STUDYING CYTOTOXIC EFFECTS OF CYCLOHEXIMIDE ON COLON CANCER CELLS

Abstract

Cycloheximide (CHX) is reported to cause apoptosis in a variety of cells. Previous studies show that CHX can sensitize the cells to TNF-α-induced apoptosis in T lymphocyte cells, leukocytes, liver cancer cells and fibroblasts. However, a mechanism behind the cytotoxicity of CHX is not completely described. In present work, cytotoxic effects of CHX on colorectal adenocarcinoma cells Caco-2 were examined. CHX triggered cell death and the viability of Caco-2 cells decreased in a dose-dependent fashion. One hypothesis is that CHX causes production of reactive oxygen species that are tightly involved in several apoptotic pathways. ROS formation after treating Caco-2 cells with 0, 5, 15 and 30 μg/ml CHX was evaluated by a confocal microscope. The cells were stained with a fluorogenic MitoSOX dye that specifically targets mitochondria. MitoSOX is readily oxidized by ROS and the product of a such reaction shows fluorescence, which allows to stain mitochondria only when there is a ROS production. Caco-2 cells were positive for MitoSOX indicating that CHX treatment causes ROS formation. Furthermore, fluorescence intensity measurements displayed that ROS were produced in a dose-dependent manner. Future studies should focus on studying how ROS production is involved in CHX-mediated cell death