Journal of Radiation Research Editorial Committee Acta Medica Okayama 0449-3060 46 1 2005 The Elevation of p53 Protein Level and SOD Activity in the Resident Blood of the Misasa Radon Hot Spring District 21 24 EN Kiyonori Yamaoka Fumihiro Mitsunobu Shuji Kojima Misako Shibakura Takahiro Kataoka Katsumi Hanamoto Yoshiro Tanizaki 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. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 56 5 2002 Camptothecin induces urokinase-type plasminogen activator gene-expression in human RC-K8 malignant lymphoma and H69 small cell lung cancer cells. 223 227 EN Misako Shibakura Kenji Niiya Toru Kiguchi Yasunari Nakata Mitsune Tanimoto Article 10.18926/AMO/31706 <p>We previously reported that anthracyclines, which could generate reactive oxygen species (ROS), could induce the urokinase-type plasminogen activator (uPA) gene expression in human RC-K8 malignant lymphoma cells and in H69 small cell lung cancer (SCLC) cells. In screening other uPA-inducible anti-cancer agents, we found that camptothecin (CPT) and its derivative, SN38, could induce uPA in RC-K8 and H69 cells. CPT and SN38, which are also used for the treatment of lymphoma and SCLC, significantly increased the uPA accumulation in the conditioned media of both cells in a dose-dependent manner. The maximum induction of uPA mRNA levels was observed 24 h after stimulation. Pretreatment with pyrrolidine dithiocarbamate (PDTC), an anti-oxidant, inhibited the CPT-induced uPA mRNA expression. Thus, CPT induces uPA through gene expression, and, therefore, CPT may influence the tumor-cell biology by up-regulating the uPA/plasmin system.</p> No potential conflict of interest relevant to this article was reported.

岡山大学医学部保健学科 Acta Medica Okayama 1345-0948 16 2 2006 国際交流に向けてのスタート 93 94 EN Kiyoko Fukai Toshizo Katsuda Mari Kondo Misako Shibakura Shoji Asari No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2003 INDUCTION OF IL-8 AND MONOCYTE CHEMOATTRACTANT PROTEIN-1 BY DOXORUBICIN IN HUMAN SMALL CELL LUNG CARCINOMA CELLS EN Misako Shibakura No potential conflict of interest relevant to this article was reported.