In Utero Exposure to Diethylstilbestrol (DES) or Bisphenol-A (BPA) Increases EZH2 Expression in the Mammary Gland: An Epigenetic Mechanism Linking Endocrine Disruptors to Breast Cancer

Diethylstilbestrol (DES) and bisphenol-A (BPA) are estrogen-like endocrine-disrupting chemicals that induce persistent epigenetic changes in the developing uterus. However, DES exposure in utero is also associated with an increased risk of breast cancer in adult women. Similarly, fetal exposure to BPA induces neoplastic changes in mammary tissue of mice. We hypothesized that epigenetic alterations would precede the increased risk of breast neoplasia after in utero exposure to endocrine disruptors. Enhancer of Zeste Homolog 2 (EZH2) is a histone methyltransferase that has been linked to breast cancer risk and epigenetic regulation of tumorigenesis. We examined the effect of BPA and DES on EZH2 expression and function in MCF-7 cells and in mammary glands of mice exposed in utero. DES and BPA treatment approximated human exposure. EZH2 functional activity was assessed by measuring histone H3 trimethylation. Treatment of MCF-7 cells with DES or BPA led to a 3- and 2-fold increase in EZH2 mRNA expression, respectively (p?2-fold increase in EZH2 expression in adult mammary tissue compared with controls (p?相似文献   

Bisphenol A (BPA) Exposure In Utero Leads to Immunoregulatory Cytokine Dysregulation in the Mouse Mammary Gland: A Potential Mechanism Programming Breast Cancer Risk

Bisphenol-A (BPA) is a ubiquitous estrogen-like endocrine disrupting compound (EDC). BPA exposure in utero has been linked to breast cancer and abnormal mammary gland development in mice. The recent rise in incidence of human breast cancer and decreased age of first detection suggests a possible environmental etiology. We hypothesized that developmental programming of carcinogenesis may involve an aberrant immune response. Both innate and adaptive immunity play a role in tumor suppression through cytolytic CD8, NK, and Th1 T-cells. We hypothesized that BPA exposure in utero would lead to dysregulation of both innate and adaptive immunity in the mammary gland. CD1 mice were exposed to BPA in utero during gestation (days 9–21) via osmotic minipump. At 6 weeks, the female offspring were ovariectomized and estradiol was given at 8 weeks. RNA and protein were extracted from the posterior mammary glands, and the mRNA and protein levels were measured by PCR array, qRT-PCR, and western blot. In mouse mammary tissue, BPA exposure in utero significantly decreased the expression of members of the chemokine CXC family (Cxcl2, Cxcl4, Cxcl14, and Ccl20), interleukin 1 (Il1) gene family (Il1β and Il1rn), interleukin 2 gene family (Il7 receptor), and interferon gene family (interferon regulatory factor 9 (Irf9), as well as immune response gene 1 (Irg1). Additionally, BPA exposure in utero decreased Esr1 receptor gene expression and increased Esr2 receptor gene expression. In utero exposure of BPA resulted in significant changes to inflammatory modulators within mammary tissue. We suggest that dysregulation of inflammatory cytokines, both pro-inflammatory and anti-inflammatory, leads to a microenvironment that may promote disordered cell growth through inhibition of the immune response that targets cancer cells.     

Hormone Replacement Therapy Appears to Be Safe After Prophylactic Adnexectomy in Premenopausal BRCA1/BRCA2 Mutation Carriers. Reaction to the 'Letter to readers' in Hereditary Cancer in Clinical Practice, 2005, 3 (2)

In writing the letter to readers of our journal three months ago I was asking about opinions concerning the use of hormone replacement therapy (HRT) in BRCA1/2 carriers after prophylactic adnexectomy, because at that time it was practically impossible to present evidence-based recommendations. Actually, most of the responses we have received have been opinions. It is important to recognise that the situation is now much clearer with studies performed by Tim Rebbeck et al which are to be published in the Journal of Clinical Oncology. The following responses have been received:     

Study Design and Rationale for Espera Trial: A Multicentre,Randomized, Phase II Clinical Trial Evaluating the Potential Efficacy of Adding SBRT to Pembrolizumab-Pemetrexed Maintenance in Responsive or Stable Advanced Non-Squamous NSCLC After Chemo-Immunotherapy Induction

BackgroundImprovement in radiotherapy techniques and expected outcomes, as well as in understanding the underlying biological mechanisms contributing to its action (immunomodulation in primis), led to the integration of this therapeutical approach in the current management of advanced non-small cell lung cancer (NSCLC), not only in oncogene-driven tumors, but also in non-oncogene addicted NSCLC where the combination of platinum-based chemotherapy plus pembrolizumab represents nowadays the pivotal strategy. In this light, we have designed a randomized phase II (ESPERa) trial to evaluate the efficacy and safety of adding Stereotactic Body Radiotherapy (SBRT) to pembrolizumab-pemetrexed maintenance in advanced NSCLC patients experiencing disease response or stability after chemo-immunotherapy induction.Patients and MethodsAdvanced non-oncogene addicted NSCLC patients with ECOG performance status of 0 or 1, who obtained disease response or stability after 4 cycles of platinum-based chemotherapy plus pembrolizumab will be randomized 2:1 to receive pembrolizumab-pemetrexed maintenance plus SBRT vs pembrolizumab-pemetrexed alone. The primary endpoint is progression-free survival (PFS). Concomitant translational researches will be performed to identify potential prognostic and/or predictive biomarkers, as well as to analyze and monitor tumour microenvironment and tumor-host interactions.ConclusionsAlthough available data suggest the safety and efficacy of combining immunotherapy and radiotherapy, their systematic integration in the current first-line landscape still remains to be explored. If the pre-planned endpoints of the ESPERa trial will be achieved, the addition of SBRT to pembrolizumab-pemetrexed maintenance as a strategy to consolidate and ideally improve the awaited benefit could be considered as a promising strategy in NSCLC undergoing first-line therapy, as well as an interesting approach to be evaluated in other disease setting, as well as in other oncological malignancies where immunotherapy represents nowadays the standard-of-care.