title: The elevation of p53 protein level and SOD activity in the resident blood of the Misasa radon hot spring district.
abstract: To clarify the mechanism by which radon hot springs prevent cancer or not, in this study, blood was collected from residents in the Misasa hot spring district and in a control district. The level of a representative cancer-suppressive gene, p53, and the activity of a representative antioxidant enzyme, superoxide dismutase (SOD), were analyzed as indices. The level of serum p53 protein in the males in the Misasa hot spring district was found to be 2-fold higher than that in the control district, which is a significant difference. In the females in the Misasa hot spring district, SOD activity was approximately 15% higher than that in the control district, which is also statistically significant, and exceeded the reference range of SOD activity despite advanced age. These results suggested that routine exposure of the residents in the Misasa hot spring district to radon at a concentration about 3 times higher than the national mean induces trace active oxygen in vivo, potentiating products of cancer-suppressive gene and antioxidant function. As the p53 protein level was high in the residents in the Misasa hot spring district, apoptosis of cancer cells may readily occur.
authors.affiliation: Department of Radiological Technology, Okayama University Medical School, Okayama, Japan. yamaoka@md.okayama-u.ac.jp
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Yamaoka
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Mitsunobu
authors.forename: Shuji
authors.initials: S
authors.lastname: Kojima
authors.forename: Misako
authors.initials: M
authors.lastname: Shibakura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kataoka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hanamoto
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Tanizaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016902:Air Pollution, Indoor / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000097:blood; D004198:Disease Susceptibility / Q000097:blood* / Q000453:epidemiology*; D005260:Female; D005786:Gene Expression Regulation / Q000528:radiation effects*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011886:Radon / Q000032:analysis*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013223:Statistics as Topic; D013482:Superoxide Dismutase / Q000097:blood*; D016159:Tumor Suppressor Protein p53 / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53; D013482:Superoxide Dismutase; D011886:Radon