@misc{oai:niigata-u.repo.nii.ac.jp:00005513,
 author = {Asai, Takao},
 month = {Sep},
 note = {Although genetic characteristics are considered to be a factor influencing the geographic variation in the prevalence of gallbladder cancer (GBC), they have not been well studied in Bolivia, which has a high prevalence rate of GBC. The purpose of this study was to examine the frequency of TP53 and K-ras mutations in Bolivian patients with GBC and to compare them with our previous data obtained in other high-GBC-prevalence countries, namely Japan, Chile, and Hungary. DNA was extracted from the cancer sites in paraffin-embedded tissue from 36 patients using a microdissection technique. TP53 mutations at exon 5 to 8 and K-ras mutations at codons 12, 13, and 61 were examined using direct sequencing techniques. The data obtained were compared with those in the other high-GBC-prevalence countries. Of the 36 patients, 18 (50.0%) had the TP53 mutation (one mutation in each of 17 patients and three mutations in one patient), and only one (2.8%) had the K-ras mutation. Of the 20 TP53 mutations, 12 were of the transition type (60.0%). This rate was significantly lower than that in Chile (12/12, P<0.05). In addition, three mutations were of the CpG transition type (15.0%), which is a feature of endogenous mutation. All three of these mutations were found in the hot spot region of the TP53 gene. In contrast, G:C to T:A transversion was found in Bolivia, suggesting the presence of exogenous carcinogens. Our findings suggest that the development of GBC in Bolivia is associated with both exogenous carcinogens and endogenous mechanisms. The identification of an environmental risk factor for GBC is needed to confirm these findings., 学位の種類: 博士（医学）. 報告番号: 甲第3945号. 学位記番号: 新大院博（医）甲第612号.学位授与年月日: 平成26年9月22日, Asian Pacific Journal of Cancer Prevention. 2014, 15(13), 5449-5454., 新大院博（医）甲第612号},
 title = {High frequency of TP53 but not K-ras gene mutations in Bolivian patients with gallbladder cancer},
 year = {2014}
}