Project description:To examine the effects of ERα antagonism (giredestrant) on Esr1-wildtype and Esr1-mutant mammary glands, animals were treated with hormone pellets (E2, P4), then dosed daily with vehicle (MCT) or giredestrant (30 mg/kg, p.o.) for four days. Following dosing, individual mammary epithelial cell populations were FACS-isolated and sequenced. Rare giredestrant-induced novel cells (at least 1000 cells per sample) were collected from WT tissues and compared to mutant-induced novel cells.
Project description:To examine the effects of ERα antagonism (giredestrant) on Esr1-wildtype and Esr1-mutant mammary glands, animals were treated with hormone pellets (E2, P4), then dosed daily with vehicle (MCT) or giredestrant (30 mg/kg, p.o.) for four days. Following dosing, individual mammary epithelial cell populations were FACS-isolated and sequenced.
Project description:To examine the effects of ERα antagonism (giredestrant) on Esr1-wildtype and Esr1-mutant mammary glands, animals were treated with hormone pellets (E2, P4), then dosed daily with vehicle (MCT) or giredestrant (30 mg/kg, p.o.) for four days. Following dosing, individual mammary epithelial cell populations were FACS-isolated and sequenced.
Project description:To examine the effects of ERα antagonism (giredestrant) on Esr1-wildtype and Esr1-mutant mammary glands, animals were treated with hormone pellets (E2, P4), then dosed daily with vehicle (MCT) or giredestrant (30 mg/kg, p.o.) for four days. Following dosing, EpCAM+ cells were isolated and used for single cell sequencing. For each condition, cells from 2 animals were pooled for sequencing.
Project description:Estrogen Receptor alpha (ERα), a nuclear receptor with transcriptional activity, is a master regulator of estrogen signaling, widely known as therapeutic target in hormone-responsive breast cancer (BC). Moreover, ERα is highly expressed in approximately 80% of High Grade Serous Ovarian Cancer (HGSOC), the most common epithelial ovarian carcinoma. Despite some promising clinical trials evaluating endocrine therapy in this type of tumor, the role of ERα is still unknown. Epigenetic changes, such as DNA methylation, are emerging as key contributing factors to carcinogenesis. Disruptor of telomeric silencing-1-like (DOT1L), the only known histone methyl transferase capable to produce H3K79 mono, di and tri-methylation, modulates ERα actions in hormone-responsive BC. Considering this evidence, ERα-DOT1L association was confirmed in ERα-positive OC cells, PEO1 and PEO4, by Co-IP. DOT1L pharmacological inhibition by EPZ004777 (EPZ) revealed the involvement of this epigenetic enzyme in cell proliferation, cell cycle progression and apoptosis. Transcriptome profiling after ICI (a Selective Estrogen Receptor Degrader) and EPZ treatment, in both cell lines, has underlined a deep impact of both compounds on ERα-modulated genes, including the down-regulation of ERα itself. On the other hand, functional analysis showed that commonly affected transcripts are involved in different cellular processes, such as cancer cell survival, chemoresistance and cell cycle progression. Moreover, ChIP-qPCR performed on ERα promoter highlighted ERα and DOT1L co-localization, both in PEO1 and in PEO4 cells, which was reduced after EPZ treatment, suggesting a role of this complex on receptor transcriptional activity. In addition, drug combination studies performed with EPZ and ICI showed an additive effect in cell growth inhibition. Taken together, these results suggest DOT1L as a potential therapeutic target in the treatment of OC.
Project description:Estrogen Receptor alpha (ERα) is the primary driver in ER+ breast cancer and can be targeted using small molecules such as fulvestrant, a selective estrogen receptor degrader (SERD). Despite being approved over two decades ago and used regularly in post-menopausal women, its precise anti-tumor mechanism remains unclear, with several reports showing efficacy without the requirement for ERα degradation. To investigate the molecular basis of fulvestrant’s action, we employed split intein-based µMap photo-proximity labeling to profile ERα-associated interactions. Our findings reveal that fulvestrant displaces oncogenic interactions induced by estradiol and promotes ERα translocation to promyelocytic leukemia (PML) nuclear bodies, leading to altered transcriptional signatures and senescence. Overall, this study offers new insights into SERD mechanism of action and establishes a framework for evaluating additional ERα modulators and degraders.
Project description:To better understand the role of SRC-1 in estrogen signaling in bone, a genome-wide analysis of ERα and SRC-1 binding sites in the absense and presence of E2 was conducted.