Prenatal Exposure to Triclocarban Impairs ESR1 Signaling and Disrupts Epigenetic Status in Sex-Specific Ways as Well as Dysregulates the Expression of Neurogenesis- and Neurotransmitter-Related Genes in the Postnatal Mouse Brain

Triclocarban is a highly effective and broadly used antimicrobial agent. Humans are continually exposed to triclocarban, but the safety of prenatal exposure to triclocarban in the context of neurodevelopment remains unknown. In this study, we demonstrated for the first time that mice that had been prenatally exposed to environmentally relevant doses of triclocarban had impaired estrogen receptor 1 (ESR1) signaling in the brain. These mice displayed decreased mRNA and protein expression levels of ESR1 as well as hypermethylation of the Esr1 gene in the cerebral cortex. Prenatal exposure to triclocarban also diminished the mRNA expression of Esr2, Gper1, Ahr, Arnt, Cyp19a1, Cyp1a1, and Atg7, and the protein levels of CAR, ARNT, and MAP1LC3AB in female brains and decreased the protein levels of BCL2, ARNT, and MAP1LC3AB in male brains. In addition, exposure to triclocarban caused sex-specific alterations in the methylation levels of global DNA and estrogen receptor genes. Microarray and enrichment analyses showed that, in males, triclocarban dysregulated mainly neurogenesis-related genes, whereas, in females, the compound dysregulated mainly neurotransmitter-related genes. In conclusion, our data identified triclocarban as a neurodevelopmental risk factor that particularly targets ESR1, affects apoptosis and autophagy, and in sex-specific ways disrupts the epigenetic status of brain tissue and dysregulates the postnatal expression of neurogenesis- and neurotransmitter-related genes.

Positive Regulation of Estrogen Receptor Alpha in Breast Tumorigenesis

Estrogen receptor alpha (ERα, NR3A1) contributes through its expression in different tissues to a spectrum of physiological processes, including reproductive system development and physiology, bone mass maintenance, as well as cardiovascular and central nervous system functions. It is also one of the main drivers of tumorigenesis in breast and uterine cancer and can be targeted by several types of hormonal therapies. ERα is expressed in a subset of luminal cells corresponding to less than 10% of normal mammary epithelial cells and in over 70% of breast tumors (ER+ tumors), but the basis for its selective expression in normal or cancer tissues remains incompletely understood. The mapping of alternative promoters and regulatory elements has delineated the complex genomic structure of the ESR1 gene and shed light on the mechanistic basis for the tissue-specific regulation of ESR1 expression. However, much remains to be uncovered to better understand how ESR1 expression is regulated in breast cancer. This review recapitulates the current body of knowledge on the structure of the ESR1 gene and the complex mechanisms controlling its expression in breast tumors. In particular, we discuss the impact of genetic alterations, chromatin modifications, and enhanced expression of other luminal transcription regulators on ESR1 expression in tumor cells.

Identification of Estrogen Signaling in a Prioritization Study of Intraocular Pressure-Associated Genes

Elevated intraocular pressure (IOP) is the only modifiable risk factor for primary open-angle glaucoma (POAG). Herein we sought to prioritize a set of previously identified IOP-associated genes using novel and previously published datasets. We identified several genes for future study, including several involved in cytoskeletal/extracellular matrix reorganization, cell adhesion, angiogenesis, and TGF-β signaling. Our differential correlation analysis of IOP-associated genes identified 295 pairs of 201 genes with differential correlation. Pathway analysis identified β-estradiol as the top upstream regulator of these genes with ESR1 mediating 25 interactions. Several genes (i.e., EFEMP1, FOXC1, and SPTBN1) regulated by β-estradiol/ESR1 were highly expressed in non-glaucomatous human trabecular meshwork (TM) or Schlemm’s canal (SC) cells and specifically expressed in TM/SC cell clusters defined by single-cell RNA-sequencing. We confirmed ESR1 gene and protein expression in human TM cells and TM/SC tissue with quantitative real-time PCR and immunofluorescence, respectively. 17β-estradiol was identified in bovine, porcine, and human aqueous humor (AH) using ELISA. In conclusion, we have identified estrogen receptor signaling as a key modulator of several IOP-associated genes. The expression of ESR1 and these IOP-associated genes in TM/SC tissue and the presence of 17β-estradiol in AH supports a role for estrogen signaling in IOP regulation.

Uncovering the differential impact of ESR1 and PIK3CA codon variants on the clinical phenotype of metastatic breast cancer (MBC) through circulating tumor DNA (ctDNA) next-generation sequencing (NGS).

1033 Background: The exposure to endocrine therapy (ET) can induce the onset of ESR1 gene alterations that have an impact on not only treatment resistance but also clinical phenotype. We previously demonstrated the potential of liquid biopsy in describing the metastatic behavior of MBC. The aim of this study was to explore the different clinical phenotype across the main ESR1 and PIK3CA codon variants. Methods: The study retrospectively analyzed a cohort of 501 MBC patients (pts) characterized for ctDNA through NGS before treatment start at Northwestern University (Chicago, IL), Massachusetts General Hospital (Boston, MA), CRO National Cancer Institute (Aviano, IT) and ASUFC Hospital (Udine, IT) between 2014 and 2020. Associations between clinical characteristics and ESR1 and PIK3CA codon variants were explored through logistic regression corrected for sites and ESR1/ PIK3CA status. Survival was tested through Cox regression both for progression-free survival (PFS) and overall survival (OS). Results: Of the total 501 pts, 289 (58%) were diagnosed with hormone-receptor positive (HRpos) MBC, 114 (23%) with HER2-positive MBC, and 93 (19%) with triple-negative MBC. ESR1 mutations were detected in 71 pts (14%) and PIK3CA in 154 pts (31%). The most represented ESR1 gene mutations were found in codons 380 (9%), 536 (23%), 537 (34%), and 538 (34%), while alterations in codons 542 (19%), 545 (21%), and 1047 (60%) were the most common for PIK3CA. As expected, ESR1 mutations were found only in HRpos pts previously exposed to ET (P < 0.001). No significant differences were observed for PIK3CA. After multivariable analysis, ESR1mutations were confirmed as highly associated with liver and bone metastases (OR 3.31, P < 0.001 and OR 5.09, P < 0.001). Moreover, an association with lung (OR 2.07, P = 0.010) was observed in this cohort. After multivariable analysis, codon 537 mutations were associated with bone involvement (OR 12.97, P = 0.014), codon 538 with liver (OR 4.73, P = 0.010), and codon 536 with soft tissue (OR 5.84, P = 0.006) and liver (OR 4.06, P = 0.048). PIK3CA mutations were associated with bone (OR 2.61, P < 0.001) and lung metastases (OR 1.62, P = 0.044). Specifically, codon 1047 mutations were the primary driver (OR 3.14, P = 0.001 and OR 1.97, P = 0.019). In HRpos MBC, baseline mutations in ESR1 codon 537 and 538 had a negative impact on OS (HR 3.73, P < 0.010 and HR 2.99, P < 0.021), while 380 and 536 had a negative impact on PFS (HR 18.98, P < 0.001 and HR 2.60, P = 0.015). No impact was observed across PIK3CA gene variants. Conclusions: This study showed the different tumor biology across ESR1 and PIK3CA gene variants. As novel selective estrogen receptor degraders (SERDS) and PIK3CA inhibitors are gaining momentum as new ET options in MBC, these results highlight the future pivotal role of ctDNA NGS in refining tumor biology characterization.

Еstrogen receptor α (ESR1) and SRC family kinase (LYN) gene's mutations associated with ovarian cancer endocrine therapy resistance

Recently multiple data accumulated concerning mutations in the ESR1 gene coding estrogen receptor α (mutESR1) and in the LYN gene coding non receptor tyrosine kinase SRC family member (mutLYN) that are associated with endocrine therapy resistance and that could be considered as markers of endocrine therapy efficiency. In case of gynecologic cancers including ovarian cancer the most frequent mutESR1 are ESR1L536H/P/R/V , ESR1Y537S/N/C/H, ESR1D538G that emerge in the course of hormonotherapy especially using aromatase inhibitors. mutLYN including LYNE159K, LYND189Y, LYNK209N, LYNA370T, LYNG418R, LYNA503D are also identified. mutESR1 and mutLYN increase transcriptional activity of estrogen receptor α (ERα) coded with ESR1 gene and catalytic activity of LYN kinase inducing endocrine therapy resistance. Interdependence of ESR1 and LYN genes is revealed at the level of proteins that they code as the kinases of the SRC family including LYN activate ERα-dependent transcription due to the phosphorylation of ERα at Y537 amino-acid residue that is the most frequently mutated in tumors with endocrine therapy resistance. The aim of the review is revealing the clinical correlations of mutESR1 and mutLYN with the ovarian cancer endocrine therapy resistance that opens perspectives of mutESR1 and mutLYN use as new predictive markers of ovarian cancer and development of more efficient anti-tumor medicaments. In the review the information obtained from PubMed database for the last 20 years using the following key words: ESR1, LYN, mutation(s), estrogen receptor α (ERα), LYN kinase, SRC family kinases, ovarian cancer, gynecologic(al) cancer is discussed.

Treatment algorithm for uterine leiomyoma for women of reproductive age taking into account genetic factors

The objective: to determine the association of estrogen receptor gene polymorphisms ESR1 and progesterone PGR with the development of uterine leiomyoma (UL) and to develop a patient management algorithm based on the results of ultrasound and genetic studiesMaterials and methods. Comprehensive examination was made for 90 women with intramural myoma in the age from 26 to 45 years, which additionally included determination of the presence of the Progins polymorphism of the PGR gene and polymorphic variants A351G and T397C of the ESR1 gene. Further treatment depended on the polymorphisms of the studied genes, the number and size of myomatous nodules (MN) and their position in relation to the uterine cavity.Results. Minor alleles for the estrogen receptor gene ESR1 T397C were detected in 87.2% of women with MN over 40 mm in diameter, while they were 54.2% in women with MN less than 20 mm (p<0.05). The minor alleles of ESR1 gene locus A351G were also significantly more common in women with large MN compared to LU less than 20 mm – 69.2% versus 37.5% (p<0.05). The polymorphism of the progesterone receptor regulator gene PGR Progins was found in 33.3% of patients with small size LU and from 7.7% to 18.5% in women with large LU and MN larger than 20 mm in diameter at ultrasound.Treatment was started with hormonal therapy and in the presence of the T1/T1 genotype of the PGR Progins gene and the absence of endometrial hyperplasia according to histological examination, was prescribed hormonal therapy with mifepristone 50 mg daily for 3 months, followed by monitoring of the course of the disease.GnRH agonists were prescribed as preoperative preparation in the case of detection of PGR Progins gene polymorphisms (T1/T2 or T2/T2 genotypes), endometrial hyperplasia and MN over 40 mm. In the case of small nodules that do not deform the uterine cavity and an ESR1 gene reference genotype, contraceptive OCs were recommended for six months or more to stabilise LU growth. MN over 30 mm distorting the uterine cavity and the presence of ESR1 minor alleles of the oestrogen receptor gene were the grounds for surgical treatment of such an LU.As a result of this approach, the incidence of pain syndrome decreased by almost 4.7 times, menstrual disorders in the form of hyperpolymenorrhoea and AUB by 8 times. An improvement in general well-being was subjectively reported by 64.4% of the patients, «without change» – by 24.4% of the patients. Only 11.1% of women reported a worsening of subjective sensations, which was associated with the side effects of therapy. The size of the lymph nodes decreased considerably in 44.4% of the patients, a partial effect was noticed by 26.7% of the women. There was observed no growth of the nodes in the patients during treatment or after it. A pregnancy occurred in 68.5% of the patients and ended in childbirth in 86.5% of cases.Conclusion. Consideration of the patient’s genetic status contributes to the improvement of LU treatment outcomes. The most effective is to prescript mifepristone in patients with MN under 40 mm, including multiple ones, when the operation is associated with a high risk. In the case of larger mets (over 50 mm), hormonal therapy is less effective and can be used for preoperative preparation. This approach allows to control symptoms and reduce the size of the node in 72.2% of patients and in 68.5% of cases the pregnancy can be achieved.