Kiyohiro Hamatani

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A major early event in papillary thyroid carcinogenesis is constitutive activation of the mitogen-activated protein kinase signaling pathway caused by alterations of a single gene, typically rearrangements of the RET and NTRK1 genes or point mutations in the BRAF and RAS genes. In childhood papillary thyroid cancer, regardless of history of radiation(More)
BACKGROUND We previously noted that among atomic bomb survivors (ABS), the relative frequency of cases of adult papillary thyroid cancer (PTC) with chromosomal rearrangements (mainly RET/PTC) was significantly greater in those with relatively higher radiation exposure than those with lower radiation exposure. In contrast, the frequency of PTC cases with(More)
This article provides an overview of the on-going molecular epidemiology studies among atomic-bomb survivors conducted at the Radiation Effects Research Foundation in Japan. The focus is on: (a) inter-individual variations in sensitivity to radiation-induced somatic mutations (glycophorin A (GPA) mutations) and their potential relevance to differences in(More)
In papillary thyroid carcinogenesis, the constitutively activated mitogen-activated protein (MAP) kinase signaling pathway caused by a genetic alteration such as RET/PTC rearrangement or mutation of RAS and BRAF genes, is thought to be a major early event. Among these, the recently identified BRAF(V600E) mutation has been found at high frequency in adult(More)
Ionizing radiation is a well known risk factor of thyroid cancer development, but the mechanism of radiation induced carcinogenesis is not clear. The RET/PTC oncogene, an activated form of the RET proto-oncogene, is frequently observed in papillary thyroid carcinoma (PTC); RET/PTC1, -2 and -3 are known to be the three major forms. High frequencies of(More)
Archival tissue specimens are valuable resources of materials for molecular biological analyses in retrospective studies, especially for rare diseases or those associated with exposure to uncommon environmental events. Although successful amplification with PCR is essential for analysis of DNA extracted from archival formalin-fixed, paraffin-embedded (FFPE)(More)
During analysis of RET/PTC rearrangements in papillary thyroid cancer (PTC) among atomic bomb survivors, a cDNA fragment of a novel type of RET rearrangement was identified in a PTC patient exposed to a high radiation dose using the improved 5' RACE method. This gene resulted from the fusion of the 3' portion of RET containing tyrosine kinase domain to the(More)
Association of gene alterations and prognosis has not fully been elucidated in hepatocellular carcinoma (HCC). To clarify the relationship between p53 and hMSH2 mutations and prognosis, we analysed these mutations in 83 HCC cases and assessed their association with various clinicopathological factors. The 3-year disease-free survival (DFS) or overall(More)
Recently, in addition to DNA, RNA extracted from archival tissue specimens has become an invaluable source of material for molecular biological analysis. Successful amplification with PCR/RT-PCR is problematic when using amplicons of short size due to degradation of DNA or RNA. We established an improved method for efficient RT-PCR amplification of RNA(More)
 Severe combined immune deficiency (scid) mice are assumed to have two types of abnormalities: one is high radiosensitivity and the other is abnormal recombination in immunoglobulin and T-cell receptor genes. The human chromosome 8 q1.1 region has an ability to complement the scid aberrations. Moreover, the localization of the subunit DNA-dependent protein(More)