Different Expressions of HIF-1alpha, Bcl-2 and Baxin DU145 Prostate Cancer Cells Transplanted in Nude Mouse between X-Ray and Neutron Irradiation.
10.3857/jkstro.2009.27.4.218
- Author:
Moonkyoo KONG
1
;
Jin Oh KANG
;
Sang Ki KIM
;
Dong Oh SHIN
;
Seo Hyun PARK
;
Chang Ju KIM
;
Hyun Kyung CHANG
Author Information
1. Department of Radiation Oncology, Kyung Hee University School of Medicine, Seoul, Korea. kangjino@paran.com
- Publication Type:Original Article
- Keywords:
HIF-1alpha;
Bcl-2;
Bax;
Neutron;
Prostate cancer
- MeSH:
Animals;
Apoptosis;
Blotting, Western;
Cell Line;
Humans;
In Situ Nick-End Labeling;
Mice;
Mice, Nude;
Neutrons;
Prostate;
Prostatic Neoplasms;
Transplants
- From:The Journal of the Korean Society for Therapeutic Radiology and Oncology
2009;27(4):218-227
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: To investigate the radiobiologic effects of neutron and X-ray irradiation on DU-145 prostate carcinoma cells by identifying the differences of HIF-1alpha expression and apoptosis. MATERIALS AND METHODS: Nude mice were injected with the human prostate cancer cell line, DU-145, and then irradiated with 2 Gy and 10 Gy X-rays, or 0.6 Gy and 3.3 Gy neutrons, respectively. The mice were sacrificed at 24 hours and 120 hours after irradiation. The expression levels of HIF-1alpha, Bcl-2 and Bax were compared with immunohistochemical staining and western blotting. The apoptotic indexes were compared with the Terminal deoxynucleotidyl biotin-dUTP nick and labeling (TUNEL) assay. RESULTS: At day 1, HIF-1alpha and Bcl-2 expression decreased, while Bax expression and the number of TUNEL positive cells increased in neutron irradiated groups for the control and X-ray irradiated groups. The Bcl-2/Bax ratio was significantly lower in the neutron irradiated groups regardless of dose (p=0.001). The same pattern of the differences in the expressions of the HIF-1alpha, Bcl-2, Bax, Bcl-2/Bax ratio, and apoptotic indexes were indentified at day 5. HIF-1alpha expression was related with Bcl-2 (p=0.031), Bax (p=0.037) expressions and the apoptotic indexes (p=0.016) at day 5. CONCLUSION: Neutron irradiation showed a decrease in HIF-1alpha, Bcl-2 expression, and Bcl-2/Bax ratio, but increased Bax expression regardless of dose. This study suggests that the differences radiobiological responses between photon and neutron irradiation may be related to different HIF-1alpha expression and subsequent apoptotic protein expressions.
