The Effect of Different Culture Conditions on The Cytotoxic Effect of Natural Killer Cell-Derived Extracellular Vesicles on Cancer Cells
Abstract
Natural Killer (NK) cells are immune cells that can kill cancer cells. Extracellular vesicles (EVs) derived from NK cells have been shown to induce apoptosis, or programmed cell death, in some cancer cell lines. NK-EVs may therefore mediate some of the cytotoxic effects of NK cells against cancer cells.
In this study, we investigated whether the effect of NK-EV-mediated killing on cancer cells would be affected by culturing the cancer cells in different commercial media containing low or high glucose concentrations (1 g/L or 4.5 g/L). Cancer cell apoptosis was measured by either cleavage of PARP1 by Western blot analysis or by activation of caspase 3/caspase 7 by flow cytometry after treating the cancer cells in different culture media with NK-EVs for 24 to 72 hrs. A reduced killing effect of NK-EVs was observed when cancer cells were cultured in high glucose containing medium. Further, the proliferation of the cancer cells grown in the different culture media was tested, showing that cells grown in low glucose medium grew faster. It was also attempted to measure lactate production from the cancer cells in order to study differences in metabolic pathways, but these studies were inconclusive due to technical difficulties.
In conclusion, this thesis provides a foundation for further studies of the role of glucose on the ability of NK-EVs to kill cancer cells.