Abstract 3360: Loss of sulf-1 reprograms energy metabolism in ovarian cancer

Abstract

Abstract We have previously shown that loss of HSulf-1, an endosulfatase that removes 6-O sulfation of HSPGs augmented heparin binding growth factor (HB-GF) signaling resulting in enhanced tumorigenesis, angiogenesis and metastasis in ovarian cancer. However, the role of HSulf-1 in energy metabolism and how the increased growth factor signaling in cells with loss of HSulf-1 altered cellular metabolism in cancer yet to be investigated. Here, we show for the first time that batch clonal lines of HSulf-1 knockdown cells [OV202 (Sh1/2)] and HSulf-1 knock out (KO) MEFs showed a significantly higher glycolytic flux (glucose uptake and lactate production) and reduced oxygen consumption rate (OCR) compared to a non-transduced control (OV202NTC) and wild-type (WT) MEF cells respectively. Conversely, enhanced expression of HSulf-1 in TOV21G cells resulted in lower glycolytic flux and higher OCR. Microarray analysis revealed that several of the genes in the glycolytic pathway such as Glut1, HK2, PFKFB3, ALDOC, PGAM, PKM2 and LDHA were upregulated in Sh1/2, cells compared to NTC cells. Expression of these genes and their respective products were validated both at the mRNA and protein levels in OV202Sh1/2, TOV21G Vec and MEFs KO cells compared to OV202NTC, TOV21G Cl13 and MEF WT respectively. Importantly, we found that loss of HSulf-1 decouples the energy flow from glycolysis to mitochondria by lowering the PDH and up-regulating PDK1 expression. We further demonstrated that loss of HSulf-1 reduced the total cellular ATP levels in Sh1/Sh2, TOV21G VEC, and MEFs KO cells, all consistent with lower mitochondrial activity as evidenced by decreased total number of mitochondria, its cross sectional area and perimeter in Sh1/Sh2, TOV21G Vec and MEF KO cells. This augmented aerobic glycolysis with loss of HSulf-1 was further corroborated by metabolomics study which showed significantly higher glycolytic metabolites such as G-6P, F1,6BP, F2,6BP, 3PG. While most of the TCA intermediates were downregulated in Sh1 and Sh2 cells; glutamate, glutamine, α-ketoglutarate and 2-hydroxyglutarate were higher upon loss of HSulf-1. These results suggests that loss of HSulf-1 plays a pivotal role in reprogramming the energy metabolism towards the Warburg effect which are critical to sustain cancer cells proliferation, transformation and angiogenesis. Citation Format: Susmita Mondal, Debarshi Roy, Juliana Camacho Pereira, Eduardo N. Chini, Vijayalakshmi Shridhar. Loss of sulf-1 reprograms energy metabolism in ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3360. doi:10.1158/1538-7445.AM2014-3360