Abstract: Objective To investigate programmed cell death induced by temozolomide in rat glioma C6 cell line. Methods Rat
glioma C6 cell line was treated by temozolomide at different concentrations and for different time lengths. MTT assay was
used to evaluate the cell inhibition rate to determine the optimal exposure time and concentration. After the exposure to 400
μg/ml temozolomide for 24 h, the cells were observed for programmed cell death using HE staining, Hochest and Tunnel
assay, Western blotting, and immunohistochemistry. Results MTT, HE staining, and Hochest and Tunnel assay all showed
temozolomide-induced apoptosis in rat glioma C6 cell line. Western blotting and immunohistochemistry revealed
up-regulation of Bax and down-regulation of Bcl-2 expression in the exposed cells, where the expressions of caspases 3, 8, 9,
and 12 remained unchanged. Conclusion Temozolomide induces apoptosis in rat glioma C6 cell line through a caspaseindependent
pathway.