RESUMO
AIM: The apoptotic effect of geldanamycin derivative may be important for the colorectal cancer therapy. The mechanisms of apoptosis require understanding of the behavior of colon cancer cell line Colo-205 which mimics colon adenocarcinoma. Therefore, the effect of IC50 dose of 17-allylamino-17-demethoxygeldanamycin (17-AAG) on the colon cancer cells in vitro was studied for its anti-apoptotic activity. METHOD: Apoptotic ratio of the Colo-205 cells was determined after 17-AAG application with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and apoptosis related genes. Apoptosis signal path related key mitochondrial proteins, cytochrome c, bcl-2, caspase 9 and Apaf-1 expression were examined with RT-PCR method. RESULTS: 17-AAG caused induction of cell death. Apoptotic related genes such as cytochrome-c, Apaf-1 and caspase-9 protein expressions were increased significantly (p < 0.05) and anti-apoptotic bcl-2 expression was decreased significantly (p < 0.05). Our results indicated that the application of 17-AAG on Colo-205 cells showed anticancer effect by the apoptosis due to alteration of apoptotic genes. CONCLUSION: The apoptotic effect of 17-AAG as an natural product for alternative medicine would be very important for the success and quality of life during the treatment of colon carcinoma with the combination of anticancer drugs (Tab. 1, Fig. 2, Ref. 32).