Tumor cell cholesterol depletion and V-ATPase inhibition as an inhibitory mechanism to prevent cell migration and invasiveness in melanoma

• Published in: Biochimica et biophysica acta Vol. 1862; no. 3; pp. 684 - 691
• Main Authors: Costa, Gildeíde Aparecida, de Souza, Sávio Bastos, da Silva Teixeira, Layz Ribeiro, Okorokov, Lev A., Arnholdt, Andrea Cristina Vetö, Okorokova-Façanha, Anna L., Façanha, Arnoldo Rocha
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2018
• Subjects: Antimetastatic target; Cholesterol rafts; Proton pumps; Proton pumps; SIET; Cholesterol rafts; PMSF; MβCD; Antimetastatic target; EDTA
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2017.12.006

V-ATPase interactions with cholesterol enriched membrane microdomains have been related to metastasis in a variety of cancers, but the underlying mechanism remains at its beginnings. It has recently been reported that the inhibition of this H+ pump affects cholesterol mobilization to the plasma membrane. Inhibition of melanoma cell migration and invasiveness was assessed by wound healing and Transwell assays in murine cell lines (B16F10 and Melan-A). V-ATPase activity was measured in vitro by ATP hydrolysis and H+ transport in membrane vesicles, and intact cell H+ fluxes were measured by using a non-invasive Scanning Ion-selective Electrode Technique (SIET). Cholesterol depletion by 5mM MβCD was found to be inhibitory to the hydrolytic and H+ pumping activities of the V-ATPase of melanoma cell lines, as well as to the migration and invasiveness capacities of these cells. Nearly the same effects were obtained using concanamycin A, a specific inhibitor of V-ATPase, which also promoted a decrease of the H+ efflux in live cells at the same extent of MβCD. We found that cholesterol depletion significantly affects the V-ATPase activity and the initial metastatic processes following a profile similar to those observed in the presence of the V-ATPase specific inhibitor, concanamycin. The results shed new light on the functional role of the interactions between V-ATPases and cholesterol-enriched microdomains of cell membranes that contribute with malignant phenotypes in melanoma. •V-type H+-ATPase activity is dependent on cholesterol membrane microdomains•Cholesterol depletion inhibits H+ efflux in live tumor cells•This disrupts extracellular and cytoplasmic pH signatures required for tumor cell migration and invasion