Estrogen-related Receptor Gene Research Articles

Effect of bisphenol A on the ovarian expressions of estrogen-related receptor gene and protein in queen honey bee (Apis mellifera)

Effect of bisphenol A on the ovarian expressions of estrogen-related receptor gene and protein in queen honey bee (Apis mellifera)

A Novel Rhipicephalus microplus Estrogen Related Receptor (RmERR), a Molecular and In Silico Characterization of a Potential Protein Binding Estrogen.

The search for targets to control ticks and tick-borne diseases has been an ongoing problem, and so far, we still need efficient, non-chemical alternatives for this purpose. This search must consider new alternatives. For example genomics analysis is a widely applied tool in veterinary health studies to control pathogens. On the other hand, we propose that regulation of endocrine mechanisms represents a feasible alternative to biologically controlling tick infestations. Thus, we performed the molecular identification of an estrogen-related receptor gene of Rhipicephalus microplus called RmERR by RT-PCR in tick ovaries, embryonic cells, and hemolymph, which allowed us to analyze its expression and propose potential functions in endocrine mechanisms and developmental stages. In addition, we performed an in silico characterization to explore the molecular interactions of RmERR with different estrogens, estrogenic antagonists, and endocrine disruptor Bisphenol A (BPA), finding potential interactions predicted by docking analysis and supported by negative values of ΔG (which suggests the potential interaction of RmERR with the molecules evaluated). Additionally, phylogenetic reconstruction revealed that RmERR is grouped with other tick species but is phylogenetically distant from host vertebrates' ERRs. In summary, this study allowed for the identification of an ERR in cattle tick R. microplus for the first time and suggested its interaction with different estrogens, supporting the idea of a probable transregulation process in ticks. The elucidation of this interaction and its mechanisms unveiled its potential as a target to develop tick control strategies.

Evolution of the expression and regulation of the nuclear hormone receptor ERR gene family in the chordate lineage

The Estrogen Related Receptor (ERR) nuclear hormone receptor genes have a wide diversity of roles in vertebrate development. In embryos, ERR genes are expressed in several tissues, including the central and peripheral nervous systems. Here we seek to establish the evolutionary history of chordate ERR genes, their expression and their regulation. We examine ERR expression in mollusc, amphioxus and sea squirt embryos, finding the single ERR orthologue is expressed in the nervous system in all three, with muscle expression also found in the two chordates. We show that most jawed vertebrates and lampreys have four ERR paralogues, and that vertebrate ERR genes were ancestrally linked to Estrogen Receptor genes. One of the lamprey paralogues shares conserved expression domains with jawed vertebrate ERRγ in the embryonic vestibuloacoustic ganglion, eye, brain and spinal cord. Hypothesising that conserved expression derives from conserved regulation, we identify a suite of pan-vertebrate conserved non-coding sequences in ERR introns. We use transgenesis in lamprey and chicken embryos to show that these sequences are regulatory and drive reporter gene expression in the nervous system. Our data suggest an ancient association between ERR and the nervous system, including expression in cells associated with photosensation and mechanosensation. This includes the origin in the vertebrate common ancestor of a suite of regulatory elements in the 3’ introns that drove nervous system expression and have been conserved from this point onwards.

FE65 defines the efficacy of tamoxifen treatment via osteopontin expression in estrogen receptor-positive breast cancer

BackgroundMetastasis and endocrine therapy resistance are clinical challenges in the treatment of estrogen receptor (ER) -positive breast tumors. Therefore, mechanistic exploration of tamoxifen (TAM) resistance is considered pivotal to improve the prognosis of ER positive breast cancer patients. We previously demonstrated the correlation between FE65 and ER, and subsequently explored the effects of FE65 on TAM and potential interaction between FE65 and Osteopontin (OPN) in ER-positive breast cancer. MethodsWe immunolocalized FE65 and OPN in ER-positive breast cancers and correlated the results with their clinicopathological variables. We then performed proximity ligation and proliferation assays to correlate TAM resistance with FE65 expression. The RT2 Profiler Human PCR Array Human Estrogen Receptor Signaling was also used to profile 96 ER related genes. Hoechst 33342 Staining was used to evaluate apoptosis. ResultsFE65 immunoreactivity was significantly associated with higher pathological N factor of the cases examined, and a potential correlation with tamoxifen resistance of the ER-positive patients. FE65 knockdown significantly increased the proportion of apoptotic carcinoma cells. The statistically significant positive correlation between FE65 and OPN was detected in this study. Subsequent immunohistochemical analyses revealed that OPN status was significantly associated with cancer metastasis and overall survival of 142 patients and FE65 status. ConclusionsWe firstly demonstrated the clinicopathological significance of FE65 in ER-positive breast cancer patients and results indicated that the effects of FE65 on ER-positive breast cancer patients were mediated through OPN expression. In addition, results suggested the clinical value of FE65 as potential prognostic factor and surrogate marker of TAM therapy in ER-positive breast cancer patients.

Abstract P4-01-15: Eribulin treatment for hormone receptor positive breast cancer cells with resistant to endocrine therapy promotes re-expression of estrogen receptor

Abstract Background: The development of resistance to endocrine therapy appears to have become a major clinical problem of hormone receptor (HR) positive breast cancer. Drug resistance is associated with changes of the tumor microenvironment due to tumor hypoxia. Eribulin, a nontaxane, synthetic microtuble dynamics inhibitor, induces G2/M cell cycle arrest. Interestingly, it also has some unique anticancer effects in breast cancer cells, such as improvement of tumor perfusion and hypoxia. In this study, we investigated the effect of eribulin for endocrine therapy resistant breast cancer. Materials and Methods: We established hypoxia resistant HR positive/human epithelial growth receptor 2 (HER2) negative breast cancer cell lines, via continuous culturing in hypoxic environment. Parental and hypoxia resistant cell lines were treated with eribulin, followed by estrogen receptor (ER), epithelial-mesenchymal transition (EMT) and hypoxia related gene and protein expression changes in each surviving cells by quantitative real-time polymerase chain reaction (qPCR) and western blot, respectively. In addition, proliferation assay was conducted in these breast cancer cell lines treated with tamoxifen alone and tamoxifen plus eribulin. For the in vivo experiment, we produced subcutaneous xenografts of each cell lines. We treated these tumors with tamoxifen alone and tamoxifen plus eribulin, and analyzed their growth activity and protein expression by immunohistochemical study of surgically resected tissues. Results: Though parental HR positive/HER2 negative breast cancer cell lines displayed an epithelial-like cuboidal phenotype, hypoxia resistant cell lines displayed a mesenchymal-like spindle-shaped phenotype. In addition, hypoxia resistant cell lines significantly decreased the expression of epithelial and ER related markers, and exhibited a higher level of resistance to tamoxifen treatment. On the other hand, eribulin treatment for hypoxia resistant cell lines increased epithelial and ER related gene and protein expressions, and enhanced the anticancer effect of tamoxifen. In in vivo xenograft models, eribulin treatment for hypoxia resistant tumor with resistance to tamoxifen induced re-expression of ER. Also, hypoxia resistant tumor after administration of eribulin became effective with tamoxifen treatment. Conclusions: Eribulin improve the tumor microenvironment changed by hypoxia, and induce re-expression of ER in hypoxia resistant breast cancer cells. Eribulin treatment for HR positive breast cancer with resistance to endocrine therapy makes possibility of re-administration of endocrine therapy. Citation Format: Wataru Goto, Shinichiro Kashiwagi, Misato Fujioka, Sae Ishihara, Yuka Asano, Tamami Morisaki, Satoru Noda, Tsutomu Takashima, Masaichi Ohira, Kosei Hirakawa. Eribulin treatment for hormone receptor positive breast cancer cells with resistant to endocrine therapy promotes re-expression of estrogen receptor [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-01-15.

Consequences of combined exposure to thermal stress and the plasticiser DEHP in Mytilus spp. differ by sex

Little is known about the combined effect of environmental factors and contaminants on commercially important marine species, and whether this effect differs by sex. In this study, blue mussels were exposed for seven days to both single and combined stressors (i.e., +3 °C elevated temperature and two environmentally relevant concentrations of the plastic softener DEHP, 0.5 and 50 μg/l) in a factorial design. Males were observed to be more sensitive to high temperature, demonstrated by the significant increase in out-of-season spawning gonads and higher gene expression of the antioxidant catalase and the estrogen receptor genes. On the other hand, while the gametogenesis cycle in females was more resilient than in males, DEHP exposure altered the estrogen-related receptor gene expression.We show that the combined stressors DEHP and increased temperature, in environmentally relevant magnitudes, have different consequences in male and female mussels, with the potential to impact the timing and breeding season success in Mytilus spp.

The relationship between estrogen-induced phenotypic transformation and proliferation of vascular smooth muscle and hypertensive intracerebral hemorrhage.

BackgroundTo explore the effect of estrogen on human cerebral vascular smooth muscle cells (VSMCs) and to clarify the molecular mechanism of estrogen inhibition of VSMC proliferation, which could provide an important reference basis for the clinical treatment of hypertensive intracerebral hemorrhage.MethodFirstly, the effects of different concentrations of estradiol and estrogen receptor (ESR) blocker (tamoxifen) on the proliferation of human VSMCs and the expression of estrogen-related receptor gene (ESR: ESR1, ESR2, GPER), myocardin (MYOCD), serum reaction factor (SRF), and apoptosis gene caspase-3 were measured to discover the effect and mechanism of tamoxifen on the proliferation and apoptosis of VSMCs. Secondly, the effects of estradiol on human VSMCs treated with angiotensin II (Ang II) were observed by measuring the expression of vascular smooth muscle markers, α-smooth muscle actin (α-SMA), SM22α, FLN, MCP-1, and TLR4.ResultsEstradiol inhibited the proliferation of VSMCs by upregulating the expression of ESR1, ESR2, and GPER and downregulating the expression of caspase-3, MYOCD, and SRF, thereby inhibiting the apoptosis of vascular smooth muscle. At the same time, tamoxifen had opposite effects. Angiotensin II decreased the expression of α-SMA and SM22α and promoted the expression of FLN, MCP-1, and TLR4 protein, while estrogen had the opposite effects.ConclusionsEstrogen suppresses apoptosis by inhibiting the proliferation of human VSMCs and preventing it from changing from contractile to synthetic. Estrogen can further prevents vascular damage and regulate peripheral inflammatory reaction, thereby producing a protective effect on cardiovascular and cerebrovascular.

Identification, characterization and mRNA transcript abundance profiles of estrogen related receptor (ERR) in Sepiella japonica imply its possible involvement in female reproduction

Estrogen related receptors (ERRs) are widely detected in vertebrates and apparently have functions in reproduction. The functions of ERRs in reproduction of invertebrates, especially in mollusk cephalopods, are largely unknown. In the present study, An homologue of vertebrate ERR gene was first cloned from female Sepiella japonica, an important Cephalopod species in coastal water of China. Results indicate the S. japonica ERR (sjERR) gene is comprised of 1513 nucleotides, containing a 1389 bp open reading frame, which encode for 463 amino acid (aa) residues. The deduced sjERR protein possessed six typical nuclear receptors (NR) domains (A–F), with a DNA-binding domain (DBD) and a highly conserved ligand-binding domain (LBD), compared to the other molluscan ERRs. Results from tissue analyses indicated that sjERR mRNA transcript abundance was in largest amounts in tissues of the brain, liver, ovary that are possibly involved in reproduction. The sjERR mRNA transcript abundance was temporally regulated during the different sexual maturation phases of female S. japonica and was affected by in vivo administrations of vertebrate steroid estradiol-17β (E2). An in vivo knockdown of sjERR gene expression resulted in a marked down-regulation in expression of genes involved in ovarian development, such as Vitellogenin, CDK1, and Cyclin B, indicating there is a possible involvement of sjERR in reproduction. Both fusion protein transient transfections and immunohistochemical analyses indicated a presence of sjERR in the nucleus, implying a possible mechanism of action of the sjERR in the nucleus through activation of specific gene transcriptions.

Relevance of estrogen-related receptor gene and ecdysone receptor gene in adult testis of the cricket Teleogryllus emma (Orthoptera: Gryllidae)

Estrogen-related receptor gene (ERR) and ecdysone receptor gene (EcR) belong to the nuclear receptor gene superfamily, both of which are associated with the regulation of insect reproductive development. However, the relationship between ERR and EcR and whether ERR participates in the 20E signal pathway during male reproduction are unclear. In this paper, adult male crickets Teleogryllus emma Ohmschi & Matsumura were divided into the experimental group, negative group, and control group. Crickets of the experimental group were injected with TeERR or TeEcR-dsRNA, and those in the negative group received EGFP-dsRNA. The efficiency of TeERR and TeEcR-RNAi was detected in the experimental group. Furthermore, the transcription level, morphological characteristics as well as weight were analyzed in the TeERR or TeEcR knocked-down testis. Results showed that the expression level of TeERR or TeEcR was significantly down-regulated (P<0.05) when treated with 2000ng TeERR or TeEcR-dsRNA for 48h. The expression level of TeERR could be down-regulated (P<0.05) using TeEcR-RNAi and vice versa. TeERR and TeEcR-RNAi caused morphological changes in testes, but they had no obvious effect on weight (P>0.05). These results indicate that TeERR and TeEcR are intimately related to each other. In addition, TeERR may be involved in the 20E signal pathway and maintain the function of adult cricket testis.

Abstract 2991: Integrative analysis of molecular and drug response data from clinical samples and PDTXs to identify pharmacogenomic associations in breast cancer

Abstract Breast cancer is the most common cancer among women showing high clinical and molecular heterogeneity. Current clinical management causes patients overtreatment with implications on both patients’ quality of life and healthcare costs. Moreover, intrinsic or acquired tumor resistance to treatment leads to incurable metastatic progression in a significant proportion of patients. Consequently, there is an urgent need for better predictive biomarkers and a better understanding of the mechanisms driving response to treatment. As part of the METABRIC initiative, we fully molecularly characterized 2000 breast primary tumors, measuring gene expression, copy number aberration, somatic mutations and methylation. In addition, a biobank of breast cancer patient-derived tumor xenograft (PDTX) models (n=92) has been generated in our lab and a comprehensive molecular characterization was also obtained. We recently demonstrated that breast cancer PDTXs maintain originating cancers intra-tumor heterogeneity, hence representing a more relevant preclinical model than cell lines. An ex-vivo drug screening was performed in these models generating response data (IC50 and AUC) for 100 different drugs, including "best in class" PI3K, PARP and CDK4/6 inhibitors, novel biological and chemical inhibitors of HER2, ER, IGF1R and HER3, as well as standard of care agents. Here we derived signatures of pathway activation/disruption by integrating different data types in the METABRIC cohort. Their association with previous breast cancer classifications, as well as their prognostic significance was studied. The predictive power of these signatures was investigated in the PDTX cohort to identify novel pharmacogenomics associations. They were tested independently as well as in combination, to derive molecular predictors of response to treatment. We found known and novel associations between genomic/transcriptomic features and drug response. For example, our results confirmed the known association between estrogen receptor-related genes and response to tamoxifen treatment. We also identified markers of response to inhibitors of the PI3K/AKT/mTOR pathway. Selected findings were validated in clinical cohorts as well as in independent PDTX models. In conclusion, by integrating molecular data from large cohorts of clinical samples and PDTX we have generated a computational framework for the systematic identification of pharmacogenomics associations in breast cancer and to generate hypothesis for rational drug-drug combinations. Citation Format: Maurizio Callari, Rajbir N. Batra, Ankita Sati Batra, Wendy Greenwood, Suet-Feung Chin, Alejandra Bruna, Oscar M. Rueda, Carlos Caldas. Integrative analysis of molecular and drug response data from clinical samples and PDTXs to identify pharmacogenomic associations in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2991. doi:10.1158/1538-7445.AM2017-2991

Endocrine-related genes are altered by antibacterial agent triclosan in Chironomus riparius aquatic larvae

Triclosan (TCS) is an antibacterial agent widely used in personal care and consumer products and commonly detected in aquatic ecosystems. In the present study, the effects of TCS on endocrine-related genes of Chironomus riparius aquatic larvae, a reference organism in aquatic toxicology, were evaluated. Twenty-four-hour in vivo exposures at 10µg/L, 100µg/L, and 1000µg/L TCS revealed that this xenobiotic was able to alter the transcriptional activity of ecdysone receptor gene (EcR), the ultraspiracle gene (usp), the estrogen-related receptor gene (ERR), and the E74 early ecdysone-inducible gene, as measured by real-time RT-PCR. Moreover, the hsp70 gene, a heat shock protein gene, was upregulated after exposure to TCS. The results of the present work provide the first evidence of the potential disruptive effects of TCS in endocrine-related genes suggesting a mode of action that mimics ecdysteroid hormones in insects.

Molecular cloning, expression, and stress response of the estrogen-related receptor gene (AccERR) from Apis cerana cerana.

Estrogen-related receptor (ERR), which belongs to the nuclear receptor superfamily, has been implicated in diverse physiological processes involving the estrogen signaling pathway. However, little information is available on ERR in Apis cerana cerana. In this report, we isolated the ERR gene and investigated its involvement in antioxidant defense. Quantitative real-time polymerase chain reaction (qPCR) revealed that the highest mRNA expression occurred in eggs during different developmental stages. The expression levels of AccERR were highest in the muscle, followed by the rectum. The predicted transcription factor binding sites in the promoter of AccERR suggested that AccERR potentially functions in early development and in environmental stress responses. The expression of AccERR was induced by cold (4°C), heat (42°C), ultraviolet light (UV), HgCl2, and various types of pesticides (phoxim, deltamethrin, triadimefon, and cyhalothrin). Western blot was used to measure the expression levels of AccERR protein. These data suggested that AccERR might play a vital role in abiotic stress responses.

Abstract P2-03-05: The heterogeneous clinical behavior of luminal breast cancers is associated with different mutational landscapes

Abstract Background: Genomic studies in estrogen-receptor (ER) positive breast cancer showed few commonly mutated genes and suggested that tumors with higher background of mutation rate were enriched in intrinsic aromatase-inhibitor-resistant tumors (Ellis MJ Nature 2012). Different combinations of proliferation (PROL) and estrogen-receptor related genes (ERS) allow the prediction of the risk of recurrence and endocrine treatment sensitivity (Bianchini G Breast Cancer Res 2013). The highPROL/lowERS is enriched in intrinsic endocrine resistant tumors. We explored whether different genomic alterations could contribute to the different clinical behavior of groups defined by PROL and ERS. Method: We defined luminal breast cancers by PAM50 and retrieved gene expression and whole-exome sequencing data of 324 luminal breast cancer cases from the Cancer Genome Atlas (TCGA). PROL and ERS were calculated as previously reported. Low and high expression groups were defined by median cut-points (Bianchini G Breast Cancer Res 2013). As a metric of the background mutation rate of each sample, we used the overall mutation frequency in whole exome (Kandoth C Nature 2013). The most frequently mutated genes (TP53, PIK3CA, MAP2K4, MAP3K1, GATA3, CDH1) were also assessed for their association with PROL and ERS defined groups. Results: The average number of mutations (Nmut) was 44.4 (5-366). High and low proliferation groups had different mutation frequency (average Nmut 53.6 and 35.3, respectively; p=6.1E-06). LowERS group also had a higher Nmut (average Nmut 54.4 vs. 34.5 in high ERS; p=1.2E-06). Notably, neither high or low expression of the ER gene (p=0.89), nor positive and negative progesterone receptor by immunohistochemistry (p=0.69) were associated with Nmut. LowERS group was associated with higher Nmut in luminal A (p=0.005) and B (p=0.006) subtypes. The group with highPROL and lowERS had the highest Nmut (average 62.1), which was not significantly different from basal-like tumors. HighPROL/lowERS was significantly associated with higher frequency of mutTP53 (32.3%) and lower rates of mutPIK3CA (28.1%), mutMAP2K4 and/or mutMAP3K1 (7.2%) and mutCHD1 (3.1%). The lowPROL/highERS had the lowest Nmut (average 29.8), with the higher rate of mutPIK3CA (61.4%) and mutMAP2K4 and/or mutMAP3K1 (29.2%), and lower rate of mutTP53 (6.7%). Discussion: In ER-positive breast cancers, the highPROL/lowERS group, which is characterized by the highest risk of early recurrences despite endocrine treatment and chemotherapy, poor down-regulation of Ki67 after neoadjuvant aromatase-inhibitor (AI), but the highest rate of pCR after neoadjuvant chemotherapy, was also associated with the highest frequency of mutations, of the same order of magnitude of basal-like tumors. This data is in line with the observation that the number of mutations is linked to intrinsic resistance to neoadjuvant AIs (Ellis MJ Nature 2012). These data could be also informative for interpreting results of the combination of everolimus and endocrine therapy (exemestane or tamoxifen) that suggest higher efficacy in tumors with acquired endocrine resistance (lower mutation rate) compared to intrinsic or primary endocrine resistance (higher mutation rate). Citation Format: Giampaolo Bianchini, Eugenia Galeota, Tingting Jiang, Maurizio Callari, Milvia Zambetti, Takayuki Iwamoto, Thomas Karn, Christos Hatzis, Lajos Pusztai, Luca Gianni. The heterogeneous clinical behavior of luminal breast cancers is associated with different mutational landscapes [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 P2-03-05.

Transcriptional changes induced by in vivo exposure to pentachlorophenol (PCP) in Chironomus riparius (Diptera) aquatic larvae

Pentachlorophenol (PCP) has been extensively used worldwide as a pesticide and biocide and is frequently detected in the aquatic environment. In the present work, the toxicity of PCP was investigated in Chironomus riparius aquatic larvae. The effects following short- and long-term exposures were evaluated at the molecular level by analyzing changes in the transcriptional profile of different endocrine genes, as well as in genes involved in the stress response and detoxification. Interestingly, although no differences were found after 12- and 24-h treatments, at 96-h exposures PCP was able to induce significant increases in transcripts from the ecdysone receptor gene (EcR), the early ecdysone-inducible E74 gene, the estrogen-related receptor gene (ERR), the Hsp70 gene and the CYP4G gene. In contrast, the Hsp27 gene appeared to be downregulated, while the ultraspiracle gene (usp) (insect ortholog of the retinoid X receptor) was not altered in any of the conditions assayed. Moreover, Glutathione-S-Transferase (GST) activity was not affected. The results obtained show the ability of PCP to modulate transcription of different biomarker genes from important cellular metabolic activities, which could be useful in genomic approaches to monitoring. In particular, the significant upregulation of hormonal genes represents the first evidence at the genomic level of the potential endocrine disruptive effects of PCP on aquatic invertebrates.

Ethylparaben affects lifespan, fecundity, and the expression levels of ERR, EcR and YPR in Drosophila melanogaster

Parabens, which mainly include methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP), are widely used as cosmetic and food preservatives. Although these chemicals, when used as preservatives, are thought to be safe for humans, many studies have demonstrated that they have estrogenic effects, and can affect the normal development and functions of the reproductive systems in a number of animal species. By treating fruit flies (Drosophila melanogaster) with EP, here we show that lower concentration of EP (0.02%) enhanced fertility while higher concentration of EP (0.10% and 0.20%) shortened the lifespan and reduced the fecundity of fruit flies. When we analyzed the expression levels of the estrogen-related receptor gene (ERR), ecdysone receptor gene (EcR) and Yolk protein receptor gene (YPR) from control and EP-treated fruit flies by using quantitative real-time PCR, we found that the expression levels of all three genes were significantly changed by EP treatment, and that female fruit flies are more sensitive to EP than males. Our data suggests that the estrogenic and the toxic effects of EP to fruit flies may have a molecular basis through the hormonal effect of EP.

A Majority of Low (1-10%) ER Positive Breast Cancers Behave Like Hormone Receptor Negative Tumors.

Background: The 2010 guidelines by ASCO-CAP have mandated that breast cancer specimens with ≥1% positively staining cells by immunohistochemistry should be considered Estrogen Receptor (ER) positive. This has led to a subclass of low-ER positive (1-10%) breast cancers. We have examined the biology and clinical behavior of these low ER staining tumors.Methods: We have developed a probabilistic score of the “ER-positivity” by quantitative estimation of ER related gene transcripts from FFPE specimens. Immunohistochemistry for ER was done on 240 surgically excised tumors of primary breast cancer. Relative transcript abundance of 3 house-keeping genes and 6 ER related genes were determined by q-RT PCR. A logistic regression model using 3 ER associated genes provided the best probability function, and a cut-off value was derived by ROC analysis. 144 high ER (>10%), 75 ER negative and 21 low-ER (1-10%) tumors were evaluated using the probability score and the disease specific survival was compared.Results: Half of the low-ER positive tumors were assigned to the ER negative group based on the probability score; in contrast 95% of ER negative and 92% of the high ER positive tumors were assigned to the appropriate ER group (p<0.0001). The survival of the low-ER group was intermediate between that of the high ER positive and ER negative groups (p<0.05).Conclusion: Our results suggest that the newly lowered ASCO-CAP criteria for ER positivity, leads to the false categorization of biologically ER negative tumors as ER positive ones. This may have particular relevance to India, where we have a much higher proportion of ER negative tumors in general.

No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals

Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs are reported to be highly susceptible to effects caused by very low concentrations of environmental estrogens which, if substantiated, would have a major impact on the risk assessment of many chemicals. The present paper describes the most thorough evaluation to-date of the susceptibility of Marisa cornuarietis ER and ERR gene transcription to modulation by vertebrate estrogens in vivo and in vitro. We investigated the effects of estradiol-17β and 4-tert-Octylphenol exposure on in vivo estrogen receptor (ER) and estrogen-related receptor (ERR) gene transcription in the reproductive and neural tissues of the gastropod snail M. cornuarietis over a 12-week period. There was no significant effect (p>0.05) of treatment on gene transcription levels between exposed and non-exposed snails. Absence of a direct interaction of estradiol-17β and 4-tert-Octylphenol with mollusc ER and ERR protein was also supported by in vitro studies in transfected HEK-293 cells. Additional in vitro studies with a selection of other potential ligands (including methyl-testosterone, 17α-ethinylestradiol, 4-hydroxytamoxifen, diethylstilbestrol, cyproterone acetate and ICI182780) showed no interaction when tested using this assay. In repeated in vitro tests, however, genistein (with mcER-like) and bisphenol-A (with mcERR) increased reporter gene expression at high concentrations only (>10−6M for Gen and >10−5M for BPA, respectively). Like vertebrate estrogen receptors, the mollusc ER protein bound to the consensus vertebrate estrogen-response element (ERE). Together, these data provide no substantial evidence that mcER-like and mcERR activation and transcript levels in tissues are modulated by the vertebrate estrogen estradiol-17β or 4-tert-Octylphenol in vivo, or that other ligands of vertebrate ERs and ERRs (with the possible exception of genistein and bisphenol A, respectively) would do otherwise.

6P - A Majority of Breast Cancer Specimens with 1-9 % ER Positivity Behave Like Hormone Receptor Negative Tumors

Background: The 2010 American Society for Clinical Oncology(ASCO) and College of American Pathologists (CAP) guidelines that breast cancer specimens with ≥1% positively staining cells should be considered Estrogen Receptor (ER) positive has led to a subclass of low ER positive (1-10 %) breast cancers. Two reports that have examined this border-line sub-class by gene-expression analysis have found that a majority are non-Luminal tumors. We have determined the biological behaviour of the low ER tumors in our cohort by quantitative estimation of ER related gene transcripts.

Estrogen receptor-related genes as an important panel of predictors for breast cancer response to neoadjuvant chemotherapy

Purpose Clinical data suggest that the estrogen receptor (ER) contributes to chemotherapeutic responsiveness. However, ER status alone is not consistently predictive. In this study, we used a microarray approach to find novel ER-related genes that predicted chemotherapy responses, with the hope of providing a robust multi-variable prediction method. Methods One hundred and ten patients with stages II and III breast cancer were included. They received four preoperative cycles of a weekly PCb (paclitaxel plus carboplatin) regimen. A total of 55 training cases were used for marker discovery and for identification of any ER-related genes that may have been associated with a chemotherapeutic response (“training cases”). The other 55 patients were available as an independent validation set (“validation cases”) to test, using immunohistochemistry (IHC). Results In the training set, 20 significantly differentially expressed genes were identified. Among these 20 genes, TFF1, ESR1, GATA3 and TFF3 were found to be ER-related. Among 55 independent validation cases, univariate analysis indicated that clinical variables and ER-related genes were all significantly associated with pCR. It was shown that the pCR rate was as high as 80% when these five factors were all negative. In contrast, these five factors were all positive in seven of nine chemo-resistant patients. Conclusion In conjunction with levels of ER-related genes, expression of ER protein may provide important predictive outcomes for responses to neoadjuvant chemotherapy and may allow for the identification of a subgroup of patients who could significantly benefit from chemotherapy (or who may be resistant to it).

Molecular effects of endocrine-disrupting chemicals on the Chironomus riparius estrogen-related receptor gene

Endocrine-disrupting chemicals (EDCs) mimic the action of endogenous estrogen hormones; consequently, they can interfere with the endocrine systems of a variety of organisms. There is global concern regarding the potential impacts of EDCs on the aquatic environment. To evaluate the effects of EDCs on the estrogen-related receptors (ERR) of Chironomus, we characterized full-length cDNA sequences of the ERR gene from Chironomus riparius. The complete cDNA sequence of the ERR gene was found to be 1332 bp in length. The results of our phylogenetic analysis demonstrated that C. riparius ERR was most closely related to that of mosquitoes. The basal level of ERR mRNA was expressed abundantly during different life-history stages, with the exception of adult males. Additionally, ERR gene expression was upregulated significantly in C. riparius exposed to bisphenol A (BPA) and 4-nonylphenol (NP) at all concentrations assayed after 24 h of exposure. The ERR gene was significantly upregulated following short periods of exposure to di(2-ethylhexyl)phthalate (DEHP) concentrations of only 50 mg L −1. However, under long-term exposure conditions, ERR expression was induced to a significant degree after BPA, NP, and DEHP exposure at all concentrations assayed. Furthermore, the luciferase reporter gene assay revealed increased ERR expression following exposure to these compounds. Collectively, these findings indicate that EDCs influence the expression of ERR in Chironomus species.