Effects of thiazole derivatives on intracellular structure and functions in murine lymphoma cells

Thiazole derivatives have cytotoxic effects towards tumor cells, such as glioblastoma, melanoma, leukemia and lymphoma. However, the intracellular mechanism of this action is not clear. The aim of our study was to investigate the action of N-(5-benzyl-1,3-thiazol-2-yl)-3,5-dimethyl-1-benzofuran-2-carboxamide (BF1) and 7-benzyl-8-methyl-2-propylpyrazolo[4,3-e]thiazolo[3,2-a]pyrimidin-4(2H)-one (PP2) on cellular structure, and bioenergetic functions of mitochondria in Nemeth-Kellner lymphoma cells (NK/Ly). The structure of treated NK/Ly cells and their mitochondria was examined using electron microscopy. The rate of oxygen uptake by isolated mitochondria was recorded by a polarographic method using a Clark electrode. The mitochondrial potential relative values were registered using fluorescence dye rhodamine 123. In the short-term (15 min), incubation with BF1 and PP2 in 10 and 50 μM concentrations induced apoptotic and necrotic changes in the structure of NK/Ly cells, such as fragmentation and disintegration of the nucleus, destruction of the plasma membrane, and an increase in numbers of lysosomes and mitochondria. a polarographic method did not show significant metabolic shifts in lymphoma mitochondria, in either in vitro or ex vivo actions of the thiazole derivatives. However, fluorescent microscopy showed a significant decrease in mitochondria potential, following a 15 min incubation of cells with 50 μM of PP2. Thus, the electron and fluorescent microscopy data suggest that mitochondria are involved in the mechanism of cytotoxic action of the studied thiazole derivatives.