High glucose levels promote glycolysis and cholesterol synthesis via ERRα and suppress the autophagy–lysosomal pathway in endometrial cancer
Abstract
Endometrial cancer (EC) patients with Diabetes Mellitus (DM) always have a poor prognosis. Estrogen-related receptor α (ERRα) is known as the metabolic-related prognostic factor for EC. However, the mechanism linking glycolipid metabolism dysfunction mediated by ERRα to poor prognosis of EC with DM is still unclear. In vitro, high-glucose (HG) levels showed enhancement of ERRα expression, cell proliferation, and inhibition of the autophagic lysosomes and apoptosis by flow cytometry analysis, transmission electron microscopy, and CCK-8 assays. Mechanistically, lose-and-gain function assay, DNA sequencing, and CO-IP revealed HG increased ERRα expression to promote the transcription of HK2 and HMGCS1, which were the key rate-limiting enzyme of glycolysis-cholesterol synthesis and their metabolites suppressed the autophagy–lysosomal pathway in an ERRα-dependent manner. Furthermore, CO-IP and molecular dynamics simulation uncovered the protein residues (ARG 769HK2 vs. ARG 313HMGCS1) of HK2 and HMGCS1 could bind to p62 to form stable protein complexes involved in the autophagy–lysosomal pathway. In EC tissue from patients with comorbid DM, ERRα was significantly higher expressed compared to EC tissue from patients without evidence for DM (p < 0.05). The 3D EC organoid model with HG stimulation showed that the cell viability of XCT790 + carboplatin treatment was similar to that of metformin+carboplatin treatment, while the obviously bigger volume of organoids was more visible in the metformin+carboplatin group, indicating the therapy of XCT790 + carboplatin had the better inhibition of EC organoids with the same carboplatin dose. Besides insights into the interaction of HG and the autophagy–lysosomal pathway via ERRα, our present study points out the potential benefit of targeting ERRα in patients with EC with dysregulation of glucose and cholesterol metabolism.
