The Liver X Receptor interferes with Estrogen Receptor-dependent genomic regulation in breast cancer cells

EVELYN OLSZANOWSK; MARIA FLORENCIA OGARA; AGUSTINA L. LAFUENTE; A. SILVINA NACHT; BELÉN BENITEZ; RODRÍGUEZ-SEGUÍ, SANTIAGO A.; DIEGO M PRESMAN; GUILLERMO VICENT; ADALI PECCI

Rosario

Congreso; SAIB2023; 2023

SAIB

Liver X Receptors (LXRs) belong to the nuclear receptors superfamily of ligand activated transcription factors, whose endogenous agonists are the oxysterols. They play a key role in the regulation of the cholesterol homeostasis, induce the de novo synthesis of triacylglycerides, and counteract pro-inflammatory effects. LXRs are also known to compromise cell proliferation in several cancer models. However, their role in breast cancer (BC) has not been studied in depth and reports are, in fact, contradictory. Here, we have examined the potential involvement of LXRs in BC cells with special emphasis on their possible crosstalk with the Estrogen Receptor alpha (ERɑ). We performed colony formation (CFA) and propidium iodide staining assays in MCF-7 cells treated with or without Estradiol (E2) and the LXR agonist, GW3965. Our results showed that GW3965 impaired the cell proliferation capacity induced by E2 (CFA: #colonies, Mean±SD: E2 208.7±25.7; E2+GW3965 131.3±23.7, n=3, padj