Androgen and Estrogen Receptors in Breast Cancer Coregulate Human UDP-Glucuronosyltransferases 2B15 and 2B17

Similarities in Structure and Function of UDP-Glycosyltransferase Homologs from Human and Plants

The uridine diphosphate glycosyltransferase (UGT) superfamily plays a key role in the metabolism of xenobiotics and metabolic wastes, which is essential for detoxifying those species. Over the last several decades, a huge effort has been put into studying human and mammalian UGT homologs, but family members in other organisms have been explored much less. Potentially, other UGT homologs can have desirable substrate specificity and biological activities that can be harnessed for detoxification in various medical settings. In this review article, we take a plant UGT homology, UGT71G1, and compare its structural and biochemical properties with the human homologs. These comparisons suggest that even though mammalian and plant UGTs are functional in different environments, they may support similar biochemical activities based on their protein structure and function. The known biological functions of these homologs are discussed so as to provide insights into the use of UGT homologs from other organisms for addressing human diseases related to UGTs.

RpUGT344J7 is involved in the reproduction switch of Rhopalosiphum padi with holocyclic life cycle

Many aphid species exhibit both cyclical parthenogenesis (CP) and the obligate parthenogenesis (OP) life history, which are genetically determined. In CP aphid lineages, the parthenogenetic individuals can switch from asexual to sexual reproduction quickly in response to environmental factors such as changes in photoperiod and temperature. However, the OP aphid lineages do not undergo sexual reproduction under any conditions. So far, mechanisms underlying the reproduction switch in CP aphids have not been fully elucidated. Rhopalosiphum padi, a serious worldwide insect pest of wheat, has both CP and OP lineages. Uridine diphosphate-glycosyltransferases (UGTs) are enzymes that participate in the metabolic detoxification of xenobiotics. Here, we identified 43 RpUGT genes from R. padi genome and transcriptome sequences, and found that: (1) the UGT content of the CP lineage was significantly higher than that in the OP lineage at the key time points when CP lineage mainly produce virginoparae, gynoparae, and males under inducing condition, while there were no significant difference under normal conditions; (2) RpUGT344J7 gene was highly expressed during the time points when CP lineages produce gynopara and males; (3) the critical time points for CP lineages to produce virginoparaee, gynoparae, and males were affected when the CP lineages were injected with dsRpUGT344J7; (4) the knockdown of RpUGT344J7 caused a significant reduction in the total number of virginoparae, gynoparae, and males in the offspring under inducing condition. The findings contribute to our understanding of the molecular mechanisms underlying the quick shift from asexual to sexual reproduction in aphid species.

Identification of a targetable JAK-STAT enriched androgen receptor and androgen receptor splice variant positive triple-negative breast cancer subtype

Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (∼80%) but also expresses AR splice variants (AR-SVs) (∼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.

Estrogen Receptor Signaling in Breast Cancer

Estrogen receptor (ER) signaling is a critical regulator of cell proliferation, differentiation, and survival in breast cancer (BC) and other hormone-sensitive cancers. In this review, we explore the mechanism of ER-dependent downstream signaling in BC and the role of estrogens as growth factors necessary for cancer invasion and dissemination. The significance of the clinical implications of ER signaling in BC, including the potential of endocrine therapies that target estrogens' synthesis and ER-dependent signal transmission, such as aromatase inhibitors or selective estrogen receptor modulators, is discussed. As a consequence, the challenges associated with the resistance to these therapies resulting from acquired ER mutations and potential strategies to overcome them are the critical point for the new treatment strategies' development.

Development and characterization of a recombinant silk network for 3D culture of immortalized and fresh tumor-derived breast cancer cells

Traditional cancer models rely on 2D cell cultures or 3D spheroids, which fail to recapitulate cell-extracellular matrix (ECM) interactions, a key element of tumor development. Existing hydrogel-based 3D alternatives lack mechanical support for cell growth and often suffer from low reproducibility. Here we report a novel strategy to make 3D models of breast cancer using a tissue-like, well-defined network environment based on recombinant spider silk, functionalized with a cell adhesion motif from fibronectin (FN-silk). With this approach, the canonical cancer cells SK-BR-3, MCF-7, and MDA-MB-231, maintain their characteristic expression of markers (i.e., ERα, HER2, and PGR) while developing distinct morphology. Transcriptomic analyses demonstrate how culture in the FN-silk networks modulates the biological processes of cell adhesion and migration while affecting physiological events involved in malignancy, such as inflammation, remodeling of the ECM, and resistance to anticancer drugs. Finally, we show that integration in FN-silk networks promotes the viability of cells obtained from the superficial scraping of patients' breast tumors.

The Prognostic Values of Androgen Receptor in Breast Cancer

CONTEXT.—

Whether androgen receptor (AR) expression can predict prognosis in breast cancer is under debate.

OBJECTIVE.—

To analyze, retrospectively, the prognostic and treatment-predictive ability of AR status in breast cancer.

DESIGN.—

A total of 5765 patients diagnosed with primary invasive breast cancer without distant metastasis in the adjuvant setting were analyzed. The propensity score-matching method was used to develop a new cohort of 3978 patients (1989 patients each) in which important prognostic factors were balanced.

RESULTS.—

Positive AR expression is an independent prognostic factor for disease-free survival and overall survival. Estrogen receptor (ER)+ and progesterone receptor (PR)+ AR+ breast cancer patients had the longest survival, whereas ER-PR-AR- breast cancer patients had the shortest survival. The ER/PR/AR combinations could not predict the treatment effects for adjuvant trastuzumab but could be used for adjuvant chemotherapy and endocrine therapy selection. The worst survival was found in ER+PR-AR- patients receiving toremifene, ER+PR-AR+ patients receiving exemestane, ER+PR+AR- patients receiving anthracycline, and ER-PR-AR+ patients receiving taxanes. ER+PR-AR-, ER-PR-AR+, and ER-PR-AR- patients were associated with the worst survival among those who received radiotherapy and anthracycline plus taxanes.

CONCLUSIONS.—

AR in combination with ER and PR could predict the prognosis and treatment effects of chemotherapy, endocrine therapy, and radiotherapy in the adjuvant setting.

Drug-drug interactions that alter the exposure of glucuronidated drugs: Scope, UDP-glucuronosyltransferase (UGT) enzyme selectivity, mechanisms (inhibition and induction), and clinical significance

Drug-drug interactions (DDIs) arising from the perturbation of drug metabolising enzyme activities represent both a clinical problem and a potential economic loss for the pharmaceutical industry. DDIs involving glucuronidated drugs have historically attracted little attention and there is a perception that interactions are of minor clinical relevance. This review critically examines the scope and aetiology of DDIs that result in altered exposure of glucuronidated drugs. Interaction mechanisms, namely inhibition and induction of UDP-glucuronosyltransferase (UGT) enzymes and the potential interplay with drug transporters, are reviewed in detail, as is the clinical significance of known DDIs. Altered victim drug exposure arising from modulation of UGT enzyme activities is relatively common and, notably, the incidence and importance of UGT induction as a DDI mechanism is greater than generally believed. Numerous DDIs are clinically relevant, resulting in either loss of efficacy or an increased risk of adverse effects, necessitating dose individualisation. Several generalisations relating to the likelihood of DDIs can be drawn from the known substrate and inhibitor selectivities of UGT enzymes, highlighting the importance of comprehensive reaction phenotyping studies at an early stage of drug development. Further, rigorous assessment of the DDI liability of new chemical entities that undergo glucuronidation to a significant extent has been recommended recently by regulatory guidance. Although evidence-based approaches exist for the in vitro characterisation of UGT enzyme inhibition and induction, the availability of drugs considered appropriate for use as 'probe' substrates in clinical DDI studies is limited and this should be research priority.

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

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

Significance of UGT1A6, UGT1A9, and UGT2B7 genetic variants and their mRNA expression in the clinical outcome of renal cell carcinoma

UDP-glucuronosyltransferase (UGT) metabolizes a number of endogenous and exogenous substrates. Renal cells express high amounts of UGT; however, the significance of UGT in patients with renal cell carcinoma (RCC) remains unknown. In this study, we profile the mRNA expression of UGT subtypes (UGT1A6, UGT1A9, and UGT2B7) and their genetic variants in the kidney tissue of 125 Japanese patients with RCC (Okayama University Hospital, Japan). In addition, we elucidate the association between the UGT variants and UGT mRNA expression levels and clinical outcomes in these patients. The three representative genetic variants, namely, UGT1A6 541A > G, UGT1A9 i399C > T, and UGT2B7-161C > T, were genotyped, and their mRNA expression levels in each tissue were determined. We found that the mRNA expression of the three UGTs (UGT1A6, UGT1A9, and UGT2B7) are significantly downregulated in RCC tissues. Moreover, in patients with RCC, the UGT2B7-161C > T variant and high UGT2B7 mRNA expression are significantly correlated with preferable cancer-specific survival (CSS) and overall survival (OS), respectively. As such, the UGT2B7-161C > T variant and UGT2B7 mRNA expression level were identified as significant independent prognostic factors of CSS and CSS/OS, respectively. Taken together, these findings indicate that UGT2B7 has a role in RCC progression and may, therefore, represent a potential prognostic biomarker for patients with RCC.

Identification of UDP-Glucuronosyltransferase 2B15 (UGT2B15) as a Target for IGF1 and Insulin Action

Normal growth and development in mammals are tightly controlled by numerous genetic factors and metabolic conditions. The growth hormone (GH)-insulin-like growth factor-1 (IGF1) hormonal axis is a key player in the regulation of these processes. Dysregulation of the GH-IGF1 endocrine system is linked to a number of pathologies, ranging from growth deficits to cancer. Laron syndrome (LS) is a type of dwarfism that results from mutation of the GH receptor (GHR) gene, leading to GH resistance and short stature as well as a number of metabolic abnormalities. Of major clinical relevance, epidemiological studies have shown that LS patients do not develop cancer. While the mechanisms associated with cancer protection in LS have not yet been elucidated, genomic analyses have identified a series of metabolic genes that are over-represented in LS patients. We hypothesized that these genes might constitute novel targets for IGF1 action. With a fold-change of 11.09, UDP-glucuronosyltransferase 2B15 (UGT2B15) was the top up-regulated gene in LS. The UGT2B15 gene codes for an enzyme that converts xenobiotic substances into lipophilic compounds and thereby facilitates their clearance from the body. We investigated the regulation of UGT2B15 gene expression by IGF1 and insulin. Both hormones inhibited UGT2B15 mRNA levels in endometrial and breast cancer cell lines. Regulation of UGT2B15 protein levels by IGF1/insulin, however, was more complex and not always correlated with mRNA levels. Furthermore, UGT2B15 expression was dependent on p53 status. Thus, UGT2B15 mRNA levels were higher in cell lines expressing a wild-type p53 compared to cells containing a mutated p53. Animal studies confirmed an inverse correlation between UGT2B15 and p53 levels. In summary, increased UGT2B15 levels in LS might confer upon patient’s protection from genotoxic damage.

Update of gene expression/methylation and MiRNA profiling in colorectal cancer; application in diagnosis, prognosis, and targeted therapy

Background

Colorectal cancer is one of the most deadliest malignancies worldwide. Due to the dearth of appropriate biomarkers, the diagnosis of this mortal disease is usually deferred, in its turn, culminating in the failure of prevention. By the same token, proper biomarkers are at play in determining the quality of prognosis. In other words, the survival rate is contingent upon the regulation of such biomarkers.

Materials and methods

The information regarding expression (GSE41258, and GSE31905), methylation (GSE101764), and miRNA (dbDEMC) were downloaded. MEXPRESS and GEPIA confirmed the validated differentially expressed/methylated genes using TCGA data. Taking advantage of the correlation plots and receiver-operating-characteristic (ROC) curves, expression and methylation profiles were compared. The interactions between validated differentially expressed genes and differentially expressed miRNA were recognized and visualized by miRTarBase and Cytoscape, respectively. Then, the protein-protein interaction (PPI) network and hub genes were established via STRING and Cytohubba plugin. Utilizing R packages (DOSE, Enrichplot, and clusterProfiler) and DAVID database, the Functional Enrichment analysis and the detection of KEGG pathways were performed. Ultimately, in order to recognize the prognostic value of found biomarkers, they were evaluated through drawing survival plots for CRC patients.

Results

In this research, we found an expression profile (with 13 novel genes), a methylation profile (with two novel genes), and a miRNA profile with diagnostic value. Concerning diagnosis, the expression profile was evaluated more powerful in comparison with the methylation profile. Furthermore, a prognosis-related expression profile was detected.

Conclusion

In addition to diagnostic- and prognostic-applicability, the discerned profiles can assist in targeted therapy and current therapeutic strategies.

Spatial maps of hepatocellular carcinoma transcriptomes highlight an unexplored landscape of heterogeneity and a novel gene signature for survival

Background

Hepatocellular carcinoma (HCC) often presents with satellite nodules, rendering current curative treatments ineffective in many patients. The heterogeneity of HCC is a major challenge in personalized medicine. The emergence of spatial transcriptomics (ST) provides a powerful strategy for delineating the complex molecular landscapes of tumours.

Methods

In this study, the heterogeneity of tissue-wide gene expression in tumour and adjacent nonneoplastic tissues using ST technology were investigated. The transcriptomes of nearly 10,820 tissue regions and identified the main gene expression clusters and their specific marker genes (differentially expressed genes, DEGs) in patients were analysed. The DEGs were analysed from two perspectives. First, two distinct gene profiles were identified to be associated with satellite nodules and conducted a more comprehensive analysis of both gene profiles. Their clinical relevance in human HCC was validated with Kaplan–Meier (KM) Plotter. Second, DEGs were screened with The Cancer Genome Atlas (TCGA) database to divide the HCC cohort into high- and low-risk groups according to Cox analysis. HCC patients from the International Cancer Genome Consortium (ICGC) cohort were used for validation. KM analysis was used to compare the overall survival (OS) between the high- and low-risk groups. Univariate and multivariate Cox analyses were applied to determine the independent predictors for OS.

Results

Novel markers for the prediction of satellite nodules were identified and a tumour clusters-specific marker gene signature model (6 genes) for HCC prognosis was constructed.

Conclusion

The establishment of marker gene profiles may be an important step towards an unbiased view of HCC, and the 6-gene signature can be used for prognostic prediction in HCC. This analysis will help us to clarify one of the possible sources of HCC heterogeneity and uncover pathogenic mechanisms and novel antitumour drug targets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02430-9.

Diverse role of androgen action in human breast cancer

Breast cancer is a hormone-dependent cancer, and sex steroids play a pivotal role in breast cancer progression. Estrogens are strongly associated with breast cancers, and the estrogen receptor (estrogen receptor α; ERα) is expressed in 70-80% of human breast carcinoma tissues. Although antiestrogen therapies (endocrine therapies) have significantly improved clinical outcomes in ERα-positive breast cancer patients, some patients experience recurrence after treatment. In addition, patients with breast carcinoma lacking ERα expression do not benefit from endocrine therapy. The androgen receptor (AR) is also expressed in >70% of breast carcinoma tissues. Growing evidence supports this novel therapeutic target for the treatment of triple-negative breast cancers that lack ERα, progesterone receptor, and human EGF receptor 2, and ERα-positive breast cancers, which are resistant to conventional endocrine therapy. However, the clinical significance of AR expression is still controversial and the biological function of androgens in breast cancers is unclear. In this review, we focus on the recent findings concerning androgen action in breast cancers and the contributions of androgens to improved breast cancer therapy.

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.

Correlation between Androgen Receptor Expression and Immunohistochemistry Type as Prognostic Factors in a Cohort of Breast Cancer Patients: Result from a Single-Center, Cross Sectional Study

Background: We investigated the correlation between the androgen receptor (AR) and immunohistochemistry (IHC) as a prognostic factor in breast cancer (BC). AR is expressed in 60–80% of BC. Methods: We evaluated the prognostic values of AR expression among 143 patients with BC for 36 months. The protocol was amended to measure androgen, estrogen and progesterone receptor expression by IHC and the percentage of hormone positive nuclei was quantified. We determined and quantified the Her2/neu status using IHC and in situ hybridization. The methodology consisted in using a Kaplan–Meier analysis and restricted mean survival time up to 36 months. The principal endpoints of the study were overall survival (OS) and progression free survival (PFS). Results: 57% of patients (n = 82) from our group had AR+ (≥ 1%). Patients with AR+ had better OS, 35.50 vs. 33.40 months, with p = 0.027. Moreover, PFS was prolonged for patients AR+, 32.60 vs. 30.50 months, with p = 0.38. Triple negative breast cancer (TNBC) patients had lower OS and no difference was observed for PFS. Conclusions: Both OS and PFS were favorably influenced by the presence of AR. TNBC had worse outcomes compared with patients with hormonal or/and Her 2/neu positive disease in terms of OS.

The androgen receptor is a tumor suppressor in estrogen receptor-positive breast cancer

The role of the androgen receptor (AR) in estrogen receptor (ER)-α-positive breast cancer is controversial, constraining implementation of AR-directed therapies. Using a diverse, clinically relevant panel of cell-line and patient-derived models, we demonstrate that AR activation, not suppression, exerts potent antitumor activity in multiple disease contexts, including resistance to standard-of-care ER and CDK4/6 inhibitors. Notably, AR agonists combined with standard-of-care agents enhanced therapeutic responses. Mechanistically, agonist activation of AR altered the genomic distribution of ER and essential co-activators (p300, SRC-3), resulting in repression of ER-regulated cell cycle genes and upregulation of AR target genes, including known tumor suppressors. A gene signature of AR activity positively predicted disease survival in multiple clinical ER-positive breast cancer cohorts. These findings provide unambiguous evidence that AR has a tumor suppressor role in ER-positive breast cancer and support AR agonism as the optimal AR-directed treatment strategy, revealing a rational therapeutic opportunity.

The Expression Profiles of ADME Genes in Human Cancers and Their Associations with Clinical Outcomes

ADME genes are a group of genes that are involved in drug absorption, distribution, metabolism, and excretion (ADME). The expression profiles of ADME genes within tumours is proposed to impact on cancer patient survival; however, this has not been systematically examined. In this study, our comprehensive analyses of pan-cancer datasets from the Cancer Genome Atlas (TCGA) revealed differential intratumoral expression profiles for ADME genes in 21 different cancer types. Most genes also showed high interindividual variability within cancer-specific patient cohorts. Using Kaplan-Meier plots and logrank tests, we showed that intratumoral expression levels of twenty of the thirty-two core ADME genes were associated with overall survival (OS) in these cancers. Of these genes, five showed significant association with unfavourable OS in three cancers, including SKCM (ABCC2, GSTP1), KIRC (CYP2D6, CYP2E1), PAAD (UGT2B7); sixteen showed significant associations with favourable OS in twelve cancers, including BLCA (UGT2B15), BRCA (CYP2D6), COAD (NAT1), HNSC (ABCB1), KIRC (ABCG2, CYP3A4, SLC22A2, SLC22A6), KIRP (SLC22A2), LIHC (CYP2C19, CYP2C8, CYP2C9, CYP3A5, SLC22A1), LUAD (SLC15A2), LUSC (UGT1A1), PAAD (ABCB1), SARC (ABCB1), and SKCM (ABCB1, DYPD). Overall, these data provide compelling evidence supporting ADME genes as prognostic biomarkers and potential therapeutic targets. We propose that intratumoral expression of ADME genes may impact cancer patient survival by multiple mechanisms that can include metabolizing/transporting anticancer drugs, activating anticancer drugs, and metabolizing/transporting a variety of endogenous molecules involved in metabolically fuelling cancer cells and/or controlling pro-growth signalling pathways.

Sparse semiparametric canonical correlation analysis for data of mixed types

Canonical correlation analysis investigates linear relationships between two sets of variables, but often works poorly on modern datasets due to high-dimensionality and mixed data types (continuous/binary/zero-inflated). We propose a new approach for sparse canonical correlation analysis of mixed data types that does not require explicit parametric assumptions. Our main contribution is the use of truncated latent Gaussian copula to model the data with excess zeroes, which allows us to derive a rank-based estimator of latent correlation matrix without the estimation of marginal transformation functions. The resulting semiparametric sparse canonical correlation analysis method works well in high-dimensional settings as demonstrated via numerical studies, and application to the analysis of association between gene expression and micro RNA data of breast cancer patients.

Enhanced Activity of P4503A4 and UGT1A10 Induced by Acridinone Derivatives C-1305 and C-1311 in MCF-7 and HCT116 Cancer Cells: Consequences for the Drugs' Cytotoxicity, Metabolism and Cellular Response

Activity modulation of drug metabolism enzymes can change the biotransformation of chemotherapeutics and cellular responses induced by them. As a result, drug-drug interactions can be modified. Acridinone derivatives, represented here by C-1305 and C-1311, are potent anticancer drugs. Previous studies in non-cellular systems showed that they are mechanism-based inhibitors of cytochrome P4503A4 and undergo glucuronidation via UDP-glucuronosyltranspherase 1A10 isoenzyme (UGT1A10). Therefore, we investigated the potency of these compounds to modulate P4503A4 and UGT1A10 activity in breast MCF-7 and colon HCT116 cancer cells and their influence on cytotoxicity and cellular response in cells with different expression levels of studied isoenzymes. We show that C-1305 and C-1311 are inducers of not only P4503A4 but also UGT1A10 activity. MCF-7 and HCT116 cells with high P4503A4 activity are more sensitive to acridinone derivatives and undergo apoptosis/necrosis to a greater extent. UGT1A10 was demonstrated to be responsible for C-1305 and C-1311 glucuronidation in cancer cells and glucuronide products were excreted outside the cell very fast. Finally, we show that glucuronidation of C-1305 antitumor agent enhances its pro-apoptotic properties in HCT116 cells, while the cytotoxicity and cellular response induced by C-1311 did not change after drug glucuronidation in both cell lines.

How glycosylation affects glycosylation: the role of N-glycans in glycosyltransferase activity

N-glycosylation is one of the most important posttranslational modifications of proteins. It plays important roles in the biogenesis and functions of proteins by influencing their folding, intracellular localization, stability and solubility. N-glycans are synthesized by glycosyltransferases, a complex group of ubiquitous enzymes that occur in most kingdoms of life. A growing body of evidence shows that N-glycans may influence processing and functions of glycosyltransferases, including their secretion, stability and substrate/acceptor affinity. Changes in these properties may have a profound impact on glycosyltransferase activity. Indeed, some glycosyltransferases have to be glycosylated themselves for full activity. N-glycans and glycosyltransferases play roles in the pathogenesis of many diseases (including cancers), so studies on glycosyltransferases may contribute to the development of new therapy methods and novel glycoengineered enzymes with improved properties. In this review, we focus on the role of N-glycosylation in the activity of glycosyltransferases and attempt to summarize all available data about this phenomenon.

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.

Gene Expression Signature Predictive of Neuroendocrine Transformation in Prostate Adenocarcinoma

Neuroendocrine prostate cancer (NEPC) can arise de novo, but much more commonly occurs as a consequence of a selective pressure from androgen deprivation therapy or androgen receptor antagonists used for prostate cancer (PCa) treatment. The process is known as neuroendocrine transdifferentiation. There is little molecular characterization of NEPCs and consequently there is no standard treatment for this kind of tumors, characterized by highly metastases rates and poor survival. For this purpose, we profiled 54 PCa samples with more than 10-years follow-up for gene and miRNA expression. We divided samples into two groups (NE-like vs. AdenoPCa), according to their clinical and molecular features. NE-like tumors were characterized by a neuroendocrine fingerprint made of known neuroendocrine markers and novel molecules, including long non-coding RNAs and components of the estrogen receptor signaling. A gene expression signature able to predict NEPC was built and tested on independently published datasets. This study identified molecular features (protein-coding, long non-coding, and microRNAs), at the time of surgery, that may anticipate the NE transformation process of prostate adenocarcinoma. Our results may contribute to improving the diagnosis and treatment of this subgroup of tumors for which traditional therapy regimens do not show beneficial effects.

Screening and Identifying Immune-Related Cells and Genes in the Tumor Microenvironment of Bladder Urothelial Carcinoma: Based on TCGA Database and Bioinformatics

Bladder cancer is the most common cancer of the urinary system and its treatment has scarcely progressed for nearly 30 years. Advances in checkpoint inhibitor research have seemingly provided a new approach for treatment. However, there have been issues predicting immunotherapeutic biomarkers and identifying new therapeutic targets. We downloaded the gene expression profile and clinical data of 408 cases bladder urinary cancer from the Cancer Genome Atlas (TCGA) portal, and the abundance ratio of immune cells for each sample was obtained via the "Cell Type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT)" algorithm. Then, four survival-related immune cells were obtained via Kaplan-Meier survival analysis, and 933 immune-related genes were obtained via a variance analysis. Enrichment, protein-protein interaction, and co-expression analyses were performed for these genes. Lastly, 4 survival-related immune cells and 24 hub genes were identified, four of which were related to overall survival. More importantly, these immune cells and genes were closely related to the clinical features. These cells and genes may have research value and clinical application in bladder cancer immunotherapy. Our study not only provides cell and gene targets for bladder cancer immunotherapy, but also provides new ideas for researchers to explore the immunotherapy of various tumors.

Transcriptome of 17β-hydroxysteroid dehydrogenase type 2 plays both hormone-dependent and hormone-independent roles in MCF-7 breast cancer cells

Breast cancer is a major cause of cancer-related death for women in western countries. 17β-Hydroxysteroid dehydrogenases (17β-HSDs) play important roles in the last step of sex-hormone activation and the first step of sex-hormone inactivation. 17β-HSD2 is responsible for oxidizing the sex hormones. We used microarray technology to analyze the effect of 17β-HSD2 on the MCF-7 cell transcript profile after knocking down 17β-HSD2. Five hundred forty-two genes were regulated 1.5-fold or higher after treatment with 17β-HSD2 siRNA. Knocking down 17β-HSD2 interrupted nucleosome assembly. Pathway-Act-Network analysis showed that the MAPK and apoptosis signaling pathways were most regulated. In the gene-gene interaction network analysis, UGT2B15, which is involved in hormone metabolism, was the most regulated core gene. FOS, GREB1, and CXCL12 were the most regulated genes, and CXCL12 was related to tumor migration. Following 17β-HSD2 knock-down, the cell viability decreased to 75.9%. The S-phase percentage decreased by 19.4%, the Q2-phase percentage in cell apoptosis testing increased by 1.5 times, and cell migration decreased to 66.0%. These results were consistent with our gene chip analysis and indicated that 17β-HSD2 plays both hormone-dependent and hormone-independent enzymatic roles. In-depth investigations of this enzyme on the genomic level will help clarify its related molecular mechanisms.

The UGTome: The expanding diversity of UDP glycosyltransferases and its impact on small molecule metabolism

The UDP glycosyltransferase (UGT) superfamily of enzymes is responsible for the metabolism and clearance of thousands of lipophilic chemicals including drugs, toxins and endogenous signaling molecules. They provide a protective interface between the organism and its chemical-rich environment, as well as controlling critical signaling pathways to maintain healthy tissue function. UGTs are associated with drug responses and interactions, as well as a wide range of diseases including cancer. The human genome contains 22 UGT genes; however as befitting their exceptionally diverse substrate ranges and biological activities, the output of these UGT genes is functionally diversified by multiple processes including alternative splicing, post-translational modification, homo- and hetero-oligomerization, and interactions with other proteins. All UGT genes are subject to extensive alternative splicing generating variant/truncated UGT proteins with altered functions including the capacity to dominantly modulate/inhibit cognate full-length forms. Heterotypic oligomerization of different UGTs can alter kinetic properties relative to monotypic complexes, and potentially produce novel substrate specificities. Moreover, the recently profiled interactions of UGTs with non-UGT proteins may facilitate coordination between different metabolic processes, as well as providing opportunities for UGTs to engage in novel 'moonlighting' functions. Herein we provide a detailed and comprehensive review of all known modes of UGT functional diversification and propose a UGTome model to describe the resulting expansion of metabolic capacity and its potential to modulate drug/xenobiotic responses and cell behaviours in normal and disease contexts.

Glucocorticoid receptor modulation decreases ER-positive breast cancer cell proliferation and suppresses wild-type and mutant ER chromatin association

Background

Non-ER nuclear receptor activity can alter estrogen receptor (ER) chromatin association and resultant ER-mediated transcription. Consistent with GR modulation of ER activity, high tumor glucocorticoid receptor (GR) expression correlates with improved relapse-free survival in ER+ breast cancer (BC) patients.

Methods

In vitro cell proliferation assays were used to assess ER-mediated BC cell proliferation following GR modulation. ER chromatin association following ER/GR co-liganding was measured using global ChIP sequencing and directed ChIP analysis of proliferative gene enhancers.

Results

We found that GR liganding with either a pure agonist or a selective GR modulator (SGRM) slowed estradiol (E2)-mediated proliferation in ER+ BC models. SGRMs that antagonized transcription of GR-unique genes both promoted GR chromatin association and inhibited ER chromatin localization at common DNA enhancer sites. Gene expression analysis revealed that ER and GR co-activation decreased proliferative gene activation (compared to ER activation alone), specifically reducing CCND1, CDK2, and CDK6 gene expression. We also found that ligand-dependent GR occupancy of common ER-bound enhancer regions suppressed both wild-type and mutant ER chromatin association and decreased corresponding gene expression. In vivo, treatment with structurally diverse SGRMs also reduced MCF-7 Y537S ER-expressing BC xenograft growth.

Conclusion

These studies demonstrate that liganded GR can suppress ER chromatin occupancy at shared ER-regulated enhancers, including CCND1 (Cyclin D1), regardless of whether the ligand is a classic GR agonist or antagonist. Resulting GR-mediated suppression of ER+ BC proliferative gene expression and cell division suggests that SGRMs could decrease ER-driven gene expression.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1164-6) contains supplementary material, which is available to authorized users.

Altered Steroid Milieu in AI-Resistant Breast Cancer Facilitates AR Mediated Gene-Expression Associated with Poor Response to Therapy

Divergent roles for androgen receptor (AR) in breast cancer have been reported. Following aromatase inhibitor (AI) treatment, the conversion of circulating androgens into estrogens can be diminished by >99%. We wished to establish whether the steroid environment can dictate the role of AR and the implications of this for subsequent therapy. This study utilizes models of AI resistance to explore responsiveness to PI3K/mTOR and anti-AR therapy when cells are exposed to unconverted weak androgens. Transcriptomic alterations driven by androstenedione (4AD) were assessed by RNA-sequencing. AR and estrogen receptor (ER) recruitment to target gene promoters was evaluated using ChIP, and relevance to patient profiles was performed using publicly available data sets. Although BEZ235 showed decreased viability across AI-sensitive and -resistant cell lines, anti-AR treatment elicited a decrease in cell viability only in the AI-resistant model. Serum and glucocorticoid-regulated kinase 3 (SGK3) and cAMP-dependent protein kinase inhibitor β (PKIB) were confirmed to be regulated by 4AD and shown to be mediated by AR; crucially, reexposure to estradiol suppressed expression of these genes. Meta-analysis of transcript levels showed high expression of SGK3 and PKIB to be associated with poor response to endocrine therapy (HR = 2.551, P = 0.003). Furthermore, this study found levels of SGK3 to be sustained in patients who do not respond to AI therapy. This study highlights the importance of the tumor steroid environment. SGK3 and PKIB are associated with poor response to endocrine therapy and could have utility in tailoring therapeutic approaches.

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.

New Opportunities for Targeting the Androgen Receptor in Prostate Cancer

Recent genomic analyses of metastatic prostate cancer have provided important insight into adaptive changes in androgen receptor (AR) signaling that underpin resistance to androgen deprivation therapies. Novel strategies are required to circumvent these AR-mediated resistance mechanisms and thereby improve prostate cancer survival. In this review, we present a summary of AR structure and function and discuss mechanisms of AR-mediated therapy resistance that represent important areas of focus for the development of new therapies.

Hydroxy metabolites of polychlorinated biphenyls (OH-PCBs) exhibit inhibitory effects on UDP-glucuronosyltransferases (UGTs)

Hydroxy metabolites of polychlorinated biphenyls (OH-PCBs) are important substance basis for the toxicity of PCBs. This study aims to investigate the inhibition of OH-PCBs on the activity of UDP-glucuronosyltransferases (UGTs), trying to elucidate the toxicity mechanism of PCBs from a new perspective. In vitrohuman recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) was used as the probe reaction. The number of chlorine atom can affect the inhibition potential of OH-PCBs towards different isoforms of UGTs, and complex structure-activity relationship was found for the inhibition of OH-PCBs on the activities of UGT isoforms. For the inhibition kinetic determination, 2'OHPCB106 and 4'OHPCB106 were selected as the representative OH-PCBs, and UGT1A1, 1A7, and 2B7 were chosen as the representative UGT isoforms. Competitive inhibition of 2'OHPCB106 and 4'OHPCB106 on the activities of UGT1A1, UGT1A7, and UGT2B7 was found. For 2'OHPCB106, the inhibition kinetic parameters (K_i) were calculated to be 0.4 μM for UGT1A1, 1.3 μM for UGT1A7, and 2.7 μM for UGT2B7, respectively. For 4'OHPCB106, K_i values were calculated to be 0.7 μM for UGT1A1, 6.8 μM for UGT1A7, and 4.8 μM for UGT2B7, respectively. In silico docking method was utilized to elucidate the inhibition difference of UGT1A1 by four OH-PCBs with similar structures (4'OHPCB9, 4'OHPCB26, 4'OHPCB112 and 4'OHPCB165). In conclusion, these data will be helpful for understanding the toxicity mechanisms of PCBs from a view of metabolic interference.

Deciphering Steroid Receptor Crosstalk in Hormone-Driven Cancers

Steroid hormone receptors (SRs) have a multitude of functions in human biology and disease progression. The SR family of related ligand-activated transcription factors includes androgen, estrogen, glucocorticoid, mineralocorticoid, and progesterone receptors. Antiestrogen or estrogen receptor (ER)-targeted therapies to block ER action remain the primary treatment of luminal breast cancers. Although this strategy is successful, ∼40% of patients eventually relapse due to endocrine resistance. The majority of hormone-independent tumors retain some level of SR expression, but sidestep hormone ablation treatments. SRs are known to crosstalk extensively with kinase signaling pathways, and this interplay has been shown to bypass ER-targeted therapies in part by providing alternative proliferation and survival signals that enable hormone independence. Modified receptors adopt alternate conformations that resist antagonism or promote agonism. SR-regulated transcription and SR-binding events have been classically studied as single receptor events using single hormones. However, it is becoming increasingly evident that individual steroids and SRs rarely act alone. Emerging evidence shows that coexpressed SRs crosstalk with each other in hormone-driven cancers, such as breast and prostate. Crosstalk between related SRs allows them to modulate signaling and transcriptional responses to noncognate ligands. This flexibility can lead to altered genomic binding and subsequent changes in SR target gene expression. This review will discuss recent mechanistic advances in elucidating SR crosstalk and the implications for treating hormone-driven cancers. Understanding this crosstalk (i.e., both opposing and collaborative) is a critical step toward expanding and modernizing endocrine therapies and will ultimately improve patient outcomes.

The Divergent Function of Androgen Receptor in Breast Cancer; Analysis of Steroid Mediators and Tumor Intracrinology

Androgen receptor (AR) is the most widely expressed steroid receptor protein in normal breast tissue and is detectable in approximately 90% of primary breast cancers and 75% of metastatic lesions. However, the role of AR in breast cancer development and progression is mired in controversy with evidence suggesting it can either inhibit or promote breast tumorigenesis. Studies have shown it to antagonize estrogen receptor alpha (ERα) DNA binding, thereby preventing pro-proliferative gene transcription; whilst others have demonstrated AR to take on the mantle of a pseudo ERα particularly in the setting of triple negative breast cancer. Evidence for a potentiating role of AR in the development of endocrine resistant breast cancer has also been mounting with reports associating high AR expression with poor response to endocrine treatment. The resurgence of interest into the function of AR in breast cancer has resulted in various emergent clinical trials evaluating anti-AR therapy and selective androgen receptor modulators in the treatment of advanced breast cancer. Trials have reported varied response rates dependent upon subtype with overall clinical benefit rates of ~19-29% for anti-androgen monotherapy, suggesting that with enhanced patient stratification AR could prove efficacious as a breast cancer therapy. Androgens and AR have been reported to facilitate tumor stemness in some cancers; a process which may be mediated through genomic or non-genomic actions of the AR, with the latter mechanism being relatively unexplored in breast cancer. Steroidogenic ligands of the AR are produced in females by the gonads and as sex-steroid precursors secreted from the adrenal glands. These androgens provide an abundant reservoir from which all estrogens are subsequently synthesized and their levels are undiminished in the event of standard hormonal therapeutic intervention in breast cancer. Steroid levels are known to be altered by lifestyle factors such as diet and exercise; understanding their potential role in dictating the function of AR in breast cancer development could therefore have wide-ranging effects in prevention and treatment of this disease. This review will outline the endogenous biochemical drivers of both genomic and non-genomic AR activation and how these may be modulated by current hormonal therapies.

Impact of phosphorylated insulin-like growth factor-1 receptor on the outcome of breast cancer patients and the prognostic value of its alteration during neoadjuvant chemotherapy

The expression of insulin-like growth factor-1 receptor (IGF-1R), which is involved in the genesis and progression of breast cancer, is thought to be associated with the overall survival (OS) of patients. However, the predictive and prognostic significance of the IGF-1R expression in breast cancer remains controversial. The present study aimed to identify the factors associated with the levels of phosphorylated (p)-IGF-1R in breast cancer, their impact on the outcomes of breast cancer patients, and the prognostic value of alterations of p-IGF-1R during neoadjuvant chemotherapy (NAC). The present study included 348 female breast cancer patients whose paraffin-embedded tumor tissue sections had been collected by biopsy and/or resection, among which the pre-NAC and post-NAC sections were available from 40 patients. Human epidermal growth factor receptor 2 (HER2) positivity and molecular subtype were significantly associated with the presence of p-IGF-1R in the tumor tissue (P<0.05). Patients with p-IGF-1R present in the tumor tissue had a shorter OS (P=0.003). The p-IGF-1R levels in the tumor after NAC differed significantly from those prior to NAC (P=0.005); however, this alteration in p-IGF-1R levels was not associated with a shorter OS. In parallel with HER2, p-IGF-1R appears to be a promising indicator for predicting clinical outcomes and may be an attractive target for improving the efficacy of antitumor therapy, particularly for patients with HER2-negative, estrogen receptor-positive and luminal B tumors.

Bioinformatic analysis suggests that UGT2B15 activates the Hippo‑YAP signaling pathway leading to the pathogenesis of gastric cancer

Gastric cancer (GC) is one of the most common malignancies that threatens human health. As the molecular mechanisms unerlying GC are not completely understood, identification of genes related to GC could provide new insights into gene function as well as potential treatment targets. We discovered that UGT2B15 may contribute to the pathogenesis and progression of GC using GEO data and bioinformatic analysis. Using TCGA data, UGT2B15 mRNA was found to be significantly overexpressed in GC tissues; patients with higher UGT2B15 had a poorer prognosis. It was further discovered that UGT2B15 and FOXA1 were both upregulated, and UGT2B15 and Foxa1 were positively correlated in GC. It is known that Foxa1 is a vital threshold to activate the Hippo-YAP signaling pathway. In addition, we suggest that a potential molecular mechanisms includes UGT2B15 which may upregulate Foxa1, activate the Hippo-YAP signaling pathway and contribute to the development of GC. Taken together, our findings demonstrate that UGT2B15 may be an oncogene in GC and is a promising therapeutic target for cancer treatment.

Hepatic Abundance and Activity of Androgen- and Drug-Metabolizing Enzyme UGT2B17 Are Associated with Genotype, Age, and Sex

The major objective of this study was to investigate the association of genetic and nongenetic factors with variability in protein abundance and in vitro activity of the androgen-metabolizing enzyme UGT2B17 in human liver microsomes (n = 455). UGT2B17 abundance was quantified by liquid chromatography-tandem mass spectrometry proteomics, and enzyme activity was determined by using testosterone and dihydrotestosterone as in vitro probe substrates. Genotyping or gene resequencing and mRNA expression were also evaluated. Multivariate analysis was used to test the association of UGT2B17 copy number variation, single nucleotide polymorphisms (SNPs), age, and sex with its mRNA expression, abundance, and activity. UGT2B17 gene copy number and SNPs (rs7436962, rs9996186, rs28374627, and rs4860305) were associated with gene expression, protein levels, and androgen glucuronidation rates in a gene dose-dependent manner. UGT2B17 protein (mean ± S.D. picomoles per milligram of microsomal protein) is sparsely expressed in children younger than 9 years (0.12 ± 0.24 years) but profoundly increases from age 9 years to adults (∼10-fold) with ∼2.6-fold greater abundance in males than in females (1.2 vs. 0.47). Association of androgen glucuronidation with UGT2B15 abundance was observed only in the low UGT2B17 expressers. These data can be used to predict variability in the metabolism of UGT2B17 substrates. Drug companies should include UGT2B17 in early phenotyping assays during drug discovery to avoid late clinical failures.

Regulation of UDP-Glucuronosyltransferase 2B15 by miR-331-5p in Prostate Cancer Cells Involves Canonical and Noncanonical Target Sites

UGT2B15 is an important androgen-metabolizing UDP-glucuronosyltransferase (UGT) and the mechanisms controlling its expression are of considerable interest. Recent studies showed that miR-376c regulates UGT2B15 in prostate cancer cells via a canonical target site in the 3' untranslated region (3'UTR). The UGT2B15 3'UTR also contains a canonical miR-331-5p target site; previous work indicated that deleting this site reduced, but did not abolish, the ability of miR-331-5p to repress a luciferase reporter carrying the UGT2B15 3'UTR We report here the discovery and characterization of a second, noncanonical miR-331-5p target site in the UGT2B15 3'UTR miR-331-5p-mediated repression of a UGT2B15 3'UTR-reporter was partly inhibited by mutating either of the two miR-331-5p target sites separately, but completely abolished by mutating the two sites simultaneously, indicating that the two sites act cooperatively. miR-331-5p mimics significantly reduced both UGT2B15 mRNA levels and glucuronidation activity in prostate cancer cells, confirming that the native transcript is a miR-331-5p target. Transfection of either miR-331-5p or miR-376c mimics repressed the activity of the UGT2B15 3'UTR-reporter; however, cotransfection of both microRNAs (miRNAs) further reduced activity, indicating cooperative regulation by these two miRNAs. A significant negative correlation between miR-331 and UGT2B15 mRNA levels was observed in a tissue RNA panel, and analysis of The Cancer Genome Atlas (TCGA) hepatocellular carcinoma data set provided further evidence that miR-331 may play an important role in regulation of UGT2B15 in vivo. There was no significant correlation between miR-331 and UGT2B15 mRNA levels in the TCGA prostate adenocarcinoma cohort, which may reflect the complexity of androgen-mediated regulation in determining UGT2B15 levels in prostate cancer. Finally, we show that miR-331-5p does not regulate UGT2B17, providing the first evidence for a post-transcriptional mechanism that differentially regulates these two important androgen-metabolizing UGTs.

Systemic and local effects of vaginal dehydroepiandrosterone (DHEA): NCCTG N10C1 (Alliance)

BACKGROUND

Dehydroepiandrosterone (DHEA) is helpful for treating vaginal symptoms. This secondary analysis evaluated the impact of vaginal DHEA on hormone concentrations, bone turnover, and vaginal cytology in women with a cancer history.

METHODS

Postmenopausal women, diagnosed with breast or gynecologic cancer, were eligible if they reported at least moderate vaginal symptoms. Participants could be on tamoxifen or aromatase inhibitors (AIs). Women were randomized to 3.25 versus 6.5 mg/day of DHEA versus a plain moisturizer (PM) control. Sex steroid hormone levels, biomarkers of bone formation, vaginal pH, and maturation index were collected at baseline and 12 weeks. Analysis included independent t tests and Wilcoxon rank tests, comparing each DHEA arm with the control.

RESULTS

Three hundred forty-five women contributed evaluable blood and 46 contributed evaluable cytology and pH values. Circulating DHEA-S and testosterone levels were significantly increased in those on vaginal DHEA in a dose-dependent manner compared to PM. Estradiol was significantly increased in those on 6.5 mg/day DHEA but not in those on 3.25 mg/day DHEA (p < 0.05 and p = 0.05, respectively), and not in those on AIs. Biomarkers of bone formation were unchanged in all arms. Maturation of vaginal cells was 100% (3.25 mg/day), 86% (6.5 mg/day), and 64% (PM); pH decreased more in DHEA arms.

CONCLUSION

DHEA resulted in increased hormone concentrations, though still in the lowest half or quartile of the postmenopausal range, and provided more favorable effects on vaginal cytology, compared to PM. Estrogen concentrations in women on AIs were not changed. Further research on the benefit of vaginal DHEA is warranted in hormone-dependent cancers.

Spontaneous miscarriage in first trimester pregnancy is associated with altered urinary metabolite profile

Threatened miscarriage is the most common gynecological emergency, occurring in about 20% of pregnant women. Approximately one in four of these patients go on to have spontaneous miscarriage and the etiology of miscarriage still remains elusive. In a bid to identify possible biomarkers and novel treatment targets, many studies have been undertaken to elucidate the pathways that lead to a miscarriage. Luteal phase deficiency has been shown to contribute to miscarriages, and the measurement of serum progesterone as a prognostic marker and the prescription of progesterone supplementation has been proposed as possible diagnostic and treatment methods. However, luteal phase deficiency only accounts for 35% of miscarriages. In order to understand the other causes of spontaneous miscarriage and possible novel urine biomarkers for miscarriage, we looked at the changes in urinary metabolites in women with threatened miscarriage. To this end, we performed a case-control study of eighty patients who presented with threatened miscarriage between 6 and 10 weeks gestation. Urine metabolomics analyses of forty patients with spontaneous miscarriages and forty patients with ongoing pregnancies at 16 weeks gestation point to an impaired placental mitochondrial β-oxidation of fatty acids as the possible cause of spontaneous miscarriage. This study also highlighted the potential of urine metabolites as a non-invasive screening tool for the risk stratification of women presenting with threatened miscarriage.

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Progesterone metabolite levels are lower in women with spontaneous miscarriage.

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Stress levels are higher in women with spontaneous miscarriage.

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Spontaneous miscarriage may be due to defects in fatty acid oxidation of placenta.

Disturbance of Mammary UDP-Glucuronosyltransferase Represses Estrogen Metabolism and Exacerbates Experimental Breast Cancer

The progression of breast cancer is closely related to the levels of estrogens within the body. UDP-glucuronosyltransferase (UGT) is an important class of phase II metabolizing enzymes, playing a pivotal role in detoxifying steroid hormone. In the present study, we aim at uncovering the potential dysregulation pattern of UGT and its role in estrogen metabolism and in the pathogenesis of breast cancer. Female Sprague-Dawley rats were treated with 100 mg/kg dimethylbenz(a)anthracene (DMBA) to induce breast cancer. Our results showed that the expression and activity of UGT in mammary tissues were downregulated significantly in DMBA rats. Consistent with this, levels of estradiol, 4-hydroxylated estradiol, and 2-hydroxylated estradiol were increased in both mammary tissues and serum, supporting a notable accumulation of toxic estrogen species in the target tissue of breast cancer. In addition, we also observed the decreased cell migration, cell proliferation, and DNA damage in UGT-transfected MCF-7 cells, suggesting a protective role of UGT against estrogen-induced mammary carcinogenesis. Taken together, these results indicated that accumulation of estrogens induced by UGT deficiency is a critical factor to induce the development of breast cancer. UGT contributes to estrogen elimination, and its glucuronidation capacity influences the estrogen signaling pathway and the pathogenesis of breast cancer.

Exemestane and Its Active Metabolite 17-Hydroexemestane Induce UDP-Glucuronosyltransferase (UGT) 2B17 Expression in Breast Cancer Cells

Exemestane (EXE) is an aromatase inhibitor indicated for endocrine therapy of breast cancer in postmenopausal women. The primary active metabolite of EXE, 17-hydroexemestane (17-HE), is inactivated via glucuronidation, mainly by UDP-glucuronosyltransferase 2B17 (UGT2B17). UGT2B17 also has a primary role in inactivation of endogenous androgens testosterone and dihydrotestosterone and may play an important role in regulation of breast and prostate tumor intracrinology. We recently reported that UGT2B17 could be induced by both estrogenic and androgenic ligands in breast cancer cells via binding of the estrogen receptor α (ERα) or the androgen receptor (AR) to a complex regulatory unit in the proximal UGT2B17 promoter. In this study we show that both EXE and 17-HE increase UGT2B17 mRNA levels in breast cancer MCF-7 and MDA-MB-453 cells, and increase glucuronidation of UGT2B17 substrates, including 17-HE and androsterone. Using antagonists of ERα and AR as well as inhibition mediated by small interfering RNA (siRNA) we demonstrate that EXE and 17-HE induce UGT2B17 expression primarily via the AR. This result is consistent with previous reports that 17-HE can act as an AR ligand. In vitro studies suggest that multiple steroid-responsive DNA elements within the proximal promoter are involved in the response to 17-HE-liganded AR. The up-regulation of UGT2B17 by EXE and 17-HE in breast cancer cells might enhance the local metabolism of 17-HE as well as that of endogenous androgens, hence impacting potentially on treatment outcomes.

Family Matters: Collaboration and Conflict Among the Steroid Receptors Raises a Need for Group Therapy

Antiestrogen therapies targeting the function of estrogen receptor (ER) have been the cornerstone of therapy for ER+ breast cancer for decades. However, as long as these therapies have been in use, it has also been evident that response to antiestrogen therapy is not based solely on ER expression but that other factors modify breast cancer antiestrogen response. Such factors may include ER's relatives in the steroid hormone receptor (HR) family, androgen receptor (AR), progesterone receptor (PR), glucocorticoid receptor (GR), and mineralocorticoid receptor (MR). A series of recent studies has demonstrated that these HRs are not bystanders in ER signaling but rather can alter ER genomic binding and subsequent control of target gene expression. For example, PR and GR may "reprogram" ER binding to DNA toward PR/GR sites; androgen receptor may reverse ER gene regulation functions or regulate ER DNA binding. Accordingly, modulation of HR function concurrently with antiestrogen therapy can either improve antiestrogen response or mediate antiestrogen resistance. This highlights the critical need to better understand how other HRs influence ER function, in particular in the context of antiestrogen therapy. This review discusses recent insights into the mechanisms by which HRs can modify ER function and antiestrogen response, as well as pharmacological implications for antiestrogen therapies and potential combined endocrine therapies.