Gildeíde Aparecida Costa1, Sávio Bastos de Souza1, Layz Ribeiro da Silva Teixeira2, Lev A Okorokov2, Andrea Cristina Vetö Arnholdt3, Anna L Okorokova-Façanha2, Arnoldo Rocha Façanha4. 1. Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ 28.013-600, Brazil. 2. Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil. 3. Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil. 4. Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ 28.013-600, Brazil. Electronic address: arnoldo@uenf.br.
Abstract
BACKGROUND: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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. GENERAL SIGNIFICANCE: 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.
BACKGROUND: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. METHODS: 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). RESULTS: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. CONCLUSIONS: 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. GENERAL SIGNIFICANCE: 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.
Authors: Gregory E Miner; Katherine D Sullivan; Chi Zhang; Logan R Hurst; Matthew L Starr; David A Rivera-Kohr; Brandon C Jones; Annie Guo; Rutilio A Fratti Journal: Traffic Date: 2019-09-02 Impact factor: 6.215