METFORMIN IN COMBINATION WITH GLUCOSE METABOLISM INHIBITORS PROMOTES AUTOPHAGY AND APOPTOSIS OF CANINE AND FELINE MELANOMA CELLS

PAN, MELISA; ARBE, MARÍA FLORENCIA; GLIKIN G.C.; FINNOCHIARO, LILIANA MARIA ELENA; VILLAVERDE M. S.

Congreso; Reunion Anual SAIC2019; 2019

We have previously demonstrated that Metformin (MET), the most wideworld prescribed hypoglycemic drug, has cytotoxic effects on different melanoma cell models. Furthermore, we described that not only the inhibition of the glycolytic but also the pentose phosphate pathway (PPP) potentiates the effect of MET. The aim of the present work was to study the mechanism involved in MET effectiveness alone or in combination with 2-deoxyglucose (2DG, HK inhibitor, first and limiting enzyme of Glycolysis) and 6-aminonicotinamide (6AN, G6PD inhibitor, the main and limiting enzyme of the PPP) on two melanoma cell lines, Sc (canine) and Dc (feline) derived from spontaneous tumors. In order to confirm the autophagic nature of the acridine orange positive vesicles (previously described by our group), Sc and Dc cells were lipofected with a plasmid construct containing LC3B gene tagged with the red fluorescent protein (RFP). After 48 h of treatment, we found that MET, MET-2DG and MET-6AN resulted in a cytoplasmic accumulation of LC3B-RFP protein also confirmed by immunofluorescence. in both melanoma cell lines. In addition, MET-6AN autophagic vesicles were inhibited by chloroquine (an autophagy inhibitor) in both cell lines (p