A Novel Chenodeoxycholic Derivative HS-1200 Enhances Radiation-induced Apoptosis in Human MCF-7 Breast Cancer Cells.
- Author:
Hyung Sik LEE
1
;
Young Min CHOI
;
Hyuk Chan KWON
;
Yeon Suk SONG
Author Information
1. Department of Radiation Oncology, College of Medicine, Dong A University, Busan, Korea. hyslee@daunet.donga.ac.kr
- Publication Type:Original Article
- Keywords:
Synthetic bile acid;
HS-1200;
Apoptosis;
Radiation-induced apoptosis;
MCF-7
- MeSH:
Apoptosis*;
Atmosphere;
Bile;
Blotting, Western;
Breast Neoplasms*;
Breast*;
Cell Survival;
Chenodeoxycholic Acid;
Cytochromes c;
Electrophoresis, Agar Gel;
Humans*;
MCF-7 Cells;
Membrane Potential, Mitochondrial;
Mitochondria;
Radiation Tolerance
- From:The Journal of the Korean Society for Therapeutic Radiology and Oncology
2004;22(2):145-154
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: To examine whether a synthetic bile acid derivatives (HS-1200) sensitizes the radiation-induced apoptosis in human breast cancer cells (MCF-7) and to investigate the underlying mechanism. MATERIALS AND MEHTODS: Human breast cancer cells (MCF-7) in exponential growth phase were treated with HS-1200 for 24 hours at 37degrees C with 5% CO2 in air atmosphere. After removal of HS-1200, cells were irradiated with 2~8 Gy X-ray, and then cultured in drug-free media for 24-96 hours. The effect of radiation on the clonogenicity of MCF-7 cells was determined with clonogenic cell survival assay with 16muM of HS-1200. The induction of apoptosis was determined using agarose gel electrophoresis and Hoechst staining. The expression level of apoptosis-related molecules, such as PARP, Bax, Bcl-2, Bak and AIF, were assayed by Western blotting analysis with 40muM of HS-1200 combined with 8 Gy irradiation. To examine the cellular location of cytochrome c, bax and AIF immunofluorescent stainings were undertaken RESULTS: Treatment of MCF-7 cells with 40muM of HS-1200 combined with 8 Gy irradiation showed several changes associated with enhanced apoptosis by agarose gel electrophoresis and Hoechst staining. HS-1200 combined with 8 Gy irradiation treatment also enhanced production of PARP cleavage products and increased Bax/Bcl-2 ratio by Western blotting. Loss of mitochondrial membrane potential (delta psi m) and increased cytochrome c staining indicated that cytochrome c had been released from the mitochondria in HS-1200 treated cells. CONCLUSION: We demonstrated that combination treatment with a synthetic chenodeoxycholic acid derivative HS-1200 and irradiation enhanced radiation-induced apoptosis of human breast cancer cells (MCF-7). We suggest that the increased Bax/Bcl-2 ratio in HS-1200 co-treatment group underlies the increased radiosensitivity of MCF-7 cells. Further futures studies are remained elusive.
