ETS1 drives EGF-induced glycolytic shift and metastasis of epithelial ovarian cancer cells

Abstract

Epithelial ovarian cancer (EOC), a leading cause of gynecological cancer-related morbidity and mortality and the most common type of ovarian cancer (OC), is widely characterized by alterations in the Epidermal Growth Factor (EGF) signaling pathways. The phenomenon of metastasis is largely held accountable for the majority of EOC-associated deaths. Existing literature reports substantiate evidence on the indispensable role of metabolic reprogramming, particularly the phenomenon of the ‘Warburg effect’ or aerobic glycolysis in priming the cancer cells towards Epithelial to Mesenchymal transition (EMT), subsequently facilitating EMT. Considering the diverse roles of growth factor signaling across different stages of oncogenesis, our prime emphasis was laid on unraveling mechanistic details of EGF-induced ‘Warburg effect’ and resultant metastasis in EOC cells. Our study puts forth Ets1, an established oncoprotein and key player in OC progression, as the prime metabolic sensor to EGF-induced cues from the tumor microenvironment (TME). EGF treatment has been found to induce Ets1 expression in OC cells predominantly through the Extracellular Signal-Regulated Kinase1/2 (ERK1/2) pathway activation. This subsequently results in pronounced glycolysis, characterized by an enhanced lactate production through transcriptional up-regulation of key determinant genes of the central carbon metabolism namely, hexokinase 2 (HK2) and monocarboxylate transporter 4 (MCT4). Furthermore, this study reports an unforeseen combinatorial blockage of HK2 and MCT4 as an effective approach to mitigate cellular metastasis in OC. Collectively, our work proposes a novel mechanistic insight into EGF-induced glycolytic bias in OC cells and also sheds light on an effective therapeutic intervention approach exploiting these insights.