Estrogen receptor-dependent and independent mechanisms of breast cancer carcinogenesis

Comparison of the effects of crizotinib as monotherapy and as combination therapy with butyric acid on different breast cancer cells

In recent years, there have been significant developments using combined therapies in cancer treatment. The present study aimed to determine the effects of using crizotinib alone and in combination with butyric acid on different types of breast cancer cells. A total of three different breast cancer models were used: MDA-MB-231, a triple negative model; MCF-7, a Luminal A model; and SKBR-3 cell line, a human epidermal growth factor receptor 2 positive model. In the experiments, proliferation rates and cell index values were obtained using the xCELLigence RTCA DP System, and mitotic index, bromodeoxyuridine labeling index and caspase activity were evaluated as cell kinetics parameters. The results showed that while proliferation rates, cell index values, mitotic index and bromodeoxyuridine labeling index decreased, caspase activity values increased. These results demonstrated that the combined application was more effective than the monotherapy application and could be used at lower concentrations than those drugs applied as monotherapy.

The anti-aromatase and anti-estrogenic activity of plant products in the treatment of estrogen receptor-positive breast cancer

Despite being the focal point of decades of research, female breast cancer (BC) continues to be one of the most lethal cancers in the world. Given that 80 % of all diagnosed BC cases are estrogen receptor-positive (ER+) with carcinogenesis driven by estrogen-ERα signalling, current standard of care (SOC) hormone therapies are geared towards modulating the function and expression levels of estrogen and its receptors, ERα and ERβ. Currently, aromatase inhibitors (AIs), selective ER modulators (SERMs) and selective ER degraders (SERDs) are clinically prescribed for the management and treatment of ER+ BC, with the anti-aromatase activity of AIs abrogating estrogen biosynthesis, while the anti-estrogenic SERMs and SERDs antagonise and degrade the ER, respectively. The use of SOC hormone therapies is, however, significantly hampered by the onset of severe side-effects and the development of resistance. Given that numerous studies have reported on the beneficial effects of plant compounds and/or extracts and the multiple pathways through which they target ER+ breast carcinogenesis, recent research has focused on the use of dietary chemopreventive agents for BC management. When combined with SOC treatments, several of these plant components and/or extracts have demonstrated improved efficacy and/or synergistic impact. Moreover, despite a lack of in vivo investigations, plant products are generally reported to have a lower side-effect profile than SOC therapies and are therefore thought to be a safer therapeutic choice. Thus, the current review summarizes the findings from the last five years regarding the anti-aromatase and anti-estrogenic activity of plant products, as well as their synergistic anti-ER+ BC effects in combination with SOC therapies.

Molecular and Pathobiology of Canine Mammary Tumour: Defining a Translational Model for Human Breast Cancer

Canine mammary tumours (CMT) have histological, clinicopathological and molecular resemblances to human breast cancer (HBC), positioning them as viable models for studying the human disease. CMT initiation and progression occur spontaneously in immune-competent animals, which challenge the suggested limitations of genetically modified mice, also enabling the evaluation of immunotherapies in canine patients. Dogs have shorter life expectancy compared to humans, and cancer advances more rapidly in this species. This makes it possible to perform studies about the clinical efficacy of new therapeutic modalities in a much shorter time than in human patients. The identification of biomarkers for tumour subtypes, progression and treatment response paves the way for the development of novel therapeutic and diagnostic approaches. This review addresses the similarities between CMT and HBC and the molecular signatures identified in CMT samples that have been explored to date. We proposed a detailed molecular exploration of the CMT stroma using state-of-the-art methods in transcriptomics and proteomics. Using CMT as an analog for HBC not only helps to understand the complexities of the disease, but also to advance comparative oncology to the next level to prove the claim of dogs as a valid translational model.

Is the percentage of hormone receptor positivity in HR+ HER2-metastatic breast cancer patients receiving CDK 4/6 inhibitor with endocrine therapy predictive and prognostic?

Purpose

There is no clear information in the literature about the relationship between the efficacy of CDK 4/6i combined with ET and HR positivity. However, we know that the longest overall survival was in the ER-strong positive/PR intermediate or strong positive groups. Therefore, we aimed to investigate CDK4/6i treatments that create positivity in HR.

Methods

Patients with the diagnosis of HR+/HER2- MBC who were treated with CDK 4/6i and HR >10% were retrospectively evaluated. To analyze the role of HR positivity, ER was moderately positive (10-49%) and ER was strongly positive (50-100%); PR was grouped as moderately positive (10-49%) and PR strongly positive (50-100%).

Results

Median follow-up of 150 patients included in the study was 15.2 months (95% CI, 2.1-40.9 months). The highest response in the whole group was obtained in the ER-strong positive/PR moderate or strong positive group, and the ER moderate positive/PR moderate or strong group. This was followed by the ER strong positive/PR negative group, and then the ER moderate positive/PR negative group. Although these advantages were not statistically significant, they were numerically higher (ORR: 83.8% vs. 83.3% vs. 77.4% vs. 62.5%, p=0.488, respectively). The highest survival in the whole group was achieved in the ER strong positive/PR moderate or strongly positive group, followed by the ER moderately positive/PR moderate or strongly positive group, the ER strongly positive/PR negative group followed by the ER moderate positive/PR negative group, respectively(p=0.410). However, these advantages were not statistically significant.

Conclusion

As a result, HR+/HER2- MBC patients receiving CDK 4/6i combined with ET suggest that the percentage of HR positivity may have a predictive and prognostic role.

A Review on Picrosides Targeting NFκB and its Proteins for Treatment of Breast Cancer

Breast cancer is the most frequently diagnosed disease causing most deaths in women worldwide. Chemotherapy and neo-adjuvant therapy are the standard method of treatment in early stages of breast cancer. However drug resistance in breast cancer limit the use of these methods for treatment. Research focus is now shifted towards identifying natural phytochemicals with lower toxicity. This review illustrates the NF κB interaction with different signaling pathways in normal condition, breast cancer and other cancer and thus represent a potential target for treatment. No reports are available on the action of picrosides on NFκB and its associated proteins for anticancer activity. In the present review, potential interaction of picrosides with NF-κB and its associated proteins is reviewed for anticancer action. Further, an important facet of this review entails the ADMET analysis of Picroside, elucidating key ADMET properties which serves to underscore the crucial characteristics of Picroside as a potential drug for treating breast cancer. Furthermore, in silico analysis of Picrosides was executed in order to get potential binding modes between ligand (Picrosides II) and NFκB.

Association between consumption of sweeteners and endometrial cancer risk: a systematic review and meta-analysis of observational studies

The purpose of this study is to further investigate the relationship between sweetener exposure and the risk of endometrial cancer (EC). Up until December 2022, a literature search in an electronic database was carried out utilizing PubMed, Web of Science, Ovid, and Scopus. The odds ratio (OR) and 95 % confidence interval (CI) were used to evaluate the results. Sweeteners were divided into nutritional sweeteners (generally refers to sugar, such as sucrose and glucose) and non-nutritional sweeteners (generally refers to artificial sweeteners, such saccharin and aspartame). Ten cohort studies and two case-control studies were eventually included. The study found that in 12 studies, compared with the non-exposed group, the incidence rate of EC in the sweetener exposed group was higher (OR = 1·15, 95 % CI = [1·07, 1·24]). Subgroup analysis showed that in 11 studies, the incidence rate of EC in the nutritional sweetener exposed group was higher than that in the non-exposed group (OR = 1·25, 95 % CI = [1·14, 1·38]). In 4 studies, there was no difference in the incidence rate of EC between individuals exposed to non-nutritional sweeteners and those who were not exposed to non-nutritional sweeteners (OR = 0·90, 95 % CI = [0·81, 1·01]). This study reported that the consumption of nutritional sweeteners may increase the risk of EC, whereas there was no significant relationship between the exposure of non-nutritional sweeteners and the incidence of EC. Based on the results of this study, it is recommended to reduce the intake of nutritional sweeteners, but it is uncertain whether use of on-nutritional sweeteners instead of nutritional sweetener.

Effects of trichlorobisphenol A on the expression of proteins and genes associated with puberty initiation in GT1-7 cells and the relevant molecular mechanism

This study evaluated the effects of Cl3BPA on kisspeptin-G-protein coupled receptor 54 (GPR54)/gonadotropin-releasing hormone (GnRH) (KGG) signals and analyzed the roles of estrogen receptor alpha (ERɑ) and G-protein coupled estrogen receptor 1 (GPER1) in regulating KGG signals. The results showed that Cl3BPA at 50 μM increased the levels of intracellular reactive oxygen species (ROS) and GnRH, upregulated the protein levels of kisspeptin and the expression of fshr, lhr and gnrh1 genes related to KGG in GT1-7 cells. In addition, 50 μM Cl3BPA significantly upregulated the phosphorylation of extracellular regulated protein kinases 1/2 (Erk1/2), the protein levels of GPER1 and the expression of the gper1 as well as the most target genes associated with mitogen-activated protein kinase (MAPK)/Erk1/2 pathways. Specific signal inhibitor experiments found that Cl3BPA activated KGG signals by activating the GPER1-mediated MAPK/Erk1/2 signaling pathway at the mRNA level. A docking test further confirmed the interactions between Cl3BPA and GPER1. The findings suggest that Cl3BPA might induce precocious puberty by increasing GnRH secretion together with KGG signaling upregulation, which is driven by GPER1-mediated signaling pathway. By comparison, ClxBPAs with fewer chlorine atoms had more obvious effects on the expression of proteins and partial genes related to KGG signals in GT1-7 cells.

Oestrogen receptor-independent actions of oestrogen in cancer

Oestrogen, the primary female sex hormone, plays a significant role in tumourigenesis. The major pathway for oestrogen is via binding to its receptor [oestrogen receptor (ERα or β)], followed by nuclear translocation and transcriptional regulation of target genes. Almost 70% of breast tumours are ER + , and endocrine therapies with selective ER modulators (tamoxifen) have been successfully applied. As many as 25% of tamoxifen-treated patients experience disease relapse within 5 years upon completion of chemotherapy. In such cases, the ER-independent oestrogen actions provide a plausible explanation for the resistance, as well as expands the existing horizon of available drug targets. ER-independent oestrogen signalling occurs via one of the following pathways: signalling through membrane receptors, oxidative catabolism giving rise to genotoxic metabolites, effects on mitochondria and redox balance, and induction of inflammatory cytokines. The current review focuses on the non-classical oestrogen signalling, its role in cancer, and its clinical significance.

Development of a framework for risk assessment of dietary carcinogens

Although there are a number of guidance documents and frameworks for evaluation of carcinogenicity, none of the current methods fully reflects the state of the science. Common limitations include the absence of dose-response assessment and not considering the impact of differing exposure patterns (e.g., intermittent, high peaks vs. lower, continuous exposures). To address these issues, we have developed a framework for risk assessment of dietary carcinogens. This framework includes an enhanced approach for weight of evidence (WOE) evaluation for genetic toxicology data, with a focus on evaluating studies based on the most recent testing guidance to determine whether a chemical is a mutagen. Included alongside our framework is a discussion of resources for evaluating tissue dose and the temporal pattern of internal dose, taking into account the chemical's toxicokinetics. The framework then integrates the mode of action (MOA) and associated dose metric category with the exposure data to identify the appropriate approach(es) to low-dose extrapolation and level of concern associated with the exposure scenario. This framework provides risk managers with additional flexibility in risk management and risk communication options, beyond the binary choice of linear low-dose extrapolation vs. application of uncertainty factors.

The role of NF-κB in breast cancer initiation, growth, metastasis, and resistance to chemotherapy

Breast cancer (BC) is the second most fatal disease and is the prime cause of cancer allied female deaths. BC is caused by aberrant tumor suppressor genes and oncogenes regulated by transcription factors (TFs) like NF-κB. NF-κB is a pro-inflammatory TF that crucially alters the expressions of various genes associated with inflammation, cell progression, metastasis, and apoptosis and modulates a network of genes that underlie tumorigenesis. Herein, we focus on NF-κB signaling pathways, its regulators, and the rationale for targeting NF-κB. This review also includes TFs that maintain NF-κB crosstalk and their roles in promoting angiogenesis and metastasis. In addition, we discuss the importance of combination therapies, resistance to treatment, and potential novel therapeutic strategies including nanomedicine that targets NF-κB.

The prognostic indicator in breast cancer treated with CDK4/6 inhibitors: the prognostic nutritional index

Aims: The aim of this study was to evaluate the effect of prognostic nutritional index (PNI) on prognosis in patients with hormone receptor-positive, HER2-negative metastatic breast cancer who received CDK4/6 inhibitor + endocrine therapy. Methods: Patients receiving a CDK4/6 inhibitor were evaluated retrospectively. The PNI was calculated as: (10 × serum albumin [g/dl]) + (total lymphocyte count [×10⁹/l] × 5). Results: In a study of 106 patients, a statistically significant survival advantage was observed in the high-PNI group over the low-PNI group (mean overall survival: 28.03 ± 0.487 months vs 22.46 ± 1.14 months; p = 0.013). Conclusion: For the first time in the literature, this study demonstrated the prognostic role of PNI in patients with hormone receptor-positive, HER2-negative metastatic breast cancer treated with CDK4/6 inhibitors.

Vascular Endothelial Growth Factor Ligands and Receptors in Breast Cancer

Breast cancer (BC) is the most common malignancy responsible for the largest number of deaths in women worldwide. The risk of developing BC is predisposed by many factors such as age, presence of genetic mutations or body weight. The diagnosis is mostly made relatively late, which is why patients are exposed to radical surgical treatments, long-term chemotherapy and lower survival rates. There are no sufficiently sensitive and specific screening tests; therefore, researchers are still looking for new diagnostic biomarkers that would indicate the appearance of neoplastic changes in the initial stage of neoplasm. The VEGF family of proteins (VEGF-A, VEGF-B, VEGF-C, VEGF-D, EG-VEGF, PlGF) and their receptors are significant factors in the pathogenesis of BC. They play a significant role in the process of angiogenesis and lymphangiogenesis in both physiological and pathological conditions. The usefulness of these proteins as potential diagnostic biomarkers has been initially proven. Moreover, the blockage of VEGF-related pathways seems to be a valid therapeutic target. Recent studies have tried to describe novel strategies, including targeting pericytes, use of miRNAs and extracellular tumor-associated vesicles, immunotherapeutic drugs and nanotechnology. This indicates their possible contribution to the formation of breast cancer and their usefulness as potential biomarkers and therapeutic targets.

The neuroprotective effects of estrogen and estrogenic compounds in spinal cord injury

Spinal cord injury (SCI) occurs when the spinal cord is damaged from either a traumatic event or disease. SCI is characterised by multiple injury phases that affect the transmission of sensory and motor signals and lead to temporary or long-term functional deficits. There are few treatments for SCI. Estrogens and estrogenic compounds, however, may effectively mitigate the effects of SCI and therefore represent viable treatment options. This review systematically examines the pre-clinical literature on estrogen and estrogenic compound neuroprotection after SCI. Several estrogens were examined by the included studies: estrogen, estradiol benzoate, Premarin, isopsoralen, genistein, and selective estrogen receptor modulators. Across these pharmacotherapies, we find significant evidence that estrogens indeed offer protection against myriad pathophysiological effects of SCI and lead to improvements in functional outcomes, including locomotion. A STRING functional network analysis of proteins modulated by estrogen after SCI demonstrated that estrogen simultaneously upregulates known neuroprotective pathways, such as HIF-1, and downregulates pro-inflammatory pathways, including IL-17. These findings highlight the strong therapeutic potential of estrogen and estrogenic compounds after SCI.

Effects of xenobiotics on CYP1 enzyme-mediated biotransformation and bioactivation of estradiol

Endogenous estradiol (E2) exerts diverse physiological and pharmacological activities, commonly used for hormone replacement therapy. However, prolonged and excessive exposure to E2 potentially increases estrogenic cancer risk. Reportedly, CYP1 enzyme-mediated biotransformation of E2 is largely concerned with its balance between detoxification and carcinogenic pathways. Among the three key CYP1 enzymes (CYP1A1, CYP1A2, and CYP1B1), CYP1A1 and CYP1A2 mainly catalyze the formation of nontoxic 2-hydroxyestradiol (2-OH-E2), while CYP1B1 specifically catalyzes the formation of genotoxic 4-hydroxyestradiol (4-OH-E2). 4-OH-E2 can be further metabolized to electrophilic quinone intermediates accompanied by the generation of reactive oxygen species (ROS), triggering DNA damage. Since abnormal alterations in CYP1 activities can greatly affect the bioactivation process of E2, regulatory effects of xenobiotics on CYP1s are essential for E2-associated cancer development. To date, thousands of natural and synthetic compounds have been found to show potential inhibition and/or induction actions on the three CYP1 members. Generally, these chemicals share similar planar polycyclic skeletons, the structural motifs and substituent groups of which are important for their inhibitory/inductive efficiency and selectivity toward CYP1 enzymes. This review comprehensively summarizes these known inhibitors and/or inductors of E2-metabolizing CYP1s based on chemical categories and discusses their structure-activity relationships, which would contribute to better understanding of the correlation between xenobiotic-regulated CYP1 activities and estrogenic cancer susceptibility.

Chemopreventive and anti-tumor potential of vitamin E in preclinical breast cancer studies: A systematic review

BACKGROUND

Vitamin E has been investigated for its antitumor potential, including the ability to change cancer gene pathways as well as promote antioxidant and pro-oxidant activity.

OBJECTIVE

Therefore, this systematic review aimed to evaluate antitumor and chemopreventive activity of different vitamin E isoforms (tocopherols and tocotrienols) through in vitro and in vivo studies.

METHOD

The systematic review was registered in PROSPERO (No. CRD4202126207) and the search was carried out in four electronic databases (PubMed, Science Direct, Scopus and Web of Science) in June 2021 by three independent reviewers. The search equation used was: "Supplementation" AND ("Vitamin E" OR Tocopherol OR Tocotrienol) AND "breast cancer" AND (chemotherapy OR therapy OR prevention). In vitro studies and animal models of breast cancer supplemented with tocopherol or tocotrienol vitamers, alone or in combination, were included.

RESULTS

The results revealed 8546 relevant studies that were initially identified in our search. After analysis, a total of 12 studies were eligible for this systematic review. All studies included animal models, and 5 of them also performed in vitro experiments on cancer cell lines. The studies performed supplementation with tocopherols, mixtures (tocopherols and tocotrienols) and synthetic vitamin E forms. There was an significant association of estradiol, dendritic cells and pterostilbene in combined therapy with vitamin E. Vitamin E delayed tumor development, reduced tumor size, proliferation, viability, expression of anti-apoptotic and cell proliferation genes, and upregulated pro-apoptotic genes, tumor suppressor genes and increased immune response. The effects on oxidative stress markers and antioxidant activity were conflicting among studies. Only one study with synthetic vitamin E reported cardiotoxicity, but it did not show vitamin E genotoxicity.

CONCLUSION

In conclusion, vitamin E isoforms, isolated or associated, showed antitumor and chemopreventive activity. However, due to studies heterogeneity, there is a need for further analysis to establish dose, form, supplementation time and breast cancer stage.

Characterization of Estrogen Receptors in Pancreatic Adenocarcinoma with Tertiary Lymphoid Structures

The role of estrogen signaling in antitumor immunology remains unknown for non-traditional sex-biased cancer types such as pancreatic adenocarcinoma (PAAD). Tertiary lymphoid structures (TLS) are active zones composed of multiple types of immune cells, whose presence indicates anti-tumor immune responses. In this study, we employed a 12-chemokine signature to characterize potential gene categories associated with TLS development and identified seventeen major gene categories including estrogen receptors (ERs). Immunohistochemistry staining revealed the expression patterns of three ERs (ERα, ERβ, and GPER) in 174 PAAD samples, and their correlation with clinicopathological characteristics, immune cell infiltration levels, and intratumoral TLS presence was analyzed. The results indicated that ERα (+) and ERβ (+) were correlated with high tumor grade, and ERβ (+) and GPER (+) were correlated with lower TNM stage, and both ERα (+) and GPER (+) displayed a beneficial effect on prognosis in this cohort. Interestingly, positive staining of all three ERs was significantly correlated with the presence of intratumoral TLSs and infiltration of more active immune cells into the microenvironment. Moreover, the chemotaxis of CD8⁺T-cells to PAAD cells was significantly increased in vitro with upregulated expression of ERα or ERβ on PAAD cells. To conclude, our study showed a novel correlation between ER expression and TLS development, suggesting that ERs may play a protective role by enhancing anti-tumor immune responses in PAAD.

Association between Consumption of Artificial Sweeteners and Breast Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies

This study intends to conduct a meta-analysis based on existing research results to further investigate their relationship between artificial sweetener exposure and breast cancer risk. An electronic database literature search was performed up to July 2022, using PubMed, Web of Science, Ovid and Scopus. The relationship between artificial sweetener exposure and breast cancer (BC) incidence was evaluated by odds ratio (OR) and 95% confidence interval (CI). Among the five studies (two case-control studies and three cohort studies) that met the inclusion criteria, 314,056 participants were recruited in the cohort study, 4,043 cancer cases and 3,910 controls were recruited in the case-control study. It was found that exposure of artificial sweeteners was not related to the risk of BC (OR = 0.98, 95% CI = [0.94-1.03]). Subgroup analysis showed that compared with the non-exposure/very-low-dose group, the exposure to low, medium and high doses of artificial sweeteners were not associated with the risk of BC, which were OR = 1.01, 95% CI = [0.95-1.07], OR = 0.98, 95% CI = [0.93-1.02], OR = 0.88, 95% CI = [0.74-1.06], respectively. This study confirmed that there was no relationship between the exposure of artificial sweeteners and the incidence of BC.

Palbociclib Adherence and Persistence in Patients with Hormone Receptor Positive/Human Epidermal Growth Factor Receptor 2 Negative (HR+/HER2-) Metastatic Breast Cancer

Purpose

To assess adherence and persistence with palbociclib therapy in patients with HR+/HER2- metastatic breast cancer (mBC) in a US real-world setting.

Methods

This retrospective study evaluated palbociclib dosing, adherence, and persistence using commercial and Medicare Advantage with Part D claims data from the Optum Research Database. Adult patients with mBC who had continuous enrollment 12 months prior to mBC diagnosis and initiated first-line palbociclib with aromatase inhibitor (AI) or fulvestrant between 02/03/2015 and 12/31/2019 were included. Demographic and clinical characteristics, palbociclib dosing and dose changes, adherence (medication possession ratio [MPR]), and persistence were measured. Adjusted logistic and Cox regression models were used to examine demographic and clinical factors associated with adherence and discontinuation.

Results

Patients (n = 1066) with a mean age of 66 years were included; 76.1% received first-line palbociclib+AI and 23.9% palbociclib+fulvestrant. Most patients (85.7%) initiated palbociclib at 125 mg/day. Of the 34.0% of patients with a dose reduction, 82.6% reduced from 125 to 100 mg/day. Overall, 80.0% of patients were adherent (MPR), and 38.3% discontinued palbociclib during a mean (SD) follow-up of 16.0 (11.2) and 17.4 (13.4) months, for palbociclib+fulvestrant and palbociclib+AI, respectively. Annual income below $75,000 was significantly associated with poor adherence. Older age (age 65-74 years (hazard ratio [HR] 1.57, 95% CI, 1.06, 2.33), age ≥75 years (HR 1.61, 95% CI: 1.08, 2.41)) and bone-only metastatic disease (HR 1.37, 95% CI, 1.06, 1.76) were significantly associated with palbociclib discontinuation.

Conclusion

In this real-world study, >85% of patients started palbociclib at 125 mg/day and 1 in 3 had dose reductions during the follow-up. Patients were generally adherent and persistent with palbociclib. Older age, bone-only disease, and low-income levels were associated with early discontinuation or non-adherence. Further studies are needed to understand the associations of clinical and economic outcomes with palbociclib adherence and persistence.

Tetrachlorobisphenol A and bisphenol AF induced cell migration by activating PI3K/Akt signaling pathway via G protein-coupled estrogen receptor 1 in SK-BR-3 cells

Different subtypes of breast cancer express positively G protein-coupled estrogen receptor 1 (GPER1). Our previous studies found that tetrachlorobisphenol A (TCBPA) and bisphenol AF (BPAF) significantly promoted SK-BR-3 cell proliferation by activating GPER1-regulated signals. The present study further investigated the effects of TCBPA and BPAF on the migration of SK-BR-3 cells and examined the role of phosphatidylinositol 3-kinase-protein kinase B (PI3K/Akt) and its downstream signal targets in this process. We found that low-concentration BPAF and TCBPA markedly accelerated the migration of SK-BR-3 cells and elevated the mRNA levels of target genes associated with PI3K/Akt and mitogen-activated protein kinase (MAPK) signals. TCBPA- and BPAF-induced upregulation of target genes was significantly reduced by GPER1 inhibitor G15, the PI3K/Akt inhibitor wortmannin (WM), and the epidermal growth factor receptor (EGFR) inhibitor ZD1839 (ZD). G15 and WM also decreased cell migration induced by TCBPA and BPAF. The findings revealed that TCBPA and BPAF promoted SK-BR-3 cell migration ability by activating PI3K/Akt signaling pathway via GPER1-EGFR.

RT-qPCR Expression Profiles of Selected Oncogenic and Oncosuppressor miRNAs in Formalin-Fixed, Paraffin-Embedded Canine Mammary Tumors

MicroRNAs (miRNAs) can act as oncogenes or oncosuppressor genes, and their involvement in nearly all cancer-associated processes makes these small molecules promising diagnostic and prognostic biomarkers in cancer, as well as specific targets for cancer therapy. This study aimed to investigate the expression of 7 miRNAs (miR-18a, miR-18b, miR-22, miR-124, miR-145, miR-21, miR-146b) in formalin-fixed, paraffin-embedded canine mammary tumors (CMTs) by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Twenty-six mammary samples were selected, including 22 CMTs (7 benign; 15 malignant) and 4 control samples (3 normal mammary gland and 1 case of lobular hyperplasia). Oncogenic miR-18a, miR-18b and miR-21 were significantly upregulated in malignant tumors compared with control tissues (p < 0.05). Conversely, oncosuppressor miR-146b was significantly downregulated in benign and malignant mammary tumors compared with control samples (p < 0.05) while, no group-related differences in the expression levels of miR-22, miR-124 and miR-145 were found (p > 0.05). Upregulated miRNAs found here, may regulate genes involved in receptor-mediated carcinogenesis and proteoglycan remodeling in cancer; while miRNA with reduced expression can regulate genes involved in Toll-like receptor and MAPK signaling pathways. According to the results obtained in the current study, the oncogenic and oncosuppressor miRNAs analyzed here are dysregulated in CMTs and the dysregulation of miRNA targets may lead to specific altered cellular processes and key pathways involved in carcinogenesis. Of note, since oncogenic miRNAs predicted to regulate neoplastic cell proliferation and hormonal activities, they may play an active role in neoplastic transformation and/or progression, having mechanistic and prognostic relevance in CMTs.

A Novel Nomogram for Predicting Breast Cancer-specific Survival in Male Patients

OBJECTIVES

To compare breast cancer-specific survival (BCSS) of nonmetastatic invasive breast cancer between male (MBC) and female (FBC) patients, define clinicopathologic variables related to BCSS in nonmetastatic invasive MBC patients, and establish a nomogram for individual risk prediction.

MATERIALS AND METHODS

On the basis of Surveillance, Epidemiology, and End Results database, 2094 MBC and 48,104 FBC cases underwent propensity score matching (PSM). We compared the prognosis of patients before and after PSM and developed a nomogram for BCSS of nonmetastatic invasive MBC patients. Internal validation was performed using the consistency index, calibration curves, and receiver operating characteristic curves. Simultaneously, data from 49 nonmetastatic invasive MBC patients diagnosed between January 2012 and May 2016 were collected for external validation.

RESULTS

Before PSM, overall survival and BCSS were significantly shorter in MBC than those in FBC patients. After PSM, MBC patients continued to have a shorter overall survival, but not BCSS, than FBC patients. Marital status, age, histologic grade, estrogen/progesterone receptor status, Tumor Lymph Node stage, and surgery were included in the prediction model.

CONCLUSIONS

The nomogram developed in this study seems to be more accurate than conventional Tumor-nodal-metastasis staging staging to predict BCSS and may serve as an effective tool for assessing the prognosis of nonmetastatic invasive MBC.

Hormonal and Genetic Regulatory Events in Breast Cancer and Its Therapeutics: Importance of the Steroidogenic Acute Regulatory Protein

Estrogen promotes the development and survival of the majority of breast cancers (BCs). Aromatase is the rate-limiting enzyme in estrogen biosynthesis, and it is immensely expressed in both cancerous and non-cancerous breast tissues. Endocrine therapy based on estrogen blockade, by aromatase inhibitors, has been the mainstay of BC treatment in post-menopausal women; however, resistance to hormone therapy is the leading cause of cancer death. An improved understanding of the molecular underpinnings is the key to develop therapeutic strategies for countering the most prevalent hormone receptor positive BCs. Of note, cholesterol is the precursor of all steroid hormones that are synthesized in a variety of tissues and play crucial roles in diverse processes, ranging from organogenesis to homeostasis to carcinogenesis. The rate-limiting step in steroid biosynthesis is the transport of cholesterol from the outer to the inner mitochondrial membrane, a process that is primarily mediated by the steroidogenic acute regulatory (StAR) protein. Advances in genomic and proteomic technologies have revealed a dynamic link between histone deacetylases (HDACs) and StAR, aromatase, and estrogen regulation. We were the first to report that StAR is abundantly expressed, along with large amounts of 17β-estradiol (E2), in hormone-dependent, but not hormone-independent, BCs, in which StAR was also identified as a novel acetylated protein. Our in-silico analyses of The Cancer Genome Atlas (TCGA) datasets, for StAR and steroidogenic enzyme genes, revealed an inverse correlation between the amplification of the StAR gene and the poor survival of BC patients. Additionally, we reported that a number of HDAC inhibitors, by altering StAR acetylation patterns, repress E2 synthesis in hormone-sensitive BC cells. This review highlights the current understanding of molecular pathogenesis of BCs, especially for luminal subtypes, and their therapeutics, underlining that StAR could serve not only as a prognostic marker, but also as a therapeutic candidate, in the prevention and treatment of this life-threatening disease.

Mechanistic Effects of Estrogens on Breast Cancer

PURPOSE

Current concepts regarding estrogen and its mechanistic effects on breast cancer in women are evolving. This article reviews studies that address estrogen-mediated breast cancer development, the prevalence of occult tumors at autopsy, and the natural history of breast cancer as predicted by a newly developed tumor kinetic model.

METHODS

This article reviews previously published studies from the authors and articles pertinent to the data presented.

RESULTS

We discuss the concepts of adaptive hypersensitivity that develops in response to long-term deprivation of estrogen and results in both increased cell proliferation and apoptosis. The effects of menopausal hormonal therapy on breast cancer in postmenopausal women are interpreted based on the tumor kinetic model. Studies of the administration of a tissue selective estrogen complex in vitro, in vivo, and in patients are described. We review the various clinical studies of breast cancer prevention with selective estrogen receptor modulators and aromatase inhibitors. Finally, the effects of the underlying risk of breast cancer on the effects of menopausal hormone therapy are outlined.

DISCUSSION

The overall intent of this review is to present data supporting recent concepts, discuss pertinent literature, and critically examine areas of controversy.

The Complex Biology of the Obesity-Induced, Metastasis-Promoting Tumor Microenvironment in Breast Cancer

Breast cancer is one of the most prevalent cancers in women contributing to cancer-related death in the advanced world. Apart from the menopausal status, the trigger for developing breast cancer may vary widely from race to lifestyle factors. Epidemiological studies refer to obesity-associated metabolic changes as a critical risk factor behind the progression of breast cancer. The plethora of signals arising due to obesity-induced changes in adipocytes present in breast tumor microenvironment, significantly affect the behavior of adjacent breast cells. Adipocytes from white adipose tissue are currently recognized as an active endocrine organ secreting different bioactive compounds. However, due to excess energy intake and increased fat accumulation, there are morphological followed by secretory changes in adipocytes, which make the breast microenvironment proinflammatory. This proinflammatory milieu not only increases the risk of breast cancer development through hormone conversion, but it also plays a role in breast cancer progression through the activation of effector proteins responsible for the biological phenomenon of metastasis. The aim of this review is to present a comprehensive picture of the complex biology of obesity-induced changes in white adipocytes and demonstrate the relationship between obesity and breast cancer progression to metastasis.

Associations of established breast cancer risk factors with urinary estrogens in postmenopausal women

PURPOSE

Circulating estrogens are an established risk factor for postmenopausal breast cancer (BCa). We describe the distribution of urinary estrogens, their metabolites, and relevant metabolic pathway ratios among healthy postmenopausal women and examine associations of several known BCa factors with these estrogen measures.

METHODS

Eligible postmenopausal women (n = 167) had no history of hormone use (previous 6 months) and cancer/metabolic disorders and had a body mass index (BMI) ≤ 35 kg/m². Estrogens were quantified in spot urine samples with liquid chromatography-high-resolution mass spectrometry and corrected for creatinine. We assessed overall distributions of estrogens and associations of age, BMI, race/ethnicity, parity/age at first birth, age at menarche, alcohol, and smoking with log-transformed estrogen measures using multivariate regression.

RESULTS

BMI was positively associated with estrone (β per unit = 0.04, 95% Confidence Interval [CI] 0.00; 0.07), combined parent estrogens (β = 0.04, 95% CI 0.01; 0.07), and E2:total estrogens (β = 0.04, 95% CI 0.02; 0.06), and inversely associated with 4-MeOE1 (β = - 0.17, 95% CI - 0.33; - 0.02), E3:parent estrogens (β = - 0.04, 95% CI - 0.07; - 0.00), and 16-pathway:parent (β = - 0.04, 95% CI - 0.07; - 0.01). Being African American vs. white was associated with higher levels of 4-MeOE1 (β = 3.41, 95% CI 0.74; 6.08), 17-epiE3 (β = 1.19, 95% CI 0.07; 2.31), 2-pathway:parent (β = 0.54, 95% CI 0.04; 1.04), and lower levels of E2:total estrogens (β = - 0.48, 95% CI - 0.83; - 0.13). Having < 7 alcohol drinks/week vs. none was associated with higher levels of 16-ketoE2 (β = 1.32, 95% CI 0.36; 2.27), 16-epiE3 (β = 1.02, 95% CI 0.24; 1.79), and 17-epiE3 (β = 0.55, 95% CI 0.02; 1.08). Smoking was positively associated with E3:parent (β = 0.29, 95% CI 0.01; 0.57), 16-pathway:parent (β = 0.25, 95% CI 0.01; 0.49), and inversely associated with estradiol (β = - 0.52, 95% CI - 0.93; - 0.10). As compared to nulliparous, parous women with age at first birth ≥ 25 years had lower levels of estrone, combined parent estrogens, 2-OHE1, and 2-OHE2.

CONCLUSION

Our findings suggest that BMI, race/ethnicity, and some reproductive and lifestyle factors may contribute to postmenopausal BCa through their effects on circulating estrogens.

Profiling of Protein Adducts of Estrogen Quinones in 5-Year Survivors of Breast Cancer Without Recurrence

Aims

The aim of this study was to simultaneously analyze estrogen quinone-derived adducts, including 17β-estradiol-2,3-quinone (E₂-2,3-Q) and 17β-estradiol-3,4-quinone (E₂-3,4-Q), in human albumin (Alb) and hemoglobin (Hb) derived from breast cancer patients with five-year postoperative treatment without recurrence in Taiwan and to evaluate the treatment-related effects on the production of these adducts.

Settings and Design

Cohort

Methods and Material: Blood samples derived from breast cancer 5-year survivors without recurrence were collected. Albumin and hemoglobin adducts of E₂-3,4-Q and E₂-2,3-Q were analyzed to evaluate the degree of disposition of estrogen to quinones and to compare these adduct levels with those in patients before treatment.

Statistical Analysis

All data are expressed as mean ± standard deviation of three determinations. We used Student’s t-test to examine subgroups. Data were transformed to the natural logarithm and tested for normal distribution for parametric analyses. Linear correlations were investigated between individual adduct levels by simple regression. Statistical analysis was performed using the SPSS Statistics 20.0.

Results

Result confirmed that logged levels of E₂-2,3-Q-derived adducts correlated significantly with those of E₂-3,4-Q-derived adducts (correlation coefficient r=.336-.624). Mean levels of E₂-2,3-Q-4-S-Alb and E₂-3,4-Q-2-S-Alb in 5-year survivors were reduced by 60-70% when compared to those in the breast cancer patients with less than one year of diagnosis/preoperative treatment (P<.001).

Conclusions

Our findings add support to the theme that hormonal therapy including aromatase inhibitors and Tamoxifen may dramatically reduce burden of estrogen quinones. We hypothesize that combination of treatment-related effects and environmental factors may modulate estrogen homeostasis and diminish the production of estrogen quinones in breast cancer patients.

Prolactin and endocrine therapy resistance in breast cancer: The next potential hope for breast cancer treatment

Breast cancer, a hormone‐dependent tumour, generally includes four molecular subtypes (luminal A, luminal B, HER2 enriched and triple‐negative) based on oestrogen receptor, progesterone receptor and human epidermal growth factor receptor‐2. Multiple hormones in the body regulate the development of breast cancer. Endocrine therapy is one of the primary treatments for hormone‐receptor‐positive breast cancer, but endocrine resistance is the primary clinical cause of treatment failure. Prolactin (PRL) is a protein hormone secreted by the pituitary gland, mainly promoting mammary gland growth, stimulating and maintaining lactation. Previous studies suggest that high PRL levels can increase the risk of invasive breast cancer in women. The expression levels of PRL and PRLR in breast cancer cells and breast cancer tissues are elevated in most ER⁺ and ER⁻ tumours. PRL activates downstream signalling pathways and affects endocrine therapy resistance by combining with prolactin receptor (PRLR). In this review, we illustrated and summarized the correlations between endocrine therapy resistance in breast cancer and PRL, as well as the pathophysiological mechanisms and clinical practices. The study on PRL and its receptor would help explore reversing endocrine therapy‐resistance for breast cancer.

Alysicarpus vaginalis Bio-Actives as ESR Signaling Pathway Inhibitor for Breast Cancer Treatment: A Network Pharmacology Approach

In our previous study Alysicarpus vaginalis (AV) has appeared as a promising target for breast cancer hence we have screened potential targets by in silico, In Vitro and In Vivo methods. A network pharmacology (NP) approach involves prediction and validating of targets via molecular modeling, western blotting and In Vivo MNU-induced mammary cancer. The PPI network showed the 573 edges between 214 nodes (targets) that are involved in breast cancer and important one are ESR-1, ESR-2, AR, EGFR, NOS3, MAPK, KDR, SRC and MET. Compound-target-pathway network involves 04 compounds and 221 interactive protein targets associated with breast cancer. GO and KEGG enrichment analysis predicted the ERR, c-MET, PDGFR-α/β, EGFR, and VEGF as a key targets in the breast cancer treatment which are validated via molecular modeling. Expression of ER-α, AR and EGFR were significantly down regulated by AV in MCF-7 cell line. In addition, the immunoreactivity of ER-α was reduced significantly in MNU-induced mammary carcinoma, which is a key target in ER + breast cancer. Overall, this study scientifically light ups the pharmacological mechanism of AV in the treatment of breast cancer, strongly associated with the regulation of ESR signaling pathway.

Endogenous estrogens-breast cancer and chemoprevention

Breast cancer is the most common female malignancy and the second leading cause of cancer related deaths. It is estimated that about 40% of all cancer in women is hormonally mediated. Both estrogens and androgens play critical roles in the initiation and development of breast cancer. Estrogens influence normal physiological growth, proliferation, and differentiation of breast tissues, as well as the development and progression of breast malignancy. Breast cancer is caused by numerous endo- and exogenous risk factors. The paper presents estrogen metabolism, in particular 17β-estradiol and related hormones. The mechanisms of estrogen carcinogenesis include the participation of estrogen receptors, the genotoxic effect of the estrogen metabolites, and epigenetic processes that are also presented. The role of reactive oxygen species in breast cancer has been described. It called attention to a role of numerous signaling pathways in neoplastic transformation. Chemoprotective agents, besides other phytoestrogens, classical antioxidants, synthetic compounds, and their mechanisms of action have been shown.

Physiologically Relevant Estrogen Receptor Alpha Pathway Reporters for Single-Cell Imaging-Based Carcinogenic Hazard Assessment of Estrogenic Compounds

Estrogen receptor alpha (ERα) belongs to the nuclear hormone receptor family of ligand-inducible transcription factors and regulates gene networks in biological processes such as cell growth and proliferation. Disruption of these networks by chemical compounds with estrogenic activity can result in adverse outcomes such as unscheduled cell proliferation, ultimately culminating in tumor formation. To distinguish disruptive activation from normal physiological responses, it is essential to quantify relationships between different key events leading to a particular adverse outcome. For this purpose, we established fluorescent protein MCF7 reporter cell lines for ERα-induced proliferation by bacterial artificial chromosome-based tagging of 3 ERα target genes: GREB1, PGR, and TFF1. These target genes are inducible by the non-genotoxic carcinogen and ERα agonist 17β-estradiol in an ERα-dependent manner and are essential for ERα-dependent cell-cycle progression and proliferation. The 3 GFP reporter cell lines were characterized in detail and showed different activation dynamics upon exposure to 17β-estradiol. In addition, they demonstrated specific activation in response to other established reference estrogenic compounds of different potencies, with similar sensitivities as validated OECD test methods. This study shows that these fluorescent reporter cell lines can be used to monitor the spatial and temporal dynamics of ERα pathway activation at the single-cell level for more mechanistic insight, thereby allowing a detailed assessment of the potential carcinogenic activity of estrogenic compounds in humans.

Insight into the mechanism of tetrachlorobisphenol A (TCBPA)-induced proliferation of breast cancer cells by GPER-mediated signaling pathways

Tetrachlorobisphenol A (TCBPA), a chlorinated derivative of bisphenol A, is an endocrine disruptor based on interaction with nuclear estrogen receptor alpha (ERα). However, there is only limited data on the mechanisms through which TCBPA-associated estrogenic activity is related to the membrane G protein-coupled estrogen receptor (GPER) pathway. In this study, three human breast cancer cell lines-MCF-7, SKBR3, and MDA-MB-231 cells were used to evaluate whether, as well as how, TCBPA at concentration range of 0.001-50 μM affect cell proliferation. The role of GPER signaling in TCBPA-induced cell proliferation was studied by analyzing the protein expression and mRNA levels of relevant signal targets. The results showed that low concentrations of TCBPA significantly induced the proliferation of MCF-7, SKBR3, and MDA-MB-231 cells, with MCF-7 cells being the most sensitive to TCBPA exposure. Low-concentration TCBPA also upregulated the expression of GPER, CyclinD1, c-Myc, and c-Fos proteins, as well as increased the phosphorylation of extracellular signal-regulated-kinase 1/2 (Erk1/2) and protein kinase B (Akt). Additionally, the mRNA levels of genes associated with estrogen signaling pathways also increased upon exposure to TCBPA. However, the phosphorylation of Erk1/2 and Akt decreased when the cells were treated with GPER inhibitor G15 and phosphatidylinositide 3-kinase (PI3K) inhibitor wortmannin (WM) prior to TCBPA exposure. Besides, the increased proliferation of breast cancer cells induced by TCBPA were also inhibited. In ERα-positive MCF-7 cells, TCBPA also upregulated ERα expression, and ERα was found to interact with GPER-mediated signaling. The results indicate that GPER activates the PI3K/Akt and Erk1/2 signal cascades to drive the cell proliferation observed for low concentrations of TCBPA. The presented results suggest a new mechanism by which TCBPA exerts estrogenic action in breast cancer cells, namely, GPER signaling in an ERα-independent manner, and also highlights the potential risks to human health of the usage of TCBPA.

Clinical Challenges in the Management of Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer: A Literature Review

Endocrine therapy (ET) is integral to the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Aromatase inhibitors (AIs; e.g., anastrozole, letrozole, exemestane), selective estrogen receptor modulators (e.g., tamoxifen), and the selective estrogen receptor degrader, fulvestrant, inhibit tumor cell proliferation by targeting ER signaling. However, the efficacy of ET could be limited by intrinsic and acquired resistance mechanisms, which has prompted the development of targeted agents and combination strategies. In recent years, the treatment landscape for HR+, HER2- MBC has evolved rapidly. AIs, historically the first-line treatment for postmenopausal patients with HR+, HER2- MBC, have been challenged by more effective ET, such as fulvestrant alone or in combination with an AI, and the cyclin-dependent kinase (CDK)4/6 inhibitors, which have increasingly become the new standard of care. For endocrine-resistant disease (≥ second-line), clinical trials demonstrated that the mammalian target of rapamycin inhibitor, everolimus, enhanced the efficacy of exemestane or fulvestrant after progression on an AI. CDK4/6 inhibitors in combination with fulvestrant have demonstrated superior progression-free survival and overall survival versus fulvestrant alone. Recently, the combination of fulvestrant with alpelisib in phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA) mutated HR+, HER2- MBC following progression on or after ET was approved, based on the SOLAR-1 study. However, the optimal sequencing of treatments is unknown, especially following disease progression on a CDK4/6 inhibitor. This review aims to provide practical guidance for the management of HR+, HER2- MBC based on available data and the utility of genomic biomarkers, including germline breast cancer genes 1 and 2 (BRCA1/2) mutations, and somatic estrogen receptor alpha gene (ESR1), HER2, and PIK3CA mutations.

Multiple-endpoint in vitro carcinogenicity test in human cell line TK6 distinguishes carcinogens from non-carcinogens and highlights mechanisms of action

Current in vitro genotoxicity tests can produce misleading positive results, indicating an inability to effectively predict a compound's subsequent carcinogenic potential in vivo. Such oversensitivity can incur unnecessary in vivo tests to further investigate positive in vitro results, supporting the need to improve in vitro tests to better inform risk assessment. It is increasingly acknowledged that more informative in vitro tests using multiple endpoints may support the correct identification of carcinogenic potential. The present study, therefore, employed a holistic, multiple-endpoint approach using low doses of selected carcinogens and non-carcinogens (0.001-770 µM) to assess whether these chemicals caused perturbations in molecular and cellular endpoints relating to the Hallmarks of Cancer. Endpoints included micronucleus induction, alterations in gene expression, cell cycle dynamics, cell morphology and bioenergetics in the human lymphoblastoid cell line TK6. Carcinogens ochratoxin A and oestradiol produced greater Integrated Signature of Carcinogenicity scores for the combined endpoints than the "misleading" in vitro positive compounds, quercetin, 2,4-dichlorophenol and quinacrine dihydrochloride and toxic non-carcinogens, caffeine, cycloheximide and phenformin HCl. This study provides compelling evidence that carcinogens can successfully be distinguished from non-carcinogens using a holistic in vitro test system. Avoidance of misleading in vitro outcomes could lead to the reduction and replacement of animals in carcinogenicity testing.

Serum sex hormone levels and hormone receptor status in identifying breast cancer risk in women

Background

The association of sex hormones with receptor status and breast cancer (BC) incidence is studied with inconclusive results. The present work assessed the serum estrogen, progesterone, and testosterone concentrations and estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status of newly diagnosed Sri Lankan BC patients and studied the possibility of risk assessment for BC using these parameters.

Methods

Serum estrogen, progesterone, and testosterone concentrations of newly diagnosed BC patients (n = 155) were assessed and compared with apparently healthy age-matched women (n = 75). Hormone concentrations were assessed with an enzyme immunoassay competition method with fluorescent detection (Biomerieux, France). Hormone receptor statuses were recorded from histopathology reports.

Results

Estrogen and progesterone concentrations were not significantly different according to the menstrual phase of premenopausal BC or healthy women or according to the menopausal status. Testosterone concentration of BC patients was significantly (P = 0.001) lower than in apparently healthy women. Estrogen and progesterone concentrations were not significantly different according to ER and PR status. However, progesterone concentrations of postmenopausal were significantly different (P = 0.021) among HER2 overexpressed women when compared to HER2-negative women. Postmenopausal women with progesterone level below 0.25 ng/mL were more likely to have HER2 overexpressed (P = 0.002).

Conclusions

Serum estrogen and progesterone concentrations of BC patients were not significantly different when compared with apparently healthy women. Women with testosterone level below 0.26 ng/mL demonstrated a higher risk of having BC. Serum progesterone concentrations of BC patients were significantly higher among HER2 overexpressed women compared to HER2-negative women.

G-protein Coupled Estrogen Receptor Expression in Growth Hormone Secreting and Non-Functioning Adenomas

PURPOSE

To evaluate the expression of G-protein coupled estrogen receptor (GPER1), aromatase, estrogen receptor α (ERα), estrogen receptor β (ERβ), pituitary tumor transforming gene (PTTG), and fibroblast growth factor 2 (FGF2) in GH-secreting and non-functioning adenomas (NFA).

METHODS

Thirty patients with acromegaly and 27 patients with NFA were included. Gene expression was determined via quantitative reverse transcription polymerase chain reaction (QRT-PCR). Protein expression was determined via immunohistochemistry.

RESULTS

There was no difference, in terms of gene expression of aromatase, ERα, PTTG, and FGF2 between the two groups (p>0.05 for all). ERβ gene expression was higher and GPER1 gene expression was lower in GH-secreting adenomas than NFAs (p<0.05 for all). Aromatase and ERβ protein expression was higher in GH-secreting adenomas than NFAs (p=0.01). None of the tumors expressed ERα. GPER1 expression was detected in 62.2% of the GH-secreting adenomas and 45% of NFAs. There was no difference in terms of GPER1, PTTG, FGF2 H scores between the two groups (p>0.05 for all). GPER1 gene expression was positively correlated to ERα, ERβ, PTTG, and FGF2 gene expression (p<0.05 for all). There was a positive correlation between aromatase and GPER1 protein expression (r=0.31; p=0.04).

CONCLUSIONS

GPER1 is expressed at both gene and protein level in a substantial portion of GH-secreting adenomas and NFAs. The finding of a positive correlation between GPER1 and ERα, ERβ, PTTG, and FGF2 gene expression and aromatase and GPER1 protein expression suggests GPER1 along with aromatase and classical ERs might mediate the effects of estrogen through upregulation of PTTG and FGF2.

LC-HRMS of derivatized urinary estrogens and estrogen metabolites in postmenopausal women

In order to undertake an epidemiologic study relating levels of parent estrogens (estrone and estradiol) and estrogen metabolites (EMs) to other breast cancer risk factors, we have optimized methods for EM quantification with ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). A two-step approach was adopted; the first step comprised method development and evaluation of the method performance. The second step consisted of applying this method to quantify estrogens in postmenopausal women and determine if the observed patterns are consistent with the existing literature and prior knowledge of estrogen metabolism. First, 1-methylimidazole-2-sulfonyl chloride (MIS) was used to derivatize endogenous estrogens and estrogen metabolites in urine from study participants. Since C18 reversed phase columns have not been able to separate all the structurally related EMs, we used a C18-pentafluorophenyl (PFP) column. The parent estrogens and EMs were baseline resolved with distinct retention times on this C18-PFP column using a 30 min gradient. This method was used to quantify the parent estrogens and 13 EMs in urine samples collected in an initial pilot study involving males as well as pre- and peri-menopausal females to assess a range of EM levels in urine samples and enable comparison to the previous literature for assay evaluation. Detection limits ranged from 1 - 20 pg/mL depending on the EM. We evaluated matrix effects and interference as well as the intra- and inter-batch reproducibility including hydrolysis, extraction, derivatization and LC-MS analysis using charcoal-stripped human urine as a matrix. Methods were then applied to the measurement of estrogens in urine samples from 169 postmenopausal women enrolled in an epidemiological study to examine relationships between breast cancer risk, the intestinal microbiome, and urinary EMs. The results from our cohort are comparable to previous reports on urinary EMs in postmenopausal women and enabled thorough evaluation of the method.

Canine mammary tumours: Size matters-a progression from low to highly malignant subtypes

The purpose of this study was to evaluate a possible association between mammary tumour size and increasing degree of malignancy. Data of 625 dogs with a total of 1459 mammary tumours were analysed retrospectively. 80.3% dogs were intact, mean age at diagnosis was 9.7 ± 2.5 years, 75.8% were pure breed dogs. Median body weight was 20.0 kg. Malignant tumours (n = 580) were significantly larger than their benign counterparts (1.94 cm vs 0.90 cm in mean, respectively; P ≤ .0001), resulting in a positive correlation between increasing tumour size and a change from benign to malignant (P ≤ .0001; r_s  = 0.214). When malignant tumours were grouped into four degrees of increasing malignancy (complex/simple/solid/anaplastic carcinomas) a significant positive correlation between increasing tumour size and more malignant tumour degree (P ≤ .0001; r_s  = 0.195) could be demonstrated. In a number of cases, highly malignant tumours were found to arise within less malignant lesions, supporting the concept of a further progression within the malignant tumour subtypes. In patients with multiple tumours, mean tumour sizes for malignant tumours were significantly smaller compared to patients with only one tumour (1.67 vs 2.71 cm in mean, respectively; P < .0001). These findings suggest that mammary tumours progress not only from benign to malignant but also from low to highly malignant. An increase in diameter of only a few millimetres may therefore have a big impact on the patient's outcome.

AGR3 promotes estrogen receptor-positive breast cancer cell proliferation in an estrogen-dependent manner

Breast cancer is one of the most common malignancies and the leading cause of cancer-associated death among women. Anterior gradient 3 (AGR3) is a cancer-associated gene and is similar to its homologous oncogene AGR2. However, whether AGR3 participates in breast cancer progression remains unclear. The present study aimed to investigate the function of AGR3 in ER-positive breast cancer. In the present study, reverse transcription-quantitative PCR was used to detect AGR3 mRNA expression in breast cancer tissues and cell lines; linear correlation analysis was used to investigate the correlation between AGR3 and estrogen receptor 1 (ESR1) expression in breast cancer via GEO dataset analysis; western blotting was used to assess the levels of AGR3, ER and GAPDH; small interfering (si)RNA transfection was used to knock down AGR3 and ESR1 expression; and finally the Cell Counting Kit-8 assay was used to evaluate cell viability. In the present study, AGR3 expression was markedly increased in estrogen receptor (ER)-positive breast cancer tissues and cell lines compared with that in ER-negative breast cancer. AGR3 expression was upregulated in estrogen-treated T47D cells, whereas 4-hydroxytamoxifen, an inhibitor of estrogen-ER activity in breast cancer cells, downregulated AGR3 expression in T47D cells. Functional assays demonstrated that knockdown of AGR3 using siRNAs inhibited T47D cell proliferation compared with that of the negative control group. Additionally, AGR3 expression was decreased after knocking down ESR1. The present results suggested that AGR3 may serve an important role in estrogen-mediated cell proliferation in breast cancer and that AGR3 knockdown may be a potential therapeutic strategy for ER-positive breast cancer.

Combination of Red Clover and Hops Extract Improved Menopause Symptoms in an Ovariectomized Rat Model

Red clover and hops are already known for their alternative menopausal therapies; however, their combination has not yet been studied. This study aimed to evaluate the efficacy of the combination of red clover and hops extract (RHEC) for treating menopausal symptoms for the first time. A high-performance liquid chromatography (HPLC) method for RHEC was developed and validated for the analysis of biochanin A in red clover extract and xanthohumol in hops extract. An in vivo study was conducted using an ovariectomized rat model treated with RHEC (125, 250, and 500 mg/kg, p.o.) for a 12-week test period. Changes in body weight, tail skin temperature (TST), serum lipid profile, bone metabolism, antioxidants, and markers of vasorelaxation and uterus endometrium were evaluated. RHEC significantly inhibited body weight gain and decreased fat weight. Changes in TST associated with flashes were significantly inhibited in the RHEC groups. Other markers related to menopausal symptoms, such as blood lipid profile (total cholesterol and low-density-lipoprotein cholesterol), bone metabolism (serum alkaline phosphatase, osteocalcin, and c-terminal telopeptide type 1), antioxidants (superoxide dismutase and malondialdehyde), and vasorelaxants (endothelin-1 and nitric oxide), were significantly improved after the administration of RHEC. We also confirmed the safety of RHEC through histopathological observation of the endometrium. Our findings demonstrate that RHEC appears to have high potential for comprehensively improving various symptoms of menopause.

Inhibition of PI3K/AKT molecular pathway mediated by membrane estrogen receptor GPER accounts for cryptotanshinone induced antiproliferative effect on breast cancer SKBR-3 cells

Background

Breast cancer is the most frequently diagnosed malignancy among women and the second leading cause of cancer death worldwide. Among which nuclear estrogen receptor (nER) negative breast cancer is always with much poor prognosis. Recently, membrane G protein coupled estrogen receptor (GPER), a newly recognized estrogen receptor has been documented to take essential part in the development and treatment of breast cancer. The present study was designed to investigate the anti nER negative breast cancer effect of cryptotanshinone (CPT), an important active compound of traditional Chinese medicine Danshen and its possible molecular pathway.

Methods

The following in vitro tests were performed in nER negative but GPER positive breast cancer SKBR-3 cells. The effect of CPT on cell proliferation rate and cell cycle distribution was evaluated by MTT cell viability test and flow cytometry assay respectively. The role of PI3K/AKT pathway and the mediated function of GPER were tested by western blot and immunofluorescence. Technique of gene silence and the specific GPER agonist G-1 and antagonist G-15 were employed in the experiments to further verify the function of GPER in mediating the anticancer role of CPT.

Results

The results showed that proliferation of SKBR-3 cells could be blocked by CPT in a time and dose dependent manner. CPT could also exert antiproliferative activities by arresting cell cycle progression in G1 phase and down regulating the expression level of cyclin A, cyclin B, cyclin D and cyclin-dependent kinase 2 (CDK2). The antiproliferative effect of CPT was further enhanced by G-1 and attenuated by G-15. Results of western blot and immunofluorescence showed that expression of PI3K and p-AKT could be downregulated by CPT and such effects were mediated by GPER which were further demonstrated by gene silence test.

Conclusion

The current study showed that the antiproliferative action of CPT on SKBR-3 cells was realized by inhibition of GPER mediated PI3K/AKT pathway. These findings provide further validation of GPER serving as useful therapeutic target.

Curcumin: a phytochemical modulator of estrogens and androgens in tumors of the reproductive system

Curcumin (Cur) is an active derivative extracted from turmeric which exerts a wide range of interactions with biomolecules through complex signaling pathways. Cur has been extensively shown to possess potential antitumor properties. In addition, there is growing body of evidence suggesting that Cur may exert potential anti-estrogen and anti-androgen activity. In vitro and in vivo studies suggest that anticancer properties of Cur against tumors affecting the reproductive system in females and males may be underlied by the Cur-mediated inhibition of androgen and estrogen signaling pathways. In this review we examine various studies assessing the crosstalk between Cur and both androgen and estrogen hormonal activity. Also, we discuss the potential chemopreventive and antitumor role of Cur in the most prevalent cancers affecting the reproductive system in females and males.

The Association of Modifiable Breast Cancer Risk Factors and Somatic Genomic Alterations in Breast Tumors: The Cancer Genome Atlas Network

BACKGROUND

The link between modifiable breast cancer risk factors and tumor genomic alterations remains largely unexplored. We evaluated the association of prediagnostic body mass index (BMI), cigarette smoking, and alcohol consumption with somatic copy number variation (SCNV), total somatic mutation burden (TSMB), seven single base substitution (SBS) signatures (SBS1, SBS2, SBS3, SBS5, SBS13, SBS29, and SBS30), and nine driver mutations (CDH1, GATA3, KMT2C, MAP2K4, MAP3K1, NCOR1, PIK3CA, RUNX1, and TP53) in a subset of The Cancer Genome Atlas (TCGA).

METHODS

Clinical and genomic data were retrieved from the TCGA database. Risk factor information was collected from four TCGA sites (n = 219 women), including BMI (1 year before diagnosis), cigarette smoking (smokers/nonsmokers), and alcohol consumption (current drinkers/nondrinkers). Multivariable regression analyses were conducted in all tumors and stratified according to estrogen receptor (ER) status.

RESULTS

Increasing BMI was associated with increasing SCNV in all women (P = 0.039) and among women with ER- tumors (P = 0.031). Smokers had higher SCNV and TSMB versus nonsmokers (P < 0.05 all women). Alcohol drinkers had higher SCNV versus nondrinkers (P < 0.05 all women and among women with ER+ tumors). SBS3 (defective homologous recombination-based repair) was exclusively found in alcohol drinkers with ER- disease. GATA3 mutation was more likely to occur in women with higher BMI. No association was significant after multiple testing correction.

CONCLUSIONS

This study provides preliminary evidence that BMI, cigarette smoking, and alcohol consumption can influence breast tumor biology, in particular, DNA alterations.

IMPACT

This study demonstrates a link between modifiable breast cancer risk factors and tumor genomic alterations.

Relationship of Serum Progesterone and Progesterone Metabolites with Mammographic Breast Density and Terminal Ductal Lobular Unit Involution among Women Undergoing Diagnostic Breast Biopsy

The association of progesterone/progesterone metabolites with elevated mammographic breast density (MBD) and delayed age-related terminal duct lobular unit (TDLU) involution, strong breast cancer risk factors, has received limited attention. Using a reliable liquid chromatography-tandem mass-spectrometry assay, we quantified serum progesterone/progesterone metabolites and explored cross-sectional relationships with MBD and TDLU involution among women, ages 40–65, undergoing diagnostic breast biopsy. Quantitative MBD measures were estimated in pre-biopsy digital mammograms. TDLU involution was quantified in diagnostic biopsies. Adjusted partial correlations and trends across MBD/TDLU categories were calculated. Pregnenolone was positively associated with percent MBD-area (MBD-A, rho: 0.30; p-trend = 0.01) among premenopausal luteal phase women. Progesterone tended to be positively associated with percent MBD-A among luteal phase (rho: 0.26; p-trend = 0.07) and postmenopausal (rho: 0.17; p-trend = 0.04) women. Consistent with experimental data, implicating an elevated 5α-pregnanes/3α-dihydroprogesterone (5αP/3αHP) metabolite ratio in breast cancer, higher 5αP/3αHP was associated with elevated percent MBD-A among luteal phase (rho: 0.29; p-trend = 0.08), but not postmenopausal women. This exploratory analysis provided some evidence that endogenous progesterone and progesterone metabolites might be correlated with MBD, a strong breast cancer risk factor, in both pre- and postmenopausal women undergoing breast biopsy. Additional studies are needed to understand the role of progesterone/progesterone metabolites in breast tissue composition and breast cancer risk.

Hepatic Estrogen Sulfotransferase Distantly Sensitizes Mice to Hemorrhagic Shock-Induced Acute Lung Injury

Hemorrhagic shock (HS) is a potential life-threatening condition that may lead to injury to multiple organs, including the lung. The estrogen sulfotransferase (EST, or SULT1E1) is a conjugating enzyme that sulfonates and deactivates estrogens. In this report, we showed that the expression of Est was markedly induced in the liver but not in the lung of female mice subject to HS and resuscitation. Genetic ablation or pharmacological inhibition of Est effectively protected female mice from HS-induced acute lung injury (ALI), including interstitial edema, neutrophil mobilization and infiltration, and inflammation. The pulmonoprotective effect of Est ablation or inhibition was sex-specific, because the HS-induced ALI was not affected in male Est-/- mice. Mechanistically, the pulmonoprotective phenotype in female Est-/- mice was accompanied by increased lung and circulating levels of estrogens, attenuated pulmonary inflammation, and inhibition of neutrophil mobilization from the bone marrow and neutrophil infiltration to the lung, whereas the pulmonoprotective effect was abolished upon ovariectomy, suggesting that the protection was estrogen dependent. The pulmonoprotective effect of Est ablation was also tissue specific, as loss of Est had little effect on HS-induced liver injury. Moreover, transgenic reconstitution of human EST in the liver of global Est-/- mice abolished the pulmonoprotective effect, suggesting that it is the EST in the liver that sensitizes mice to HS-induced ALI. Taken together, our results revealed a sex- and tissue-specific role of EST in HS-induced ALI. Pharmacological inhibition of EST may represent an effective approach to manage HS-induced ALI.

Estrogen signaling and estrogen receptors as prognostic indicators in laryngeal cancer

Laryngeal squamous cell carcinoma (LSCC) has been shown to respond to 17β-estradiol. However, the presence and characterization of estrogen receptors (ER) and other sex hormone receptors in LSCC are still being determined. Sex hormone receptors and the way sex hormones impact LSCC tumors are important for understanding which patients would benefit from hormone therapies, such as anti-estrogen therapies. This information also has prognostic value, as there may be a correlation between ER profiles and LSCC aggression. Recent work by our team and others has shown that the canonical ER, estrogen receptor α (ERα), and its splice variant ERα36, are important modulators of estrogen signaling in LSCC. This review describes some common 17β-estradiol signaling pathways, and explains how these signaling pathways might control LSCC tumor growth. We also show that loss of ERα, but not ERα36, imbues LSCC with enhanced aggression, a pattern which has previously only been observed in breast cancer. We make a case for using ERα as a tumorigenic modulator and pathogenic marker in LSCC on par with the use of ERα as a prognostic marker in breast cancer.

Dissimilar associations of same metabolic parameters with main chronic noncommunicable diseases (cancer vs some other NCDs)

Hormone-dependent tissues' cancers (mainly breast and endometrial and several others) are among the most frequent malignancies in adults and are often discussed in context of their correlation with other chronic noncommunicable diseases (NCDs), for example, cardiovascular and cerebrovascular conditions, and their risk factors, which may also be hormone metabolic. An idea that is often expressed delineates common factors leading to NCDs of malignant and nonmalignant nature. However, this idea is not always confirmed by study results. The reasons for this discrepancy are not clear and require further analysis. This editorial tries to show the importance of this problem with a few examples (in particular, by attracting information on the role of birthweight, adult height and family history of diabetes) which may help us understand some mechanisms behind interconnections of major NCDs, including cancer.

Molecular Links between Central Obesity and Breast Cancer

Worldwide, breast cancer (BC) is the most common malignancy in women, in regard to incidence and mortality. In recent years, the negative role of obesity during BC development and progression has been made abundantly clear in several studies. However, the distribution of body fat may be more important to analyze than the overall body weight. In our review of literature, we reported some key findings regarding the role of obesity in BC development, but focused more on central adiposity. Firstly, the adipose microenvironment in obese people bears many similarities with the tumor microenvironment, in respect to associated cellular composition, chronic low-grade inflammation, and high ratio of reactive oxygen species to antioxidants. Secondly, the adipose tissue functions as an endocrine organ, which in obese people produces a high level of tumor-promoting hormones, such as leptin and estrogen, and a low level of the tumor suppressor hormone, adiponectin. As follows, in BC this leads to the activation of oncogenic signaling pathways: NFκB, JAK, STAT3, AKT. Moreover, overall obesity, but especially central obesity, promotes a systemic and local low grade chronic inflammation that further stimulates the increase of tumor-promoting oxidative stress. Lastly, there is a constant exchange of information between BC cells and adipocytes, mediated especially by extracellular vesicles, and which changes the transcription profile of both cell types to an oncogenic one with the help of regulatory non-coding RNAs.

The estrogen effect; clinical and histopathological evidence of dichotomous influences in dogs with spontaneous mammary carcinomas

The purpose of this study was to investigate the associations and explore the relationships between hormonal factors (serum estrogen, estrogen receptors and ovariohysterectomy) and other clinical/histological prognostic factors and their impact on outcome in dogs with mammary carcinomas. Data from two separate prospective studies on dogs with spontaneous mammary carcinomas were used for this research. All dogs underwent standardized diagnostic testing, staging, surgery and follow-up examinations. Serum estrogen was analyzed by competitive enzyme immunoassay or radioimmunoassay, and tumor estrogen receptor (ER) expression was analyzed by immunohistochemistry. A total of 159 dogs were included; 130 were spayed and 29 remained. High serum estrogen was associated with an overall longer time to metastasis (p = 0.021). When stratifying based on spay group, the effect was only significant in spayed dogs, (p = 0.019). Positive tumor ER expression was also associated with a longer time to metastasis (p = 0.025), but similar to above, only in dogs that were spayed (p = 0.049). Further subgroup analysis revealed that high serum estrogen was significantly associated with improved survival in dogs with ER positive tumors, but only in spayed dogs (p = 0.0052). Interestingly, the effect of spaying was the opposite in dogs with ER negative tumors; here, intact dogs with high serum estrogen but ER negative tumors had a significantly longer time to metastasis (p = 0.036). Low serum estrogen was associated with increased risk for the development of non-mammary tumors in the post-operative period (p = 0.012). These results highlight the dual effect of estrogen in cancer: Estrogen acts as a pro-carcinogen in ER positive mammary tumors, but a may have a protective effect in ER negative tumors, potentially via non-receptor mechanisms. The latter is supported by the decreased risk for non-mammary tumors in dogs with high serum estrogen, and explains the increased incidence of certain non-mammary tumors in in dogs spayed at an early age.