The balance between apoptosis and autophagy plays a key role in cancer biology and treatment strategies. The aim of this study was to assess the effect of the mTOR kinase inhibitor everolimus and chloroquine on the regulation of proliferation, caspase-3 activation, and apoptosis in melanoma cells. We studied the activity of caspase-3 and the levels of caspase-3 and -9 using the Western blot technique. Cellular apoptosis was examined using a DNA fragmentation assay, and changes in the cell nucleus and cytoskeleton were examined using fluorescence microscopy DAPI, OA/IP. We also studied the rearrangement of lipid structures using fluorescent dyes: Nile Red and Nile Blue. A low nanomolar concentration of the mTOR kinase inhibitor everolimus in combination with chloroquine activated the apoptosis process and decreased cell proliferation. These changes were accompanied by an obvious change in cell morphology and rearrangement of lipid structures. Alterations in lipid redistribution accompanying the process of apoptosis and autophagy are among the first to occur in the cell and can be easily monitored in in vitro studies. The combination of mTOR inhibitors and chloroquine represents a promising area of research in cancer therapy. It has the potential to enhance treatment efficacy through complementary mechanisms.
Keywords: apoptosis; chloroquine; everolimus; immunosuppressive treatment; lipids; melanoma.