The cytotoxic activity of oxysterols, 7β-hydroxycholesterol (7β-OHC) and 25-hydroxycholesterol (25-OHC), has been evaluated using various leukemia cell lines. Among the tested cell lines, both oxysterols showed the highest cytotoxicity to THP-1, human monocytic leukemia cell line. These oxysterols induced apoptosis through down-regulation of Bcl-2 expression and activation of caspases. Also, the oxysterols showed the accumulation at G2/M phase of cell cycle through down-regulation of cyclin B1 expression. Taken together, these results indicated that both 7β-OHC and 25-OHC inhibited the proliferation of THP-1 cells through apoptosis and cell cycle accumulation at G2/M phase.
- Cell cycle