Co-expression Of Androgen Receptor Research Articles

Heterogeneity of canonical prostate cancer markers across lesions in metastatic castration-resistant prostate cancer.

219 Background: Metastatic castration-resistant prostate cancers (mCRPC) show a diversity of clinical responses and phenotypes, suggesting molecular heterogeneity. Understanding molecular phenotypes is critical for patient stratification and selection of therapeutic targets. Treatment with androgen receptor (AR) pathway inhibitors are thought to drive AR-negative disease and the emergence of neuroendocrine lineages. There are several emerging biomarkers for mCRPC, including novel targets, such as PSMA and STEAP1, and markers of neuroendocrine and aggressive disease, such as INSM1, DLL3, and loss of p53, RB1 and PTEN. Our understanding of the co-expression of such biomarkers across multiple metastatic sites is currently limited. This study aimed to determine biomarker expression in multiple anatomical sites within individual mCRPC patients. Methods: Through the rapid-autopsy CASCADE program at the Peter MacCallum Cancer Centre, tissue was obtained from 5-14 tumor sites from 12 individual mCRPC patients yielding samples from a total of 110 tumor sites (8 primary and 102 metastatic). Ten patients were diagnosed with prostate adenocarcinoma (89 sites), and 2 patients with neuroendocrine histopathology in all sites (21 sites). Tissue was stained for AR, PSMA, STEAP1, INSM1, DLL3 p53, RB1 and PTEN by immunohistochemistry (IHC). Serial sections were reviewed and scored by a pathologist. IHC results were corroborated with genetic information derived from DNA sequencing. Results: In the adenocarcinoma cohort, on average 77% of sites of individual patients had AR expression, suggesting intra-patient heterogeneity. Co-expression of AR and PSMA was common (55/89 sites), but 6/10 adenocarcinoma patients had 1 to 6 PSMA+AR- lesions. Co-expression of PSMA and STEAP1 was also common in adenocarcinoma patients (60/89 sites), although 8/10 patients had 1 to 2 PSMA-STEAP1+ lesions, and 7 patients had 1 to 3 PSMA+STEAP1- lesions. Expression of INSM1 and DLL3 was mostly seen in the 2 patients (20/21 sites) with neuroendocrine prostate cancer. In contrast, only 2 INSM1+DLL3+ tumor sites in liver and 1 INSM1-DLL3+ prostate cancer sample were detected in the adenocarcinoma cohort. Of the 110 sites, p53 loss was observed in 9, RB1 loss in 30 and PTEN loss in 25 sites. Of these, 8/9, 14/30 and 8/25 occurred in INSM1+DLL3+ sites, suggesting that loss of these markers does not always correlate with INSM1 and DLL3 expression. Conclusions: While AR, PSMA and STEAP1 expression are frequently detected in a single site of disease, this co-expression is not consistent across all sites. In this dataset, INSM1 and DLL3 expression was almost exclusively confined to neuroendocrine prostate cancer. Loss of RB1 and PTEN often occurs without INSM1 and DLL3 expression. Understanding differential biomarker expression in mCRPC may guide future targeted treatments and warrants further research.

Clinical, pathologic, and molecular features of amphicrine prostate cancer.

Amphicrine prostate carcinoma (AMPC) is a poorly defined subset of prostate cancer in which cells co-express luminal prostate epithelial and neuroendocrine markers. The optimal treatment strategy is unknown. We sought to further characterize the clinical, histomorphologic, and molecular characteristics of AMPC and to identify areas of potential future treatment investigations. We retrospectively identified 17 cases of AMPC at a single institution, defined as synaptophysin expression in >70% of cells and co-expression of androgen receptor(AR) signaling markers (either AR, PSA, or NKX3.1) in >50% of cells. Clinical and histologic features of AMPC cases as well as response to treatment and clinical outcomes were described. Five AMPC cases arose de novo in the absence of prior systemic treatment and behaved distinctly from cases that were treatment-emergent. In these de novo cases, despite expression of neuroendocrine markers, prognosis appeared more favorable than high-grade neuroendocrine carcinoma, with two (40%) patients with de novo metastatic disease, universal response to androgen deprivation therapy, and no deaths at a median follow-up of 12.3 months. Treatment-emergent AMPC arose a median of 41.1 months after androgen deprivation therapy initiation and was associated with poor response to therapy. We show that amphicrine prostate cancer is a unique entity and differs in clinical and molecular features from high-grade neuroendocrine carcinomas of the prostate. Our study highlights the need to recognize AMPC as a unique molecularly defined subgroup of prostate cancer.

Expression of hormone receptors predicts survival and platinum sensitivity of high-grade serous ovarian cancer.

High-grade serous ovarian cancer (HGSOC) has abundant expression of hormone receptors, including androgen receptor (AR), estrogen receptor α (ER), and progesterone receptor (PR). The effects of hormone receptors on prognosis of HGSOC were first evaluated in online databases. Their prognostic values were then explored and validated in our inhouse TJ-cohort (92 HGSOC patients) and in a validation cohort (33 HGSOC patients), wherein hormone receptors were detected immunohistochemically. High expression of hormone receptors denoted longer progression-free survival (PFS), overall survival (OS), and platinum-free interval (PFI). Platinum-sensitive patients had higher expression of hormone receptors than their counterparts. Correlation analysis revealed significant positive correlations between hormone receptors expression and survival. AR, ER, and PR had predictive and prognostic values, alone and in combination. By receiver operating characteristic curve (ROC) analysis, co-expression of AR, ER, and PR had an improved predictive performance with an area under the curve (AUC) value of 0.945. Expression of hormone receptors predicts survival and platinum sensitivity of HGSOC. AR, ER, and PR might be feasible prognostic biomarkers for HGSOC by immunohistochemical analysis.

Androgen Receptor and PIM1 Expression in Tumor Tissue of Patients With Triple-negative Breast Cancer.

Effective targeted therapies for triple-negative breast cancer (TNBC) are limited. In a subset of TNBC, androgen receptor (AR) plays an important role, while the human proviral integration site for Moloney murine leukemia virus-1 (PIM1) overexpression is also implicated. PIM1 kinases phosphorylate AR, thus regulating its transcriptional activity, regardless of the presence or not of androgens. We evaluated the expression of AR and PIM1 and their prognostic significance in TNBC. AR and PIM1 transcripts were quantified by quantitative reverse transcription polymerase chain reaction in formalin-fixed paraffin-embedded tumor from 141 patients with TNBC. AR was expressed in 38.3%, PIM1 in 10.6%, while co-expression of AR and PIM1 was detected in 7/141 cases (5.0%). No prognostic significance of AR or PIM1 was reached for overall or disease-free survival. Co-expression of AR and PIM1 exists in only in a small percentage of patients with TNBC. The implications of this finding in the therapeutic management of patients with TNBC should be investigated in larger patient cohorts.

Abstract 6271: Hormone receptor inhibition as a strategy for radiosensitization of breast cancer

Abstract Purpose: Expression of the androgen receptor (AR) has been identified as a driver of tumor growth in triple negative breast cancers (TNBC), and previous work has nominated AR as a target for radiosensitization. In addition, 70-95% of all estrogen receptor (ER) positive (ER+) breast cancers also have coexpression of AR, suggesting extended utility of AR inhibition in the radiosensitization of these AR+, ER+ tumors. Here we assessed the efficacy of AR inhibition in ER+, AR+ breast cancers to better understand the role of AR signaling across breast cancer models. Further, we also investigated the effect of ER inhibition on radiosensitization of ER+ breast cancer models. Methods: IC50 values were determined for MDV3100 (enzalutamide), ARN-509 (apalutamide), and ODM-201 (darolutamide) in TNBC cell lines (AR+ TNBC: MDA-MB-453, ACC-422, and SUM-185PE, and AR- TNBC: MDA-MB-231) and ER+ breast cancer cell lines (AR+, ER+: ZR-75-1, BT-474, CAMA-1, and AR-, ER+: MCF-7). IC50 values for tamoxifen were determined for ER+ breast cancer cell lines (MCF-7, T47D, ZR-75-1), and ER- (SUM-159) cells. Clonogenic survival assays were performed to assess radiosensitization with ER or AR inhibition with tamoxifen or second generation anti-androgens, respectively, in TNBC and ER+ breast cancer models. Results: AR inhibition with enzalutamide, apalutamide, and darolutamide showed limited single agent growth inhibition efficacy in AR+ TNBC and AR+, ER+ breast cancer cell lines (IC50 > 10 μM). AR inhibition with enzalutamide did not induce radiosensitivity in vitro. In AR+, ER+ CAMA-1 cells, AR blockade with enzalutamide had a radioprotective effect with enhancement ratios (enhR) of 0.76-0.83. No radiosensitization was observed in BT-474 (enhR: 0.92-1.01) or ZR-75-1 cells (enhR: 0.94-1.00). Radiosensitization was also assessed with anti-androgens apalutamide and darolutamide in AR+ breast cancer models. Inhibition of ER with tamoxifen, however, induced radiosensitization in MCF-7 (enhR: 1.14-1.50) and T47D (enhR: 1.33-1.60) cells. No radiosensitization was observed with tamoxifen in ER- SUM-159 cells. Conclusion: Although AR is a mediator of radioresistance in AR+ TNBC, AR inhibition does not provide comparable radiosensitization in AR+, ER+ models and may actually confer a radioprotective effect. In contrast, our results demonstrate ER inhibition is an effective radiosensitizing strategy in ER+ breast cancers, independent of AR status. This work highlights the complexities of androgen and estrogen receptor signaling in AR+, ER+ breast tumors and underscores the necessity for understanding context dependent effects when translating into patients with AR+ breast cancer. Citation Format: Anna R. Michmerhuizen, Amanda Zhang, Rachel Schwartz, Andrea M. Pesch, Benjamin C. Chandler, Cassandra L. Ritter, Meilan Liu, Kari Wilder-Romans, Daniel E. Spratt, Daniel R. Wahl, Shyam Nyati, Lori J. Pierce, Corey Speers. Hormone receptor inhibition as a strategy for radiosensitization of breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6271.

Co-Expression of Androgen Receptor and Cathepsin D Defines a Triple-Negative Breast Cancer Subgroup with Poorer Overall Survival

Background: In the triple-negative breast cancer (TNBC) group, the luminal androgen receptor subtype is characterized by expression of androgen receptor (AR) and lack of estrogen receptor and cytokeratin 5/6 expression. Cathepsin D (Cath-D) is overproduced and hypersecreted by breast cancer (BC) cells and is a poor prognostic marker. We recently showed that in TNBC, Cath-D is a potential target for antibody-based therapy. This study evaluated the frequency of AR/Cath-D co-expression and its prognostic value in a large series of patients with non-metastatic TNBC. Methods: AR and Cath-D expression was evaluated by immunohistochemistry in 147 non-metastatic TNBC. The threshold for AR positivity (AR+) was set at ≥1% of stained cells, and the threshold for Cath-D positivity (Cath-D+) was moderate/strong staining intensity. Lymphocyte density, macrophage infiltration, PD-L1 and programmed cell death (PD-1) expression were assessed. Results: Scarff-Bloom-Richardson grade 1–2 and lymph node invasion were more frequent, while macrophage infiltration was less frequent in AR+/Cath-D+ tumors (62.7%). In multivariate analyses, higher tumor size, no adjuvant chemotherapy and AR/Cath-D co-expression were independent prognostic factors of worse overall survival. Conclusions: AR/Cath-D co-expression independently predicted overall survival. Patients with TNBC in which AR and Cath-D are co-expressed could be eligible for combinatory therapy with androgen antagonists and anti-Cath-D human antibodies.

Distribution and characteristics of androgen receptor (AR) in breast cancer among women in Addis Ababa, Ethiopia: A cross sectional study.

Evaluation of the role of androgen receptor (AR) in the biology of breast cancer is an emerging area of research. There are compelling evidences that AR expression may be used to further refine breast cancer molecular subtyping with prognostic and therapeutic implications. Many studies indicated co-expression of AR with the hormonal receptors in breast cancer has a favorable prognosis. AR is also investigated by many researchers as a potential therapeutic target in treatment of breast cancer. Studies on the frequency and distribution of AR in breast cancer among Africans is barely available. Given the heightened interest to understand its role in breast cancer, we determined AR expression and assessed its association with clinicopathological parameters among Ethiopian women. In this study, 112 newly diagnosed patient with invasive breast cancer at Tikur Anbessa Specialized Hospital were enrolled. Immunohistochemical assessment of AR, ER, PR, Ki67 and HER2 were performed using tissue microarrays (TMA) constructed from their primary tumor block. Out of the 112 participants, 91 (81%) were positive for AR expression and the remaining 21 participants (19%) were negative for AR expression. Expression of AR in ER+, HER2+ and TNBC cases were 93%, 83% and 48% respectively. Our study reveals AR is expressed in a significant number of breast cancers patients and this may indicate that breast cancers cases in Ethiopia have favorable prognosis and could benefit from progresses in AR targeted treatments. Since AR expression has important consequences on the prognosis and treatment of breast cancer, further studies with an increased number of participants is necessary to confirm our reports.

The Expression and Prognostic Significance of Claudin-8 and Androgen Receptor in Breast Cancer.

PurposeClaudin-8 (CLDN8) has been identified as an androgen-regulated gene in prostate cancer. However, the role of CLDN8 has not been fully explored in breast cancer. We aimed to explore the expression of CLDN8 and androgen receptor (AR), determine the correlation between CLDN8 and AR, assess the prognostic value of CLDN8 and AR co-expression, and investigate the possible CLDN8 expression molecular mechanism in breast cancer.Materials and MethodsTwenty-eight pairs of fresh tumor tissues and adjacent noncancerous tissues were evaluated by Western blot for CLDN8. Then, 142 breast cancer samples were determined by immunohistochemistry for CLDN8 and AR. The association of clinicopathological features with CLDN8, AR and CLDN8, and AR co-expression was examined. The Cancer Genome Atlas (TCGA) was used to demonstrate the expression of CLDN8 and correlation between CLDN8 and AR. Kaplan–Meier survival analysis was performed to assess the prognostic impact of CLDN8 and AR co-expression. The mechanisms related to CLDN8 expression in breast cancer were explored by Gene Set Enrichment Analysis (GSEA).ResultsCLDN8 was downregulated in breast cancer tissues and positively correlated with none lymph node metastasis (P=0.016), low histological grade (P=0.006), positive ER (P=0.014), positive PR (P=0.003), low Ki-67 index (P=0.017) and molecular subtypes (P=0.012). CLDN8 level was significantly associated with AR level (r=0.348; P<0.001). CLDN8 and AR co-expression was positively correlated with none lymph node metastasis (P=0.007), low histological grade (P=0.017), positive ER (P=0.019), positive PR (P=0.015) and low Ki-67 index group (P=0.038). CLDN8 and AR co-expression had a better clinical prognosis.ConclusionThe expression of CLDN8 is directly related to the expression of AR. CLDN8 and AR co-expression might be a potential prognostic evaluation factor for breast cancer patients.

Abstract P5-11-07: The significance of androgen receptor co-expression in ER+ metastatic breast cancer patients treated with palbociclib

Abstract Background: The PALOMA-1 and PALOMA-3 studies demonstrated a significant progression-free survival (PFS) advantage for palbociclib, a CDK4/6 inhibitor, in combination with letrozole or fulvestrant in the first or second line setting compared to these therapies alone in estrogen receptor (ER)+, HER2-negative metastatic breast cancer (MBC). Recent studies have revealed preliminary efficacy signals for androgen receptor (AR) blockade in MBC, predominately in AR+, triple negative patients. We sought to further evaluate AR expression and its significance in ER+ MBC patients treated with palbociclib early in their metastatic treatment course. Methods: A retrospective review identified 22 patients treated with palbociclib for ER+, HER2- MBC after its FDA approval between January 1st, 2015 and October 1st, 2016 at our center with available pre-treatment tumor samples for analysis. Records were reviewed and clinical characteristics for each patient were analyzed. Archival tumor tissue was tested for AR, phosphorylated retinoblastoma (pRb), CDK6, p16, and CyclinE1 by immunohistochemistry assay for each patient. For AR, nuclear staining &amp;gt;0% was considered positive. For all other IHC studies, intensity of staining &amp;gt;2+ or staining in &amp;gt;10% of cells was considered positive. Results: The median age was 63.5 years (range 34-84); 23% were ≥ age 70. Our cohort was 35% African American, 60% Caucasian, and 5% Asian American. 64% of patients were post-menopausal and 59% had visceral metastases. 45% of patients were on their first line of treatment, 23% second line, and 32% third line. 68% of patients were on an aromatase inhibitor. Median follow up was 18.7 months (95% CI 13.9, 23.3 months). The AR was expressed in 59% of patients; 55% had expression &amp;gt;10% and 41% had expression &amp;gt;20%. AR+ patients were significantly more likely to experience event-free survival (EFS) (HR 0.26, p=0.01), with a median EFS of 18.8 months (AR- median EFS 5.4 months). AR expression was significantly associated with expression of pRb (100% of AR+ patients, p=0.02). CDK6, p16, and CyclinE1 expression were not associated with AR expression or EFS. Conclusions: Our data show preliminary evidence of the significance of ER and AR co-expression in ER+, HER2- MBC. ER+, AR+ patients have significantly improved EFS when treated with palbociclib and endocrine therapy as compared with AR-, ER+ patients. There is evidence that AR expression is associated with pRB expression, which may represent a mechanism by which cell cycle inhibition with palbociclib is particularly efficacious in these patients. AR expression rates in ER+, HER2- MBC are significant, and may provide rationale for combining CDK4/6 inhibitors with AR targeting as a subsequent line of targeted therapy in these patients before cytotoxic chemotherapy is initiated. Further studies based on these results are underway. Citation Format: Landry CA, Ru M, Jaffer S, Dimitrova M, Tiersten A. The significance of androgen receptor co-expression in ER+ metastatic breast cancer patients treated with palbociclib [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-11-07.

The Prevalence of Triple Negative Breast Cancer and Its Androgen Receptor Coexpression in Harare, Zimbabwe

The Prevalence of Triple Negative Breast Cancer and Its Androgen Receptor Coexpression in Harare, Zimbabwe

Expression of Hormone Receptors and HER-2 in Benign and Malignant Salivary Gland Tumors.

With the advent of targeted therapies, expression of sex hormone receptors and HER-2 in salivary gland tumors (SGTs) is of clinical interest. Previous reports of estrogen (ER) and progesterone (PR) receptor expression have varied. Androgen receptor (AR) and HER-2 overexpression are frequently reported in salivary duct carcinoma (SDC), but have not been studied systematically in other SGTs. This study examines ER, PR, AR, and HER-2 expression in SGTs. Immunohistochemistry for ER, PR, AR, and HER-2 was performed on 254 SGTs (134 malignant). ER, PR, and AR expression was scored using Allred system. HER-2 expression was scored using Dako HercepTest guidelines. FISH for HER-2 amplification was performed on select cases with HER-2 overexpression (2-3+). No SGT demonstrated strong expression of ER or PR. Combined strong AR and HER-2 expression was seen in 22 carcinomas: 14/25 SDC, 3/16 poorly differentiated, two oncocytic, and one each carcinoma ex pleomorphic adenoma, squamous cell, and intraductal carcinoma. Eighteen additional high grade carcinomas had HER-2 overexpression with absent, weak, or moderate AR expression; eight high grade carcinomas had isolated strong AR expression with 0-1+ HER-2 staining. Of 15 tested cases, six demonstrated HER-2 amplification by FISH, all of which had 3+ immunoreactivity. Neither benign nor malignant SGTs had strong expression of ER or PR. None of the benign SGTs overexpressed AR or HER-2. Coexpression of AR and HER-2 should not define SDC, but immunostaining should be considered in high grade salivary carcinomas, as some show overexpression and may benefit from targeted therapy.

High-Throughput Screen for Inhibitors of Androgen Receptor-RUNX2 Transcriptional Regulation in Prostate Cancer.

Runt-related transcription factor 2 (RUNX2) plays a critical role in prostate cancer progression. RUNX2 interacts with the androgen receptor (AR) and modulates its transcriptional activity in a locus-specific manner. RUNX2 and AR synergistically stimulate a subset of genes, including the pro-oncogene snail family zinc finger 2 (SNAI2). AR-RUNX2 signaling cooperatively induces invasiveness of prostate cancer cells via SNAI2; and coexpression of AR, RUNX2, and SNAI2 in prostate cancer biopsy samples predicts disease recurrence. Competitive inhibition of AR alone could not disrupt the synergistic activation of SNAI2. We therefore established a phenotypic cell-based screening assay for compounds that could inhibit AR-RUNX2 synergistic activity either directly or indirectly. This assay was used to screen 880 compounds as a proof of concept, resulting in identification of several compounds that disrupted the synergistic stimulation of genes. Further investigation suggested the involvement of epidermal growth factor receptor (EGFR) signaling in AR/RUNX2 synergistic activity. Our assay is amenable to high-throughput screening and can be used to identify inhibitors of the AR-RUNX2 interaction in prostate cancer cells.

Comprehensive Immunophenotypic Characterization of Adult and Fetal Testes, the Excretory Duct System, and Testicular and Epididymal Appendages.

The immunophenotype of a normal testis and the excretory duct system has not been studied comprehensively in fetal and adult patients without testicular disease or hormonal manipulation so far. In addition, testicular (TA) and epididymal (EA) appendages are frequent paratesticular structures without previously reported comprehensive immunophenotypic studies. Immunohistochemistry for multiple markers, including the androgen receptor (AR), the estrogen receptor (ER), the progesterone receptor (PR), the prostate-specific antigen, the prostate-specific membrane antigen, PAX8, WT1, calretinin, CK7, CK20, OCT4, SALL4, and CD117, was performed on full sections of testicular/paratesticular tissue from a large cohort of adult and fetal autopsy patients. In contrast to adult germ cells (GC), fetal GC strongly express OCT4 and CD117, although the expression of these proteins is lost in the early postnatal period; SALL4, in contrast, is expressed in both fetal and adult GC, with only weak and focal expression in adult patients. Fetal Sertoli cells (SC) express WT1 and calretinin strongly and diffusely, in contrast to adult SC. Both fetal and adult excretory duct systems express CK7 and PAX8 with frequent AR coexpression, and all 3 main segments of the excretory duct system (ductuli efferentes, epididymis, and vas deferens) have unique immunophenotypes. The rete testis also has a unique immunohistochemical expression pattern, which includes strong expression of CK7, PAX8, WT1, calretinin, and AR. Finally, of the adult autopsy patients examined, 80% had a TA, and 60% had an EA; these paratesticular structures occurred at stereotypical locations, demonstrated reproducible morphologic features, and had a unique immunophenotype relative to other studied structures, with strong CK7, PAX8, WT1, AR, ER, and PR coexpression. The testis and the paratestis may be involved by diverse neoplastic and non-neoplastic processes, and knowledge of the immunophenotypic expression spectrum of these tissues may aid in clinical diagnosis and advance our understanding of the pathogenesis of both oncologic and nononcologic disease processes.

Expression patterns of GATA3 and the androgen receptor are strongly correlated in patients with triple-negative breast cancer

GATA-binding protein 3 (GATA3) is a diagnostically useful immunohistochemical marker of breast cancer. Because of its strong association with estrogen receptor expression, GATA3 has markedly reduced sensitivity in triple-negative breast cancer (TNBC). We constructed a tissue microarray using a large series of TNBCs and evaluated GATA3 expression by TNBC subtype as defined by surrogate immunohistochemical markers. A total of 205 TNBCs were classified into cancers of the molecular apocrine type (n=23, 11.2%), claudin-low type (n=21, 10.2%), basal-like type (n=91, 44.4%), mixed type (n=62, 30.2%), and null type (n=8, 3.9%). The GATA3 scores (staining intensity × proportion) were categorized as negative (0), focally positive (1-10), or positive (11-300). GATA3 staining was negative in 153 cancers (74.6%), focally positive in 11 (5.4%), and positive in 41 (20.0%). The rate of focal positivity or positivity for GATA3 was significantly higher in the molecular apocrine type (73.9%, 17/23) than in other types of TNBCs (P=.001). The mean GATA3 score of molecular apocrine-type TNBC was significantly higher than that of the other types (P=.001) and differed significantly between androgen receptor (AR)-positive and AR-negative TNBCs (P<.001). In conclusion, GATA3 expression was correlated strongly with AR-positive, molecular apocrine-type TNBCs. Co-expression of AR and GATA3 is a specific feature of molecular apocrine-type TNBC, which may serve as a diagnostic aid for cancer of unknown primary.

Dysregulation of miR-212 Promotes Castration Resistance through hnRNPH1-Mediated Regulation of AR and AR-V7: Implications for Racial Disparity of Prostate Cancer.

The causes of disproportionate incidence and mortality of prostate cancer among African Americans (AA) remain elusive. The purpose of this study was to investigate the mechanistic role and assess clinical utility of the splicing factor heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) in prostate cancer progression among AA men. We employed an unbiased functional genomics approach coupled with suppressive subtractive hybridization (SSH) and custom cDNA microarrays to identify differentially expressed genes in microdissected tumors procured from age- and tumor grade-matched AA and Caucasian American (CA) men. Validation analysis was performed in independent cohorts and tissue microarrays. The underlying mechanisms of hnRNPH1 regulation and its impact on androgen receptor (AR) expression and tumor progression were explored. Aberrant coexpression of AR and hnRNPH1 and downregulation of miR-212 were detected in prostate tumors and correlate with disease progression in AA men compared with CA men. Ectopic expression of miR-212 mimics downregulated hnRNPH1 transcripts, which in turn reduced expression of AR and its splice variant AR-V7 (or AR3) in prostate cancer cells. hnRNPH1 physically interacts with AR and steroid receptor coactivator-3 (SRC-3) and primes activation of androgen-regulated genes in a ligand-dependent and independent manner. siRNA silencing of hnRNPH1 sensitized prostate cancer cells to bicalutamide and inhibited prostate tumorigenesis in vivo Our findings define novel roles for hnRNPH1 as a putative oncogene, splicing factor, and an auxiliary AR coregulator. Targeted disruption of the hnRNPH1-AR axis may have therapeutic implications to improve clinical outcomes in patients with advanced prostate cancer, especially among AA men.

Lin28A and androgen receptor expression in ER-/Her2+ breast cancer.

The aim of this study was to examine the expression of Lin28A and androgen receptor (AR) in ER-/Her2+ breast cancer, and to research the association of Lin28A and AR co-expression status with patients' prognosis. The expression of Lin28A and AR in formalin-fixed and paraffin-embedded surgical sections from 305 patients with ER-/Her2+ breast cancer was analyzed by immunohistochemistry, and the co-expression patterns in breast cancer cells were investigated by immunofluorescent staining. The impact of the expression of Lin28A and AR in prognosis was also assessed by the Kaplan-Meier, univariate, and multivariate logistic regression models. This study included 305 cases ER-/Her2+ breast cancer patients. Lin28A and AR were expressed in 240 cases (78.7 %) and 220 cases (72.1 %), respectively. Lin28A tended to be higher in AR-positive patients (75.0 %). Lin28A and AR co-expression (Lin28+/AR+) was significantly associated with high tumor grade (G3) (p = 0.023) and high Ki67 index (p = 0.020). The mRNA and protein expression levels of Lin28A and AR were higher in MDA-MB-453 cells (ER-/Her2+) than in the MDA-MB-231 cells (ER-/Her2-). In univariate analysis, Lin28A+/AR+ was significant risk factors associated with unfavorable OS (p = 0.049) and RFS (p = 0.019). Kaplan-Meier analysis showed that Lin28A+/AR+ expression showed lower RFS rates compared with Lin28A-/AR+ (p = 0.043) and Lin28A-/AR- patients(p = 0.019). Multivariate cox model showed that Lin28A+/AR+ remained an independent negative prognostic factor for RFS. Our study showed that Lin28A and AR co-expressed in ER-/Her-2+ breast cancer and correlated with poor prognosis. The possibility that Lin28A may drive AR expression via a positive feedback mechanism remains to be tested.

Abstract P3-04-07: Androgen receptor expression in triple negative breast cancer

Abstract Background: Patients with androgen receptor (AR) positive triple-negative breast cancer (TNBC) may derive a significant benefit from anti-androgen therapy. While AR positivity is often defined by protein expression by immunohistochemistry (IHC), the benefit of anti-androgen therapy in patients who have the Luminal Androgen Receptor (LAR) molecular subtype as defined by genomic profiling is unclear. Our aim was to study the clinical, pathologic and molecular profiles of AR+ tumors by IHC in a diverse set of TNBC. Methods: Tissue microarrays from two separate, well-annotated institutional cohorts (Case Western Reserve University, Yale University) of early-stage TNBC were evaluated for AR expression by IHC (clone SP107, Ventana Benchmark Ultra). AR positivity was defined as greater than or equal to 10% staining in tumor nuclei. AR expression was correlated with clinical and pathologic features such as age, race, grade, and stage within and between the two cohorts. Gene expression was analyzed with the DASL assay (Illumina) on RNA extracted from formalin-fixed paraffin-embedded material using the Ambion RecoverAll kit (Applied Biosystems AM1975). Pietenpol TNBC molecular subtypes were calculated using the online TNBC type tool. Co-expression of AR with other hormone-related proteins including gross cystic disease fluid protein-15 (GCDFP-15, clone EP1582Y, Ventana Benchmark Ultra) and GATA transcription factor 3 (GATA3, clone L50-823, Bondmax Leica) were also assessed. Results: Overall, 22% of cases (n=192) were AR+ by IHC. There was no association between AR expression and age, race, grade or stage within or between the two cohorts. Gene expression data was available on 88 tumors with AR staining results and demonstrated that AR positivity by IHC was not exclusive for the TNBC LAR molecular subtype. Three of five (3/5) tumors that were classified and LAR were in fact AR+ by IHC. Tumors that were AR+ by IHC were also identified in the basal-like 2 (BL2), mesenchymal stem-like (MSL), immunomodulatory (IM), and unstable molecular TNBC categories with low frequency. Notably, of cases that were rejected as ER+ by gene expression profiling despite being clinically TNBC, three of five (3/5) were in fact AR+ by IHC. Examination of other hormone-related proteins in a subset of these patients revealed that AR expression was significantly associated with GCDFP-15 expression (p=0.0007) and was borderline significant for GATA3 expression (p=0.068). Conclusions: AR protein expression levels by IHC were similar in two separate institutional archival cohorts of TNBC and did not correlate with age, race, grade or stage. Comparison of AR IHC data with genomic data suggests that the AR+ phenotype is not unique to LAR subtype of TNBC by gene expression profiling. AR protein expression may be seen in clinically TNBC patients who have a more luminal subtype as evidenced by co-expression of GCDFP-15 and GATA3. Our results suggest that AR staining by IHC may be necessary to capture all patients who may benefit from anti-androgen therapy. Citation Format: Hannah Gilmore, Vinay Varadan, Nicole Williams, Cheryl L Thompson, Stephanie Kim, Peter Hsu, Kristy Miskimen, Aditi Palkar, Shaveta Vinayak, Robert Lindner, Lyndsay Harris. Androgen receptor expression in triple negative breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-04-07.

Restoration of spermatogenesis and male fertility using an androgen receptor transgene.

Androgens signal through the androgen receptor (AR) to regulate male secondary sexual characteristics, reproductive tract development, prostate function, sperm production, bone and muscle mass as well as body hair growth among other functions. We developed a transgenic mouse model in which endogenous AR expression was replaced by a functionally modified AR transgene. A bacterial artificial chromosome (BAC) was constructed containing all AR exons and introns plus 40 kb each of 5' and 3' regulatory sequence. Insertion of an internal ribosome entry site and the EGFP gene 3’ to AR allowed co-expression of AR and EGFP. Pronuclear injection of the BAC resulted in six founder mice that displayed EGFP production in appropriate AR expressing tissues. The six founder mice were mated into a Sertoli cell specific AR knockout (SCARKO) background in which spermatogenesis is blocked at the meiosis stage of germ cell development. The AR-EGFP transgene was expressed in a cyclical manner similar to that of endogenous AR in Sertoli cells and fertility was restored as offspring were produced in the absence of Sertoli cell AR. Thus, the AR-EGFP transgene under the control of AR regulatory elements is capable of rescuing AR function in a cell selective, AR-null background. These initial studies provide proof of principle that a strategy employing the AR-EGFP transgene can be used to understand AR functions. Transgenic mice expressing selective modifications of the AR-EGFP transgene may provide crucial information needed to elicit the molecular mechanisms by which AR acts in the testis and other androgen responsive tissues.

Targeting the androgen receptor in prostate and breast cancer: several new agents in development.

Prostate cancer (PCa) and breast cancer (BCa) share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to PCa therapy. Recently, there has been increased interest in the role of the AR in BCa development and growth, with results indicating AR co-expression with estrogen, progesterone, and human epidermal growth factor receptors, across all intrinsic subtypes of BCa. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable to both tumor types. In this review, we offer an overview of available agents which target the AR axis in both PCa and BCa and provide insights into the novel drugs in development for targeting this signaling pathway.

558 ANDROGEN ACTIVATES β-CATENIN SIGNALING IN ANDROGEN RECEPTOR-POSITIVE BLADDER CANCER CELLS

You have accessJournal of UrologyBladder Cancer: Basic Research I1 Apr 2012558 ANDROGEN ACTIVATES β-CATENIN SIGNALING IN ANDROGEN RECEPTOR-POSITIVE BLADDER CANCER CELLS Yi Li, Yichun Zheng, Koji Izumi, Bo Ye, Faqian Li, and Hiroshi Miyamoto Yi LiYi Li Rochester, NY More articles by this author , Yichun ZhengYichun Zheng Rochester, NY More articles by this author , Koji IzumiKoji Izumi Rochester, NY More articles by this author , Bo YeBo Ye Rochester, NY More articles by this author , Faqian LiFaqian Li Rochester, NY More articles by this author , and Hiroshi MiyamotoHiroshi Miyamoto Rochester, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.633AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Androgen receptor (AR) signals play an important role in bladder carcinogenesis and tumor progression. Activation of Wnt/β-catenin signaling has also been reported to correlate with poor prognosis in bladder cancer patients. However, cross-talk between AR and β-catenin pathways in bladder cancer remains unknown. METHODS We performed western blotting to assess the expression of total β-catenin (TBC), an active form of β-catenin (ABC), and its downstream targets in human urothelial carcinoma cell lines, including AR-positive UMUC3 and AR-negative 5637 and J82 (with or without stable expression of AR), following treatment with dihydrotestosterone (DHT) and/or an anti-androgen hydroxyflutamide (HF). We also performed immunohistochemistry to determine expression levels of β-catenin (as well as AR) and its localization in human bladder cancer tissues. RESULTS In AR-positive bladder cancer cells, DHT increased the expression of ABC over mock treatment and HF at least partially blocked the effect of DHT. DHT also slightly augmented TBC levels in these cells. DHT enhanced nuclear expression of β-catenin (TBC and ABC) in 5637-AR and J82-AR, but not in 5637 and J82. In addition, DHT up-regulated the expression of downstream of β-catenin, c-myc and epidermal growth factor receptor, in the AR-positive cells, but not in their parental AR-negative cells. In 24 radical cystectomy specimens, β-catenin was expressed in all non-neoplastic urothelial tissues, while the signals were weaker or lost in 62% of cancer tissues (p=0.0015). Loss of membrane/cytosol β-catenin signals was strongly associated with muscle-invasion (≥pT2) (p=0.0474). Interestingly, there was a strong relationship between nuclear AR expression and nuclear β-catenin expression (p=0.0215). Kaplan-Meier and log-rank tests further revealed that loss of β-catenin expression in membrane/cytosol significantly correlated with poorer prognosis (p=0.0326). Furthermore, co-expression of nuclear AR/β-catenin (p=0.0010), but not nuclear β-catenin expression alone (p=0.2424), correlated with tumor progression. CONCLUSIONS Our results suggest that androgen activates β-catenin signaling via the AR pathway in bladder cancer cells. Co-expression of AR and β-catenin in bladder cancer likely predicts poor prognosis. AR signals may thus contribute to the progression of bladder cancer via regulation of the Wnt/β-catenin pathway. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e228 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yi Li Rochester, NY More articles by this author Yichun Zheng Rochester, NY More articles by this author Koji Izumi Rochester, NY More articles by this author Bo Ye Rochester, NY More articles by this author Faqian Li Rochester, NY More articles by this author Hiroshi Miyamoto Rochester, NY More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...