Crosstalk of TGF-β and estrogen receptor signaling in breast cancer

Unveiling epigenetic regulatory elements associated with breast cancer development

Breast cancer is the most common cancer in women and the 2nd most common cancer worldwide, yearly impacting over 2 million females and causing 650 thousand deaths. It has been widely studied, but its epigenetic variation is not entirely unveiled. We aimed to identify epigenetic mechanisms impacting the expression of breast cancer related genes to detect new potential biomarkers and therapeutic targets. We considered The Cancer Genome Atlas database with over 800 samples and several omics datasets such as mRNA, miRNA, DNA methylation, which we used to select 2701 features that were statistically significant to differ between cancer and control samples using the Monte Carlo Feature Selection and Interdependency Discovery algorithm, from an initial total of 417,486. Their biological impact on cancerogenesis was confirmed using: statistical analysis, natural language processing, linear and machine learning models as well as: transcription factors identification, drugs and 3D chromatin structure analyses. Classification of cancer vs control samples on the selected features returned high classification weighted Accuracy from 0.91 to 0.98 depending on feature-type: mRNA, miRNA, DNA methylation, and classification algorithm. In general, cancer samples showed lower expression of differentially expressed genes and increased β-values of differentially methylated sites. We identified mRNAs whose expression is well explained by miRNA expression and differentially methylated sites β-values. We recognized differentially methylated sites possibly affecting NRF1 and MXI1 transcription factors binding, causing a disturbance in NKAPL and PITX1 expression, respectively. Our 3D models showed more loosely packed chromatin in cancer. This study successfully points out numerous possible regulatory dependencies.

Non-coding RNAs and estrogen receptor signaling in breast cancer: Nanotechnology-based therapeutic approaches

This review investigates the regulatory role of non-coding RNAs (ncRNAs) in estrogen receptor (ER) signaling pathways, particularly in the context of breast cancer therapy, with an emphasis on the emerging potential of nanotechnology for drug delivery. The information was obtained from reputable databases, including PubMed, Elsevier, Springer, Wiley, Taylor, and Francis, which contain past and present research. Breast cancer remains the most prevalent cancer among women worldwide, and ER signaling mechanisms heavily influence its progression. Treatment options have traditionally encompassed surgery, chemotherapy, radiation therapy, targeted therapy, and hormone therapy. In recent decades, nanomedicine has emerged as a promising approach to breast cancer treatment. By passively targeting tumor cells and reducing toxicity, nanodrugs can overcome the challenges of conventional chemotherapy. Additionally, nanocarriers can stimulate tumor cells, enhancing treatment efficacy. Recent advancements in nanomedicine offer promising approaches for targeted cancer therapy, potentially overcoming the limitations of conventional treatments. This review explores the interactions between long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) with ER pathways, their impact on breast cancer progression, and how these interactions can be leveraged to enhance therapeutic efficacy through nanotechnology-based drug delivery systems.

Transcriptional responses to direct and indirect TGFB1 stimulation in cancerous and noncancerous mammary epithelial cells

BACKGROUND

Transforming growth factor beta (TGFβ) is important for the morphogenesis and secretory function of the mammary gland. It is one of the main activators of the epithelial-mesenchymal transition (EMT), a process important for tissue remodeling and regeneration. It also provides cells with the plasticity to form metastases during tumor progression. Noncancerous and cancer cells respond differently to TGFβ. However, knowledge of the cellular signaling cascades triggered by TGFβ in various cell types is still limited.

METHODS

MCF10A (noncancerous, originating from fibrotic breast tissue) and MCF7 (cancer, estrogen receptor-positive) breast epithelial cells were treated with TGFB1 directly or through conditioned media from stimulated cells. Transcriptional changes (via RNA-seq) were assessed in untreated cells and after 1-6 days of treatment. Differentially expressed genes were detected with DESeq2 and the hallmark collection was selected for gene set enrichment analysis.

RESULTS

TGFB1 induces EMT in both the MCF10A and MCF7 cell lines but via slightly different mechanisms (signaling through SMAD3 is more active in MCF7 cells). Many EMT-related genes are expressed in MCF10A cells at baseline. Both cell lines respond to TGFB1 by decreasing the expression of genes involved in cell proliferation: through the repression of MYC (and the protein targets) in MCF10A cells and the activation of p63-dependent signaling in MCF7 cells (CDKN1A and CDKN2B, which are responsible for the inhibition of cyclin-dependent kinases, are upregulated). In addition, estrogen receptor signaling is inhibited and caspase-dependent cell death is induced only in MCF7 cells. Direct incubation with TGFB1 and treatment of cells with conditioned media similarly affected transcriptional profiles. However, TGFB1-induced protein secretion is more pronounced in MCF10A cells; therefore, the signaling is propagated through conditioned media (bystander effect) more effectively in MCF10A cells than in MCF7 cells.

CONCLUSIONS

Estrogen receptor-positive breast cancer patients may benefit from high levels of TGFB1 expression due to the repression of estrogen receptor signaling, inhibition of proliferation, and induction of apoptosis in cancer cells. However, some TGFB1-stimulated cells may undergo EMT, which increases the risk of metastasis.

Glucocorticoid receptor: a harmonizer of cellular plasticity in breast cancer-directs the road towards therapy resistance, metastatic progression and recurrence

Recent therapeutic advances have significantly uplifted the quality of life in breast cancer patients, yet several impediments block the road to disease-free survival. This involves unresponsiveness towards administered therapy, epithelial to mesenchymal transition, and metastatic progression with the eventual appearance of recurrent disease. Attainment of such characteristics is a huge adaptive challenge to which tumour cells respond by acquiring diverse phenotypically plastic states. Several signalling networks and mediators are involved in such a process. Glucocorticoid receptor being a mediator of stress response imparts prognostic significance in the context of breast carcinoma. Involvement of the glucocorticoid receptor in the signalling cascade of breast cancer phenotypic plasticity needs further elucidation. This review attempted to shed light on the inter-regulatory interactions of the glucocorticoid receptor with the mediators of the plasticity program in breast cancer; which may provide a hint for strategizing therapeutics against the glucocorticoid/glucocorticoid receptor axis so as to modulate phenotypic plasticity in breast carcinoma.

Paper-Based Coculture Platform to Evaluate the Effects of Fibroblasts on Estrogen Signaling in ER+ Breast Cancers

Cell-based assays enable molecular-level studies of cellular responses to drug candidates or potential toxins. Transactivation assays quantify the activation or inhibition of nuclear receptors, key transcriptional regulators of gene targets in mamalian cells. One such assay couples the expression of luciferase to the transcriptional activity of estrogen receptor-alpha (ERα). While this assay is regularly used to screen for agonists and antagonists of the estrogen signaling pathway, the setup relies on monolayer cultures in which cells are plated directly onto the surface of cell-compatible plasticware. The tumor microenvironment is more than a collection of cancerous cells and is profoundly influenced by tissue architecture, the presence of extracellular matrices, and intercellular signaling molecules produced by non-cancerous neighboring cells (e.g., fibroblasts). There exists a need for three-dimensional culture platforms that can be rapidly prototyped to assess new configurations and readily produced in the large numbers needed for translational studies and screening applications. Here, we demonstrate the utility of the paper-based culture platform to probe the effects of intercellular signaling between two cell types. We used paper scaffolds to generate tumor-like environments, forming a defined volume of breast cancer cells suspended in collagen. By placing the paper scaffolds in commercial 96-well plates, we compared monocultures of only breast cancer cells with coculture configurations containing fibroblasts in different locations that mimicked the stages of breast cancer progression. We show that ERα transactivation in the T47D-KBluc cell line is affected by the presence, number, and proximity of fibroblasts, and is a consequence of intercellular signaling molecules. After screening a small library of fibroblast-secreted signaling molecules, we showed that interleukin-6 (IL-6) was the primary driver of reduced estradiol sensitivity. These effects were mitigated in the coculture configurations by the addition of an IL-6 neutralizing antibody. We also assessed estrogen receptor expression and transcriptional regulation, further demonstrating the utility of the paper-based platform for detailed mechanistic studies.

Generational effects and abnormalities in craniofacial chondrogenesis in zebrafish (Danio rerio) embryos upon maternal exposure to estrogen endocrine disrupting chemicals

Bisphenol A (BPA) and diethyl phthalate (DEP) are estrogenic endocrine disrupting chemicals (EEDCs). The present study reconfirmed that the angle of the ceratohyal cartilage (CH) in embryos were larger from maternal BPA and E2, but smaller from DEP compared to the control. However, it is still unknown whether both the BPA and DEP chemicals disrupted the action of E2 and thereby influence the estrogen signaling pathways. Additionally, it remains unclear whether they also disrupted certain related genes in the migratory pathways of neural crest cells (NCCs) in their offspring. The present data showed that nuclear estrogen receptors and membrane estrogen receptors have different disrupted profiles among female zebrafish exposed to BPA (F-BPA), and DEP (F-DEP), and external E2 (F-E2). However, certain related genes in the migratory pathways of NCCs in embryos from F-BPA and F-E2 such as the sox10, chm1, and tgfbr1a mRNA expressions showed a positive relationship compared with CH angles; the gene expressions of sox9a, smad3, and col2a1a and the CH angles of embryos exhibited an opposite relationship upon F-DEP treatments. Thus, we suggested that the genes involved in NCCs migration were potentially induced by the residual maternal DEP contents. Two sets of genes, chm1/tgfb3 and chm1/gper1, exhibited an identical profile in the ovary and its offspring at 2 h of post fertilization upon F-E2 and F-BPA treatments, respectively. We suggested that the maternal mRNA from female to embryos were transferred before the maternal-to-zygotic transition stage.

Sex-biased TGFβ signalling in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare cardiovascular disorder leading to pulmonary hypertension and, often fatal, right heart failure. Sex differences in PAH are evident, which primarily presents with a female predominance and increased male severity. Disturbed signalling of the transforming growth factor-β (TGFβ) family and gene mutations in the bone morphogenetic protein receptor 2 (BMPR2) are risk factors for PAH development, but how sex-specific cues affect the TGFβ family signalling in PAH remains poorly understood. In this review, we aim to explore the sex bias in PAH by examining sex differences in the TGFβ signalling family through mechanistical and translational evidence. Sex hormones including oestrogens, progestogens, and androgens, can determine the expression of receptors (including BMPR2), ligands, and soluble antagonists within the TGFβ family in a tissue-specific manner. Furthermore, sex-related genetic processes, i.e. Y-chromosome expression and X-chromosome inactivation, can influence the TGFβ signalling family at multiple levels. Given the clinical and mechanistical similarities, we expect that the conclusions arising from this review may apply also to hereditary haemorrhagic telangiectasia (HHT), a rare vascular disorder affecting the TGFβ signalling family pathway. In summary, we anticipate that investigating the TGFβ signalling family in a sex-specific manner will contribute to further understand the underlying processes leading to PAH and likely HHT.

Role of long non-coding RNAs and TGF-β signaling in the regulation of breast cancer pathogenesis and therapeutic targets

The cytokine known as transforming growth factor (TGF) is essential for cell development, differentiation, and apoptosis in BC. TGF-β dysregulation can either promote or inhibit tumor development, and it is a key signaling pathway in BC spread. A recently identified family of ncRNAs known as lncRNAs has received a great deal of effort and is an important regulator of many cellular processes, including transcription of genes, chromatin remodeling, progression of the cell cycle, and posttranscriptional processing. Furthermore, both TGF-β signaling and lncRNAs serve as important early-stage biomarkers for BC diagnosis and prognosis and also play a significant role in BC drug resistance. According to recent studies, lncRNAs can regulate TGF-β by modulating its cofactors in BC. However, the particular functions of lncRNAs and the TGF-β pathway in controlling BC progression are not well understood yet. This review explores the lncRNAs' functional properties in BC as tumor suppressors or oncogenes in the regulation of genes, with a focus on dysregulated TGF-β signaling. Further, we emphasize the functional roles of lncRNAs and TGF-β pathway in the progression of BC to discover new treatment strategies and better comprehend the fundamental cellular pathways.

WFDC3 inhibits tumor metastasis by promoting the ERβ-mediated transcriptional repression of TGFBR1 in colorectal cancer

Estrogen plays a protective role in colorectal cancer (CRC) and primarily functions through estrogen receptor β (ERβ). However, clinical strategies for CRC therapy associated with ERβ are still under investigation. Our discoveries identified WFDC3 as a tumor suppressor that facilitates estrogen-induced inhibition of metastasis through the ERβ/TGFBR1 signaling axis. WFDC3 interacts with ERβ and increases its protein stability by inhibiting its proteasome-dependent degradation. WFDC3 represses TGFBR1 expression through ERβ-mediated transcription. Blocking TGFβ signaling with galunisertib, a drug used in clinical trials that targets TGFBR1, impaired the migration of CRC cells induced by WFDC3 depletion. Moreover, there was clinical significance to WFDC3 in CRC, as CRC patients with high WFDC3 expression in tumor cells had favorable prognoses. Therefore, this work suggests that WFDC3 could be an indicator for therapies targeting the estrogen/ERβ pathway in CRC patients.

Polyploid giant cancer cells, cytokines and cytomegalovirus in breast cancer progression

BACKGROUND

Breast cancer is the most common cancer among women. Accumulated evidence over the past decades indicates a very high prevalence of human cytomegalovirus (HCMV) in breast cancer. High-risk HCMV strains possess a direct oncogenic effect displayed by cellular stress, polyploid giant cancer cells (PGCCs) generation, stemness, and epithelial-to-mesenchymal transition (EMT) leading to cancer of aggressive phenotype. Breast cancer development and progression have been regulated by several cytokines where the latter can promote cancer cell survival, help in tumor immune evasion, and initiate the EMT process, thereby resulting in invasion, angiogenesis, and breast cancer metastasis. In the present study, we screened cytokines expression in cytomegalovirus-transformed HMECs (CTH cells) cultures infected with HCMV high-risk strains namely, HCMV-DB and BL, as well as breast cancer biopsies, and analyzed the association between cytokines production, PGCCs count, and HCMV presence in vitro and in vivo.

METHODS

In CTH cultures and breast cancer biopsies, HCMV load was quantified by real-time qPCR. PGCCs count in CTH cultures and breast cancer biopsies was identified based on cell morphology and hematoxylin and eosin staining, respectively. CTH supernatants were evaluated for the production of TGF-β, IL-6, IL1-β, and IL-10 by ELISA assays. The above-mentioned cytokines expression was assessed in breast cancer biopsies using reverse transcription-qPCR. The correlation analyses were performed using Pearson correlation test.

RESULTS

The revealed PGCCs/cytokine profile in our in vitro CTH model matched that of the breast cancer biopsies, in vivo. Pronounced cytokine expression and PGCCs count were detected in particularly CTH-DB cultures and basal-like breast cancer biopsies.

CONCLUSIONS

The analysis of cytokine profiles in PGCCs present mostly in basal-like breast cancer biopsies and derived from CTH cells chronically infected with the high-risk HCMV strains might have the potential to provide novel therapies such as cytokine-based immunotherapy which is a promising field in cancer treatments.

Effect of Poly(methacrylic acid) on the Cytokine Level in an In Vivo Tumor Model

Cancer is a leading cause of mortality globally. Despite remarkable improvements in cancer-treatment approaches, disease recurrence and progression remain major obstacles to therapy. While chemotherapy is still a first-line treatment for a variety of cancers, the focus has shifted to the development and application of new approaches to therapy. Nevertheless, the relationship between immune response, neoplastic diseases and treatment efficiency is not fully understood. Therefore, the aim of the study was to investigate the immunopharmacological effects of methacrylic acid homopolymer in an in vivo tumor model. Materials and methods: Monomeric methacrylic acid was used to synthesize polymers. Methacrylic acid was polymerized in dioxane in the presence of 4-Cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid. To study the molecular weight characteristics of PMAA by GPC, carboxyl groups were preliminarily methylated with diazomethane. An experimental cancer model was obtained by grafting RMK1 breast cancer cells. The serum levels of IL-6, IL-10, IL-17, transforming growth factor β1 (TGF-β1), and tumor necrosis factor α (TNF-α) were measured by ELISA. Results: The effect of PMAA on the serum concentrations of several cytokines was studied upon its single administration to laboratory animals in early neoplastic process. The IL-6, IL-17 and TGF-β1 concentrations were found to change significantly and reach the level observed in intact rats. The IL-10 concentration tended to normalize. Conclusion: The positive results obtained are the basis for further studies on the effect of methacrylic-acid polymers with different molecular-weight characteristics on the neoplastic process.

ENDORSE: a prognostic model for endocrine therapy in estrogen-receptor-positive breast cancers

Advanced and metastatic estrogen receptor-positive (ER+ ) breast cancers are often endocrine resistant. However, endocrine therapy remains the primary treatment for all advanced ER+ breast cancers. Treatment options that may benefit resistant cancers, such as add-on drugs that target resistance pathways or switching to chemotherapy, are only available after progression on endocrine therapy. Here we developed an endocrine therapy prognostic model for early and advanced ER+ breast cancers. The endocrine resistance (ENDORSE) model is composed of two components, each based on the empirical cumulative distribution function of ranked expression of gene signatures. These signatures include a feature set associated with long-term survival outcomes on endocrine therapy selected using lasso-regularized Cox regression and a pathway-based curated set of genes expressed in response to estrogen. We extensively validated ENDORSE in multiple ER+ clinical trial datasets and demonstrated superior and consistent performance of the model over clinical covariates, proliferation markers, and multiple published signatures. Finally, genomic and pathway analyses in patient data revealed possible mechanisms that may help develop rational stratification strategies for endocrine-resistant ER+ breast cancer patients.

Estradiol Ameliorates Acute Kidney Ischemia-Reperfusion Injury by Inhibiting the TGF-βRI-SMAD Pathway

Renal ischemia–reperfusion injury (IRI) is less extensive in females than males in both animals and humans; however, this protection diminishes after menopause, suggesting that estrogen plays a pivotal role in IRI, but the underlying mechanism remains largely unknown. Our study found that 45 min of warm ischemia was sufficient to induce significant pathological changes without causing death in model animals. Compared with male rats, female rats exhibited less extensive apoptosis, kidney injury, and fibrosis; these effects were worsened in ovariectomized (OVX) rats and ameliorated upon estradiol (E₂) supplementation. Furthermore, the levels of TGF-βRI, but not TGF-βRII or TGF-β1, were significantly increased in OVX rats, accompanied by phosphorylated SMAD2/3 activation. Interestingly, the alteration trend of the nuclear ERα level was opposite that of TGF-βRI. Furthermore, dual luciferase reporter and chromatin immunoprecipitation assays showed that ERα could bind to the promoter region of TGF-βRI and negatively regulate its mRNA expression. Moreover, an in vitro study using NRK-52E cells showed that ERα knockdown blocked E₂-mediated protection, while TGF-βRI knockdown protected cells against hypoxic insult. The findings of this study suggest that renal IRI is closely related to the TGF-βRI-SMAD pathway in females and that E₂ exert its protective effect via the ERα-mediated transcriptional inhibition of TGF-βRI expression.

Selective estrogen receptor modulators contribute to prostate cancer treatment by regulating the tumor immune microenvironment

Prostate cancer (PC) has previously been established as a cold tumor and develops in an inert immunosuppressive environment. Current research focuses on altering the immune microenvironment of PC from cold to hot; thus, in the present review, the diverse roles of estrogen and estrogen receptor (ER) signaling was examined in the tumor cell and tumor immune microenvironment (TIM). We hypothesized that ERα promotes PC progression and ERβ impedes epithelial-mesenchymal transition in PC cells, while in the TIM, ERβ mediates the immunosuppressive environment, and low levels of ERα is associated with disease development. Selective estrogen receptor modulators (SERMs) or selective ER degraders play diverse roles in the regulation of ER isoforms. Patients with PC may benefit from the use of SERMs, including raloxifene, in combination with anti-PD1/PD-L1 checkpoint immunotherapy, or TGF-β or Wnt antagonists. The present review demonstrated that immunotherapy-based strategies combined with SERMs may be an option for the future of PC-targeting therapy.

Molecular and cellular mechanisms of melatonin in breast cancer

Breast cancer is considered as one of the most important health problems due to its poor prognosis and high rate of mortality and new diagnosed cases. Annually, a great number of deaths are reported in men and women; this means that despite all the improvements in cancer diagnosis and treatment, still, an intense need for more effective approaches exists. Melatonin is a multivalent compound which has a hand in several cellular and molecular processes and therefore, is an appropriate candidate for treatment of many diseases like cancer. Currently, considerable properties of this agent have oriented the research towards investigating its effects specifically in breast cancer. In this review, we gathered a bunch of evidence in order to give a new sight for breast cancer treatment utilizing melatonin. We expect that in coming years, melatonin will become one of the most common therapeutic drugs with lesser side-effects than other chemotherapeutic drugs.

Therapeutic Potential of Thymoquinone in Triple-Negative Breast Cancer Prevention and Progression through the Modulation of the Tumor Microenvironment

To date, the tumor microenvironment (TME) has gained considerable attention in various areas of cancer research due to its role in driving a loss of immune surveillance and enabling rapid advanced tumor development and progression. The TME plays an integral role in driving advanced aggressive breast cancers, including triple-negative breast cancer (TNBC), a pivotal mediator for tumor cells to communicate with the surrounding cells via lymphatic and circulatory systems. Furthermore, the TME plays a significant role in all steps and stages of carcinogenesis by promoting and stimulating uncontrolled cell proliferation and protecting tumor cells from the immune system. Various cellular components of the TME work together to drive cancer processes, some of which include tumor-associated adipocytes, fibroblasts, macrophages, and neutrophils which sustain perpetual amplification and release of pro-inflammatory molecules such as cytokines. Thymoquinone (TQ), a natural chemical component from black cumin seed, is widely used traditionally and now in clinical trials for the treatment/prevention of multiple types of cancer, showing a potential to mitigate components of TME at various stages by various pathways. In this review, we focus on the role of TME in TNBC cancer progression and the effect of TQ on the TME, emphasizing their anticipated role in the prevention and treatment of TNBC. It was concluded from this review that the multiple components of the TME serve as a critical part of TNBC tumor promotion and stimulation of uncontrolled cell proliferation. Meanwhile, TQ could be a crucial compound in the prevention and progression of TNBC therapy through the modulation of the TME.

Role of TGF-β signaling in the mechanisms of tamoxifen resistance

The transforming growth factor beta (TGF-β) signaling pathway plays complex role in the regulation of cell proliferation, apoptosis and differentiation in breast cancer. TGF-β activation can lead to multiple cellular responses mediating the drug resistance evolution, including the resistance to antiestrogens. Tamoxifen is the most commonly prescribed antiestrogen that functionally involved in regulation of TGF-β activity. In this review, we focus on the role of TGF-β signaling in the mechanisms of tamoxifen resistance, including its interaction with estrogen receptors alfa (ERα) pathway and breast cancer stem cells (BCSCs). We summarize the current reported data regarding TGF-β signaling components as markers of tamoxifen resistance and review current approaches to overcoming tamoxifen resistance based on studies of TGF-β signaling.

TGFβ1 pathway components in breast cancer tissue from aggressive subtypes correlate with better prognostic parameters in ER-positive and p53-negative cancers

Background

TGFβ signaling exerts context-specific effects in breast cancer (BC) pathogenesis and single nucleotide polymorphisms (SNPs) in TGFβ-signaling components play a role in the genetic control of their expression and in BC susceptibility and clinical presentation. However, studies investigating the association between the TGFβ-signaling molecules and BC prognosis rarely considered disease subtypes and SNPs. Therefore, the present study aimed to evaluate the expression of TGFβ-signaling components in BC tissue from patients with available data regarding TGFB1 and TGFBR2 SNPs and plasmatic TGFβ1 levels.

Methods

Immunostaining for TGFβ1, TGFβRII and phosphorylated (p)-SMAD2/3 was investigated in primary tumor tissue from 34 patients with luminal-B-HER2+ (LB-HER2), HER2-enriched (HER2) and triple negative (TN) BC subtypes genotyped for TGFB1 (rs1800468, rs1800469, rs1800470 and rs1800471) and TGFBR2 (rs3087465) SNPs.

Results

Strong positive correlations were observed between TGFβ1, TGFβRII and p-SMAD2/3 in tumor tissue, and an inverse correlation was observed between intratumor and plasmatic TGFβ1 levels in TN BCs. In LB-HER2+ tumors, p-SMAD2/3 was associated with older age at diagnosis and inversely correlated with p53 staining and lymph-node metastasis, while tumor-size negatively correlated with TGFβ1 and TGFβRII in this BC subgroup. Also, in p53-negative BCs, tumor size and Ki67 negatively correlated with both TGFβ1, TGFβRII and p-SMAD2/3. No correlation was found between SNPs and TGFβ1-signaling components expression.

Conclusion

TGFβ1 canonical signaling is activated in approximately half of BCs, and correlation between TGFβ components indicate a paracrine activation, which may exert tumor suppressor effects in p53-negative or Luminal-B-HER2+ subgroups.

Molecular mechanisms of mammary gland remodeling: A review of the homeostatic versus bisphenol a disrupted microenvironment

Mammary gland (MG) undergoes critical points of structural changes throughout a woman's life. During the perinatal and pubertal stages, MG develops through growth and differentiation to establish a pre-mature feature. If pregnancy and lactation occur, the epithelial compartment branches and differentiates to create a specialized structure for milk secretion and nurturing of the newborn. However, the ultimate MG modification consists of a regression process aiming to reestablish the smaller and less energy demanding structure until another production cycle happens. The unraveling of these fascinating physiologic cycles has helped the scientific community elucidate aspects of molecular regulation of proliferative and apoptotic events and remodeling of the stromal compartment. However, greater understanding of the hormonal pathways involved in MG developmental stages led to concern that endocrine disruptors such as bisphenol A (BPA), may influence these specific development/involution stages, called "windows of susceptibility". Since it is used in the manufacture of polycarbonate plastics and epoxy resins, BPA is a ubiquitous chemical present in human everyday life, exerting an estrogenic effect. Thus, descriptions of its deleterious effects on the MG, especially in terms of serum hormone concentrations, hormonal receptor expression, molecular pathways, and epigenetic alterations, have been widely published. Therefore, allied to a didactic description of the main physiological mechanisms involved in different critical points of MG development, the current review provides a summary of key mechanisms by which the endocrine disruptor BPA impacts MG homeostasis at different windows of susceptibility, causing short- and long-term effects.

RUNX1T1, a potential prognostic marker in breast cancer, is co-ordinately expressed with ERα, and regulated by estrogen receptor signalling in breast cancer cells

BACKGROUND

RUNX1T1 is extensively studied in the context of AML1-RUNX1T1 fusion protein in acute myeloid leukemia. Little is known about the function of RUNX1T1 itself, although data on its function and regulation have begun to emerge from clinical, and in vitro studies. It is a putative tumor suppressor, whose expression is altered in a variety of solid tumors. Recently, reduced expression of RUNX1T1 in triple-negative breast tumors, and its influence on prognosis was reported.

METHODS AND RESULTS

The Kaplan-Meier Plotter online tool was used to study the relationship between RUNX1T1 expression and survival of breast cancer patients. High RUNX1T1 expression was associated with longer overall survival (OS), relapse-free survival (RFS) and distant metastasis free survival (DMFS). RUNX1T1 expression positively and negatively influenced OS of patients with ERα-positive and ERα-negative breast tumors, respectively. It was also associated with prolonged RFS, and DMFS in tamoxifen-treated patients. Expression of RUNX1T1 and ERα mRNA was analyzed in 40 breast tumor samples, and breast cancer cell lines using RT-PCR. TCGA-BRCA data was mined to study the relationship between RUNX1T1 and ERα mRNA expression. ERα-positive breast tumors showed significantly higher RUNX1T1 mRNA expression compared to ERα-negative tumors. RUNX1T1 mRNA expression was analyzed by qRT-PCR in MCF-7 or T47D cells, which were treated with 17β-estradiol, or the ERα agonist PPT, alone or in combination with 4-hydroxytamoxifen. Effect of ERα knockdown was also investigated. Results indicate that estrogen downmodulated RUNX1T1 mRNA expression via ERα.

CONCLUSION

Higher expression of RUNX1T1 in breast tumors is associated with favourable prognosis. RUNX1T1 and ERα show co-ordinated expression in breast tumors, and breast cancer cell lines. Estrogen-ERα signalling downmodulates the expression of RUNX1T1 mRNA in ERα-positive breast cancer cells. In-depth investigations on the interaction between RUNX1T1 and ERα are warranted to unravel the role and relevance of RUNX1T1 in breast cancer.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Crosstalk between 17β-Estradiol and TGF-β Signaling Modulates Glioblastoma Progression

Epithelial–mesenchymal transition (EMT) is an essential mechanism contributing to glioblastoma multiforme (GBM) progression, the most common and malignant brain tumor. EMT is induced by signaling pathways that crosstalk and regulate an intricate regulatory network of transcription factors. It has been shown that downstream components of 17β-estradiol (E2) and transforming growth factor β (TGF-β) signaling pathways crosstalk in estrogen-sensitive tumors. However, little is known about the interaction between the E2 and TGF-β signaling components in brain tumors. We have investigated the relationship between E2 and TGF-β signaling pathways and their effects on EMT induction in human GBM-derived cells. Here, we showed that E2 and TGF-β negatively regulated the expression of estrogen receptor α (ER-α) and Smad2/3. TGF-β induced Smad2 phosphorylation and its subsequent nuclear translocation, which E2 inhibited. Both TGF-β and E2 induced cellular processes related to EMT, such as morphological changes, actin filament reorganization, and mesenchymal markers (N-cadherin and vimentin) expression. Interestingly, we found that the co-treatment of E2 and TGF-β blocked EMT activation. Our results suggest that E2 and TGF-β signaling pathways interact through ER-α and Smad2/3 mediators in cells derived from human GBM and inhibit EMT activation induced by both factors alone.

Pubertal mammary gland development is a key determinant of adult mammographic density

Mammographic density refers to the radiological appearance of fibroglandular and adipose tissue on a mammogram of the breast. Women with relatively high mammographic density for their age and body mass index are at significantly higher risk for breast cancer. The association between mammographic density and breast cancer risk is well-established, however the molecular and cellular events that lead to the development of high mammographic density are yet to be elucidated. Puberty is a critical time for breast development, where endocrine and paracrine signalling drive development of the mammary gland epithelium, stroma, and adipose tissue. As the relative abundance of these cell types determines the radiological appearance of the adult breast, puberty should be considered as a key developmental stage in the establishment of mammographic density. Epidemiological studies have pointed to the significance of pubertal adipose tissue deposition, as well as timing of menarche and thelarche, on adult mammographic density and breast cancer risk. Activation of hypothalamic-pituitary axes during puberty combined with genetic and epigenetic molecular determinants, together with stromal fibroblasts, extracellular matrix, and immune signalling factors in the mammary gland, act in concert to drive breast development and the relative abundance of different cell types in the adult breast. Here, we discuss the key cellular and molecular mechanisms through which pubertal mammary gland development may affect adult mammographic density and cancer risk.

Exploring the extensive crosstalk between the antagonistic cytokines- TGF-β and TNF-α in regulating cancer pathogenesis

A plethora of cytokines are produced in the tumor microenvironment (TME) those play a vital role in cancer prognosis. Though it is completely contextual, cytokines produced from an inflammatory micro-environment can either modulate cancer progression at early stages of tumor development or in later stages cytokine derived cues can in turn control tumor cell invasion and metastasis. Therefore, understanding the crosstalk between the key cytokines regulating cancer prognosis is critical for the development of an effective therapy. In this regard, the role of transforming growth factor-beta (TGF-β) in cancer is controversially discussed in general inhibition of TGF-β promotes de novo tumorigenesis whereas paradoxically, TGF-β can promote malignancy in already established tumors. Another important cytokine, TNF-α have intense crosstalk with TGF-β from the fact that in a non-cancer context, TGF-β promotes fibrosis whereas TNF-α has anti-fibrotic activity. We have recently reported that TGF-β-induced differentiation of epithelial cells to mesenchymal type is suppressed by TNF-α through regulation of cellular homeostatic machinery- autophagy. Moreover, there are also rare reports of synergy between these two cytokines as well. The crosstalk between TGF-β and TNF-α is not only limited to regulating cancer cell differentiation and proliferation but also includes involvement in cell death. In this review, we hence summarize the molecular mechanisms by which these two important cytokines, TGF-β and TNF-α control cancer prognosis.

Infant Formula Feeding Changes the Proliferative Status in Piglet Neonatal Mammary Glands Independently of Estrogen Signaling

BACKGROUND

Soy infant formula contains isoflavones, which are able to bind to and activate estrogen receptor (ER) pathways. The mammary gland is sensitive to estrogens, raising concern that the use of soy formulas may promote premature development.

OBJECTIVE

We aimed to determine if soy formula feeding increases mammary gland proliferation and differentiation in comparison to other infant postnatal diets.

METHODS

White-Dutch Landrace piglets aged 2 d received either sow milk (Sow), or were provided milk formula (Milk), soy formula (Soy), milk formula supplemented with 17-beta-estradiol (2 mg/(kg·d); M + E2), or milk formula supplemented with genistein (84 mg/L of diet; M + G) until day 21. Mammary gland proliferation and differentiation was assessed by histology, and real-time RT-PCR confirmation of differentially expressed genes identified by microarray analysis.

RESULTS

Mammary terminal end bud numbers were 19-31% greater in the Milk, Soy, and M + G groups relative to the Sow and M + E2, P <0.05. Microarray analysis identified differentially expressed genes between each formula-fed group relative to the Sow (±1.7-fold, P <0.05). Real-time RT-PCR confirmed 2- to 4-fold increases in mRNA transcripts of genes involved in cell proliferation, insulin-like growth factor 1 (IGF1), fibroblast growth factor 10 (FGF10), and fibroblast growth factor 18 (FGF18), in all groups relative to the Sow, P <0.05. In contrast, genes involved in cell differentiation and ductal morphogenesis, angiotensin II receptor type 2 (AGTR2), microtubule associated protein 1b (MAP1B), and kinesin family member 26b (KIF26B), were significantly upregulated by 2-, 4-, and 13-fold, respectively, in the M + E2 group. Additionally, mRNA expression of ER-specific gene targets, progesterone receptor (PGR), was increased by 12-fold, and amphiregulin (AREG) and Ras-like estrogen regulated growth inhibitor (RERG) expression by 1.5-fold in the M + E2 group, P <0.05. In the soy and M + G groups, mRNA expressions of fatty acid synthesis genes were increased 2- to 4-fold.

CONCLUSIONS

Our data indicate soy formula feeding does not promote ER-signaling in the piglet mammary gland. Infant formula feeding (milk- or soy-based) may initiate proliferative pathways independently of estrogenic signaling.

The relation between anti-TGBFR1 immunohistochemical reaction and low Ki67, small tumor size and high estrogen receptor expression in invasive breast cancer

Most breast cancers are derived from the luminal epithelium, which composes the inside of the breast ductal structure. Ductal carcinoma in situ (DCIS) leads to invasive ductal carcinoma, but noncancerous intraductal proliferative lesions are also a risk factor for ductal carcinoma. The transforming growth factor beta (TGFB) signaling pathway behaves as a tumor suppressor in the early stage of cancer, and conversely as a tumor growth factor in invasive stages in several cancers. In this study, we performed immunohistochemistry with an antibody that detects the cytoplasmic region of TGFB receptor 1 (TGFBR1) and elucidated TGFBR1 protein expression in luminal epithelial cells of noncancerous breast ducts and in several cases of DCIS and invasive carcinoma. TGFBR1 expression was higher in noncancerous breast tissue than in cancerous tissue, and a difference in expression was also seen among histological subtypes. Comparing the expression level of TGFBR1 in cancer cells and clinico-pathological parameters, cases expressing low TGFBR1 tended to show low estrogen receptor expression, large tumor size (≥10 mm), and a high Ki67 labeling index. These data suggested that TGFBR1 protein expression may be related to the suppression of breast cancer cell growth.

Glycosylation is a novel TGFβ1-independent post-translational modification of Smad2

Smad2 is a crucial component of intracellular signaling by transforming growth factor-β (TGFβ). Here we describe that Smad2 is glycosylated, which is a novel for Smad2 post-translational modification. We showed that the Smad2 glycosylation was inhibited upon treatment of cells with 17β-estradiol, and was enhanced in cells in a dense culture as compared to cells in a sparse culture. The Smad2 glycosylation was not dependent on the C-terminal phosphorylation of Smad2, and was not affected by TGFβ1 treatment of the cells. Smad2 was glycosylated at multiple sites, and one of the predicted sites is Serine110. Thus, Smad2 is glycosylated, and this post-translational modification was modulated by 17β-estradiol but not by TGFβ1.

Non-Coding RNAs in Pediatric Solid Tumors

Pediatric solid tumors are a diverse group of extracranial solid tumors representing approximately 40% of childhood cancers. Pediatric solid tumors are believed to arise as a result of disruptions in the developmental process of precursor cells which lead them to accumulate cancerous phenotypes. In contrast to many adult tumors, pediatric tumors typically feature a low number of genetic mutations in protein-coding genes which could explain the emergence of these phenotypes. It is likely that oncogenesis occurs after a failure at many different levels of regulation. Non-coding RNAs (ncRNAs) comprise a group of functional RNA molecules that lack protein coding potential but are essential in the regulation and maintenance of many epigenetic and post-translational mechanisms. Indeed, research has accumulated a large body of evidence implicating many ncRNAs in the regulation of well-established oncogenic networks. In this review we cover a range of extracranial solid tumors which represent some of the rarer and enigmatic childhood cancers known. We focus on two major classes of ncRNAs, microRNAs and long non-coding RNAs, which are likely to play a key role in the development of these cancers and emphasize their functional contributions and molecular interactions during tumor formation.

Melatonin is an appropriate candidate for breast cancer treatment: Based on known molecular mechanisms

Breast cancer is the most prevalent cancer and one of the most important causes of death in women throughout the world. Breast cancer risk factors include smoking, alcohol consumption, personal and family history, hypertension, and hormone therapy, long-term use of nonsteroidal anti-inflammatory drugs and tobacco usage. Surgery, chemotherapy, radiotherapy, immunotherapy, and neoadjuvant therapy are the current means for breast cancer treatment. Despite hormonal agents and chemotherapy, which have beneficial effects on lowering breast cancer death rate, the reaction of different people to these treatments is still a challenging point. Melatonin (N-acetyl-5-methoxy tryptamine) is a methoxy indole compound that is mainly secreted by the pineal gland at night; it is as an antioxidant, anti-inflammatory, and oncostatic agent. On the basis of recent studies, melatonin has antitumor properties on different cancer types and it may suppress cancer development in vitro and as well as in animal models. It is suggested that melatonin inhibits the development of breast cancer by various mechanisms. This paper summarizes the roles of melatonin in breast cancer treatment from the aspect of its molecular actions.

Inverse association between estrogen receptor-α DNA methylation and breast composition in adolescent Chilean girls

Background

Estrogen receptor-α (ER-α) is a transcriptional regulator, which mediates estrogen-dependent breast development, as well as breast tumorigenesis. The influence of epigenetic regulation of ER-α on adolescent breast composition has not been previously studied and could serve as a marker of pubertal health and susceptibility to breast cancer. We investigated the association between ER-α DNA methylation in leukocytes and breast composition in adolescent Chilean girls enrolled in the Growth and Obesity Cohort Study (GOCS) in Santiago, Chile. Breast composition (total breast volume (BV; cm³), fibroglandular volume (FGV; cm³), and percent fibroglandular volume (%FGV)) was measured at breast Tanner stage 4 (B4). ER-α promoter DNA methylation was assessed by pyrosequencing in blood samples collected at breast Tanner stages 2 (B2; n = 256) and B4 (n = 338).

Results

After adjusting for fat percentage at breast density measurement, ER-α methylation at B2, and cellular heterogeneity, we observed an inverse association between B4 average ER-α DNA methylation and BV and FGV. Geometric mean BV was 15% lower (95% CI: − 28%, − 1%) among girls in the highest quartile of B4 ER-α methylation (6.96–23.60%) relative to the lowest (0.78–3.37%). Similarly, FGV was 19% lower (95% CI: − 33%, − 2%) among girls in the highest quartile of B4 ER-α methylation relative to the lowest. The association between ER-α methylation and breast composition was not significantly modified by body fat percentage and was not influenced by pubertal timing.

Conclusions

These findings suggest that the methylation profile of ER-α may modulate adolescent response to estrogen and breast composition, which may influence breast cancer risk in adulthood.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0553-5) contains supplementary material, which is available to authorized users.

Signaling pathways and steroid receptors modulating estrogen receptor α function in breast cancer

Estrogen receptor α (ER) is the major driver of ∼75% of breast cancers, and multiple ER targeting drugs are routinely used clinically to treat patients with ER+ breast cancer. However, many patients relapse on these targeted therapies and ultimately develop metastatic and incurable disease, and understanding the mechanisms leading to drug resistance is consequently of utmost importance. It is now clear that, in addition to estrogens, ER function is modulated by other steroid receptors and multiple signaling pathways (e.g., growth factor and cytokine signaling), and many of these pathways affect drug resistance and patient outcome. Here, we review the mechanisms through which these pathways impact ER function and drug resistance as well as discuss the clinical implications.

Increased α-actinin-1 destabilizes E-cadherin-based adhesions and associates with poor prognosis in basal-like breast cancer

The controlled formation and stabilization of E-cadherin-based adhesions is vital for epithelial integrity. This requires co-operation between the E-cadherin-based adhesions and the associated actin cytoskeleton. In cancer, this co-operation often fails, predisposing cells to migration through molecular mechanisms that have only been partially characterized. Here, we demonstrate that the actin filament cross-linker α-actinin-1 is frequently increased in human breast cancer. In mammary epithelial cells, the increased α-actinin-1 levels promote cell migration and induce disorganized acini-like structures in Matrigel. This is accompanied by a major reorganization of the actin cytoskeleton and the associated E-cadherin-based adhesions. Increased expression of α-actinin-1 is particularly noted in basal-like breast cancer cell lines, and in breast cancer patients it associates with poor prognosis in basal-like subtypes. Downregulation of α-actinin-1 in E-cadherin expressing basal-like breast cancer cells demonstrate that α-actinin-1-assembled actin fibers destabilize E-cadherin-based adhesions. Taken together, these results indicate that increased α-actinin-1 expression destabilizes E-cadherin-based adhesions, which is likely to promote the migratory potential of breast cancer cells. Furthermore, our results identify α-actinin-1 as a candidate prognostic biomarker in basal-like breast cancer.

Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats

Blackcurrants (Ribes nigrum L.) contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM) component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113) and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE) and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity^® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL) and four types of anthocyanins (10 μM) altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III) and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

The crossroads of breast cancer progression: insights into the modulation of major signaling pathways

Cancer is the disease with highest public health impact in developed countries. Particularly, breast cancer has the highest incidence in women worldwide and the fifth highest mortality in the globe, imposing a significant social and economic burden to society. The disease has a complex heterogeneous etiology, being associated with several risk factors that range from lifestyle to age and family history. Breast cancer is usually classified according to the site of tumor occurrence and gene expression profiling. Although mutations in a few key genes, such as BRCA1 and BRCA2, are associated with high breast cancer risk, the large majority of breast cancer cases are related to mutated genes of low penetrance, which are frequently altered in the whole population. Therefore, understanding the molecular basis of breast cancer, including the several deregulated genes and related pathways linked to this pathology, is essential to ensure advances in early tumor detection and prevention. In this review, we outline key cellular pathways whose deregulation has been associated with breast cancer, leading to alterations in cell proliferation, apoptosis, and the delicate hormonal balance of breast tissue cells. Therefore, here we describe some potential breast cancer-related nodes and signaling concepts linked to the disease, which can be positively translated into novel therapeutic approaches and predictive biomarkers.

TGF-β Stimulation of EMT Programs Elicits Non-genomic ER-α Activity and Anti-estrogen Resistance in Breast Cancer Cells

AIM

Estrogen receptor-α (ER-α) activation drives the progression of luminal breast cancers. Signaling by transforming growth factor-β (TGF-β) typically opposes the actions of ER-α; it also induces epithelial-mesenchymal transition (EMT) programs that promote breast cancer dissemination, stemness, and chemoresistance. The impact of EMT programs on nongenomic ER-α signaling remains unknown and was studied herein.

METHODS

MCF-7 and BT474 cells were stimulated with TGF-β to induce EMT programs, at which point ER-α expression, localization, and nongenomic interactions with receptor tyrosine kinases and MAP kinases (MAPKs) were determined. Cell sensitivity to anti-estrogens both before and after traversing the EMT program was also investigated.

RESULTS

TGF-β stimulated MCF-7 and BT474 cells to acquire EMT phenotypes, which enhanced cytoplasmic accumulation of ER-α without altering its expression. Post-EMT cells exhibited (i) elevated expression of EGFR and IGF1R, which together with Src formed cytoplasmic complexes with ER-α; (ii) enhanced coupling of EGF, IGF-1 and estrogen to the activation of MAPKs; and (iii) reduced sensitivity to tamoxifen, an event reversed by administration of small molecule inhibitors against the receptors for TGF-β, EGF, and IGF-1, as well as those against MAPKs.

CONCLUSION

EMT stimulated by TGF-β promotes anti-estrogen resistance by activating EGFR-, IGF1R-, and MAPK-dependent nongenomic ER-α signaling.

Estrogen-related receptor α participates transforming growth factor-β (TGF-β) induced epithelial-mesenchymal transition of osteosarcoma cells

Osteosarcoma patients often exhibit pulmonary metastasis, which results in high patient mortality. Understanding the mechanisms of advanced metastasis in osteosarcoma cell is important for the targeted treatment and drug development. Our present study revealed that transforming growth factor-β (TGF-β) treatment can significantly promote the in vitro migration and invasion of human osteosarcoma MG-63 and HOS cells. The loss of epithelial characteristics E-cadherin (E-Cad) and up regulation of mesenchymal markers Vimentin (Vim) suggested TGF-β induced epithelial-mesenchymal transition (EMT) of osteosarcoma cells. TGF-β treatment obviously increased the expression of Snail, a key EMT-related transcription factor, in both MG-63 and HOS cells. Silencing of Snail markedly attenuated TGF-β induced down regulation of E-cad and up regulation of Vim. TGF-β treatment also significantly increased the expression and nuclear translocation of estrogen-related receptors α (ERRα), while had no obvious effect on the expression of ERα, ERβ, or ERRγ. Knock down of ERRα or its inhibitor XCT-790 significantly attenuated TFG-β induced EMT and transcription of Snail in osteosarcoma cells. Collectively, our present study revealed that TGF-β treatment can trigger the EMT of osteosarcoma cells via ERRα/Snail pathways. Our data suggested that ERRα/Snail pathways might be potential therapeutic targets of metastasis of osteosarcoma cells.

Mechanism of immune evasion in breast cancer

Breast cancer (BC) is the most common malignant tumor among women, with high morbidity and mortality. Its onset, development, metastasis, and prognosis vary among individuals due to the interactions between tumors and host immunity. Many diverse mechanisms have been associated with BC, with immune evasion being the most widely studied to date. Tumor cells can escape from the body’s immune response, which targets abnormal components and foreign bodies, using different approaches including modification of surface antigens and modulation of the surrounding environment. In this review, we summarize the mechanisms and factors that impact the immunoediting process and analyze their functions in detail.

MicroRNA-137 inhibits BMP7 to enhance the epithelial-mesenchymal transition of breast cancer cells

Bone morphogenetic protein-7 (BMP7) is known to antagonize transforming growth factor β 1 (TGFβ1)-mediated fibrosis through suppressing epithelial-mesenchymal transition (EMT). We recently reported that BMP7 also antagonizes the effects of TGFβ1 in breast cancer (BC) tumorigenesis-related EMT. Nevertheless, the control of BMP7 expression in BC remains ill-defined. Here, we detected significantly lower levels of BMP7 and significantly higher levels of microRNA-137 (miR-137) in the BC specimens, relative to paired adjacent non-tumor breast tissue. BMP7 and miR-137 levels were correlated inversely. Additionally, the high miR-137 levels in BC specimens were correlated with reduced patient survival. In vitro, overexpression of miR-137 significantly increased cell EMT and invasion, while depletion of miR-137 significantly decreased cell EMT and invasion in BC cells. The increases in BC cell invasiveness by miR-137 appeared to result from its suppression of BMP7, through direct binding of miR-137 to the 3'-UTR of BMP7 mRNA, thereby blocking its protein translation in BC cells. This study sheds light on miR-137 as a crucial factor that enhances BC cell EMT and invasiveness, and points to miR-137 as a promising innovative therapeutic target for BC treatment.

BMP4 Cross-talks With Estrogen/ERα Signaling to Regulate Adiposity and Glucose Metabolism in Females

Similar to estrogens, bone morphogenetic protein 4 (BMP4) promotes the accumulation of more metabolically active subcutaneous fat and reduction of visceral fat. However, whether there is a cross-talk between BMP4 and estrogen signaling remained unknown. Herein, we found that BMP4 deficiency in white adipose tissue (WAT) increased the estrogen receptor α (ERα) level and its signaling, which prevented adult female mice from developing high fat diet (HFD)-induced obesity and insulin resistance; estrogens depletion up regulated BMP4 expression to overcome overt adiposity and impaired insulin sensitivity with aging, and failure of BMP4 regulation due to genetic knockout led to more fat gain in aged female mice. This mutual regulation between BMP4 and estrogen/ERα signaling may also happen in adipose tissue of women, since the BMP4 level significantly increased after menopause, and was inversely correlated with body mass index (BMI). These findings suggest a counterbalance between BMP4 and estrogen/ERα signaling in the regulation of adiposity and relative metabolism in females.

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BMP4 knockout improves ERα stability and its signaling in WAT of female mice.

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BMP4 knockout female mice get higher energy expenditure.

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Depletion of estrogens up regulates BMP4 level in adipose tissue.

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Failure of BMP4 regulation leads to obesity and insulin resistance in aged females.

Estrogens play a beneficial role in regulating adiposity and glucose metabolism, however not all women with low estrogen levels become obese and develop insulin resistance. Such variation may be related to other factors involved. In the present study, we revealed a reciprocal interaction between bone morphogenetic protein 4 (BMP4) and estrogen/ERα signaling in regulating fat accumulation and insulin sensitivity. Our findings may explain why cycling females are less prone to gain weight and less susceptible to glucose dysmetabolism than menopausal females and males. The regulation of BMP4 may offer a new opportunity of intervention in the control of excessive obesity.

Estrogen Enhances the Cell Viability and Motility of Breast Cancer Cells through the ERα-ΔNp63-Integrin β4 Signaling Pathway

Estrogen induces ERα-positive breast cancer aggressiveness via the promotion of cell proliferation and survival, the epithelial-mesenchymal transition, and stem-like properties. Integrin β4 signaling has been implicated in estrogen/ERα-induced tumorigenicity and anti-apoptosis; however, this signaling cascade poorly understood. ΔNp63, an N-terminally truncated isoform of the p63 transcription factor, functions as a transcription factor of integrinβ4 and therefore regulates cellular adhesion and survival. Therefore, the aim of the present study was to investigate the estrogen-induced interaction between ERα, ΔNp63 and integrin β4 in breast cancer cells. In ERα-positive MCF-7 cells, estrogen activated ERα transcription, which induced ΔNp63 expression. And ΔNp63 subsequently induced integrin β4 expression, which resulted in AKT phosphorylation and enhanced cell viability and motility. Conversely, there was no inductive effect of estrogen on ΔNp63-integrinβ4-AKT signaling or on cell viability and motility in ERα-negative MDA-MB-231 cells. ΔNp63 knockdown abolishes these estrogen-induced effects and reduces cell viability and motility in MCF-7 cells. Nevertheless, ΔNp63 knockdown also inhibited cell migration in MDA-MB-231 cells through reducing integrin β4 expression and AKT phosphorylation. In conclusion, estrogen enhances ERα-positive breast cancer cell viability and motility through activating the ERα-ΔNp63-integrin β4 signaling pathway to induce AKT phosphorylated activation. Those findings should be useful to elucidate the crosstalk between estrogen/ER signaling and ΔNp63 signaling and provide novel insights into the effects of estrogen on breast cancer progression.

Deptor enhances triple-negative breast cancer metastasis and chemoresistance through coupling to survivin expression

Transforming growth factor-β (TGF-β) functions to suppress tumorigenesis in normal mammary tissues and early-stage breast cancers and, paradoxically, acts to promote the metastasis and chemoresistance in late-stage breast cancers, particularly triple-negative breast cancers (TNBCs). Precisely how TGF-β acquires oncogenic characteristics in late-stage breast cancers remains unknown, as does the role of the endogenous mammalian target of rapamycin (mTOR) inhibitor, Dep domain-containing mTOR-interacting protein (Deptor), in coupling TGF-β to TNBC development and metastatic progression. Here we demonstrate that Deptor expression was downregulated in basal-like/TNBCs relative to their luminal counterparts. Additionally, Deptor expression was 1) inversely correlated with the metastatic ability of human (MCF10A) and mouse (4T1) TNBC progression series and 2) robustly repressed by several inducers of epithelial-mesenchymal transition programs. Functional disruption of Deptor expression in 4T07 cells significantly inhibited their proliferation and organoid growth in vitro, as well as prevented their colonization and tumor formation in the lungs of mice. In stark contrast, elevated Deptor expression was significantly associated with poorer overall survival of patients harboring estrogen receptor α-negative breast cancers. Accordingly, enforced Deptor expression in MDA-MB-231 cells dramatically enhanced their 1) organoid growth in vitro, 2) pulmonary outgrowth in mice, and 3) resistance to chemotherapies, an event dependent on the coupling of Deptor to survivin expression. Collectively, our findings highlight the dichotomous functions of Deptor in modulating the proliferation and survival of TNBCs during metastasis; they also implicate Deptor and its stimulation of survivin as essential components of TNBC resistance to chemotherapies and apoptotic stimuli.

Phytoestrogenic activity of blackcurrant (Ribes nigrum) anthocyanins is mediated through estrogen receptor alpha

SCOPE

Blackcurrants (Ribes nigrum L., Grossulariaceae) contain high amounts of anthocyanin polyphenols, which have antioxidant and anti-carcinogenic health benefits. This study analyzed the potential phytoestrogenic effects of blackcurrant extract (BCE) in breast cancer (MCF-7) and human endometrial cancer (Ishikawa) cell lines that over-express estrogen receptor alpha (ERα), as well as in immature female rats.

METHODS AND RESULTS

Microarray analysis and Ingenuity® Pathway Analysis showed that BCE activated the ERα pathway, whereas quantitative-PCR confirmed that BCE and four types of anthocyanins up-regulated genes downstream of ERα. BCE (0.1-1.0 μg/mL) and anthocyanins (0.1-10 μM) induced MCF-7 cell proliferation; however, this effect was blocked by ER antagonist fulvestrant. Flow cytometry showed that anthocyanins reduced and increased the number of MCF-7 cells in the G0/G1 and G2/M phases, respectively. Anthocyanins stimulated ERα transcriptional activity in human ERα reporter assays and induced alkaline phosphatase activity in Ishikawa cells. Competition assays and in silico analysis indicated that anthocyanins bind to ERα. Finally, BCE focally induced stratification of columnar epithelial cells in the rat uterus and increased cytoplasmic mucin levels in these cells.

CONCLUSION

These results suggest that blackcurrant anthocyanins act as phytoestrogens in vitro and in vivo.

Estrogenic endocrine disruptors: Molecular mechanisms of action

A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

Transcriptomic Heterogeneity in Cancer as a Consequence of Dysregulation of the Gene-Gene Interaction Network

Many pathways are dysregulated in cancer. Dysregulation of the regulatory network results in less control of transcript levels in the cell. Hence, dysregulation is reflected in the heterogeneity of the transcriptome: the more dysregulated the pathway, the more the transcriptomic heterogeneity. We identify four scenarios for a transcriptomic heterogeneity increase (i.e., pathway dysregulation) in cancer: (1) activation of a molecular switch, (2) a structural change in a regulator, (3) a temporal change in a regulator, and (4) weakening of gene–gene interactions. These mechanisms are statistically motivated, explored in silico, and their plausibility to occur in vivo illustrated by means of oncogenomics data of breast cancer studies.

Transforming growth factor-β signaling pathway cross-talking with ERα signaling pathway on regulating the growth of uterine leiomyoma activated by phenolic environmental estrogens in vitro

The aim of this paper is to study the participation of transforming growth factor-β (TGF-β) signaling pathway in mediating the growth of human uterine leiomyoma (UL) activated by phenolic environmental estrogens (EEs), via the interaction between TGF-β and ER signaling pathways. The UL cells were prepared by primary culture and subculture methods. To validate the role of TGF-β3 (5 ng/ml) for the viability of human uterine leiomyoma cells, CCK-8 assay was performed in each of five treatment groups including E2 group (E2 10(9) mol/l), BPA group (bisphenol A 10 μmol/l), NP group (nonylphenol 32 μmol/l), OP group (octylphenol 8 μmol/l), or control group (DMSO only). Subsequently, qRT-PCR was applied to detect mRNA expressions of ERα and c-fos, while western blot assay was used to test the expressions of p-Smad3, SnoN, and c-fos proteins in all settings mentioned above; the expressions were compared among different groups, and also in settings with and without synchronous treatment of ICI 182,780. Primarily cultured UL cells were successfully established. Compared with the control group, there were statistically significant increases in the proliferation rate of the UL cells in all EE groups or treated with TGF-β3 only (p < 0.05). Nevertheless, a slight decrease in proliferation rate of UL was detected in coexistence with TGF-β3 in all EE groups (p > 0.05). Interestingly, mRNA expressions of ERα and c-fos reduced in the setting of coexistence of TGF-β3 and EEs compared to isolated EE treatment (p < 0.05). Compared with the control group, the expression of p-Smad3 and c-fos proteins significantly decreased (p < 0.05) in each of E2, BPA, NP, and OP group, and the expression of SnoN protein also significantly reduced only in BPA and NP groups (p < 0.05), followed by TGF-β3 treatment. When adding ICI 182,780, the expression of p-Smad3 protein significantly increased in OP group (p < 0.05), but slightly increased in E2, BPA, NP, and OP groups (p > 0.05). However, compared with the control group, the expressions of SnoN and c-fos proteins significantly decreased (p < 0.05) after adding ICI182,780. Moreover, there was a significant statistical difference in the expression of p-Smad3, SnoN, and c-fos proteins between pre- and post-treatment of ICI 182,780 in all groups (p < 0.05). The ERα signaling pathway and TGF-β signaling pathway have different roles in the control of UL cell proliferation. The phenolic EEs can be a promoter of UL cell proliferation, which is mediated by ERα signaling pathway and its cross-talking with TGF-β signaling pathway. Both less exposure to EEs and blockade of TGF signaling pathway are necessary strategies to prevent UL.

Girl power: estrogen promotes HSC self-renewal

Although some hematopoietic cell types are known to respond to sex hormones, hematopoietic stem cells (HSCs) are generally thought to function similarly in both sexes. Recently in Nature, Nakada et al. (2014) show that HSCs respond to higher levels of estrogen in females, resulting in enhanced self-renewal and increased erythropoiesis.