Effects of 3-Bromo-2-oxopropionic acid and LiCl treatment combined with electroporation on apoptotic and metabolic responses in DLD-1 colon cancer cells.

Colon cancer is particularly increasing in incidence in developed countries, and it ranks first in terms of morbidity and mortality worldwide. As in other types of cancer, metabolic changes and cellular death mechanisms play a critical role in cancer treatment. Cancer cells prefer glycolysis for energy production even in the presence of oxygen; this phenomenon is known as the Warburg effect. Glycolysis, which is essentially an anaerobic process, provides metabolic adaptation by preventing mitochondrial oxidative phosphorylation in cancer cells. Electroporation (EP) is a method that increases the uptake of drugs into the cell by creating temporary pores in the cell membrane. 3-Bromo-2-oxopropionic acid and Lithium chloride (LiCl) are agents that may show anticancer potential through different mechanisms. The aim of this study was to investigate the potential anticancer effects of the EP-assisted combination of 3-Bromo-2-oxopropionic acid and LiCl agents in DLD-1 colon cancer cells and to evaluate how these effects occur at the level of cell viability, apoptotic activity and metabolic markers. In the study, cell viability was evaluated by WST-8 tetrazolium based colorimetric method. Within the scope of analysis of apoptotic activity and metabolic responses; caspase-3, Phosphatidylinositol 3-kinase (PI3K) and Glucose transporter-1 (GLUT-1) levels were determined by ELISA method. While no change in cell viability was observed at 10 and 20 µM doses of 3-Bromo-2-oxopropionic acid, a significant decrease was detected in its combination with EP. IC value was determined as 37.99 ± 2.34 µM in a single application and as 27.33 ± 1.99 µM in its combination with EP. While low doses of LiCl (5 and 10 mM) did not affect cell viability, a significant decrease was detected at doses of 50, 75 and 100 mM. In its combination with EP, a significant loss of viability was observed even at low doses and the IC value decreased from 98.92 ± 0.64 mM to 81.88 ± 1.64 mM. A decrease in IC doses is observed in the treatment with the combination of both 3-Bromo-2-oxopropionic acid and LiCl with EP. The combined treatment enables the same lethal effect on cancer cells with lower drug doses. Caspase-3 activity increased significantly in combined applications with EP. While 3-Bromo-2-oxopropionic acid alone did not change the level of PI3K, it caused a significant increase in its combination with EP. While LiCl caused an increase in the level of PI3K at low doses, a decrease was detected in its combination with EP. Regular partial increases in GLUT-1 level were determined in a dose-dependent manner in 3-Bromo-2-oxopropionic acid treatment alone. A similar increase was determined at 20 and 30 µM doses combined with EP, while a decrease occurred at 40 µM. While no significant increase was detected in GLUT-1 levels compared to the control group in 10 mM LiCl treatment alone and in combination with EP, a significant increase was detected in 50 and 75 mM LiCl doses compared to the control group. In conclusion, 3-Bromo-2-oxopropionic acid and LiCl show anticancer potential by affecting apoptotic and metabolic processes, and their combination with EP increases these effects. In order to explain the effectiveness of these treatment approaches from every perspective, it is recommended to conduct in vitro studies on different colon cancer cell lines and evaluate them with more comprehensive in vivo and clinical studies.