Tohoku university school of medicine

We have focused our research on biological research for radiotherapy and effects of low dose irradiation. Our current research projects can be summarized as follows:
1. Mechanisms of cancer stem cell radioresistance.
Cancer stem cells are known to show resistance to ionizing radiation and some types of chemotherapeutic agent. The molecular mechanisms underlying this resistance have still to be elucidated. ATM, a key protein in DNA double-strand breaks repair, is suggested to be involved in cellar antioxidant ability and maintenance of cancer stem cell phenotype. We are investigating the molecular mechanisms and signal transduction pathways in these functions of ATM.
2. Roles of DNA double-strand breaks repair in radiation sensitivity
Cellular radiation sensitivity mainly depends on DNA double-strand breaks and their repair. Our aim of the investigation is radiation sensitization through regulation of DNA double-strand breaks repair.
3. Biological effects of low doses of ionizing radiation
Low doses of ionizing radiation show different biological effects compared with those induced by high doses of ionizing radiation. We have previously reported augmentation of immune responses and anti-tumor effects by low dose irradiation. Recent our interests are the molecular mechanisms of myocardial infarction and brain infarction induced by low dose and low dose rate irradiation.

1) Loss of life after evacuation: lessons learned from the Fukushima accident. Lnacet 379: 889-891 2012

2) Hosoi Y, Kapp LN, Murnane JP, Matsumoto Y, Enomoto A, Ono T, Miyagawa K: Suppression of anchorage-independent growth by expression of the ataxia-telangiectasia group D complementing gene, ATDC. Biochemical and Biophysical Research Communications 348: 728-734 2006

3) Src tyrosine kinase inhibitor PP2 suppresses ERK1/2 activation and epidermal growth factor receptor transactivation by X-irradiation. Biochemical and Biophysical Research Communications 342: 363-368 2006

4) Phosphorothioate oligonucleotides, suramin and heparin inhibit DNA-dependent protein kinase activity. British Journal of Cancer 86:1143-1149 2001

5) DNA-dependent protein kinase activity correlates with Ku70 expression and radiation sensitivity in esophageal cancer cell lines. Clinical Cancer Research 6:1073-1078 2000

radiation, radiation oncology, low dose radiation, DNA double strand breaks, DNA repair, radiation emergency medicine