Nuclear ERα Expression Research Articles

Expression Pattern of Estrogen Receptor Alpha and Progesterone Receptor in Gallbladder Carcinoma and Their Association with Clinicopathological Parameters and Overall Survival.

Gallbladder cancer (GBC) is a highly aggressive malignant tumor with a poor prognosis. Despite being first described two centuries ago, there are no targeted therapies available beyond conventional cytotoxic therapy. Epidemiological studies have shown that the incidence of gallbladder cancer is higher in females than males. This suggests that the gallbladder may be a female sex hormone-responsive organ, and these hormones might be involved in the pathogenesis of gallbladder cancer. Therefore, we aimed to analyze the expression of ERα and PR in GBC and correlate their expression with clinicopathological variables and overall survival. A total of 235 histopathologically diagnosed GBC cases were included in this hospital-based cross-sectional study. Clinicopathological data were collected, and the expression of ERα and PR was evaluated by immunohistochemistry. The mean age of this study population was 55.47 ± 8.45 with range 28-87years. Females were predominated over male with a male-to-female ratio of 1:3.5. Positive nuclear expression of the ERα and PR was found in 13 (5.5%) and eight (3.4%) cases, respectively. Apart from nuclear staining, cytoplasmic expression of ERα and PR was found in three (1.2%) and 31 (13.2%) cases, respectively. Higher percentage of positive nuclear expression of ER was found in < 50years age (p value = 0.04), parity > 4 (p value = 0.02), advanced pT stage (T3) (p value = 0.01), lymphovascular invasion (p value = 0.02), and liver invasion (p value = 0.04) which were statistically significant. Higher percentage of PR expression was also observed in < 50years age (p value = 0.01), and tumor associated with gallstone (p value = 0.04). There was no significant correlation between cytoplasmic expression of ER, PR, and clinicopathological variables. In multivariate analysis, there was no significant correlation between ER or PR positive expression and overall survival. Although nuclear expression of ERα was significantly associated with progressive disease factors but the positive expression was found in very small percentage of GBC cases. So anti-hormone therapy might be an option in patient with ER α positive gallbladder carcinoma.

Additional confirmation of successful cell suspension fractionation of metastatic axillary node tissue

We present herein an extension to our recently developed and published method termed "Fractionation of Nodal Cell Suspension" (FNCS). The method enables efficient subcellular fractionation into nuclear (N) and cytosolic (C) compartments of extremely fibrous and problematic metastatic axillary lymph node (mALN) tissue, using the entire nodule. For the purpose of the present study, a case of invasive lobular breast cancer (BC) patient with pT2N3aMx status and defined primary tumor markers (ERα 8, PR-B 8, and HER2 score 0) was available. Initially, the mALN tissue of this patient was analyzed by immunohistochemistry (IHC), and a positive correlation of nodal ERα, PR-B and HER2 biomarkers to those of the primary tumor was obtained. Subsequently, the mALN was FNCS fractionated into N and C, and Western blot (WB) analysis demonstrated a single band for ERα, PR-B and nuclear loading control (HDAC1) in nuclear, but not in the cytosolic compartments, confirming the efficiency of our fractionation protocol. At the same time, HER2 bands were not observed in either compartment, in accordance with HER2 negativity determined by IHC in both primary tumor and mALN tissue. In conclusion, by confirming the nuclear expression of ERα and PR-B biomarkers in metastatic loci, we demonstrate the purity of the FNCS-generated compartments - the protocol that offers a reliable tool for further analysis of nuclear versus cytosolic content in downstream analysis of novel biomarkers in the whole mALN of BC patients.

The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression.

Just like the androgen receptor (AR), the estrogen receptor α (ERα) is expressed in the prostate and is thought to influence prostate cancer (PCa) biology. Yet the incomplete understanding of ERα functions in PCa hinders our ability to fully comprehend its clinical relevance and restricts the repurposing of estrogen-targeted therapies for the treatment of this disease. Using 2 human PCa tissue microarray cohorts, we first demonstrate that nuclear ERα expression was heterogeneous among patients, being detected in only half of the tumors. Positive nuclear ERα levels were correlated with disease recurrence, progression to metastatic PCa, and patient survival. Using in vitro and in vivo models of the normal prostate and PCa, bulk and single-cell RNA-Seq analyses revealed that estrogens partially mimicked the androgen transcriptional response and activated specific biological pathways linked to proliferation and metabolism. Bioenergetic flux assays and metabolomics confirmed the regulation of cancer metabolism by estrogens, supporting proliferation. Using cancer cell lines and patient-derived organoids, selective estrogen receptor modulators, a pure anti-estrogen, and genetic approaches impaired cancer cell proliferation and growth in an ERα-dependent manner. Overall, our study revealed that, when expressed, ERα functionally reprogrammed PCa metabolism, was associated with disease progression, and could be targeted for therapeutic purposes.

Abstract 5873: ERα coordinates with squalene synthase to confer statin resistance in lung cancer

Abstract Statins are widely used to treat hypercholesterolemia by inhibiting hydroxymethylglutaryl coenzyme A reductase (HMGCR). Accumulating evidence suggests that statins also have protective effects against cancer recurrence. However, the role of statins in preventing lung cancer and biomarkers for predicting statin treatment response remains lacking. This study analyzes molecular features that dictate statin sensitivity in lung cancer by correlating large-scale statin sensitivity data and basal gene expression in a collection of 125 lung cancer patients. We identified a gene signature associated with lovastatin sensitivity and showed that gene expression in mesenchymal molecular features, the cholesterol biosynthesis pathway, and estrogen receptor alpha (ERα) signaling were key determinants of lovastatin sensitivity in lung cancer cells. To this end, we further discovered that overexpression of a committed step enzyme in cholesterol biosynthesis farnesyl-diphosphate farnesyltransferase 1 (FDFT1), also known as squalene synthase (SQS), is capable of activating ERα and is associated with increased statin tolerance. In clinical specimens, overexpression of SQS positively correlated with nuclear expression of ERα in lung cancer patients, and the combination of SQS and ERα is a powerful prognostic predictor for lung cancer. Activation of the SQS-ERα signaling axis and epithelial-to-mesenchymal transition (EMT) status represents two important features in determining statin sensitivity in lung cancer. Keywords: Statin, cholesterol biosynthesis, squalene synthase, estrogen receptor α, Epithelial-mesenchymal transition Citation Format: Yi-Fang Yang. ERα coordinates with squalene synthase to confer statin resistance in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5873.

Abstract 3046: The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression

Abstract Just as the androgen receptor (AR), the estrogen receptor α (ERα) is expressed in the prostate and is thought to influence prostate cancer (PCa) biology. Yet, the incomplete understanding of ERα cellular functions in PCa hinders our ability to fully comprehend its clinical relevance and restricts the repurposing of estrogen-targeted therapies for treatment of this disease. Using two human PCa tissue microarray cohorts, we first demonstrated that nuclear ERα expression was heterogeneous between patients, being only detected in half of tumors. Positive nuclear ERα levels were correlated with disease recurrence, progression to metastatic PCa, and patient survival. Using in vitro and in vivo models of the normal prostate and PCa, bulk and single cell RNA-seq analyses revealed that estrogens partially mimic the androgen transcriptional response and induce specific biological pathways linked to cellular proliferation and metabolism. Bioenergetic flux assays and metabolomics confirmed regulation of cancer metabolism by estrogens, supporting proliferation. Using cancer cell lines and patient-derived organoids, selective estrogen receptor modulators, a pure anti-estrogen, and genetic approaches impaired cancer cell proliferation and growth in an ERα-dependent manner. Overall, our study revealed that, when expressed, ERα functionally reprograms PCa metabolism, is associated with disease progression, and could be targeted for therapeutic purposes. Citation Format: Camille Lafront, Lucas Germain, Gabriel H. Campolina-Silva, Cindy Weidmann, Line Berthiaume, Hélène Hovington, Hervé Brisson, Cynthia Jobin, Lilianne Frégeau-Proulx, Raul Cotau, Kevin Gonthier, Aurélie Lacouture, Patrick Caron, Claire Ménard, Chantal Atallah, Julie Riopel, Éva Latulippe, Alain Bergeron, Paul Toren, Chantal Guillemette, Martin Pelletier, Yves Fradet, Clémence Belleannée, Frédéric Pouliot, Louis Lacombe, Éric Lévesque, Étienne Audet-Walsh. The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3046.

Estrogen and Progesterone Receptors Are Dysregulated at the BPH/5 Mouse Preeclamptic-Like Maternal-Fetal Interface.

The etiopathogenesis of preeclampsia, a leading hypertensive disorder of pregnancy, has been proposed to involve an abnormal circulating sex hormone profile and misexpression of placental estrogen and progesterone receptors (ER and PR, respectively). However, existing research is vastly confined to third trimester preeclamptic placentas. Consequently, the placental-uterine molecular crosstalk and the dynamic ER and PR expression pattern in the peri-conception period remain overlooked. Herein, our goal was to use the BPH/5 mouse to elucidate pre-pregnancy and early gestation Er and Pr dynamics in a preeclamptic-like uterus. BPH/5 females display low circulating estrogen concentration during proestrus, followed by early gestation hypoestrogenemia, hyperprogesteronemia, and a spontaneous preeclamptic-like phenotype. Preceding pregnancy, the gene encoding Er alpha (Erα, Esr1) is upregulated in the diestrual BPH/5 uterus. At the peak of decidualization, Esr1, Er beta (Erβ, Esr2), and Pr isoform B (Pr-B) were upregulated in the BPH/5 maternal-fetal interface. At the protein level, BPH/5 females display higher percentage of decidual cells with nuclear Erα expression, as well as Pr downregulation in the decidua, luminal and glandular epithelium. In conclusion, we provide evidence of disrupted sex hormone signaling in the peri-conception period of preeclamptic-like pregnancies, potentially shedding some light onto the intricate role of sex hormone signaling at unexplored timepoints of human preeclampsia.

The PAPSS1 gene is a modulator of response to cisplatin by regulating estrogen receptor alpha signaling activity in ovarian cancer cells

BackgroundCancer cells may develop resistance to cisplatin by various mechanisms. Yet, the exact mechanism of cisplatin in ovarian cancer remains unclear. Recent studies have shown that 3’-phospoadenosine 5’-phosphosulfate synthase 1 (PAPSS1) inhibition combined with low-dose cisplatin increases DNA damage. The aim of this study was to determine the value of targeting PAPSS1 as a cisplatin modulator in epithelial ovarian cancer (EOC).ResultsIncreased expression of PAPSS1 was observed in both EOC cells and tissues. Also, its higher nuclear expression was distinctly associated with FIGO (The International Federation of Gynecology and Obstetrics) stage, histological subtype, metastasis, and recurrence. Down-regulation of the PAPSS1 gene increased the cisplatin sensitivity of EOC in vitro and in vivo. Expression of PAPSS1 was negatively correlated with estrogen receptor α (ERα) in EOC. Also, low nuclear PAPSS1 and high nuclear ERα expression in EOC were associated with longer overall survival and progression-free survival in all ovarian cancer and ovarian cancer patients who received platinum-based chemotherapy. PAPSS1 silencing increased the activity of ERα-signaling in EOC cells, thus sensitizing tumors to cisplatin.ConclusionsThese findings characterize a novel interplay between PAPSS1-mediated sulfation and ERα-signaling in EOC cisplatin resistance. PAPSS1 may be exploited as a cisplatin-sensitizing therapeutic target.

Nitric Oxide Regulates Estrus Cycle Dependent Colonic Motility in Mice.

Women are more susceptible to functional bowel disorders than men and the severity of their symptoms such as diarrhea, constipation, abdominal pain and bloating changes over the menstrual cycle, suggesting a role for sex hormones in gastrointestinal function. Nitric oxide (NO) is a major inhibitory neurotransmitter in the gut and blockade of nitric oxide synthase (NOS; responsible for NO synthesis) increases colonic motility in male mice ex vivo. We assessed the effects of NOS inhibition on colonic motility in female mice using video imaging analysis of colonic motor complexes (CMCs). To understand interactions between NO and estrogen in the gut, we also quantified neuronal NOS and estrogen receptor alpha (ERα)-expressing myenteric neurons in estrus and proestrus female mice using immunofluorescence. Mice in estrus had fewer CMCs under control conditions (6 ± 1 per 15 min, n = 22) compared to proestrus (8 ± 1 per 15 min, n = 22, One-way ANOVA, p = 0.041). During proestrus, the NOS antagonist N-nitro-L-arginine (NOLA) increased CMC numbers compared to controls (189 ± 46%). In contrast, NOLA had no significant effect on CMC numbers during estrus. During estrus, we observed more NOS-expressing myenteric neurons (48 ± 2%) than during proestrus (39 ± 1%, n = 3, p = 0.035). Increased nuclear expression of ERα was observed in estrus which coincided with an altered motility response to NOLA in contrast with proestrus when ERα was largely cytoplasmic. In conclusion, we confirm a cyclic and sexually dimorphic effect of NOS activity in female mouse colon, which could be due to genomic effects of estrogens via ERα.

Estrogenic activities of 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside and physcion in MCF-7 cells

Polygonum multiflorum (PM) is a perennial herbal medicine that inhibits osteopenia of osteoporosis caused by estrogen deficiency and shows estrogen-like activity. Components such as 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside (TSG), physcion, rhein, emodin, and chrysophanol are contained in PM, and TSG and physcion of the stilbene and anthraquinone series are dominant in PM. Among them, TSG and physcion are known to have various biological activities, but the estrogen activity is unknown. In this study, we investigated the estrogenic activities of TSG and physcion in MCF-7 cells (a breast cancer cell line). Cell proliferation and cytotoxicity were measured using BrdU assay and cell counting kit-8. The cell cycle of MCF-7 cells and expression of estrogen receptor alpha (ERα) were analyzed using FACS. Both TSG and physcion dose-dependently stimulated cell proliferation of MCF-7 cells in the concentration range 1 to 100 μM. Furthermore, this proliferation was inhibited by cotreatment with the estrogen receptor antagonist ICI 182,780. Treatment with TSG (10 to 100 μM) or physcion (1 to 100 μM) was found to increase the proportion of cells in the S phase significantly, and this increase was also inhibited by ICI 182,780 cotreatment. In addition, the nuclear expression of ERα in MCF-7 cells was significantly upregulated by TSG (1 to 100 μM) or physcion (10 to 100 μM) but these upregulations were also inhibited by ICI 182,780 cotreatment. These observations indicate both TSG and physcion and induce estrogen-like activity via ERα.

Metformin Promotes Anti-tumor Biomarkers in Human Endometrial Cancer Cells

Metformin (MET) is increasingly implicated in reducing the incidence of multiple cancer types in patients with diabetes. However, similar effects of MET in non-diabetic women with endometrial cancer (EC) remain unknown. In a pilot study, obese non-diabetic women diagnosed with type 1, grade 1/2 EC, and consenting to participate were randomly assigned to receive MET or no MET (control (CON)) during the pre-surgical window between diagnosis and hysterectomy. Endometrial tumors obtained at surgery (MET, n = 4; CON, n = 4) were analyzed for proliferation (Ki67), apoptosis (TUNEL), and nuclear expression of ERα, PGR, PTEN, and KLF9 proteins in tumor glandular epithelial (GE) and stromal (ST) cells. The percentages of immunopositive cells for PGR and for KLF9 in GE and for PTEN in ST were higher while those for ERα in GE but not ST were lower, in tumors of MET vs. CON patients. The numbers of Ki67- and TUNEL-positive cells in tumor GE and ST did not differ between groups. In human Ishikawa endometrial cancer cells, MET treatment (60 μM) decreased cell numbers and elicited distinct temporal changes in ESR1, KLF9, PGR, PGR-B, KLF4, DKK1, and other tumor biomarker mRNA levels. In the context of reduced KLF9 expression (by siRNA targeting), MET rapidly amplified PGR, PGR-B, and KLF4 transcript levels. Our findings suggest that MET acts directly in EC cells to modify steroid receptor expression and signaling network and may constitute a preventative strategy against EC in high-risk non-diabetic women.

Association between decreased expression of estrogen receptor alpha, androgen receptor and phosphatase and tensin homolog immunoexpression in the canine prostate

ABSTRACT: Canine prostate gland is a hormonal dependent organ and its imbalance of estrogen and androgen receptor expressions are directly associated with the development of different diseases. Due to the lack of information regarding the behavior of the aforementioned receptors in canine prostate cancer (PC), this study aimed to identify estrogen receptor alpha (ERα), androgen receptor (AR), Ki67 and phosphatase and tensin homolog (PTEN) protein expressions in canine PC by immunohistochemistry. We found nuclear expression of ERα and AR in the epithelial cells of normal canine samples and a loss of protein expression in PC samples. Normal samples showed Ki67 expression in a few basal cells and the PC samples showed the highest mean of positive cells (253.1). Canine prostate cancer showed a high proliferative index, which was associated with independence of hormonal actuation. PTEN showed positive nuclear and cytoplasmic expression in normal canine samples and a loss in PC. Loss of ERα, AR and PTEN indicated that canine PC exhibits the same immunohistochemical phenotype as in human patients with PC resistant to hormonal therapy. Therefore, canine PC should be considered as a model to study human PC resistant to hormonal therapy.

Estrogen receptor subtypes dictate the proliferative nature of the mammary gland.

Estrogen induces proliferation of breast epithelial cells and is responsible for breast development at puberty. This tightly regulated control is lost in estrogen-receptor-positive (ER+) breast cancers, which comprise over 70% of all breast cancers. Currently, breast cancer diagnosis and treatment considers only the α isoform of ER; however, there is a second ER, ERβ. Whilst ERα mediates estrogen-driven proliferation of the normal breast in puberty and breast cancers, ERβ has been shown to exert an anti-proliferative effect on the normal breast. It is not known how the expression of each ER (alone or in combination) correlates with the ability of estrogen to induce proliferation in the breast. We assessed the levels of each ER in normal mouse mammary glands subdivided into proliferative and non-proliferative regions. ERα was most abundant in the proliferative regions of younger mice, with ERβ expressed most abundantly in old mice. We correlated this expression profile with function by showing that the ability of estrogen to induce proliferation was reduced in older mice. To show that the ER profile associated with breast cancer risk, we assessed ER expression in parous mice which are known to have a reduced risk of developing ERα breast cancer. ERα expression was significantly decreased yet co-localization analysis revealed ERβ expression increased with parity. Parous mice had less unopposed nuclear ERα expression and increased levels of ERβ. These changes suggest that the nuclear expression of ERs dictates the proliferative nature of the breast and may explain the decreased breast cancer risk with parity.

Shugan Liangxue Decoction () Down-Regulates Estrogen Receptor α Expression in Breast Cancer Cells.

To observe the effect of Shugan Liangxue Decoction (, SGLXD) on estrogen receptor α (ERα) in human breast cancer cells. The effect of SGLXD (0.85-5.10 mg/mL) on the proliferation of breast cancer cells were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The nuclear ERα protein levels in MCF-7, T47D and ZR-75-1 cells which treated by SGLXD for 24 h were examined by western blot and immunofluorescence assay. MCF-7 and MDA-MB-231 cells were treated by 17β-estradiol (E2) with or without SGLXD, for 24 h, and the E2 targeted genes c-myc and bcl-2 protein product was evaluated by western blot. SGLXD showed dose-dependent inhibition on the proliferation of MCF-7, T47D and ZR-75-1 cells, but did not inhibit the proliferation of MDA-MB-231 cells. Furthermore, the promotive effect on cell growth induced by E2 was also significantly inhibited by SGLXD treatment. With the treatment of 1.70, 3.40, 5.10 mg/mL SGLXD, the nuclear ERα protein level was reduced to 88.1%, 70.4% and 60.9% in MCF-7 cells, and was decreased to 43.0%, 38.4% and 5.9% in ZR-75-1 cells as compared with the control group. In T47D cells, the nuclear ERα protein was down-regulated to 51.3% and 4.3% by 3.40 and 5.10 mg/mL SGLXD treatment. The down-regulative effect of SGLXD on nuclear ERα was confirmed by immunofluorescence assay. SGLXD decreased the protein product of c-myc and bcl-2. SGLXD may exhibit selective inhibition effect on the proliferation of ER positive breast cancer cells. SGLXD reduced the nuclear ERα expression and the protein product of E2 target gene c-myc and bcl-2.

Nuclear estrogen receptor-α expression is an independent predictor of recurrence in male patients with pT1aN0 lung adenocarcinomas, and correlates with regulatory T-cell infiltration.

Tumor biology of estrogen receptor-α (ERα) and progesterone receptor (PR) has been studied in breast cancers. However, clinical impact in lung cancer remains controversial. In our study, we investigate whether ERα and PR expression predicts disease recurrence and correlates with immunologic factors in stage I lung adenocarcinoma. We reviewed patients with pathologic stage I resected lung adenocarcinoma. Tumors were classified according to the IASLC/ATS/ERS classification. Immunostaining of ERα and PR was performed using tissue microarrays (n = 913). Immunostaining of CD3+ and forkhead box P3 (FoxP3)+ lymphocyte infiltration, interleukin-7 receptor (IL-7R), and IL-12Rβ2 were performed. Cumulative incidence of recurrence (CIR) analysis was used to estimate probability of recurrence. Nuclear ERα expression was observed in 157 (17%) patients and presented more frequently in females (P = 0.038) and smaller tumors (P = 0.019). Nuclear ERα expression was not identified in mucinous tumors. In pT1a patients, 5-year CIR of patients with ERα-positive tumors was significantly higher (5-year CIR, 20%) than those with ERα-negative tumors (8%; P = 0.018). This difference was statistically significant in males (P = 0.003) but not females (P = 0.55). On multivariate analysis, nuclear ERα expression was an independent predictor of recurrence (hazard ratio = 2.27; P = 0.030). In pT1a patients, nuclear ERα expression positively correlated with tumoral FoxP3+ lymphocytes (P < 0.001), FoxP3/CD3 index (P < 0.001), and IL-7R (P = 0.022). Nuclear ERα expression is an independent predictor of recurrence in pT1a lung adenocarcinomas and correlates with poor prognostic immune microenvironments.

Differential expression of estrogen receptor alpha in the embryonic adrenal–kidney–gonadal complex of the oviparous lizard, Calotes versicolor (Daud.)

Estrogen signalling is critical for ovarian differentiation in reptiles with temperature-dependent sex determination (TSD). To elucidate the involvement of estrogen in this process, adrenal–kidney–gonadal (AKG) expression of estrogen receptor (ERα) was studied at female-producing temperature (FPT) in the developing embryos of the lizard, Calotes versicolor which exhibits a distinct pattern of TSD. The eggs of this lizard were incubated at 31.5±0.5°C (100% FPT). The torso of embryos containing adrenal–kidney–gonadal complex (AKG) was collected during different stages of development and subjected to Western blotting and immunohistochemistry analysis.The ERα antibody recognized two protein bands with apparent molecular weight ∼55 and ∼45kDa in the total protein extracts of embryonic AKG complex of C. versicolor. The observed results suggest the occurrence of isoforms of ERα. The differential expression of two different protein isoforms may reveal their distinct role in cell proliferation during gonadal differentiation. This is the first report to reveal two isoforms of the ERα in a reptile during development.Immunohistochemical studies reveal a weak, but specific, cytoplasmic ERα immunostaining exclusively in the AKG during late thermo-sensitive period suggesting the responsiveness of AKG to estrogens before gonadal differentiation at FPT.Further, cytoplasmic as well as nuclear expression of ERα in the medulla and in oogonia of the cortex (faint activity) at gonadal differentiation stage suggests that the onset of gonadal estrogen activity coincides with sexual differentiation of gonad. Intensity and pattern of the immunoreactions of ERα in the medullary region at FPT suggest endogenous production of estrogen which may act in a paracrine fashion to induce neighboring cells into ovarian differentiation pathway.

Differential expression patterns and clinical significance of estrogen receptor-α and β in papillary thyroid carcinoma

BackgroundThe incidence of papillary thyroid cancer (PTC) is markedly higher in women than men during the reproductive years. In vitro studies have suggested that estrogen may play an important role in the development and progression of PTC through estrogen receptors (ERs). This study aimed to investigate the expression patterns of the two main ER subtypes, α and β1 (wild-type ERβ), in PTC tissue and their clinical significance.MethodsImmunohistochemical staining of thyroid tissue sections was performed to detect ER expression in female patients with PTC (n = 89) and nodular thyroid goiter (NTG; n = 30) using the Elivision™ plus two-step system. The relationships between ER subtype expression and clinicopathological/biological factors were further analyzed.ResultsThe positive percentage and expression levels of ERα were significantly higher in female PTC patients of reproductive age (18–45 years old; n = 50) than age-matched female NTG patients (n = 30), while ERβ1 exhibited the opposite pattern. There was no difference in ERα or ERβ1 expression between female PTC patients of reproductive age and those of advanced reproductive age (>45 years old; n = 39). In the female PTC patients of reproductive age, ERα expression level was positively correlated with that of Ki-67, while ERβ1 was negatively correlated with mutant P53. Furthermore, more patients with exclusively nuclear ERα expression had extrathyroidal extension (ETE) as compared with those with extranuclear ERα localization. VEGF expression was significantly decreased in female PTC patients of reproductive age with only nuclear ERβ1 expression when compared with those with extranuclear ERβ1 localization. In PTC patients of advanced reproductive age, neither ERα nor ERβ1 expression showed any correlation with that of Ki-67, mutant P53, VEGF, tumor size, TNM stage, ETE, or lymph node metastases.ConclusionsThe differential expression patterns of the two ER subtypes between PTC and NTG indicate that ERα may be a useful immunohistochemical marker for differential diagnosis of PTC. The associations of ER subtype expression with Ki-67, mutant P53, VEGF expression and ETE in female PTC patients of reproductive age suggest that estrogen-activated ERα may mediate stimulatory effects on PTC growth and progression whereas ERβ1 has some inhibitory actions.

Lack of association of hepatic estrogen receptor-alpha expression with histopathological and biochemical findings in chronic hepatitis C

Estrogens exert a protective effect against hepatic steatosis and fibrosis. Loss of estrogen receptor-alpha (ER-α) in the liver is associated with hepatic steatosis and inflammation in animal models. We conducted a study in order to investigate the presence and extent of ER-α expression in HCV infection, and its relationship with histological and biochemical findings. Ninety biopsy-proven chronic hepatitis C (CHC) patients were enrolled in the study. Liver biopsy specimens were immunohistochemically stained for ER-α expression. Nuclear ER-α expression percentage was calculated. ER-α was positive in 69 of the patients (76%). ER-α positive and negative groups were not significantly different in terms of age, gender, necroinflammatory activity, fibrosis, steatosis, serum levels of AST, ALT, ALP, GGT, and bilirubin. ER-α expression percentage was not correlated with fibrosis, steatosis, necroinflammatory activity and biochemical findings. Although estrogens are known to be protective against fibrosis and steatosis in animal models, we did not find any significant correlation between ER-α expression and histopathological and biochemical findings in CHC patients. These findings should be verified in further large scale studies.

Presence and extent of estrogen receptor-alpha expression in patients with simple steatosis and NASH

Loss of estrogen receptor-alpha (ER-α) in the liver is associated with hepatic steatosis and inflammation. We conducted a study in order to investigate the presence and extent of ER-α expression in NASH, and its relationship with histological findings. Fifty-four patients with histologically confirmed NASH, 12 patients with simple steatosis (SS), and 6 patients with normal liver tissue (NLT) were included. NASH activity score and fibrosis score were calculated according to biopsy findings. Liver biopsy specimens were immunohistochemically stained for ER-α expression. Nuclear ER-α expression percentage (staining index) was calculated. Mean staining index was significantly different across the NASH, SS, and NLT groups (6.3±9.9 vs. 22.1±26.4 vs. 44.2±24.8, respectively, p<0.001 for all comparisons). Staining index was significantly higher in women than in men (19.4±22.2 vs. 7.9±15.3, respectively, p=0.003). Staining index negatively correlated with serum ALT (r=−0.240; p=0.04), fasting plasma glucose (r=−0.261; p=0.027), and fibrosis score (r=−0.312; p=0.011). As a conclusion, hepatic nuclear ER-α expression percentage (staining index) is lower in patients with NASH when compared to SS and NLT groups. Staining index is negatively correlated with serum ALT levels, plasma glucose, and fibrosis score. Further studies are required to clarify the significance of ER-α expression in NASH.

Leptin attenuates the anti-estrogen effect of tamoxifen in breast cancer

BackgroundLeptin is a circulating peptide hormone, encoded by the obesity (ob) gene, acting as a regulator of food intake via hypothalamic-mediated effects. Recent studies have shown that leptin and leptin receptor (ObR) are involved in the carcinogenesis and development of breast cancer. In addition, functional cross talk between leptin and estrogen signaling has been registered. Here, we investigated the relation of leptin and ObR expression with survival in women with breast cancer treated with the anti-estrogen tamoxifen, and whether leptin can interfere with the estrogen receptor alpha (ERα) and the effect of tamoxifen in breast cancer cells. MethodsThe protein expression of leptin and ObRb in 114 breast cancer samples was evaluated by immunohistochemistry, quantified by Immunoreactivity Score (IRS) and correlated to survival and other clinicopathological features. The expression of ObRb in ERα positive MCF-7 breast cancer cells was examined by immunofluorescence and western blot. Leptin effect on cell proliferation was determined by MTT assay. The interference of leptin with tamoxifen on ERα degradation was studied by western blot and immunofluorescence. Effects of leptin on the transcriptional activity of ERα were explored using luciferase reporter assays. ResultsPositive staining (Immunoreactivity Score, IRS≥1) of leptin and ObR isoform ObRb in breast cancer tissues were seen in 79.8% and 85.1% of patients respectively. In overall and in tamoxifen-treated breast cancer patients, leptin expression (IRS≥1) correlated with poor prognosis, (log-rank test, P=0.016, overall; P=0.031, tamoxifen-treated). Overexpressed ObRb was found by western blotting andimmunofluorescence in MCF-7 as well as in MDA-MB-231, T47D, and MDA-MB-435 cell lines. Tamoxifen (1000μM) significantly inhibited the proliferation of MCF-7 cells, degraded ERα and reduced ERα-dependent transcription from estrogen response element-containing promoter. On the contrary, simultaneous treatment with leptin (100ng/ml) significantly attenuated these effects, similar to the effects of estradiol. ConclusionsLeptin correlated significantly with poor prognosis in overall and tamoxifen-treated breast cancer patients. Leptin interferes with the action of tamoxifen in MCF-7 cells, at least partly, through inducing increased nuclear expression of ERα. Thus, leptin may contribute to tamoxifen resistance and consequently, leptin suppression could be a novel way of circumventing resistance to anti-estrogen treatment.

Abstract 953: Therapeutic significance of estrogen receptor ≤ agonists in gliomas

Abstract Purpose: Gliomas are the most common type of primary brain tumors with bleak prognosis. Gliomas exhibit gender bias with females at lower risk than males, implicating estrogen mediated protective effects. Estrogen functions are mediated by two ER subtypes: ERbeta, that functions as tumor promoter and ERbeta that function as tumor suppressor. In this study, we examined the status of ERbeta and tested whether natural ERbeta agonists have therapeutic potential on gliomas. Experimental Design: Tumor microarrays (TMAs) were utilized to determine the levels of ERbeta in gliomas. Therapeutic effect of three ERbeta agonists was determined using proliferation, foci formation and cell cycle progression assays. Functionality of ERbeta signaling in gliomas was determined by reporter assays and localization by confocal microscopy. The therapeutic potential of liquiritigenin was determined by systemic administration in a glioma xenograft model. Results: TMA analysis revealed that ERα expression is down regulated in high-grade gliomas. Glioma model cells exhibited detectable ERα with functional ERα signaling. Treatment of glioma cells with ERα agonists resulted in significant decreases in proliferation. Further, ERbeta agonist treatment induced the expression of ERα. Compared to control mice, animals treated with liquiritigenin had 50% reduction in tumor volume and size. IHC analysis of tumors revealed a significant increase in the nuclear ERα expression with a concomitant decrease in cell proliferation in the liquiritigenin-treated group. Conclusion: We found that ERα agonists promote both expression and tumor suppressive functions of ERα. Liquiritigenin, a plant-derived ERα agonist significantly reduced in vivo tumor growth in a xenograft model. Our results suggest that ERα signaling has a tumor suppressive function in gliomas and thus ERα agonists may represent a novel class of drugs for curbing glioma progression. Since ERα agonists are currently in clinical trials and are well tolerated with fewer side effects, identification of an ERα agonist as a therapeutic agent can be readily extended to clinical use with current chemotherapies, providing an additional tool for enhancing survival in glioma patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 953. doi:1538-7445.AM2012-953