Androgen Receptor CAG Repeat Polymorphism and Epigenetic Influence among the South Indian Women with Polycystic Ovary Syndrome

The present study was carried out to assess the role of androgen receptor CAG repeat polymorphism and X chromosome inactivation (XCI) pattern among Indian PCOS women and controls which has not been hitherto explored and also to test the hypothesis that shorter CAG alleles would be preferentially activated in PCOS. CAG repeat polymorphism and X chromosome methylation patterns were compared between PCOS and non-PCOS women. 250 PCOS women and 299 controls were included for this study. Androgen receptor CAG repeat sizes, XCI percentages, and clinical and biochemical parameters were measured. The mean CAG repeat number is similar between the cases (18.74±0.13) and controls (18.73±0.12). The obese PCOS women were significantly more frequent in the <18 and >20 CAG repeat category than the lean PCOS women, yielding a highly significant odds (p = 0.001). Among the women with non-random X-inactivation, alleles with <19 repeats were more frequently activated among cases than controls (p = 0.33). CAG repeat polymorphism by itself cannot be considered as a useful marker for discriminating PCOS. We observed a trend of preferential activation of the shorter allele among the PCOS cases with non random XCI pattern. In the obese PCOS women, this microsatellite variation may account for the hyperandrogenicity to a larger extent than the lean PCOS women.     

The Androgen Hormone-Induced Increase in Androgen Receptor Protein Expression Is Caused by the Autoinduction of the Androgen Receptor Translational Activity

The androgen receptor (AR) plays a central role in prostate, muscle, bone and adipose tissue. Moreover, dysregulated AR activity is a driving force in prostate cancer (PCa) initiation and progression. Consequently, antagonizing AR signalling cascades via antiandrogenic therapy is a crucial treatment option in PCa management. Besides, very high androgen levels also inhibit PCa cells’ growth, so this effect could also be applied in PCa therapy. However, on the molecular and cellular level, these mechanisms have hardly been investigated so far. Therefore, the present study describes the effects of varying androgen concentrations on the viability of PCa cells as well as localization, transactivation, and protein stability of the AR. For this purpose, cell viability was determined via WST1 assay. Alterations in AR transactivity were detected by qPCR analysis of AR target genes. A fluorescent AR fusion protein was used to analyse AR localization microscopically. Changes in AR protein expression were detected by Western blot. Our results showed that high androgen concentrations reduce the cell viability in LNCaP and C4-2 cell lines. In addition, androgens have been reported to increase AR transactivity, AR localization, and AR protein expression levels. However, high androgen levels did not reduce these parameters. Furthermore, this study revealed an androgen-induced increase in AR protein synthesis. In conclusion, inhibitory effects on cell viability by high androgen levels are due to AR downstream signalling or non-genomic AR activity. Moreover, hormonal activation of the AR leads to a self-induced stabilization of the receptor, resulting in increased AR activity. Therefore, in clinical use, a therapeutic reduction in androgen levels represents a clinical target and would lead to a decrease in AR activity and, thus, AR-driven PCa progression.     

Effects of Aluminum Exposure on Serum Sex Hormones and Androgen Receptor Expression in Male Rats

The effects of aluminum (Al) exposure on reproductive functions of male rats were investigated. Forty male Wistar rats (4?weeks old) weighing 75-95?g were randomly divided into four groups and orally exposed to 0 (control group GC), 64.18 (low-dose group GL), 128.36 (middle-dose group GM), and 256.72 (high-dose group GH) mg/kg aluminum trichloride in drinking water for 120?days. The levels of testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were determined by radioimmunoassay. The androgen receptor (AR) expressions in testes were detected respectively by immunohistochemistry and time quantitative PCR. Results showed that the levels of T and LH in GM and GH were lower than those in GC (P??0.05). AR protein expressions in GM and GH were lower than those in GC (P?相似文献   

Prognostic Value of Mitotic Index and Bcl2 Expression in Male Breast Cancer

The incidence of male breast cancer (MBC) is rising. Current treatment regimens for MBC are extrapolated from female breast cancer (FBC), based on the assumption that FBC prognostic features and therapeutic targets can be extrapolated to MBC. However, there is yet little evidence that prognostic features that have been developed and established in FBC are applicable to MBC as well. In a recent study on FBC, a combination of mitotic index and Bcl2 expression proved to be of strong prognostic value. Previous papers on Bcl2 expression in MBC were equivocal, and the prognostic value of Bcl2 combined with mitotic index has not been studied in MBC. The aim of the present study was therefore to investigate the prognostic value of Bcl2 in combination with mitotic index in MBC. Immunohistochemical staining for Bcl2 was performed on tissue microarrays of a total of 151 male breast cancer cases. Mitotic index was scored. The prognostic value of Bcl2 expression and Bcl2/mitotic index combinations was evaluated studying their correlations with clinicopathologic features and their prediction of survival. The vast majority of MBC (94%) showed Bcl2 expression, more frequently than previously described for FBC. Bcl2 expression had no significant associations with clinicopathologic features such as tumor size, mitotic count and grade. In univariate survival analysis, Bcl2 had no prognostic value, and showed no additional prognostic value to tumor size and histological grade in Cox regression. In addition, the Bcl2/mitotic index combination as opposed to FBC did not predict survival in MBC. In conclusion, Bcl2 expression is common in MBC, but is not associated with major clinicopathologic features and, in contrast to FBC, does not seem to have prognostic value, also when combined with mitotic index.     

Bone Mass and the CAG and GGN Androgen Receptor Polymorphisms in Young Men

Background

To determine whether androgen receptor (AR) CAG (polyglutamine) and GGN (polyglycine) polymorphisms influence bone mineral density (BMD), osteocalcin and free serum testosterone concentration in young men.

Methodology/Principal Findings

Whole body, lumbar spine and femoral bone mineral content (BMC) and BMD, Dual X-ray Absorptiometry (DXA), AR repeat polymorphisms (PCR), osteocalcin and free testosterone (ELISA) were determined in 282 healthy men (28.6±7.6 years). Individuals were grouped as CAG short (CAG_S) if harboring repeat lengths of ≤21 or CAG long (CAG_L) if CAG >21, and GGN was considered short (GGN_S) or long (GGN_L) if GGN ≤23 or >23. There was an inverse association between logarithm of CAG and GGN length and Ward''s Triangle BMC (r = −0.15 and −0.15, P<0.05, age and height adjusted). No associations between CAG or GGN repeat length and regional BMC or BMD were observed after adjusting for age. Whole body and regional BMC and BMD values were similar in men harboring CAG_S, CAG_L, GGN_S or GGN_L AR repeat polymorphisms. Men harboring the combination CAG_L+GGN_L had 6.3 and 4.4% higher lumbar spine BMC and BMD than men with the haplotype CAG_S+GGN_S (both P<0.05). Femoral neck BMD was 4.8% higher in the CAG_S+GGN_S compared with the CAG_L+GGN_S men (P<0.05). CAG_S, CAG_L, GGN_S, GGN_L men had similar osteocalcin concentration as well as the four CAG-GGN haplotypes studied.

Conclusion

AR polymorphisms have an influence on BMC and BMD in healthy adult humans, which cannot be explained through effects in osteoblastic activity.     

Detection of Long Non-Coding RNA in Archival Tissue: Correlation with Polycomb Protein Expression in Primary and Metastatic Breast Carcinoma

A major function of long non-coding RNAs (lncRNAs) is regulating gene expression through changes in chromatin state. Experimental evidence suggests that in cancer, they can influence Polycomb Repressive Complexes (PRC) to retarget to an occupancy pattern resembling that of the embryonic state. We have previously demonstrated that the expression level of lncRNA in the HOX locus, including HOTAIR, is a predictor of breast cancer metastasis. In this current project, RNA in situ hybridization of probes to three different lncRNAs (HOTAIR, ncHoxA1, and ncHoxD4), as well a immunohistochemical staining of EZH2, is undertaken in formalin-fixed paraffin-embedded breast cancer tissues in a high throughput tissue microarray format to correlate expression with clinicopathologic features. Though overall EZH2 and HOTAIR expression levels were highly correlated, the subset of cases with strong HOTAIR expression correlated with ER and PR positivity, while the subset of cases with strong EZH2 expression correlated with an increased proliferation rate, ER and PR negativity, HER2 underexpression, and triple negativity. Co-expression of HOTAIR and EZH2 trended with a worse outcome. In matched primary and metastatic cancers, both HOTAIR and EZH2 had increased expression in the metastatic carcinomas. This is the first study to show that RNA in situ hybridization of formalin fixed paraffin-embedded clinical material can be used to measure levels of long non-coding RNAs. This approach offers a method to make observations on lncRNAs that may influence the cancer epigenome in a tissue-based technique.     

Identification of the Classical Androgen Receptor in Male Rat Liver

Abstract

Male rat liver contains components in both cytosol and nucleosol which bind the synthetic testosterone derivative, mibolerone, with a high affinity, low capacity and a high specificity for androgens. Gel filtration chromatography shows two binding components. A high molecular weight component (M.Wt 230,000) present in cytosol alone and a low molecular weight component (M.Wt 60,000) present in cytosol and nucleosol. Male rat liver contains the classical androgen receptor.     

Insulin Receptor Substrate Adaptor Proteins Mediate Prognostic Gene Expression Profiles in Breast Cancer

Therapies targeting the type I insulin-like growth factor receptor (IGF-1R) have not been developed with predictive biomarkers to identify tumors with receptor activation. We have previously shown that the insulin receptor substrate (IRS) adaptor proteins are necessary for linking IGF1R to downstream signaling pathways and the malignant phenotype in breast cancer cells. The purpose of this study was to identify gene expression profiles downstream of IGF1R and its two adaptor proteins. IRS-null breast cancer cells (T47D-YA) were engineered to express IRS-1 or IRS-2 alone and their ability to mediate IGF ligand-induced proliferation, motility, and gene expression determined. Global gene expression signatures reflecting IRS adaptor specific and primary vs. secondary ligand response were derived (Early IRS-1, Late IRS-1, Early IRS-2 and Late IRS-2) and functional pathway analysis examined. IRS isoforms mediated distinct gene expression profiles, functional pathways, and breast cancer subtype association. For example, IRS-1/2-induced TGFb2 expression and blockade of TGFb2 abrogated IGF-induced cell migration. In addition, the prognostic value of IRS proteins was significant in the luminal B breast tumor subtype. Univariate and multivariate analyses confirmed that IRS adaptor signatures correlated with poor outcome as measured by recurrence-free and overall survival. Thus, IRS adaptor protein expression is required for IGF ligand responses in breast cancer cells. IRS-specific gene signatures represent accurate surrogates of IGF activity and could predict response to anti-IGF therapy in breast cancer.     

乳腺癌中EGFR蛋白表达和基因扩增的检测结果比较

目的:比较免疫组织化学技术检测乳腺癌中EGFR蛋白表达和荧光原位杂交检测EGFR基因扩增的结果的符合率,为EGFR靶向治疗病例的选择提供依据。方法:随机选取2005年1月到2011年12月冷水江市人民医院和湖南省肿瘤医院病理科的147例乳腺癌档案病例,采用免疫组织化学技术检测乳腺癌组织中EGFR蛋白表达,荧光原位杂交检测EGFR的基因扩增,比较两种方法阳性结果的符合率。结果:免疫组化染色结果显示EGFR在原发性和转移性乳腺癌中的阳性表达率分别为85%(105/123)和79%1(9/24),两组比较无显著差异(P0.05)。FISH检测结果显示原发性和转移性乳腺癌中分别有12%(15/123)和8%(2/24)存在EGFR基因扩增,两组比较结果无显著差异(P0.05)。所有存在EGFR基因扩增的原发性和转移性乳腺癌的EGFR免疫组织化学结果均为阳性。在原发性和转移性乳腺癌中,免疫组化阳性和基因扩增程度间呈显著正相关(P0.05),但免疫组化结果预测基因扩增的特异性较低。结论:免疫组织化学检测EGFR只能作为EGFR靶向治疗病例选择的初步筛选,进一步进行荧光原位杂交检测EGFR基因扩增是必须的。     

乳腺癌中EGFR蛋白表达和基因扩增的检测结果比较

目的：比较免疫组织化学技术检测乳腺癌中EGFR蛋白表达和荧光原位杂交检测EGFR基因扩增的结果的符合率,为EGFR靶向治疗病例的选择提供依据。方法：随机选取2005年1月到2011年12月冷水江市人民医院和湖南省肿瘤医院病理科的147例乳腺癌档案病例,采用免疫组织化学技术检测乳腺癌组织中EGFR蛋白表达,荧光原位杂交检测EGFR的基因扩增,比较两种方法阳性结果的符合率。结果：免疫组化染色结果显示EGFR在原发性和转移性乳腺癌中的阳性表达率分别为85%（105/123）和79%1（9/24）,两组比较无显著差异（P〉0.05）。FISH检测结果显示原发性和转移性乳腺癌中分别有12%（15/123）和8%（2/24）存在EGFR基因扩增,两组比较结果无显著差异（P〉0.05）。所有存在EGFR基因扩增的原发性和转移性乳腺癌的EGFR免疫组织化学结果均为阳性。在原发性和转移性乳腺癌中,免疫组化阳性和基因扩增程度间呈显著正相关（P〈0.05）,但免疫组化结果预测基因扩增的特异性较低。结论：免疫组织化学检测EGFR只能作为EGFR靶向治疗病例选择的初步筛选,进一步进行荧光原位杂交检测EGFR基因扩增是必须的。     

Expression of the Androgen Receptor,pAkt, and pPTEN in Breast Cancer and Their Potential in Prognostication

BACKGROUNDImportance of androgen receptor (AR) as an independent prognostic marker in Pakistani women with breast cancer (BCa) remains unexplored. Our aim was to identify the expression and potential prognostic value of AR, its upstream regulator (pAkt) and target gene (pPTEN) in invasive BCa.METHODSThis study used a cohort of 200 Pakistani women with invasive BCa diagnosed during 2002-2011. Expression of AR, pAkt and pPTEN was determined on formalin fixed paraffin embedded tissue sections by immunohistochemistry. The association of AR, pAkt and pPTEN with clinicopathological parameters was determined. Survival analyses were undertaken on patients with ≥ 5 years of follow-up (n = 82).RESULTSExpression of AR, pAkt and pPTEN was observed in 47.5%, 81.3% and 50.6% of patients, respectively. AR-expressing tumors were low or intermediate in grade (P < .001) and expressed ER (P = .002) and PR (P = .001). Patients with AR⁺ tumors had significantly higher OS (Mean OS = 10.2 ± 0.465 years) compared to patients with AR^? tumors (Mean OS = 5.8 ± 0.348 years) (P = .047). Furthermore, AR-positivity was associated with improved OS in patients receiving endocrine therapy (P = .020). Patients with AR⁺ /pAkt⁺ /pPTEN^? tumors, had increased OS (Mean OS = 7.1 ± 0.535 years) compared to patients with AR^?/pAkt⁺/pPTEN^? tumors (Mean OS = 5.1 ± 0.738 years).CONCLUSIONAR-expressing tumors are frequently characterized by low or intermediate grade tumors, expressing ER and PR. In addition, expression of AR, pAkt and pPTEN, could be considered in prognostication of patients with invasive BCa.     

Expression of Autophagy-Related Proteins According to Androgen Receptor and HER-2 Status in Estrogen Receptor-Negative Breast Cancer

Purpose

The purpose of this study was to investigate the expression of autophagy-related proteins in relation to androgen receptor (AR) status in estrogen receptor (ER)-negative breast cancers.

Methods

We extracted 334 ER-negative breast cancer samples to construct tissue microarrays (TMAs), which were immunohistochemically stained for autophagy-related proteins (beclin-1, LC3A, LC3B, p62) and for AR and HER-2.

Results

There were 127 AR-positive cases and 207 AR-negative cases, and 140 HER-2-positive cases and 194 HER-2 negative cases. The AR-negative group was associated with tumoral LC3A expression (P<0.001), while the AR-positive group was associated with tumoral BNIP3 expression (P<0.001). Tumoral LC3A was most highly expressed in the AR-negative and HER-2 negative group, while stromal LC3A showed the highest expression in the AR-negative and HER-2-positive group. Tumoral BNIP3 and stromal BNIP3 were highest in the AR-positive and HER-2-negative group. In the AR-positive and HER-2-negative group, stromal p62 positivity was an independent factor that was statistically significant in its association with shorter disease-free survival (DFS) (Hazard ratio: 10.21, 95% CI: 1.130–92.31, P = 0.039). Shorter DFS was associated with tumoral LC3A positivity (Hazard ratio: 10.28, 95% CI: 2.068–51.19, P = 0.004) in the AR-negative and HER-2-positive group.

Conclusion

In ER-negative breast cancers, AR status was associated with expression of different types of autophagy-related proteins. Tumoral LC3A was most highly expressed in AR-negative breast cancers, while tumor BNIP3 was highest in AR-positive breast cancers.     

Reduced Androgen Receptor Expression Accelerates the Onset of ERBB2 Induced Breast Tumors in Female Mice

Androgen receptor (AR) is commonly expressed in both the epithelium of normal mammary glands and in breast cancers. AR expression in breast cancers is independent of estrogen receptor alpha (ERα) status and is frequently associated with overexpression of the ERBB2 oncogene. AR signaling effects on breast cancer progression may depend on ERα and ERBB2 status. Up to 30% of human breast cancers are driven by overactive ERBB2 signaling and it is not clear whether AR expression affects any steps of tumor progression in this cohort of patients. To test this, we generated mammary specific Ar depleted mice (MARKO) by combining the floxed allele of Ar with the MMTV-cre transgene on an MMTV-NeuNT background and compared them to littermate MMTV-NeuNT, Ar^fl/+ control females. Heterozygous MARKO females displayed reduced levels of AR in mammary glands with mosaic AR expression in ductal epithelium. The loss of AR dramatically accelerated the onset of MMTV-NeuNT tumors in female MARKO mice. In this report we show that accelerated MMTV-NeuNT-dependent tumorigenesis is due specifically to the loss of AR, as hormonal levels, estrogen and progesterone receptors expression, and MMTV-NeuNT expression were similar between MARKO and control groups. MMTV-NeuNT induced tumors in both cohorts displayed distinct loss of AR in addition to ERα, PR, and the pioneer factor FOXA1. Erbb3 mRNA levels were significantly elevated in tumors in comparison to normal mammary glands. Thus the loss of AR in mouse mammary epithelium accelerates malignant transformation rather than the rate of tumorigenesis.     

The Impact of Androgen Receptor Expression on Breast Cancer Survival: A Retrospective Study and Meta-Analysis

Recent studies have highlighted the role of androgen receptor (AR) as a prognostic biomarker of breast cancer. However, its predictive role in disease free survival (DFS) and overall survival (OS) still remains inconclusive. The present study aimed to retrospectively investigate the association between AR and survival outcomes in breast cancer and also identify this association by a meta-analysis of published researches. Clinical data from 109 patients with breast cancer, who underwent surgery at Ruijin Hospital, Shanghai, were retrospectively analyzed for immunohistochemical AR expression measured by tissue microarray. For meta-analysis, articles available in Pubmed on the relationship between AR and breast cancer outcomes were included. Data obtained from both were combined and analyzed. Women with AR positive tumors in the retrospective study had a significantly better DFS (HR 0.24, 95% CI 0.07-0.88) and OS (HR 0.19, 95% CI 0.04-0.85) than women with AR negative ones. Meta-analysis showed that AR expression in breast tumors was an indicator of better DFS (HR 0.52, 95% CI 0.43-0.64). In subgroup analysis, AR could predict DFS outcome in estrogen receptor (ER) positive (HR 0.45, 95% CI 0.34-0.59), ER negative (HR 0.42, 95% CI 0.26-0.67), and triple negative breast cancer (HR 0.40, 95% CI 0.23-0.69). Moreover, in ER positive breast cancer patients, the expression of AR could predict better OS (HR 0.39, 95% CI 0.19-0.82). The present analysis indicated that AR expression was associated with lower risk of recurrence in patients with all breast cancer types and better OS in cases with ER positive.     

The Use of Three Long Non-Coding RNAs as Potential Prognostic Indicators of Astrocytoma

Long noncoding RNAs (lncRNAs) are pervasively transcribed and play a key role in tumorigenesis. The aim of the study was to determine the lncRNA expression profile in astrocytomas and to assess its potential clinical value. We performed a three-step analysis to establish the lncRNA profile for astrocytoma: a) the lncRNA expression was examined on 3 astrocytomas as well as 3 NATs (normal adjacent tissues) using the lncRNA microarray; b) the top-hits were validated in 40 astrocytomas (WHO grade II-IV) by quantitative real time-PCR (qRT-PCR); c) the hits with significant differences were re-evaluated using qRT-PCR in 90 astrocytomas. Finally, 7 lncRNAs were found to have a significantly different expression profile in astrocytoma samples compared to the NAT samples. Unsupervised clustering analysis further revealed the potential of the 7-lncRNA profile to differentiate between tumors and NAT samples. The upregulation of ENST00000545440 and NR_002809 was associated with advanced clinical stages of astrocytoma. Using Kaplan-Meier survival analysis, we showed that the low expression of BC002811 or XLOC_010967, or the high expression of NR_002809 was significantly associated with poor patient survival. Moreover, Cox proportional hazard regression analysis revealed that this prognostic impact was independent of other clinicopathological factors. Our results indicate that the lncRNA profile may be a potential prognostic biomarker for the prediction of post-surgical outcomes.     

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.     

Androgen Receptor (AR), E-Cadherin,and Ki-67 as Emerging Targets and Novel Prognostic Markers in Triple-Negative Breast Cancer (TNBC) Patients

BackgroundTNBC is an aggressive subset of breast cancer (BC) without specific target therapy.MethodsThis observational, retrospective study included 45 cases of TNBC. The aim of this study was to evaluate the expression of the AR, E-cadherin and Ki-67 in relation to histological type, time to relapse and overall survival (OS). Immunohistochemistry (IHC) was carried out on formalin-fixed paraffin-embedded tumor samples obtained from patients defined TNBC.ResultsThe AR was positive (IHC >10%) in 26.6%. E-cadherin (CDH1) expression was considered positive if the score was ≥ 2. This expression was negative in 53.3% cases. The Ki-67 index was ≥ 20% in 37.7%. Univariate analyses showed that AR, CDH1 and Ki-67 are significantly associated with OS. Multivariate analysis showed that AR and Ki-67 expression are independent variables associated with OS. The statistical analysis showed that patients with AR negative and Ki-67 positive expression have a significant correlation with poor outcome.ConclusionsOur data suggest that the combination of AR and E-cadherin expression as well as Ki-67 status might be useful prognostic markers in TNBC. Hence, these molecular determinants could play an interesting role to classify subgroups of TNBC.