ERβ Expression Research Articles

Global Cerebral Ischemia Induces Short-Term Changes to Estrous Cycle Regularity and Alters Hypothalamic-Pituitary-Gonadal Axis Function

Global cerebral ischemia (GCI), which mimics cardiac arrest in humans, induces numerous functional alterations throughout the brain, but its impact on the hypothalamic-pituitary-gonadal (HPG) axis remains largely unknown. Importantly, the HPG axis modulates sex hormones and neuropeptides, such as estrogen and kisspeptin, as well as estrous cycle regularity. The goals of this study were to determine if estrous cycle regularity is affected by GCI and to characterize HPG axis functionality post-ischemia. Adult female Wistar rats underwent vaginal lavage for 2 weeks to confirm estrous cycle regularity before being subjected to GCI for 10 minutes or sham surgery. Estrous cycle regularity was monitored for 4 weeks following surgery, after which rats were euthanized. Immunofluorescence was used to detect kisspeptin receptors (Kiss1) and estrogen receptors alpha (ERα) and beta (ERβ) expression in the arcuate nucleus (ARC) of the hypothalamus, as well as the CA1 and dentate gyrus (DG) of the hippocampus. Following surgery, all sham subjects maintained a regular estrous cycle, whereas two thirds of ischemic rats presented a disrupted cycle following GCI (persistent diestrus, average length 13 days), before resuming regular cycling. T-test revealed a significant increase in Kiss1 receptors in the ARC of GCI rodents, as well as a trend for higher ERα expression in the CA1 of ischemic rats. Overall, our results highlight that while estrous cycle disruptions resolve within 2 weeks after the ischemic event, HPG axis dysregulation persists up to one month after GCI, hinting at possible long-term impacts on the reproductive axis.

The Phytoestrogenic Effect of Hibiscus sabdariffa Involves Estrogen Receptor α in Ovariectomized Wistar Rats.

The calyxes of Hibiscus sabdariffa present multiple pharmacological effects primarily attributed to their high anthocyanin content; however, little is known about their phytoestrogenic effect. Ovarian hypofunction (OH) is a process characterized by the rapid detention of the production of ovarian hormones, which compromises reproductive and cognitive functions. Hormone replacement therapy (HRT) efficiently compensates for OH; nevertheless, questions have been raised on its secondary effects and safety. One of the alternatives to tackling OH involves using phytoestrogens such as anthocyanins for their structural similarity to natural estrogens. In a Wistar rat model of ovariectomy (OVX), we recently reported the beneficial properties of an anthocyanin-rich extract prepared from the calyces of H. sabdariffa (HSE) in hindering the adverse effects of OH on memory performance and highlighted a possible phytoestrogenic impact through the modulation of estrogen receptor (ER) expression. We now report that HSE and estradiol differentially affected the expression of ERα and ERβ. ERα was more sensitive to HSE; meanwhile, estradiol preferentially modulated ERβ. Thus, our study leads to further research on using H. sabdariffa as a nutrition-based alternative to HRT.

11-Ethoxyviburtinal improves chronic restraint stress-induced anxiety-like behaviors in gender-specific mice via PI3K/Akt and E2 /ERβ signaling pathways.

Anxiety disorder is a chronic and disabling psychiatric disorder that is more prevalent in females than in males. 11-Ethoxyviburtinal is an iridoid extracted from Valeriana jatamansi Jones, which has anxiolytic potential. The aim of the present work was to study the anxiolytic efficacy and mechanism of 11-ethoxyviburtinal in gender-specific mice. We first evaluated the anxiolytic-like efficacy of 11-ethoxyviburtinal in chronic restraint stress (CRS) mice of different sexes through behavioral experiments and biochemical indexes. In addition, network pharmacology and molecular docking were used to predict potential targets and important pathways for the treatment of anxiety disorder with 11-ethoxyviburtinal. Finally, the influence of 11-ethoxyviburtinal on phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, estrogen receptor β (ERβ) expression, and anxiety-like behavior in mice was verified by western blotting, immunohistochemistry staining, antagonist intervention methods, and behavioral experiments. 11-ethoxyviburtinal alleviated the anxiety-like behaviors induced by CRS and inhibited neurotransmitter dysregulation and HPA axis hyperactivity. It inhibited the abnormal activation of the PI3K/Akt signaling pathway, modulated estrogen production, and promoted ERβ expression in mice. In addition, the female mice may be more sensitive to the pharmacological effects of 11-ethoxyviburtinal. 11-ethoxyviburtinal may exert its anxiolytic-like effects through PI3K/Akt and E2/ERβ signaling pathways. Meanwhile, by comparing the male and female mice, gender differences may affect the therapy and development of anxiety disorder.

Upregulated Expression of ERBB2/HER2 in Multiple Myeloma as a Predictor of Poor Survival Outcomes.

The main goal of the present study was to examine if the RNA-sequencing (RNAseq)-based ERBB2/HER2 expression level in malignant plasma cells from multiple myeloma (MM) patients has clinical significance for treatment outcomes and survival. We examined the relationship between the RNAseq-based ERBB2 messenger ribonucleic acid (mRNA) levels in malignant plasma cells and survival outcomes in 787 MM patients treated on contemporary standard regimens. ERBB2 was expressed at significantly higher levels than ERBB1 as well as ERBB3 across all three stages of the disease. Upregulated expression of ERBB2 mRNA in MM cells was correlated with amplified expression of mRNAs for transcription factors (TF) that recognize the ERBB2 gene promoter sites. Patients with higher levels of ERBB2 mRNA in their malignant plasma cells experienced significantly increased cancer mortality, shorter progression-free survival, and worse overall survival than other patients. The adverse impact of high ERBB2 expression on patient survival outcomes remained significant in multivariate Cox proportional hazards models that accounted for the effects of other prognostic factors. To the best of our knowledge, this is the first demonstration of an adverse prognostic impact of high-level ERBB2 expression in MM patients. Our results encourage further evaluation of the prognostic significance of high-level ERBB2 mRNA expression and the clinical potential of ERBB2-targeting therapeutics as personalized medicines to overcome cancer drug resistance in high-risk as well as relapsed/refractory MM.

Adavosertib Enhances Antitumor Activity of Trastuzumab Deruxtecan in HER2-Expressing Cancers.

Cyclin E (CCNE1) has been proposed as a biomarker of sensitivity to adavosertib, a Wee1 kinase inhibitor, and a mechanism of resistance to HER2-targeted therapy. Copy number and genomic sequencing data from The Cancer Genome Atlas and MD Anderson Cancer Center databases were analyzed to assess ERBB2 and CCNE1 expression. Molecular characteristics of tumors and patient-derived xenografts (PDX) were assessed by next-generation sequencing, whole-exome sequencing, fluorescent in situ hybridization, and IHC. In vitro, CCNE1 was overexpressed or knocked down in HER2+ cell lines to evaluate drug combination efficacy. In vivo, NSG mice bearing PDXs were subjected to combinatorial therapy with various treatment regimens, followed by tumor growth assessment. Pharmacodynamic markers in PDXs were characterized by IHC and reverse-phase protein array. Among several ERBB2-amplified cancers, CCNE1 co-amplification was identified (gastric 37%, endometroid 43%, and ovarian serous adenocarcinoma 41%). We hypothesized that adavosertib may enhance activity of HER2 antibody-drug conjugate trastuzumab deruxtecan (T-DXd). In vitro, sensitivity to T-DXd was decreased by cyclin E overexpression and increased by knockdown, and adavosertib was synergistic with topoisomerase I inhibitor DXd. In vivo, the T-DXd + adavosertib combination significantly increased γH2AX and antitumor activity in HER2 low, cyclin E amplified gastroesophageal cancer PDX models and prolonged event-free survival (EFS) in a HER2-overexpressing gastroesophageal cancer model. T-DXd + adavosertib treatment also increased EFS in other HER2-expressing tumor types, including a T-DXd-treated colon cancer model. We provide rationale for combining T-DXd with adavosertib in HER2-expressing cancers, especially with co-occuring CCNE1 amplifications. See related commentary by Rolfo et al., p. 4317.

An Analysis of Clinical and Pathologic Features, RecurIndex Genomic Profiles, and Survival Outcomes in HER2-Low Breast Cancer.

In recent years, breast cancer has become the most common cancer in the world, increasing women's health risks. Approximately 60% of breast cancers are categorized as human epidermal growth factor receptor 2 (HER2)-low tumors. Recently, antibody-drug conjugates have been found to have positive anticancer efficacy in patients with HER2-low breast cancer, but more studies are required to comprehend their clinical and molecular characteristics. In this study, we retrospectively analyzed the data of 165 early breast cancer patients with pT1-2N1M0 who had undergone the RecurIndex testing. To better understand HER2-low tumors, we investigated the RecurIndex genomic profiles, clinicopathologic features, and survival outcomes of breast cancers according to HER2 status. First, there were significantly more hormone receptor (HR)-positive tumors, luminal-type tumors, and low Ki67 levels in the HER2-low than in the HER2-zero. Second, RI-LR (P = .0294) and RI-DR (P = .001) scores for HER2-low and HER2-zero were statistically significant. Third, within HER2-negative disease, HR-positive/HER2-low tumors showed highest ESR1, NFATC2IP, PTI1, ERBB2, and OBSL1 expressions. Fourth, results of the survival analysis showed that lower expression of HER2 was associated with improved relapse-free survival for HR-positive tumors, but not for HR-negative tumors. The present study highlights the unique features of HER2-low tumors in terms of their clinical characteristics as well as their gene expression profiles. HR status may influence the prognosis of patients with HER2-low expression, and patients with HR-positive/HER2-low expression may have a favorable outcome.

NGR4 and ERBB4 as Promising Diagnostic and Therapeutic Targets for Metabolic Disorders.

Obese individuals are at high risk for developing type 2 diabetes mellitus, cardiovascular diseases, and nonalcoholic fatty liver disease. The aim of this review was to analyze the scientific literature and databases to reveal the fundamental role of neuregulin 4 (NRG4) and its receptors in the development of obesity-associated metabolic disorders. This review demonstrates that NRG4 and its receptors are promising therapeutic targets for the treatment of socially significant obesity-associated pathologies. The review contains nine chapters. Information on the structure of ERBB4 and NRG4 splice isoforms and subsequent activation of downstream targets is presented. The tissue-specific features of the NRG4 and ERBB4 genes and protein production are also highlighted. The role of NRG4 and ERBB3/4 in the pathophysiological mechanisms of the development of metabolic disorders in obesity is discussed in detail. The final chapter of the review is devoted to the miRNA-dependent regulation of NRG4 and ERBB4. Recent studies have shown that several miRNAs regulate ERBB4 expression, but no information was found on the interaction of NRG4 with miRNAs. We now demonstrate the putative relationships between NRG4 and let-7a-5p, let-7c-5p, miR-423-5p, miR-93-5p, miR-23a-3p, and miR-15b-5p for the first time. In addition, we found SNP mutations affecting the interaction of NRG4 and ERBB4 with miRNA in these genes as well as in miRNAs. In summary, this review provides a detailed and comprehensive overview of the role of NRG4 in obesity-associated metabolic disorders. The review summarizes all current studies on this topic and opens perspectives for future research.

Understanding the Phytoestrogen Genistein Actions on Breast Cancer: Insights on Estrogen Receptor Equivalence, Pleiotropic Essence and Emerging Paradigms in Bioavailability Modulation.

Prevalent as a major phenolic ingredient of soy and soy products, genistein is recognized as an eminent phytoestrogen owing to its interacting ability with estrogen receptors (ERs). The metabolic conversion of plant-derived genistin to genistein by gut microbes and intestinal enzymes enhances its absorption at intestinal pH of ~7.5-7.8. Genistein interferes in breast cancer (BC) development via pleiotropic actions on cell proliferation, survival, angiogenesis, and apoptosis. Though multiple investigations have demonstrated genistein intake-driven reduced BC risk, similar efficacy has not been replicated in clinical trials. Furthermore, multiple studies have structurally and functionally equated genistein extents with 17-β-estradiol (E2), the most available physiological estrogen in females, culminating in aggravated BC growth. Of note, both genistein and E2 function via interacting with ERs (ERα and ERβ). However, although E2 shows almost equal affinity towards both ERα and ERβ, genistein shows more affinity towards ERβ than ERα. Our cautious literature survey revealed typical intake mode, ER expression pattern and the ratio of ERα and ERβ, transactivators/ regulators of ERα and ERβ expression and activities, patient age, and menopausal status as decisive factors affecting genistein BC activities. Of further interest are the mechanisms by which genistein inhibits triple-negative breast cancers (TNBCs), which lack ERs, progesterone receptors (PRs), and human epidermal growth factor receptors (HER2). Herein, we attempt to understand the dosage-specific genistein actions in BC cells and patients with an insight into its better response via derivative development, nanocarrier-assisted, and combinatorial delivery with chemotherapeutic drugs.

ERBB2 (HER2) gene amplification concordance analysis of circulating tumor cells and tumor tissue in patients with breast cancer.

e13047 Background: HER2 targeted therapies, such as HER2 monoclonal antibodies, HER2 tyrosine kinase inhibitors, and HER2 antibody drug conjugates, are approved for the treatment of HER2-positive breast, gastric and colorectal cancers. However, inter- and intra-tumoral heterogeneity in HER2 status presented a significant challenge in identifying patients that may benefit from HER2-targeted therapies. Detection of ERBB2 amplification in Circulating Tumor Cells (CTCs) may circumvent tissue heterogeneity issues and effectively predict the response of patients to anti-HER2 agents as a non-invasive alternative approach. Methods: A twenty-four patient pilot study was designed to compare HER2 status of traditional needle biopsies to high sensitivity CTC based liquid biopsies. HER2 status was determined using immunohistochemistry (IHC) and Fluorescence in Situ Hybridization (FISH) for tissue samples and FISH analysis for CTCs. Currently 21 patient samples have been compared in this study. Results: CTCs with HER2 amplified signals were found in patients with stages 2, 3, or 4 breast cancers. Based on the biopsies of the primary tumor or metastatic disease, 6 patients (29%) had HER2-overexpressing as defined by either HER2 IHC 3+ or HER2 FISH amplified. Analysis of CTCs showed 100% concordance (HER2 amplification detected in CTCs) in these patients with HER2-overexpressing breast cancer. Furthermore, an additional 4 (19%) patients had HER2 amplification by CTC analysis but not on needle biopsy. Conclusions: Our finding demonstrates that LiquidScan can be used as a rapid analysis tool to evaluate HER2 amplification in CTCs. This approach can potentially help identify additional cohort of patients (HER2 non-amplified tumor / HER2 amplified CTCs) who may benefit from the new generation of HER2 targeted therapies. Studies are ongoing to include an expanded cohort of patients with early stage disease, as well as HER2-low disease, in order to evaluating dynamics of ERBB2 gene amplification, expression, and pathway activation while on active systemic therapy.

RNA sequencing as a confirmatory assay and its impact on patient care in multiple cancer types.

e15058 Background: Increasing evidence shows the ability of RNA sequencing (RNA-seq) to detect expression of multiple biomarkers with improved sensitivity and scalability, offering a more objective and reproducible interpretation of data compared to pathological assessment methods by immunohistochemistry (IHC). Further, ongoing research demonstrating strong correlation between RNA-seq gene expression values and IHC values suggests the utility of RNA-seq as an objective diagnostic approach. Here, we highlight 4 cases where discordance in expression levels measured by IHC and RNA-seq resulted in re-evaluation of IHC values and a subsequent change in the clinical course. Methods: All patients underwent RNA and DNA sequencing of tumor tissue as part of a standard-of-care workflow. Sequencing was performed and reported with the BostonGene Tumor Portrait test, utilizing whole-exome sequencing (WES) and transcriptome sequencing data for tumor analysis. Gene expression levels were evaluated by comparison to a reference cohort of patients with a similar diagnosis. Results: In one case, a 53-year-old female was diagnosed with metastatic cholangiocarcinoma. While IHC of her biopsy reported positive HER2 (+3) expression, RNA-seq revealed low expression. A repeated IHC assay confirmed negative HER2 expression, leading to a change in therapy options. Another 61-year-old female was diagnosed with triple negative breast cancer (TNBC) (IHC: ER 0%, PR 0%, HER2 1+). Integrated WES and RNA-seq analysis detected HER2 amplification (+8 copies), ERBB2-activating mutation, high ERBB2 (HER2) expression and a HER2-enriched PAM50 subtype. IHC was repeated, now showing positive HER2 (+3) expression. In order to target HER2, systemic treatment was changed to a combination containing trastuzumab and pertuzumab, resulting in pathological complete response. In the third case of an 85-year-old female with relapsed TNBC, IHC demonstrated 1% PDL-1 staining. In contrast, RNA-seq detected high PD-L1 expression leading the treating physician to repeat IHC. Staining showed high PDL-1 (CPS50), prompting a change in therapy to an anti-PDL-1 (pembrolizumab) therapy. Lastly, while IHC of a 21-year-old female diagnosed with diffuse large B-cell lymphoma (DLBCL) showed negative CD30, subsequent RNA-seq detected relatively high CD30 expression that prompted a second IHC evaluation confirming positive CD30 expression. Eventually, the diagnosis was changed to primary mediastinal B-cell lymphoma and DA-EPOCH was selected as the therapy. Conclusions: RNA-seq is emerging as an objective tool to evaluate key diagnostic and targetable events in multiple cancer types. The use of RNA-seq can also add value as an objective measurement to confirm critical IHC findings, potentially changing clinical care.

Complex Extract of Polygonatum sibiricum and Nelumbinis semen Improves Menopause Symptoms via Regulation of Estrogen Receptor Beta in an Ovariectomized Rat Model.

Menopause is a hormone-deficiency state that causes facial flushing, vaginal dryness, depression, anxiety, insomnia, obesity, osteoporosis, and cardiovascular disease as ovarian function decreases. Hormone-replacement therapy is mainly used to treat menopause; however, its long-term use is accompanied by side effects such as breast cancer and endometriosis. To identify the effect of a complex extract of Polygonatum sibiricum (PS) and Nelumbinis semen (NS) on improving menopause without side effects, an ovariectomized rat model was established to analyze several menopause symptoms. Compared to single extracts, the complex extract restored vaginal epithelial cell thickness and decreased serotonin concentration by increasing the estrogen receptors ERα (ESR1) and ERβ (ESR2), depending on the ratio. Although the complex extract exerted a lower weight-loss effect than the single extracts, improved blood-lipid metabolism was observed after increasing high-density lipoprotein cholesterol levels and decreasing low-density lipoprotein cholesterol and triglyceride levels, and ovariectomy-induced osteoporosis was alleviated by suppressing osteoclast production. Thus, by increasing only ERβ expression without regulating ERα expression in the uterus, the complex extract of PS and NS may be a natural treatment for improving menopause symptoms without side effects, such as endometriosis.

The impacts of exposure to bisphenol A in the adult female prostate Meriones unguiculatus

The female prostate is associated with the urogenital system and presents homology in morphological terms with the male prostate. Due to its responsiveness to endogenous hormones, this gland is under a constant risk of developing prostatic pathologies and neoplasia when exposed to certain exogenous compounds. Bisphenol A (BPA) is an endocrine disruptor found in different plastic and resin products. Studies have emphasized the effects of perinatal exposure to this compound on different hormone-responsive organs. However, there have been few studies highlighting the influence on female prostate morphology of perinatal exposure to BPA. The objective of this study was to describe the histopathological alterations caused by perinatal exposure to BPA (50 µg/kg) and 17-β estradiol (E2) (35 µg/kg) in the prostate of adult female gerbils. The results showed that E2 and BPA induced proliferative lesions in the female prostate and acted along similar pathways by modulating steroid receptors in the epithelium. BPA was also found to be a pro-inflammatory and pro-angiogenic agent. The impacts of both agents were marked in the prostatic stroma. An increase in the thickness of the smooth muscle layer and a decrease in AR expression were observed, but no alterations in the expression of ERα and ERβ, leading to estrogenic sensitivity of the prostate. However, a peculiar response of the female prostate was to diminish the collagen frequency under BPA exposure correlated to smooth muscle layer. These data therefore indicate the development of features related to estrogenic and non-estrogenic tissue repercussions by BPA perinatally exposure in gerbil female prostate.

ERβ promoted invadopodia formation-mediated non-small cell lung cancer metastasis via the ICAM1/p-Src/p-Cortactin signaling pathway.

In a previous study, our research group observed that estrogen promotes the metastasis of non-small cell lung cancer (NSCLC) through the estrogen receptor β (ERβ). Invadopodia are key structures involved in tumor metastasis. However, it is unclear whether ERβ is involved in the promotion of NSCLC metastasis through invadopodia. In our study, we used scanning electron microscopy to observe the formation of invadopodia following the overexpression of ERβ and treatment with E2. In vitro experiments using multiple NSCLC cell lines demonstrated that ERβ can increase the formation of invadopodia and cell invasion. Mechanistic studies revealed that ERβ can upregulate the expression of ICAM1 by directly binding to estrogen-responsive elements (EREs) located on the ICAM1 promoter, which in turn can enhance the phosphorylation of Src/cortactin. We also confirmed these findings in vivo using an orthotopic lung transplantation mouse model, which validated the results obtained from the in vitro experiments. Finally, we examined the expressions of ERβ and ICAM1 using immunohistochemistry in both NSCLC tissue and paired metastatic lymph nodes. The results confirmed that ERβ promotes the formation of invadopodia in NSCLC cells through the ICAM1/p-Src/p-Cortactin signaling pathway.

Estrogen receptor beta expression in triple negative breast cancers is not associated with recurrence or survival

BackgroundTriple negative BCa (TNBC) is defined by a lack of expression of estrogen (ERα), progesterone (PgR) receptors and human epidermal growth factor receptor 2 (HER2) as assessed by protein expression and/or gene amplification. It makes up ~ 15% of all BCa and often has a poor prognosis. TNBC is not treated with endocrine therapies as ERα and PR negative tumors in general do not show benefit. However, a small fraction of the true TNBC tumors do show tamoxifen sensitivity, with those expressing the most common isoform of ERβ1 having the most benefit. Recently, the antibodies commonly used to assess ERβ1 in TNBC have been found to lack specificity, which calls into question available data regarding the proportion of TNBC that express ERβ1 and any relationship to clinical outcome.MethodsTo confirm the true frequency of ERβ1 in TNBC we performed robust ERβ1 immunohistochemistry using the specific antibody CWK-F12 ERβ1 on 156 primary TNBC cancers from patients with a median of 78 months (range 0.2–155 months) follow up.ResultsWe found that high expression of ERβ1 was not associated with increased recurrence or survival when assessed as percentage of ERβ1 positive tumor cells or as Allred > 5. In contrast, the non-specific PPG5-10 antibody did show an association with recurrence and survival.ConclusionsOur data indicate that ERβ1 expression in TNBC tumours does not associate with prognosis.

Distribution of estrogen receptors alpha and beta in the brain of male rats with same-sex preference

Two distinct estrogen receptors (ERs) exist, ERα and ERβ. Both receptors participate in sexual differentiation of the rat brain and likely participate in the regulation of adult sexual orientation (i.e. partner preference). This last idea was investigated herein by examining males treated with the aromatase inhibitor, letrozole, administered prenatally (0.56 μg/kg G10–22). This treatment usually provokes same-sex preference in 1–2 males per litter. Vehicle-treated males (with female preference) and females in spontaneous proestrus (with male preference) were included as controls. ERα and ERβ expression was analyzed by immunohistochemistry in brain areas known to control masculine sexual behavior and partner preference, like the medial preoptic area (MPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA) and ventromedial hypothalamic nucleus (VMH), as well as other brain regions suspected to participate in these processes. In addition, serum levels of estradiol were determined in all male groups. Letrozole-treated male rats that preferred sexually experienced males (LPM) showed over-expressed ERα in the hippocampal cornu Ammonis (CA 1, 3, 4) and dentate gyrus. The LPM group showed up-regulated ERβ expression in the CA2 and reticular thalamic nucleus. The levels of estradiol did not differ between the groups. Higher expression of ERs in these males was different than their expression in females, with male sex-preference. This suggests that males with same-sex preference showed a unique brain, this sui generis steroid receptor expression probably participates in the biological underpinnings of sexual preference.

Survival Outcomes in Patients With Hormone Receptor–Positive Metastatic Breast Cancer With Low or No ERBB2 Expression Treated With Targeted Therapies Plus Endocrine Therapy

Approximately 45% to 60% of hormone receptor (HR)-positive metastatic breast cancer (mBC) shows a low-level expression of ERBB2. Low ERBB2 expression is defined as ERBB2 immunohistochemical expression of 1+ or 2+ with a negative ERBB2 amplification by in situ hybridization. The efficacy of the antibody-drug conjugate trastuzumab deruxtecan in low-ERBB2, HR-positive mBC has been practice changing. However, there are conflicting data on the prognostic value of low ERBB2 expression in HR-positive mBC and whether low ERBB2 expression is a separate entity. To examine whether outcomes differ by immunohistochemical analysis for patients with HR-positive mBC with low ERBB2 expression vs those without ERBB2 expression when treated with targeted therapy (TT) plus endocrine therapy (ET). This single-institution cohort study used prospectively collected electronic data from the MD Anderson Cancer Center for patients with a diagnosis of HR-positive mBC treated with ET in combination with a TT (cyclin-dependent kinase 4/6 inhibitors [CDK4/6is], everolimus, or alpelisib) between January 1, 2010, and December 31, 2021. HR-positive mBC with either low or no ERBB2 expression. The main outcomes were median progression-free survival and overall survival. Data on demographic characteristics, estrogen and progesterone receptor status, ERBB2 status, histologic subtype, menopausal status, treatment duration, and survival status were collected. A total of 1585 women (median [range] age, 51 [24-92] years) were included in the study. Of these women, 1013 (63.9%) had mBC with low ERBB2 expression and 572 (36.1%) had mBC with no ERBB2 expression. A total of 1084 (68.4%) were treated with a CDK4/6i (912 patients were treated in the first line and 172 were treated in the second line); 475 (30.0%) received everolimus and 26 (1.6%) received alpelisib. In the patients who received a first-line CDK4/6i, 618 (67.8%) received an aromatase inhibitor as their ET backbone and 265 (29.1%) received fulvestrant. With a median follow-up time of 17.9 months (range, 1-111 months), progression-free survival and overall survival were not statistically different between the patients with low and no ERBB2 expression treated with TT plus ET. In this cohort study of patients with HR-positive mBC treated with TT plus ET, low ERBB2 expression did not have a significant association with prognosis.

O002 Expression of MLN64 (lymph node metastasis 64) gene transcript in clinical gastric cancer and relationship with the ERBB4

Abstract Introduction MLN64 (Lymph Node Metastasis 64, or STARD3 (StAR Related Lipid Transfer Domain Containing 3)) has a role in the progression of certain cancers including breast and prostate cancers and connected to the pattern of ERBB2 (Her2). The present study explored the expression of MLN64 in clinical gastric cancer in connection with the ERBB family. Methods A gastric cancer cohort (n=322) was tested for the expression profile of MLN64 along with the ERBB family members. Comparisons were made between clinical, pathological subgroups and the clinical outcome together with ERBB expression status. Results Gastric tumours expressed significantly raised levels of MLN64 than normal tissues (p=0.0012) and showed a stepwise increase with increased tumour grade and TNM staging. However, there was no significant difference between node negative and node positive tumours. MLN64 alone had a weak value in evaluating the overall (OS) and disease free (DFS) survival. Amongst the four ERBB family members, MLN64 had a significant correlation with ERBB4 (Her4) (p=0.004). Stratification of patients by ERBB4 expression status indicates that in patients with low ERBB4 tumours, MLN64 presents a significant factor in assessing both disease free (DFS) p=0.027) and overall survival (OS) (p=0.048). Similarly, MLN64 expression identified a subpopulation of node positive patients with a most adverse clinical outcome (p=0.009 for DFS and p=0.048 for OS). Conclusion MLN64 expression is an indicator for the disease progression and clinical outcome in gastric cancer. Together with the expression pattern of ERBB4, it makes a prognostic factor for the patients.

Female Sex but Not Oestrogen Receptor Expression Predicts Survival in Advanced Gastroesophageal Adenocarcinoma-A Post-hoc Analysis of the GO2 Trial.

Gastroesophageal adenocarcinoma is a disease of older adults that is associated with a very poor prognosis. It is less common and has better outcomes in females. The reason for this is unknown but may relate to signalling via the main oestrogen receptors (ER) α and β. In this study, we sought to investigate this using the GO2 clinical trial patient cohort. GO2 recruited older and/or frail patients with advanced gastroesophageal cancer. Immunohistochemistry was performed on tumour samples from 194 patients. The median age of the population was 76 years (range 52-90), and 25.3% were female. Only one (0.5%) tumour sample was positive for ERα, compared to 70.6% for ERβ expression. There was no survival impact according to ERβ expression level. Female sex and younger age were associated with lower ERβ expression. Female sex was also associated with improved overall survival. To our knowledge, this is the largest study worldwide of ER expression in a cohort of patients with advanced gastroesophageal adenocarcinoma. It is also unique, given the age of the population. We have demonstrated that female sex is associated with better survival outcomes with palliative chemotherapy but that this does not appear to be related to ER IHC expression. The differing ER expression according to age supports the concept of a different disease biology with age.

Profiling estrogen, progesterone, and androgen receptors in colorectal cancer in relation to gender, menopausal status, clinical stage, and tumour sidedness.

Although estrogen (ERα/ERβ), progesterone (PGR), and androgen (AR) receptors are pathologically altered in colorectal cancer (CRC), their simultaneous expression within the same cohort of patients was not previously measured. ERα/ERβ/PGR/AR proteins were measured in archived paired normal and malignant colon specimens (n =120 patients) by immunohistochemistry, and results were analyzed by gender, age (≤50 vs. ≥60 years), clinical stages (early-stage I/II vs. late-stage III/IV), and anatomical location (right; RSCs vs. left; LSCs). Effects of 17β-estradiol (E2), progesterone (P4), and testosterone alone or combined with the specific blockers of ERα (MPP dihydrochloride), ERβ (PHTPP), PGR (mifepristone), and AR (bicalutamide) on cell cycle and apoptosis were also measured in the SW480 male and HT29 female CRC cell lines. ERα and AR proteins increased, whilst ERβ and PGR declined markedly in malignant specimens. Moreover, male neoplastic tissues showed highest AR expression, whilst ERβ and PGR weakest alongside ERα strongest expression was seen in cancerous tissues from women aged ≥60 years. Late-stage neoplasms also revealed maximal alterations in the expression of sex steroid receptors. By tumor location, LSCs disclosed significant elevations in ERα with marked declines in PGR compared with RSCs, and ERα strongest alongside PGR weakest expression was detected in advanced LSCs from women aged ≥60 years. Late-stage LSCs from females aged ≥60 years also showed weakest ERβ and strongest AR expression. In contrast, male RSC and LSC tissues exhibited equal ERβ and AR expression in all clinical stages. ERα and AR proteins also correlated positively, whereas ERβ and PGR inversely, with tumor characteristics. Concomitantly, E2 and P4 monotherapies triggered cell cycle arrest and apoptosis in the SW480 and HT29 cells, and while pre-treatment with ERα-blocker enhanced the effects of E2, ERβ-blocker and PGR-blocker suppressed the E2 and P4 anti-cancer actions, respectively. In contrast, treatment with the AR-blocker induced apoptosis, whilst co-treatment with testosterone hindered the effects. This study advocates that protein expression of sex steroid receptors in malignant tissues could represent prognostic markers, as well as hormonal therapy could provide an alternative strategy against CRC, and their efficacies could be dependent on gender, clinical stage, and tumor location.

Gut microbiome-derived isoflavone metabolites may ameliorate experimental autoimmune encephalomyelitis (EAE) through estrogen receptor signaling in CD8 T-cells

Abstract Multiple sclerosis (MS) is an autoimmune demyelinating disease of the CNS which may be influenced by diet- and gut bacteria-produced metabolites. We have shown that phytoestrogen-metabolizing bacteria are reduced in MS patients compared to healthy individuals. The importance of phytoestrogen-metabolizing bacteria was validated in EAE, an animal model of MS, where lack of isoflavones (a type of phytoestrogen) in the diet and/or lack of phytoestrogen-metabolizing bacteria lead to increased disease severity. However, the cellular and molecular pathways through which isoflavones/gut microbiota modulate EAE is unknown. Cellular analysis of the gut and periphery showed that isoflavone-fed mice have an increased number of CD8 T-cell in the colon compared to mice on an isoflavone-free diet. Moreover, CD8 T-cell knockout mice lose isoflavone-mediated disease protection, suggesting an important role of CD8 T-cells in this process. Due to the structural similarity between isoflavone metabolites and endogenous estrogen, we hypothesize that isoflavone metabolites may induce regulatory CD8 T-cells via engagement of estrogen receptors (ERs). Flow cytometric analysis of colonic CD8 T-cells showed that isoflavone-fed mice had higher expression of both ERα and ERβ and produced lower levels of IFNγ, perforin, and IL10. We are utilizing conditional KO mice lacking ERα or ERβ exclusively in CD8 cells to determine the importance of ERs in the generation of diet-induced CD8 T-cells. In summary, our data suggest that bacterial metabolism of isoflavones may lead to EAE disease suppression through immunomodulation of CD8 T-cells via estrogen receptor signaling. Supported by grants from NIH (1R01AI137075-01) and VA (1I01CX002212)