 polymorphism of UGT2B15 gene in 360 subjects consisted of 120 healthy controls, 120 prostate cancer (PC) patients and 120 benign prostatic hyperplasia (BPH) patients. No association was detected for the mentioned polymorphisms and the risk of PC. However, a significant association was detected between UGT2B17 copy number variation and BPH risk (OR=2.189; 95% CI, 1.303-3.675; p=0.003). Furthermore, we observed that the D85Y polymorphism increases the risk of BPH when analyzed in combination with the copy number variation of UGT2B17 gene (OR=0.135; 95% CI, 0.036-0.512; p=0.003). Our findings suggest that the D85Y polymorphism of UGT2B15 and CNVs in UGT2B28 and UGT2B17 genes is not associated with prostate cancer risk in Iranian patients. To our knowledge, this is the first report that implicates the role of CNV of UGT2B17 gene in BPH.

UDP-glucuronosyltransferases and biochemical recurrence in prostate cancer progression

Background

Uridine 5′-diphosphate-glucuronosyltransferase 2B (UGT2B) genes code for enzymes that catalyze the clearance of testosterone, dihydrotestosterone (DHT), and DHT metabolites in the prostate basal and luminal tissue. The expression of the UGT2B15, UGT2B17, and UGT2B28 enzymes has not been evaluated in prostate tissue samples from hormone therapy-naïve patients.

Methods

We determined the expression of UGT2B15, UGT2B17, and UGT2B28 enzymes in 190 prostate tissue samples from surgical specimens of a multiethnic cohort of patients undergoing radical prostatectomy at the Durham Veterans Affairs Medical Center. The association between each protein’s percent positive and H-score, a weighted score of staining intensity, and the risk of biochemical recurrence (BCR) was tested using separate Cox proportional hazards models. In an exploratory analysis, UGT2B17 total positive and H-score were divided at the median and we tested the association between UGT2B17 group and risk of BCR.

Results

The median follow-up for all patients was 118 months (IQR: 85-144). Of 190, 83 (44%) patients developed BCR. We found no association between UGT2B15 or UGT2B28 and risk of BCR. However, there was a trend for an association between UGT2B17 and BCR (HR = 1.01, 95% CI 1.00-1.02, p = 0.11), though not statistically significant. Upon further investigation, we found that patients with UGT2B17 higher levels of expression had a significant increased risk of BCR on univariable analysis (HR = 1.57, 95% CI 1.02-2.43, p = 0.041), although this association was attenuated in the multivariable model (HR = 1.50, 95% CI 0.94-2.40, p = 0.088).

Conclusions

Our findings suggest that UGT2B17 overexpression may be associated with a significant increased risk of BCR. These results are consistent with previous reports which showed UGT2B17 significantly expressed in advanced prostate cancer including prostate tumor metastases.

Inverse Regulation of DHT Synthesis Enzymes 5α-Reductase Types 1 and 2 by the Androgen Receptor in Prostate Cancer

5α-Reductase types 1 and 2, encoded by SRD5A1 and SRD5A2, are the two enzymes that can catalyze the conversion of testosterone to dihydrotestosterone, the most potent androgen receptor (AR) agonist in prostate cells. 5α-Reductase type 2 is the predominant isoform expressed in the normal prostate. However, its expression decreases during prostate cancer (PCa) progression, whereas SRD5A1 increases, and the mechanism underlying this transcriptional regulatory switch is still unknown. Interrogation of SRD5A messenger RNA expression in three publicly available data sets confirmed that SRD5A1 is increased in primary and metastatic PCa compared with nontumoral prostate tissues, whereas SRD5A2 is decreased. Activation of AR, a major oncogenic driver of PCa, induced the expression of SRD5A1 from twofold to fourfold in three androgen-responsive PCa cell lines. In contrast, AR repressed SRD5A2 expression in this context. Chromatin-immunoprecipitation studies established that AR is recruited to both SRD5A1 and SRD5A2 genes following androgen stimulation but initiates transcriptional activation only at SRD5A1 as monitored by recruitment of RNA polymerase II and the presence of the H3K27Ac histone mark. Furthermore, we showed that the antiandrogens bicalutamide and enzalutamide block the AR-mediated regulation of both SRD5A1 and SRD5A2, highlighting an additional mechanism explaining their beneficial effects in patients. In summary, we identified an AR-dependent transcriptional regulation that explains the differential expression of 5α-reductase types 1 and 2 during PCa progression. Our work thus defines a mechanism by which androgens control their own synthesis via differential regulatory control of the expression of SRD5A1 and SRD5A2.

Testosterone Levels Correlate With Grade Group 5 Prostate Cancer: Another Step Toward Personalized Medicine

BACKGROUND

Controversial results have shown a significant association with either low or high total testosterone (tT) levels and high risk prostate cancer (PCa). We tested the relationship between circulating tT and grade group 5 (G5) PCa at radical prostatectomy (RP) in patients with preoperative low- to intermediate-risk disease.

METHODS

Serum sex hormones were assessed the day before RP in a cohort of 846 patients with low- to intermediate-risk PCa. Patients were segregated using the new 5-tiered Gleason grade groups. Restricted cubic spline functions and logistic regression analyses tested the association between sex hormones and G5 PCa. Differences in potential predictive accuracy (PA) were assessed for tT and prostate-specific antigen (PSA) levels.

RESULTS

Overall, 27 men (3.2%) had G5 PCa at RP, and this group had higher PSA values than patients with G1-G4 PCa (P = 0.02). The groups did not differ in terms of preoperative mean hormonal values. Both low and high circulating tT values depicted a nonlinear U-shaped correlation with G5 PCa at RP. The lowest and highest (10th and 90th percentiles) tT values and biopsy PCa grade emerged as multivariable independent predictors of G5 PCa at RP (all P < 0.05). PA for G5 PCa did not differ between tT (area under the curve [AUC] 0.631) and PSA (AUC 0.636).

CONCLUSIONS

Circulating tT was a significant predictor of G5 PCa at RP in patients with preoperative low- to intermediate-risk disease. Preoperative tT and PSA values showed similar PA for the most aggressive disease, confirming a potential role for circulating androgens in preoperative risk assessment of PCa patients. Prostate 77:234-241, 2017. © 2016 Wiley Periodicals, Inc.

UGT2B28 genomic variation is associated with hepatitis B e-antigen seroconversion in response to antiviral therapy

Seroconversion of hepatitis B virus (HBV) e-antigen (HBeAg) is a critical but often-missed therapeutic goal in standard antiviral treatments. An extreme-phenotype genome-wide association study was performed, comparing untreated spontaneous recoverers (with seroconversion of HBV surface antigen) versus entecavir-treated patients failing to achieve HBeAg seroconversion. A single-nucleotide-polymorphism rs2132039 on the UGT2B28 gene, alongside an adjacent copy number polymorphism (CNP605), manifested the strongest clinical associations (P = 3.4 × 10-8 and 0.001, respectively). Multivariate analysis showed that rs2132039-TT genotypes, but not CNP605 copy numbers, remained associated to spontaneous recoverers (P = 0.009). The clinical association of rs2132039 was validated successfully in an independent cohort (n = 302; P = 0.002). Longitudinal case-only analyses revealed that the rs2132039-TT genotype predicted shorter time-to-HBeAg-seroconversion in all antiviral-treated patients (n = 380, P = 0.012), as well as the peginterferon-treated subgroup (n = 123; P = 0.024, Hazard ratio [HR] = 2.104, Confidence interval [CI] = 1.105-4.007). In the entecavir-treated subgroup, the predictive effect was restricted by pretreatment alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, with effective prediction observed in patients with ALT < 200 IU/ml and ALT/AST ratio <2 (n = 132; P = 0.013, HR = 10.538, CI = 1.420-78.196).

UGT2B17 Expedites Progression of Castration-Resistant Prostate Cancers by Promoting Ligand-Independent AR Signaling

Castration-resistant prostate cancer (CRPC) is characterized by a shift in androgen receptor (AR) signaling from androgen-dependent to androgen (ligand)-independent. UDP-glucuronosyltransferase 2B17 (UGT2B17) is a key enzyme that maintains androgen homeostasis by catabolizing AR agonists into inactive forms. Although enhanced UGT2B17 expression by antiandrogens has been reported in androgen-dependent prostate cancer, its roles in regulating AR signaling transformation and CRPC progression remain unknown. In this study, we show that higher UGT2B17 protein expression in prostate tumors is associated with higher Gleason score, metastasis, and CRPC progression. UGT2B17 expression and activity were higher in androgen-independent compared to androgen-dependent cell lines. UGT2B17 stimulated cancer cell proliferation, invasion, and xenograft progression to CRPC after prolonged androgen deprivation. Gene microarray analysis indicated that UGT2B17 suppressed androgen-dependent AR transcriptional activity and enhanced of ligand-independent transcriptional activity at genes associated with cell mitosis. These UGT2B17 actions were mainly mediated by activation of the c-Src kinase. In CRPC tumors, UGT2B17 expression was associated positively with c-Src activation. These results indicate that UGT2B17 expedites CRPC progression by enhancing ligand-independent AR signaling to activate cell mitosis in cancer cells. Cancer Res; 76(22); 6701-11. ©2016 AACR.

Classical and Non-Classical Roles for Pre-Receptor Control of DHT Metabolism in Prostate Cancer Progression

Androgens play an important role in prostate cancer (PCa) development and progression. Accordingly, androgen deprivation therapy remains the front-line treatment for locally recurrent or advanced PCa, but patients eventually relapse with the lethal form of the disease termed castration resistant PCa (CRPC). Importantly, castration does not eliminate androgens from the prostate tumor microenvironment which is characterized by elevated tissue androgens that are well within the range capable of activating the androgen receptor (AR). In this mini-review, we discuss emerging data that suggest a role for the enzymes mediating pre-receptor control of dihydrotestosterone (DHT) metabolism, including AKR1C2, HSD17B6, HSD17B10, and the UGT family members UGT2B15 and UGT2B17, in controlling intratumoral androgen levels, and thereby influencing PCa progression. We review the expression of steroidogenic enzymes involved in this pathway in primary PCa and CRPC, the activity and regulation of these enzymes in PCa experimental models, and the impact of genetic variation in genes mediating pre-receptor DHT metabolism on PCa risk. Finally, we discuss recent data that suggests several of these enzymes may also play an unrecognized role in CRPC progression separate from their role in androgen inactivation.