Beauvericin, produced by Fusarium oxysporum inhibits bisphenol A-induced proliferation of human breast cancer cell line by regulating ERα/p38 pathway

Beauvericin (BEA) is a cyclic depsipeptide secondary metabolite of Fusarium species. It causes chemical hazards in food products and exists in an environment containing soil and various food types. On the other hand, the purified BEA has various biological activities and is regarded as a potential candidate for pharmaceutical research. This study was performed to assess the anti-proliferation activity of BEA against human breast cancer cells by regulating the estrogen receptor-alpha (ERα)/p38 pathway. TA and BA assays verified that BEA is a completed ER antagonist. Additionally, BEA suppressed cell proliferation in the anti-proliferation assay involving ER-positive human breast cancer cells co-treated with BPA and BEA. In respect to an anti-proliferation activity, the BPA-induced phosphorylation of p38 protein was inhibited in the presence of BEA. These results suggested that BEA exerts inhibitory potentials on endocrine disrupting effect and possibly acts as a natural therapeutic material for human estrogen hormonal health.

Age alters the oncogenic trajectory toward luminal mammary tumors that activate unfolded proteins responses

A major limitation in the use of mouse models in breast cancer research is that most mice develop estrogen receptor-alpha (ERα)-negative mammary tumors, while in humans, the majority of breast cancers are ERα-positive. Therefore, developing mouse models that best mimic the disease in humans is of fundamental need. Here, using an inducible MMTV-rtTA/TetO-NeuNT mouse model, we show that despite being driven by the same oncogene, mammary tumors in young mice are ERα-negative, while they are ERα-positive in aged mice. To further elucidate the mechanisms for this observation, we performed RNAseq analysis and identified genes that are uniquely expressed in aged female-derived mammary tumors. We found these genes to be involved in the activation of the ERα axis of the mitochondrial UPR and the ERα-mediated regulation of XBP-1s, a gene involved in the endoplasmic reticulum UPR. Collectively, our results indicate that aging alters the oncogenic trajectory towards the ERα-positive subtype of breast cancers, and that mammary tumors in aged mice are characterized by the upregulation of multiple UPR stress responses regulated by the ERα.

NDV-D90 inhibits 17β-estradiol-mediated resistance to apoptosis by differentially modulating classic and nonclassic estrogen receptors in breast cancer cells

Newcastle disease virus (NDV) is endowed with the oncolytic ability to kill tumor cells, while rarely causing side effects in normal cells. Both estrogen receptor α (ERα) and the G protein estrogen receptor (GPER) modulate multiple biological activities in response to estrogen, including apoptosis in breast cancer (BC) cells. Here, we investigated whether NDV-D90, a novel strain isolated from natural sources in China, promoted apoptosis by modulating the expression of ERα or the GPER in BC cells exposed to 17β-estradiol (E2). We found that NDV-D90 significantly killed the tumor cell lines MCF-7 and BT549 in a time- and dose-dependent manner. We also found that NDV-D90 exerted its effects on the two cell lines mainly by inducing apoptosis but not necrosis. NDV-D90 induced apoptosis via the intrinsic and extrinsic signaling pathways in MCF-7 cells (ER-positive cells) during E2 exposure not only by disrupting the E2/ERα axis and enhancing GPER expression but also by modulating the expression of several apoptosis-related proteins through ERα-and GPER-independent processes. NDV-D90 promoted apoptosis via the intrinsic signaling pathway in BT549 cells (ER-negative cells), possibly by impairing E2-mediated GPER expression. Furthermore, NDV-D90 exerted its antitumor effects in vivo by inducing apoptosis. Overall, these results demonstrated that NDV-D90 promotes apoptosis by differentially modulating the expression of ERα and the GPER in ER-positive and negative BC cells exposed to estrogen, respectively, and can be utilized as an effective approach to treating BC.

Association between estrogen receptor-alpha gene PvuII and XbaI polymorphisms and osteoarthritis risk: a meta-analysis

Estrogen receptor-alpha (ER-α) gene PvuII (T/C) and XbaI (A/G) polymorphisms have been hypothesized to be associated with osteoarthritis (OA) risk by several epidemiological studies, however, the available results were inconclusive and conflicting. We conducted a meta-analysis of 10 case-control studies that included 3328 osteoarthritis cases and 6390 case-free controls. We assessed the strength of the association, using odds ratios (ORs) with 95% confidence intervals (CIs). This meta-analysis showed that the ER-α PvuII and XbaI polymorphisms were not associated with OA risk in overall population. For the PvuII (T/C) polymorphism, however, in the subgroup analysis by country, a significantly reduced risk was observed among Chinese (TC vs. CC: OR = 0.73, 95% CI 0.54-0.99, I (2) = 0%, P heterogeneity = 0.498; dominant model, OR = 0.73, 95% CI = 0.55-0.98, I (2) = 0%, P heterogeneity = 0.555). For the XbaI (A/G) polymorphism, when stratifying by sample size, a significantly elevated risk was found in sample size ≤ 500 (AA vs. GG: OR = 2.60, 95% CI 1.10-6.18, I (2) = 42.9%, P heterogeneity = 0.135; dominant model: OR = 2.04, 95% CI 1.12-3.71, I (2) = 11.4%, P heterogeneity = 0.341; and recessive model: OR = 1.69, 95% CI 1.12-2.55, I (2) = 40.2%, P heterogeneity = 0.154). No publication bias was found in the present study. This meta-analysis suggests that ER-α PvuII (T/C) polymorphism may be associated with a reduced OA risk among Chinese and the XbaI (A/G) polymorphism may not be associated with OA risk, while the observed increase in OA risk for XbaI polymorphism may be due to small-study bias.

Energy status determines hindbrain signal transduction pathway transcriptional reactivity to AMPK in the estradiol-treated ovariectomized female rat

Dorsal vagal complex (DVC) AMPK regulation of food intake in the estradiol-treated ovariectomized (OVX) female rat is energy state-dependent. Here, RT-PCR array technology was used to identify estradiol-sensitive AMPK-regulated DVC signal transduction pathways that exhibit differential reactivity to sensor activation during energy balance versus imbalance. The AMP mimetic AICAR correspondingly reduced or stimulated cDVC phosphoAMPK (pAMPK) and estrogen receptor-beta (ERβ) proteins in full-fed (F) versus 12-h food-deprived (D) estradiol-treated ovariectomized (OVX) rats, but elevated ER-alpha (ERα) in F only. Estradiol suppressed DVC ERβ protein and hypoxia, NFκB, STAT3, STAT6, and Hedgehog signaling pathway marker genes against oil-implanted OVX controls. F+(A)ICAR and D+(S)aline groups each exhibited further inhibition of NFκB, STAT3, and Hedgehog pathway genes, and diminished PPAR, Notch, and STAT5 transcripts versus F+S. Conversely, genes in these six pathways were up-regulated by AICAR treatment of D. Results show that in this animal model, acute AMP augmentation or feeding cessation each inhibit both pAMPK and ERβ expression, but in combination increase these protein profiles. pAMPK protein and DVC TNF (NFκB), SOCS3 (JAK/STAT), WNT6 (Hedgehog), and FABP1 (PPAR) mRNAs were down- or upregulated in parallel by AICAR in F versus D states, respectively. Further research is needed to determine the impact of ERβ on opposing directionality of these responses, and to characterize the role of the aforementioned signaling pathways in hyperphagic responses in the female to AICAR-induced DVC AMPK activation during acute interruption of feeding.

Neonatal overexpression of estrogen receptor-α alters midbrain dopamine neuron development and reverses the effects of low maternal care in female offspring

Maternal behavior is dependent on estrogen receptor-alpha (ERα; Esr1) and oxytocin receptor (OTR) signaling in the medial preoptic area (MPOA) of the hypothalamus, as well as dopamine signaling from the ventral tegmental area (VTA) to forebrain regions. Previous studies in rats indicate that low levels of maternal care, particularly licking/grooming (LG), lead to reduced levels of MPOA ERα and VTA dopamine neurons in female offspring and predict lower levels of postpartum maternal behavior by these offspring. The aim of this study was to determine the functional impact on maternal behavior of neonatal manipulation of ERα in females that had experienced low versus high levels of postnatal maternal LG. Adenovirus expressing ESR1 was targeted to the MPOA in female pups from low and high LG litters on postnatal day 2-3. Overexpression of ESR1 in low LG offspring elevated the level of ERα-immunoreactive cells in the MPOA and of tyrosine hydroxylase cells in the VTA to that observed in high LG females. Amongst juvenile female low LG offspring, ESR1 overexpression also decreased the latency to engage in maternal behavior toward donor pups. These results show that virally mediated expression of ESR1 in the neonatal rat hypothalamus results in lasting changes in ESR1 expression through the juvenile period, and can "rescue" hormone receptor levels and behavior of offspring reared by low LG dams, potentially mediated by downstream alterations within reward circuitry. Thus, the transmission of maternal behavior from one generation to the next can be augmented by neonatal ERα in the MPOA.

Aromatase and estrogen receptor α deficiency

Studies on the phenotypes of women and men with mutations disrupting estrogen biosynthesis and action have significantly advanced our knowledge of the physiologic roles of estrogen in humans. Aromatase deficiency results from autosomal recessive inheritance of mutations in the CYP19A1 gene. It gives rise to ambiguous genitalia in 46,XX fetuses. At puberty, affected girls have hypergonadotropic hypogonadism, do not develop secondary sexual characteristics, and exhibit progressive virilization. The affected 46,XY men have normal male sexual differentiation and pubertal maturation. These men, however, are extremely tall and have eunucoid proportions with continued linear growth into adulthood, severely delayed epiphyseal closure, and osteoporosis due to estrogen deficiency. Although estrogen has been shown to be essential for normal sperm production and function in mice, its role in fertility is not clear in men. Thus far, one man and an unrelated woman with estrogen resistance due to mutations in the estrogen receptor α (ESR1) gene have been described. Their clinical presentations are similar to that of aromatase-deficient men and women.

Sex steroid receptor expression and localization in benign prostatic hyperplasia varies with tissue compartment

Androgens and estrogens, acting via their respective receptors, are important in benign prostatic hyperplasia (BPH). The goals of this study were to quantitatively characterize the tissue distribution and staining intensity of androgen receptor (AR) and estrogen receptor-alpha (ERα), and assess cells expressing both AR and ERα, in human BPH compared to normal prostate. A tissue microarray composed of normal prostate and BPH tissue was used and multiplexed immunohistochemistry was performed to detect AR and ERα. We used a multispectral imaging platform for automated scanning, tissue and cell segmentation and marker quantification. BPH specimens had an increased number of epithelial and stromal cells and increased percentage of epithelium. In both stroma and epithelium, the mean nuclear area was decreased in BPH relative to normal prostate. AR expression and staining intensity in epithelial and stromal cells was significantly increased in BPH compared to normal prostate. ERα expression was increased in BPH epithelium. However, stromal ERα expression and staining intensity was decreased in BPH compared to normal prostate. Double positive (AR and ERα) epithelial cells were more prevalent in BPH, and fewer double negative (AR and ERα) stromal and epithelial negative cells were observed in BPH. These data underscore the importance of tissue layer localization and expression of steroid hormone receptors in the prostate. Understanding the tissue-specific hormone action of androgens and estrogens will lead to a better understanding of mechanisms of pathogenesis in the prostate and may lead to better treatment for BPH.

Estrogen receptor signaling pathways in human non-small cell lung cancer

Lung cancer is the most common cause of cancer mortality in male and female patients in the US. The etiology of non-small cell lung cancer (NSCLC) is not fully defined, but new data suggest that estrogens and growth factors promote tumor progression. In this work, we confirm that estrogen receptors (ER), both ERalpha and ERbeta, occur in significant proportions of archival NSCLC specimens from the clinic, with receptor expression in tumor cell nuclei and in extranuclear sites. Further, ERalpha in tumor nuclei was present in activated forms as assessed by detection of ER phosphorylation at serines-118 and -167, residues commonly modulated by growth factor receptor as well as steroid signaling. In experiments using small interfering RNA (siRNA) constructs, we find that suppressing expression of either ERalpha or ERbeta elicits a significant reduction in NSCLC cell proliferation in vitro. Estrogen signaling in NSCLC cells may also include steroid receptor coactivators (SRC), as SRC-3 and MNAR/PELP1 are both expressed in several lung cell lines, and both EGF and estradiol elicit serine phosphorylation of SRC-3 in vitro. EGFR and ER also cooperate in promoting early activation of p42/p44 MAP kinase in NSCLC cells. To assess new strategies to block NSCLC growth, we used Faslodex alone and with erlotinib, an EGFR kinase inhibitor. The drug tandem elicited enhanced blockade of the growth of NSCLC xenografts in vivo, and antitumor activity exceeded that of either agent given alone. The potential for use of antiestrogens alone and with growth factor receptor antagonists is now being pursued further in clinical trials.