RalA regulates ROS and ATP production in cancer cells by association with cavelolin-1 / 医用生物力学

ABSTRACT

Objective By analyzing mitochondrial function, reactive oxygen species (ROS) and adenosine triphosphate (ATP) production under different levels of RalA and caveolin-1 (Cav-1) expression, to investigate the regulation role of RalA played in cancer metabolism and explore the possibility of its regulation role involved in Cav-1 and caveolae motility. Methods Firstly, RalA and Cav-1 expression were inhibited by siRNA in breast cancer cell line MDA-MB-231, and then the changes of mitochondrial membrane potential (MMP), ROS production, ATP generation and L-lactate level before and after inhibition were assessed by Western blotting, confocal microscope and fluorescence quantification. Results (1) The decreased RalA and Cav-1 expression led to a significant reduction of MMP directly. (2) Low RalA and Cav-1 expression resulted in an inhibition of ATP production and an increase of H2O2 generation. With the reduction of MMP, mitochondrial malfunction was observed. (3) With mitochondrial function suppression, an elevated level of glycolysis metabolite L-lactate was also detected in RalA and Cav-1 deprived cells. Conclusions RalA and Cav-1 mediate cellular metabolic switch by inhibiting mitochondrial function and simultaneously boosting glycolysis. This regulation role of RalA depends on its association with Cav-1, and possibly is related to the endocytosis and motility of caveolae. The research findings enrich the cancer metabolic studies, and provide a novel approach for cancer therapeutic strategy targeted to cellular metabolism.