Differences In Androgen Receptor Expression Research Articles

Differences in Androgen Receptor Expression in Human Heart Tissue in Various Types of Cardiomyopathy and in Aortic Valve Stenosis.

Background: Sex-specific differences in heart disease outcomes are influenced by the levels of the steroid hormones, estrogen and testosterone. While the roles of estrogen receptors in cardiac disease are well-studied in animals and humans, respective research on androgen receptors (AR) is limited. Here we investigate AR protein and mRNA expression in human myocardium of various cardiac diseases. Methods: AR expression was analyzed by western blotting in myocardium from human non-failing hearts (NF, n = 6) and patients with aortic stenosis (AS, n = 6), hypertrophic cardiomyopathy (HCM, n = 7), dilated cardiomyopathy (DCM, n = 7), and ischemic cardiomyopathy (ICM, n = 7). Using an AR45-specific antibody, a subsequent western blot assessed samples from male and female patients with HCM (n = 10) and DCM (n = 10). The same sample set was probed for full-length AR and AR45 mRNA expression. Immunohistochemistry (IHC) localized AR in myocardium from HCM and AS hearts. Results: Full-length AR was notably enriched in AS and HCM hearts compared to ICM, DCM, and NF. Similarly, AR45 was more abundant in HCM than in DCM. In contrast to the pattern observed for AR protein, full-length AR mRNA levels were lower in HCM compared to DCM, with no discernible difference for the AR45 isoform. Although gender differences in AR expression were not detected in western blots or qRT-PCR, IHC showed stronger nuclear AR signals in males than in females. Conclusions: Our findings indicate disease-specific regulation of AR mRNA and/or AR protein in cardiac hypertrophy, underscoring a potential role in this cardiac pathology.

Assessment of the Androgen Receptor in Older Women with Primary Breast Cancer: Association with a Panel of Biomarkers and Breast Cancer Specific Survival.

Breast cancer in older women tends to have more favourable biology, compared to younger women. Androgen receptor (AR) is significant for breast tumour carcinogenesis; however, the role of AR in older women has not been fully explored. Surgical specimens were obtained from an existing series of 1758 older women (≥ 70years) with primary breast cancer, treated in a single institution with long-term (≥ 37years) follow-up. As part of previous work, it was possible to construct good quality tissue microarrays (TMAs) in 575 surgical specimens and a panel of 24 biomarkers was measured by immunohistochemistry (IHC) in these TMAs. AR positivity was assessed by IHC and defined as H-score ≥ 40. The relationship between AR in this cohort was compared to an equivalent group of younger women (< 70years, n = 1708); the panel of 24 biomarkers and breast cancer specific survival (BCSS) in the older cohort. AR was assessed in 509 samples. Overall, 59% of the older women cohort had positive expression of AR, compared to 63% in the younger cohort. AR positivity (regardless of age) was associated with smaller size of tumour, lower grade of tumour, lower tubule formation, lower nuclear polymorphism and lower mitotic frequency. AR positivity was associated with positive expression of oestrogen receptor (ER), progesterone receptor (PR), breast cancer gene1 (BRCA1), cytokeratin (CK) 7/8, CK18, CK19, Bcell lymphoma (Bcl)2 and Mucin1 (Muc1) expression. Conversely, AR-positive expression was associated with negative expression of human epidermal growth factor receptor2 (HER2), Ki-67, CK5, CK17, epidermal growth factor receptor (EGFR), and CD44 expression. Older women with AR-positive tumours had better BCSS compared to AR-negative tumours (p = 0.009). There was no difference in AR expression between older and younger women with breast cancer. AR has prognostic potential in terms of BCSS. Further work is needed to investigate AR as a therapeutic target.

Abstract 5913: Genetic landscape changes in metastatic prostate cancer after sequential steps of androgen targeted therapy

Abstract Metastatic prostate cancer is non-curable fatal disease requiring active treatment. Prostate cancer cell proliferation requires androgen hormones mediated by androgen receptor (AR). Typical metastatic prostate cancer treatment exploits this dependency by systemic androgen deprivation and AR inhibition. While androgen deprivation therapy (ADT) effectively halts cancer cell proliferation, the cells adapt to the limited androgen supply over time by up-regulating AR, making ADT ineffective and creating castration-resistant prostate cancer (CRPC). Androgen receptor signaling inhibitors (ARSIs) such as enzalutamide remain effective even after CRPC development. These drugs have effectively replaced usage of AR inhibitors such as bicalutamide in clinical management of CRPC. However, over time cancer cells undergo further genetic transformations leading to ARSI resistance. Some genetic adaptation mechanisms behind this are known, e.g., AR over-expression and alternative splicing of AR. However, detailed genetic landscape shift is unknown. Moreover, it is unknown whether different AR inhibitors or their sequencing may affect cancer cell genotype and phenotype similarly. We compare genetic profiles of two different multiresistant VCaP cell populations achieved by long-term cell culture. Two treatment paths are: A. ADT, bicalutamide (BIC), and enzalutamide (ENZA) sequentially; and B. ADT and ENZA sequentially, without bicalutamide. Each consequent treatment is continued as long as it takes for the cells to regain cellular proliferation despite the treatment in order to induce adaptive genetic transformations required for treatment resistance. Once cell proliferation resumes, the obtained resistant cell population is sequenced for mRNA expression levels and splice variant distribution. The genetic profiles of treatment path A and B are compared by analyzing differentially expressed genes and splice variant expression distributions. At the end of the treatment paths, both cell populations are exposed to variable doses of docetaxel to investigate whether ADT- and ARSI-resistant genetic profile affects vulnerability to subsequent chemotherapy. There was no difference in AR expression or AR splice variant distribution between the treatment paths A and B. AR splicing variants are observed after ARSI resistance. However, multiple other cancer-related genes are differentially expressed between the treatment paths, including FOS, CCND1, IGF1R, and AGR2 which were down-regulated by BIC and heavily up-regulated by ENZA. These genetic alterations also translate into proteomic changes. Remarkably, cells treated with BIC prior to ENZA responded significantly better to docetaxel than ENZA-only treated cells (100 nM dose treatment left 73.75% and 64.55 % cells dead, respectively). ENZA treatment drives genetic landscape shift in cancer cells when achieving treatment resistance. However, this differs by treatment sequencing; observed genetic transformations differ by whether ENZA treatment was preceded by BIC exposure. Importantly, the differences in the genetic profile lead to greater chemoresistance in cells not treated with BIC before ENZA as compared to cells receiving both treatments. This observation may have implications in optimal sequencing of treatment in CRPC. Citation Format: Paavo V. H. Raittinen, Pasi Pennanen, Heimo Syvälä, Merja Bläuer, Niina Ikonen, Reetta Nätkin, Matti Nykter, Teuvo Tammela, Pauliina Ilmonen, Teemu T. Murtola. Genetic landscape changes in metastatic prostate cancer after sequential steps of androgen targeted therapy [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 5913.

Abstract PR18: Prognostic role of androgen receptor in triple-negative breast cancer: A global multi-institutional experience

Abstract Background: African American (AA) triple-negative breast cancer (TNBC) patients experience worse clinical outcomes and exhibit 40% higher mortality rate than their European Americans (EAs) counterparts. There are currently no distinctions in inherent tumor biology between the ethnically distinct TNBC patients that serve as risk-predictive markers allowing new tailored treatments. Recently, androgen receptor (AR) has emerged as a new target for treating TNBC. However, the prognostic value of AR in TNBC remains controversial. To reconcile conflicting reports about the impact of AR loss on prognosis of TNBC and uncover the molecular pathways that may underlie the racial disparity in outcomes among AR-negative TNBCs, we determined the prognostic value of AR in diverse TNBC cohorts. Since loss of AR is associated with worse clinical outcome and African and AA women are more prone to aggressive disease course, we hypothesized that AR loss may underlie the global disparate burden in TNBC. Methods: We evaluated AR expression in well-annotated formalin-fixed, paraffin-embedded TNBC resection samples (n=1351) obtained from multiple hospitals from US, UK, Norway, Ireland, Nigeria and India. Samples with ≥1% nuclei staining positive for AR were deemed to be AR-positive. Associations between AR status, clinicopathologic variables and overall survival (OS) were evaluated. We performed gene set enrichment analysis for AR low and high group in AA and EA TNBCs. In vitro experiments were performed to examine whether AR loss increased the metastatic potential of TNBC cells. Results: We observed a significant difference in AR expression among EA and AA TNBCs (p=0.02) with AR loss associated with women of African ancestry (&amp;gt;90%, p&amp;lt;0.05). AR loss was significantly associated with poor OS in TNBC patients from US cohort (p=0.0324; n=316 for AR-negative, n=104 for AR-positive) and Nigerian cohort (p=0.0251; AR-negative=164, AR-positive=16). AR-negative was associated with poor OS in adjuvant-treated high Ki67 (&amp;gt;14%) (HR=1.72; p=0.095) AA TNBC (n=98) when compared to EA TNBCs (n=80). Furthermore, AR status retained its significant prognostic value (HR=1.549, p=0.036) after controlling for age, grade, Ki67, race and chemotherapy status. Gene set enrichment analysis revealed that Wnt/β-catenin signaling was the top-enriched gene ontology in the AR-low TNBC subgroup. Moreover, β-catenin protein levels are higher in AA AR-low TNBCs compared with AA AR-high TNBCs (p&amp;lt;0.05), suggesting Wnt signaling upregulation in AA women with AR-negative TNBC. In TNBC cell lines, loss of AR was significantly associated with higher cell proliferation, migration and invasion (p&amp;lt;0.05). Conclusion: Our study suggests a striking association of AR loss in TNBC with women of African ancestry. Our data offer compelling evidence that oncogenic Wnt/β-catenin signaling may link AR loss to more aggressive disease course and represent actionable biology in AA AR-negative TNBCs for whom no targeted treatments are currently on the horizon. This abstract is also being presented as Poster C102. Citation Format: Shristi Bhattarai, Sergey Klimov, Karuna Mittal, Uma Krishnamurthi, Xiaoxian Bill Li, Deepika Wali, Ceyda Sonmez Wetherilt, Ansa Riaz, Mohammad A. Aleskandarany, Andrew R. Green, Ian O. Ellis, Meenakshi Gupta, Lauren E. McCullough, Upender Manne, Johnson Agboola, Brett Baskovich, Emiel A. Janssen, Grace Callagy, Anurag Mehta, Tanuja Shet, Rakha A. Emad, Padmashree C.G. Rida, Ritu Aneja. Prognostic role of androgen receptor in triple-negative breast cancer: A global multi-institutional experience [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr PR18.

Abstract P6-05-07: Comparison of androgen receptor expression in core needle biopsies with surgical samples in primary breast cancer

Abstract Background Breast cancer subtypes are important for the prognosis and optimal treatment of breast cancer patients. Moreover, these subtypes are determined by immunohistochemistry (IHC) using ER, PgR, HER2 and Ki-67 expressions in practical medicine. The androgen receptor (AR) is frequently expressed in breast cancer but has not yet been standardized. IHC is the standard procedure when using preoperative biopsy specimens to determine biomarker expressions. In this study, the differences in AR expression between core needle biopsy (CNB) and matched surgical samples were examined and the relationship between AR expression and the clinicopathological factors was investigated. Patients and Methods Primary breast cancer patients (n=432) who underwent surgery between March 2017 and June 2019 were diagnosed pathologically using CNB. The biomarker expression of 220 of the patients were determined using surgical samples without preoperative treatment. The AR expression was evaluated using IHC and the expression was divided into the negative, low (&amp;lt;10%) and high (≥10%) groups. The H-score (staining intensity x percentage of positive cells) was used to compare the extent of nuclear immunoreactivity for AR between CNB and the matched surgical samples in 119 CNB cases with an AR ≥ 10%. Breast cancer subtypes were categorized using the IHC data derived from ER/PgR, HER2 and Ki-67 (cutoff: 20%) values. Results 1. The AR positive rates was 57.5%(low: 10%; high: 47.5%)in all primary cases. AR expression significantly correlated with positive ER/PgR, lower Ki-67 values and nuclear grade, negative p53 and HER2. The AR expression rate was 73.4% in Luminal A, 59.3% in Luminal B, 65.2% in Luminal HER2, 43.3% in HER2 enriched and 22.2% in triple negative cases. 2. The AR positive rates of the matched cases were 65.0% in CNB cases (low: 10.9%; high: 54.1%) and 44.5% (low: 8.8%; high: 35.9%) in surgical sample cases (p&amp;lt;0.0001). However, there was no significant difference between AR expression and ER, PgR and HER2 status. Ki-67 index values were higher in the surgical samples (median: 35.0%) than CNB samples (median: 27.0%). 3. The median H-score was 130.0 (mean+/- SD: 143.2+/-63.0%) in CNB samples and 85.0 (mean+/-SD: 94.8+/-59.5%) in the surgical samples (p&amp;lt;0.0001), respectively. Conclusion A discordance in the AR expression and H-score between the core needle biopsies and matched surgical samples was found. These findings suggest that a fixation condition may affect the expression status after resection of samples. AR expression using IHC should be evaluated in core needle biopsies. However, further studies are needed for clinical use. Citation Format: Nobuyuki Arima, Reiki Nishimura, Tomofumi Osako, Yasuhiro Okumura, Masahiro Nakano, Mamiko Fujisue. Comparison of androgen receptor expression in core needle biopsies with surgical samples in primary breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-05-07.

Evaluation of androgen receptor status in urothelial carcinoma of the urinary bladder in Egyptian patients: an immunohistochemical study

BackgroundThe roles of androgen and androgen receptor (AR) signaling in the oncogenesis of prostate cancer are very well established. What is more poorly understood is the role of AR in other human malignancies including bladder cancer. The incidence of bladder cancer is much higher in males than females, but the exact etiology has not been fully elucidated. This gender disparity has raised the possibility of the AR pathway being involved in the genesis of this disease. Thereby, the aim of this work was to evaluate the expression of AR in a group of Egyptian patients with urothelial bladder carcinoma and to assess whether its expression was correlated with other pathological tumor features. Urothelial bladder carcinoma tissue samples from 50 patients were studied by immunostaining for AR expression in tumor cells.ResultsAR was positively expressed in 29 (58%) patients, while negative expression was observed in 21 (42%) patients. No statistically significant difference in AR expression with respect to tumor grade (P = 0.07) and pT stage (P = 0.09) was observed.ConclusionsThe results obtained in this study indicates a clinical value of the AR expression in Egyptian patients with urothelial bladder carcinoma, providing the basis for further studies to evaluate its role and the possibility of new target-based therapies for urothelial bladder carcinoma.

Androgen receptor expression in preputial dartos tissue correlates with physiological androgen exposure in congenital malformations of the penis and in controls

The androgen receptor (AR) plays an important role in the development of male genitalia, and impaired androgen signalling has been hypothesised to underlie congenital penile malformations (CPM) such as hypospadias. Previous studies exploring the role of AR expression in the development of CPM have yielded conflicting results. To assess AR expression in human foreskin of boys/men born with hypospadias, buried penis versus controls. Foreskin samples of 428 boys and men undergoing primary penile surgery (198 controls, 197 hypospadias, and 33 buried penis) were collected between October 2013 and July 2018. AR staining was performed in all samples and semi-quantitatively scored by two researchers independently, using a modified quick score (mQuicks) that assesses the proportion and intensity of AR staining in smooth muscle fibres. The interobserver variability of the mQuicks had a high level of agreement for the total score, as well as for the subscores. Two phases of high AR expression were observed in all groups, the first following the postnatal gonadotropin surge (i.e., mini-puberty) and the second in (pre-) puberty. No differences in AR expression were found in hypospadias or buried penis cases as compared to controls matched for age at time of surgery. This study describes the physiological evolution in AR expression in the human foreskin of boys with CPM and explains the cause of the previously reported, conflicting results. Despite the very large cohort, the limitations of this study are the low number of cases younger than sixmonthsat the time of surgery and the lack of Tanner stages to correlate with the mQuicks in adolescents. The mQuicks is a straightforward and informative tool to semi-quantitatively assess AR expression in the dartos tissue. In this study, AR expression in human foreskin shows a bimodal distribution in boys with CMP and controls, following physiological androgen exposure. No statistically significant difference in AR expression could be found between both groups. Whether other local mechanisms are affected by these physiological changes is currently unclear. However, strict age-matching should be considered when exploring the mechanisms underlying disturbed penile and urethral development in CMP.

Evaluation of androgen receptor expression in core needle biopsies and clinico-pathological factors in primary breast cancer.

e12023 Background: Immunohistochemistry (IHC) is used to determine breast cancer subtypes and to evaluate the ER, PgR, and HER2 expressions and the Ki-67 index value. The androgen receptor (AR) is frequently expressed in breast cancer but has not been standardized. IHC is recommended when using preoperative biopsy specimens to determine biomarker expressions. In this study, the differences in AR expression between core needle biopsy and matched surgical samples were investigated. The AR expression was evaluated as a predictor for neoadjuvant chemotherapy and grade of malignancy. Methods: Primary breast cancer patients (n = 363) who underwent surgery between March 2017 and December 2018 were divided into 3 groups; the core needle biopsy and matched surgical comparison group (n = 167), the neoadjuvant chemotherapy group (n = 54), and the without neoadjuvant chemotherapy group (n = 309). The AR expression was evaluated using IHC and the expression was divided into the negative, low ( &lt; 10%) and high (≥10%) groups. Breast cancer subtypes were categorized using the IHC data derived from ER/PgR, HER2 and Ki-67 (cutoff 20%) values. Results: 1. There was no difference between the ER, PgR and HER2 expressions in the comparison group. AR was significantly lower in the surgical specimens. 2. The pCR rate was significantly higher in the ER and PgR negative cases. AR and the Ki-67 value did not correlate with pCR. 3. The AR positive rate was 61.2% in invasive carcinoma cases. Apocrine carcinoma showed a 100% positive rate. 4. AR expression significantly correlated with positive ER and PgR, a lower Ki-67 value, negative p53, and a lower nuclear grade. Luminal A type showed a higher AR rate (78.2%) than the TN and HER2 types. The AR rate was significantly lower (17.1%) in the TN type cases. Conclusions: discordance in the AR expression between the core needle biopsies and matched surgical specimens was found. AR expression using IHC should be evaluated in core needle biopsies.

Association between cadmium and androgen receptor protein expression differs in prostate tumors of African American and European American men

Cadmium is a known carcinogen that has been implicated in prostate cancer, but how it affects prostate carcinogenesis in humans remains unclear. Evidence from basic science suggests that cadmium can bind to the androgen receptor causing endocrine disruption. The androgen receptor is required for normal prostate development and is the key driver of prostate cancer progression. In this study, we examined the association between cadmium content and androgen receptor protein expression in prostate cancer tissue of African American (N = 22) and European American (N = 30) men. Although neither overall tumor cadmium content (log transformed) nor androgen receptor protein expression level differed by race, we observed a race-cadmium interaction with regard to androgen receptor expression (P = 0.003) even after accounting for age at prostatectomy, smoking history, and Gleason score. African American men had a significant positive correlation between tumor tissue cadmium content and androgen receptor expression (Pearson correlation = 0.52, P = 0.013), while European Americans showed a non-significant negative correlation between the two (Pearson correlation = −0.19, P = 0.31). These results were unchanged after further accounting for tissue zinc content or dietary zinc or selenium intake. African American cases with high-cadmium content (>median) in tumor tissue had more than double the androgen receptor expression (0.021 vs. 0.008, P = 0.014) of African American men with low-cadmium level. No difference in androgen receptor expression was observed in European Americans by cadmium level (high 0.015 vs. low 0.011, P = 0.30). Larger studies are needed to confirm these results and if upheld, determine the biologic mechanism by which cadmium increases androgen receptor protein expression in a race-dependent manner. Our results suggest that cadmium may play a role in race disparities observed in prostate cancer.

Are There Differences in Androgen Receptor Expression in Invasive Breast Cancer in African (Tanzanian) Population in Comparison With the Caucasian (Italian) Population?

Androgen receptor (AR) has been shown to have prognostic implication on breast cancer (BC). Data on the biological features of African BCs are poor. We decided for the first time to compare AR expression of Tanzanian and Italian BC patients. Of the 69 consecutive patients seen at the Bugando Medical Center (Mwanza, Tanzania) from 2003 to 2010, who underwent resection of primary BC evaluable for estrogen receptor, progesterone receptor (PgR), and HER2 only 65 were evaluable for AR by immunohistochemistry. Histopathological assessment and biomolecular determinations were performed at the Cancer Institute of Romagna [Istituto Scientifico Romagnolo per lo studio e la cura dei tumori (IRST)-IRCCS, Meldola, Italy]. Caucasian BC patients were selected from an electronic database and matched (1:2 ratio) for year of diagnosis and age at diagnosis. The median age of patients at diagnosis was 51 (range 29-83) years for Tanzanian and 53 (range 26-86) years for Italian patients. Tanzanian patients harbored tumors with lower AR expression than Italian patients according to the median percentage of immunopositive tumor cells (30% versus 80%, p < 0.0001) and staining intensity (p = 0.0003). The proportion of AR negative patients was likewise higher among Tanzanian patients as regards both ≥1% and ≥10% cutoffs. AR-positive BCs were higher in luminal A and B tumors and decreased in triple-negative (TN) and HER2-enriched tumors in Tanzanian population. AR loss could represent an unfavorable prognostic marker in the African population. The high frequency of TN tumors with high AR expression could open new perspectives of therapy for population in this low income country.

Expression of androgen receptor and epidermal growth factor receptor in invasive breast cancer: A retrospective study of 1,438 patients from China.

e12587 Background: Triple-negative breast cancer (TNBC) is lack of clinically efficient targeted therapies and usually more aggressive with higher rate of distant metastasis and poor overall survival as compared with other breast cancer subtypes. Recent evidence demonstrates that androgen receptor (AR) and epidermal growth factor receptor (EGFR) are involved in the pathogenesis of TNBC. The aim of this study was to explore the expression of AR and EGFR in invasive breast cancer and evaluate the potential of AR and EGFR as biomarkers in TNBC. Methods: In this retrospective study, we analyzed 1438 patients with invasive breast cancer in our hospital from 2015 to 2016. Estrogen receptor (ER) expression, progesterone receptor (PR) expression, Ki-67 index, AR and EGFR expression were detected by immunohistochemical assay. HER2 state was determined by immunohistochemical and FISH assay. χ2 test was used for the analysis. Results: Among 1438 breast cancer patients, 272 (18.9%) cases were TNBC and 1165 (81.0%) cases were non-TNBC. TNBC patients had a low AR expression as compared with non-TNBC patients (29.8% vs 90.2%). There was a significant difference in AR expression in TNBC compared in non-TNBC ( P= 0.000). In contrast, TNBC patients had a high EGFR expression as compared with non-TNBC patients (90.9% vs 21.1%) ( P= 0.000). There was also a significant difference in Ki-67 index in TNBC compared in non-TNBC (89.9% vs 70.1%) ( P= 0.000). AR-positive TNBC patients had a low Ki-67 index expression as compared to AR-negative TNBC (82.7% vs 93.6%). No significant difference of EGFR expression was found between AR-positive TNBC and AR-negative TNBC. Conclusions: AR expression is associated with Ki-67 index and may be as a potential biomarker for targeted therapy in AR-positive TNBC patients.

Increased androgenic sensitivity in the hind limb muscular system marks the evolution of a derived gestural display

Physical gestures are prominent features of many species' multimodal displays, yet how evolution incorporates body and leg movements into animal signaling repertoires is unclear. Androgenic hormones modulate the production of reproductive signals and sexual motor skills in many vertebrates; therefore, one possibility is that selection for physical signals drives the evolution of androgenic sensitivity in select neuromotor pathways. We examined this issue in the Bornean rock frog (Staurois parvus, family: Ranidae). Males court females and compete with rivals by performing both vocalizations and hind limb gestural signals, called "foot flags." Foot flagging is a derived display that emerged in the ranids after vocal signaling. Here, we show that administration of testosterone (T) increases foot flagging behavior under seminatural conditions. Moreover, using quantitative PCR, we also find that adult male S. parvus maintain a unique androgenic phenotype, in which androgen receptor (AR) in the hind limb musculature is expressed at levels ∼10× greater than in two other anuran species, which do not produce foot flags (Rana pipiens and Xenopus laevis). Finally, because males of all three of these species solicit mates with calls, we accordingly detect no differences in AR expression in the vocal apparatus (larynx) among taxa. The results show that foot flagging is an androgen-dependent gestural signal, and its emergence is associated with increased androgenic sensitivity within the hind limb musculature. Selection for this novel gestural signal may therefore drive the evolution of increased AR expression in key muscles that control signal production to support adaptive motor performance.

Species differences in androgen receptor expression in the medial preoptic and anterior hypothalamic areas of adult male and female rodents

The medial preoptic and anterior hypothalamic areas (MPO/AH) are important androgen targets regulating homeostasis, neuroendocrinology and circadian rhythm as well as instinctive and sociosexual behaviors. Although species differences between rats and mice have been pointed out in terms of morphology and physiology, detailed distributions of androgen receptor (AR) have never been compared between the two rodents. In the present study, AR distribution was examined immunohistochemically in serial sections of the MPO/AH and compared for adult rats and mice. Western blotting and immunohistochemistry clearly demonstrated that AR expression in the brain was stronger in mice than in rats and was stronger in males than in females. In addition, we found (1) an “obliquely elongated calbindin-ir cell island” in mice medial preoptic nucleus (MPN) expressed AR intensely, as well as the sexually dimorphic nucleus in the MPN (SDN–MPN) in rats, strongly supporting a “putative SDN–MPN” previously proposed in mice; (2) AR expression in the suprachiasmatic nucleus (SCN) was much more prominent in mice than in rats and differed in localization between the two species; (3) a mouse-specific AR-ir cell cluster was newly identified as the “tear drop nucleus (TDN)”, with male-dominant sexual dimorphism; and (4) two rat-specific AR-ir cell clusters were also newly identified as the “rostral and caudal nebular islands”, with male-dominant sexual dimorphism. The present results may provide basic morphological evidence underlying species differences in androgen-modified psychological, physiological and endocrinergic responses. Above all, the findings of the mouse-specific TDN and differing AR expression in the SCN might explain not only species difference in gonadal modification of circadian rhythm, but also distinct structural bases in the context of transduction of SCN oscillation. The current study could also serve as a caution that data on androgen-sensitive functions obtained from one species should not always be directly applied to others among rodents.

Immunohistochemical evaluation of androgen receptor and nerve structure density in human prepuce from patients with persistent sexual side effects after finasteride use for androgenetic alopecia.

Finasteride is an inhibitor of 5-α-reductase used against male androgenetic alopecia (AGA). Reported side effects of finasteride comprise sexual dysfunction including erectile dysfunction, male infertility, and loss of libido. Recently these effects were described as persistent in some subjects. Molecular events inducing persistent adverse sexual symptoms are unexplored. This study was designed as a retrospective case-control study to assess if androgen receptor (AR) and nerve density in foreskin prepuce specimens were associated with persistent sexual side effects including loss of sensitivity in the genital area due to former finasteride use against AGA. Cases were 8 males (aged 29–43 years) reporting sexual side effects including loss of penis sensitivity over 6 months after discontinuation of finasteride who were interviewed and clinically visited. After informed consent they were invited to undergo a small excision of skin from prepuce. Controls were 11 otherwise healthy matched men (aged 23–49 years) who undergone circumcision for phimosis, and who never took finasteride or analogues. Differences in AR expression and nerve density in different portions of dermal prepuce were evaluated in the 2 groups. Density of nuclear AR in stromal and epithelial cells was higher in cases (mean 40.0%, and 80.6% of positive cells, respectively) than controls (mean 23.4%, and 65.0% of positive cells, respectively), P = 0.023 and P = 0.043, respectively. Conversely, percentage of vessel smooth muscle cells positive for AR and density of nerves were similar in the 2 groups. The ratio of AR positive stromal cells % to serum testosterone concentrations was 2-fold higher in cases than in controls (P = 0.001). Our findings revealed that modulation of local AR levels might be implicated in long-term side effects of finasteride use. This provides the first evidence of a molecular objective difference between patients with long-term adverse sexual effects after finasteride use versus drug untreated healthy controls in certain tissues.

Androgen Receptor Status Is a Prognostic Marker in Non-Basal Triple Negative Breast Cancers and Determines Novel Therapeutic Options

Triple negative breast cancers are a heterogeneous group of tumors characterized by poor patient survival and lack of targeted therapeutics. Androgen receptor has been associated with triple negative breast cancer pathogenesis, but its role in the different subtypes has not been clearly defined. We examined androgen receptor protein expression by immunohistochemical analysis in 678 breast cancers, including 396 triple negative cancers. Fifty matched lymph node metastases were also examined. Association of expression status with clinical (race, survival) and pathological (basal, non-basal subtype, stage, grade) features was also evaluated. In 160 triple negative breast cancers, mRNA microarray expression profiling was performed, and differences according to androgen receptor status were analyzed. In triple negative cancers the percentage of androgen receptor positive cases was lower (24.8% vs 81.6% of non-triple negative cases), especially in African American women (16.7% vs 25.5% of cancers of white women). No significant difference in androgen receptor expression was observed in primary tumors vs matched metastatic lesions. Positive androgen receptor immunoreactivity was inversely correlated with tumor grade (p<0.01) and associated with better overall patient survival (p = 0.032) in the non-basal triple negative cancer group. In the microarray study, expression of three genes (HER4, TNFSF10, CDK6) showed significant deregulation in association with androgen receptor status; eg CDK6, a novel therapeutic target in triple negative cancers, showed significantly higher expression level in androgen receptor negative cases (p<0.01). These findings confirm the prognostic impact of androgen receptor expression in non-basal triple negative breast cancers, and suggest targeting of new androgen receptor-related molecular pathways in patients with these cancers.

Differential androgen receptor expression andDNAmethylation state in striatum song nucleus Area X between wild and domesticated songbird strains

In songbirds, a specialized neural system, the song system, is responsible for acquisition and expression of species-specific vocal patterns. We report evidence for differential gene expression between wild and domesticated strains having different learned vocal phenotypes. A domesticated strain of the wild white-rumped munia, the Bengalese finch, has a distinct song pattern with a more complicated syntax than the wild strain. We identified differential androgen receptor (AR) expression in basal ganglia nucleus Area X GABAergic neurons between the two strains, and within different domesticated populations. Differences in AR expression were correlated with the mean coefficient of variation of the inter-syllable duration in the two strains. Differential AR expression in Area X was observed before the initiation of singing, suggesting that inherited and/or early developmental mechanisms may affect expression within and between strains. However, there were no distinct differences in regions upstream of the AR start codon among all the birds in the study. In contrast, an epigenetic modification, DNA methylation state in regions upstream of AR in Area X, was observed to differ between strains and within domesticated populations. These results provide insight into the molecular basis of behavioral evolution through the regulation of hormone-related genes and demonstrate the potential association between epigenetic modifications and behavioral phenotype regulation.

Androgens Affect Myogenesis In Vitro and Increase Local IGF-1 Expression

The mechanism whereby anabolic androgens are associated with hypertrophy of skeletal muscle is incompletely understood but may involve an interaction with locally generated insulin-like growth factor (IGF) 1. The present investigation utilized a cell culture model of human skeletal muscle-derived cell maturation to test the hypothesis that androgens increase differentiation of human muscle precursor cells in vitro and to assess effects of androgen with or without IGF-1 on IGF-1 messenger RNA (mRNA) expression in human muscle precursor cells. Differentiation of muscle-derived cells was induced under standard low-serum conditions. Cultures were then exposed to androgen (testosterone (T)) at 50, 100, and 500 nM or IGF-1 (10-50 ng·mL⁻¹). Immunocytochemistry and real-time polymerase chain reaction (RT-PCR) were used to assess effects of androgens and IGF-1 after 3- (early) or 7-d (late) muscle differentiation, respectively; RT-PCR was used to quantify the effects on androgen receptor expression. Under low-serum conditions, 3-d exposure to androgens or IGF-1 or both resulted in no significant increase in cellular myogenic commitment. After 7-d exposure, however, T and IGF-1 were both found to increase fusion index with no observable synergistic effect. T also increased IGF-1 mRNA generation (P < 0.0001), whereas exogenous IGF-1 (P < 0.001) reduced IGF-1 mRNA transcription relative to control. The T effect was reversible after treatment with flutamide, an androgen receptor antagonist. Both T and IGF-1 increase myogenic commitment after 7-d exposure to a differentiation medium. With T causing a concomitant increase in IGF-1 mRNA underpinning IGF-1 as a central mediator in the cellular pathways associated with muscle hypertrophy, including those affected by androgens. The novel system described has the potential for elucidating the pattern of growth factor effects associated with androgens in skeletal muscle.

Effects of long-term tibolone treatment on nuclear sex steroid hormone receptors and G-protein–coupled estrogen receptor-1 expression in the macaque uterus

Tibolone is an alternative hormone treatment for managing climacteric symptoms in postmenopausal women. The aim of this study was to determine the effects of long-term tibolone (TIB) treatment in comparison with conventional hormone therapy on the expression and distribution of estrogen receptor (ER) α, ER-β, G-protein-coupled ER-1 (GPER), progesterone receptor (PR) A, PRB, androgen receptor (AR), and syndecan-1 in the macaque uterus. Eighty-eight cynomolgus macaques (Macaca fascicularis) were ovariectomized and treated orally with TIB, a combination of conjugated equine estrogens (CEE) and medroxyprogesterone acetate (MPA), CEE alone, or vehicle for 2 years. Immunohistochemistry was used to evaluate the protein expression and distribution of the receptors in the monkey uterus. In the TIB group, immunostaining of ER-α and GPER was higher in the luminal and glandular epithelium, respectively, as compared with the CEE + MPA group. PRA and PRB protein expression was increased in the stroma and myometrium of the TIB group as compared with the controls. AR immunoreactivity was also up-regulated by TIB treatment in the stroma as compared with no treatment. Furthermore, epithelial immunoreactivity of AR was higher after TIB treatment as compared with CEE + MPA treatment. TIB treatment influences the protein expression of sex hormone receptors in monkey endometrium differently from that observed after conventional hormone therapy. We suggest that the observed differences in AR expression by TIB as compared with combined treatment may be of importance for endometrial atrophy as well as for the beneficial bleeding profile associated with this treatment.

Loss of androgen receptor expression is not associated with pathological stage, grade, gender or outcome in bladder cancer: a large multi‐institutional study

• To investigate androgen receptor (AR) expression in a large series of patients with bladder cancer (BC) because data on a limited number of patients showed that loss of AR expression was associated with invasive BC. • A total of 472 patients with urothelial bladder carcinoma (UBC) from two institutional centres (Toronto and Dallas) were analysed. Tissue microarrays comprising both non-muscle-invasive UBC (n= 167) and muscle-invasive UBC (n= 305) were accrued and immunohistochemical staining for AR was performed. • We used bright-field microscopy imaging coupled with advanced colour detection software to detect, classify and count stained cellular objects and manual scoring. • Results obtained in Dallas were blindly reviewed and validated in Toronto and samples randomly chosen were further analysed in Rochester, NY, USA. • The AR were positively expressed in 61/472 (12.9%) bladder tumours. No statistically significant difference in AR expression between men and women was observed. • Only 9.0% of non-muscle-invasive BC expressed the AR compared with 15.1% of muscle-invasive tumours (P= 0.059). The highest percentage of AR positivity (28.9% of cases) was found in T2 tumours. • There was no statistically significant difference in death from BC, time to death, or time to recurrence between AR-positive and AR-negative cases. • In contrast to previous reports, based on our large BC series, we did not observe a decrease in AR protein expression in bladder tumours with increased pathological stage. Our data do not suggest that loss of AR expression is gender-related nor is it associated with invasive BC.

Does benign prostatic hyperplasia originate from the peripheral zone of the prostate? A preliminary study

To compare the histological characteristics, cell proliferation, apoptosis and biological features in benign prostatic hyperplasia (BPH) in the peripheral (PZ) and transition zone (TZ) of the prostate. Tissue from BPH in TZ and PZ was obtained from 68 patients undergoing transrectal ultrasonography-guided biopsy and used for both morphometric analysis and immunohistochemical studies. The epithelial, stromal and luminal composition of the tissue was determined using a computer-assisted method for quantitative morphometric analysis. Apoptosis was detected as the apoptotic index (AI) using the TdT dUTP nick-end labelling assay. Cell proliferation was determined as the proliferation index (PI) using Ki-67 immunostaining. The expression of epidermal growth factor receptor (EGFR), transforming growth factor beta1 (TGFbeta1), androgen receptor (AR) and bcl-2 were assessed immunohistochemically. There was no difference in the stroma/epithelium ratio between PZ and TZ hyperplastic nodules (P > 0.05). The mean AI in epithelium was almost identical to the corresponding PI. In stroma, no apoptotic cells were detectable. There was a significantly higher PI and AI in the glandular epithelial cells in PZ hyperplastic than in TZ hyperplastic nodules, but no difference in PI of the stromal cells between PZ and TZ hyperplastic nodules. There was significantly higher expression of TGFbeta1 and lower expression of EGFR and bcl-2 in PZ than TZ hyperplastic nodules (P < 0.05). There was no difference in AR expression between PZ and TZ hyperplastic nodules (P > 0.05). These results indicate that some hyperplastic nodules in PZ might originate from the PZ, and the formation of these nodules might be modulated in a different way from that in the TZ.