Abstract 288: Glycolysis is enriched to propagating waves in cell cortex as a new mechanism for cancer progression
Authors: Zhan Huiwang David , Borleis Jane , Janetopoulos Chris , Devreotes Peter 
Published: April 2023

Abstract
Tumors preferentially metabolize glucose anaerobically through glycolysis with lower ATP production efficiency rather than aerobically even when oxygen is available. This was reported by Otto Warburg 100 years ago, yet the mechanism is hitherto not well-understood. Glycolysis is canonically thought to occur only in cytosol; if and how it is regulated by the actin cytoskeletal network is controversial. I found that, in epithelial cells, 6 of the 9 glycolytic enzymes (HK, PFK, ALDO, GAPDH, ENO, and PK, others not tested) are enriched at newly formed LifeAct labeled waves and protrusions, where mitochondria are barely detected by Mito-Tracker. The application of glycolysis inhibitors but not oxidative phosphorylation inhibitors abolishes cell migration. These results indicate that cells rely on the local ATP production from glycolysis enriched in the cortical waves and protrusions to move. We visualized and measured glycolysis production in confocal and TIRF microscopes using a series of biosensors for ATP, NADH/NAD+ ratio, and pyruvate. We then found glycolysis was enhanced by perturbations that increase wave formation such as EGF/Insulin stimulation or recruiting ActA to membrane, and reduced by wave decrease from PI3K inhibition, hyper- and hypo-osmotic shock, or F-actin assembly inhibition. This suggests that enriching glycolytic enzymes on waves results in higher glycolysis production. We do not think the changes of glycolysis by wave perturbations are merely due to direct regulation on glycolytic enzymes by canonical signaling pathways (e.g., Ras-PI3K-AKT), since ActA recruitment or F-actin inhibition does not lead to acute changes in these signaling pathways but mainly causes the assembly or disassembly of the F-actin/glycolytic waves. These findings together lead to our new theory that energy production from glycolysis is enhanced by recruiting the glycolytic enzymes to the waves and protrusions on the cell cortex. This is potentially paradigm-shifting because for many decades glycolysis - one of the two major ways in a cell to produce ATP - has been thought to only occur in cytosol. Interestingly, we also found glycolytic enzymes enriched in F-actin labeled protrusions of Dictyostelium cells, which indicates that this can possibly be an evolutionally conserved mechanism. Additionally, we investigated non-cancer MCF-10A cells (M1) and a series of M1-derived cancer cell lines (M2 - M4) with increased metastatic index and cancer malignancy, and found a sequential increase in actin wave and glycolysis activities from M1 to M4 cells. Cancer cells such as M3 had a larger drop in glycolysis than non-cancer parental M1 cells upon wave inhibition. These results provide a new explanation for the Warburg effect that increased cortical waves in cancer cells will accelerate and improve glycolysis, which will not only greatly contribute to our understanding of cancer but also the design of new interventions.
Citation Format: Huiwang David Zhan, Jane Borleis, Chris Janetopoulos, Peter Devreotes. Glycolysis is enriched to propagating waves in cell cortex as a new mechanism for cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 288.