Effects of Extremely Low Frequency Elecromagnetic Fields on Thyroid Carcinogenesis Induced by N-bis(2-hydroxypropyl)nitrosamine and Sulfadimethoxine.
10.4174/jkss.2009.77.3.161
- Author:
Soo Hwan LEE
1
;
Young Jin PARK
;
Eon Sub PARK
;
Young Seok KIM
;
Yoo Shin CHOI
;
Beom Gyu KIM
;
Sung Jun PARK
;
Se Min CHONG
Author Information
1. Department of Surgery, College of Medicine, Chung-Ang University, Seoul, Korea. kimbg0526@paran.com
- Publication Type:Original Article
- Keywords:
Extremely low frequency magnetic field;
Thyroid carcinogenesis;
N-bis(2-hydroxypropyl)nitrosamine (DHPN);
Apoptosis;
Cell cycle-related proteins
- MeSH:
Adenoma;
Animals;
Apoptosis;
Caspase 3;
Cell Cycle;
Cell Proliferation;
Cell Transformation, Neoplastic;
Cyclin D1;
Drinking Water;
Electromagnetic Fields;
Humans;
Hyperplasia;
Male;
Nitrosamines;
Proteins;
Rats;
Rats, Inbred F344;
Sulfadimethoxine;
Thyroid Gland
- From:Journal of the Korean Surgical Society
2009;77(3):161-169
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Long-term exposure to extremely low-frequency (60 Hz) electromagnetic fields (ELF-EMF) raises the questions of the induction of biological effects including tumorigenesis. One mechanism through which ELF-MFS could influence neoplastic development is the imbalance of cellular proliferation and cell apoptosis. The present study investigated the effect of ELF-EMF on chemically-induced thyroid carcinogenesis in a rat. METHODS: We examined cellular proliferation index measured by anti-Ki-67 antigen, apoptosis, apoptosis related proteins such as caspase 3 and p53, and cell cycle-related proteins (cyclin D1 and p21(WAF1/Cip1)). Forty Male F344 rats received a subcutaneous N-bis(2-hydroxypropyl)nitrosamine (DHPN, 2,800 mg/kg) injection, and 1 week later were allowed free access to drinking water containing sulfadimethoxine (0.1%) for 12 weeks. Twenty rats were exposed by ELF-EMF. During the carcinogenesis, sequential histological changes from hyperplasia, adenoma, and ultimately to overt carcinomas were noted. RESULTS: The exposure group of ELF-EMF, significantly increases the number size of carcinomas. Also, the proliferative and apoptotic indices were significantly increased in the ELF-EMF exposure group than in the control group. The caspase 3 protein expression did not show any significant changes between ELF-EMF group and control group. The p53 protein was not detected in both ELF-EMF exposure and control group. Among the cell cycle related proteins, cyclin D1, not p21(WAF1/Cip1), was significantly increased in adenomas and carcinomas in ELF-EMF exposure group compared with the control group. CONCLUSION: Exposure of ELF-EMF effects on chemically-induced rat thyroid carcinogenesis as results of altered increase of cellular proliferation, apoptosis, and cyclin D1 expression.
