Age dependence of neutron-induced medulloblastoma in Ptch1 heterozygous mice

2014 Fiscal Year Final Research Report

• Project/Area Number: 24700956
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Carcinogenesis
• Research Institution: National Institute of Radiological Sciences
• Principal Investigator: TSURUOKA Chizuru 独立行政法人放射線医学総合研究所, 放射線防護研究センター, 博士研究員 (60415411)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 中性子線 / 発がん / 被ばく時年齢依存性

Outline of Final Research Achievements

The available data on the carcinogenic mechanisms of neutron exposure in children are still limited. We examined the effects of neutron irradiation using Ptch1 heterozygous mice, which are prone to spontaneous and radiogenic medulloblastoma (MB), comparing with the effects of gamma-rays.
We found that the effects of gamma-rays and neutron radiation on MB induction were dependent on the age at exposure. The MB incidence was significantly higher for neutron irradiation compared with gamma-irradiation during the prenatal and early postnatal period. Irradiation with either gamma-rays or neutrons at postnatal day 10 resulted in MB incidence lower than spontaneous MB. These results indicate opposing effects of radiation, clearly inducing MB during the prenatal and early postnatal periods while seemingly suppressing MB below the spontaneous levels in these sensitive mutant mice. Neutrons appear to be more effective than gamma rays at the same for both inducing and suppressing MB.

Free Research Field

放射線生物学