title: The BRAFT1796A transversion is a prevalent mutational event in human thyroid microcarcinoma.
abstract: Mutation in exon 15 of the BRAF gene is a characteristic feature of human thyroid papillary carcinoma (PTC). To determine the role of such mutation(s) in the neoplastic progression of thyroid papillary microcarcinoma (PMC), we analyzed 46 cases from 31 Russian and 15 Japanese patients with PMC. Mutated BRAF (the BRAFT1796A transversion in all cases) was detected in 13/46 (28.2%) of the tumors: 9/31 (29.0%) and 4/15 (26.6%) in Russian and Japanese individuals, respectively, displaying no signs of difference in the mutational rates in the PMCs from patients with diverse genetic background seen in PTCs. Occurrence of the BRAF mutation did not significantly correlate with the patients' gender, age at presentation, metastatic indices or with papillary, mixed papillary and follicular, and solid/trabecular PMC histotype. On the contrary, the tumors of follicular morphology significantly associated with the mutation-free genotype (P=0.018), and in the mixed-type tumors characterized by co-occurrence of well-differentiated and less differentiated components, the BRAF mutational frequency was significantly elevated (P=0.020). The results indicate the BRAFT1796A mutation is prevalent in PMCs, and thus these tumors may have a spectrum of genetic events partly overlapping with that of PTCs.
authors.affiliation: Department of Molecular Medicine, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Ilya
authors.initials: I
authors.lastname: Sedliarou
authors.forename: Vladimir
authors.initials: V
authors.lastname: Saenko
authors.forename: Dmitry
authors.initials: D
authors.lastname: Lantsov
authors.forename: Tatiana
authors.initials: T
authors.lastname: Rogounovitch
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Namba
authors.forename: Aleksandr
authors.initials: A
authors.lastname: Abrosimov
authors.forename: Eugeny
authors.initials: E
authors.lastname: Lushnikov
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kumagai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakashima
authors.forename: Serik
authors.initials: S
authors.lastname: Meirmanov
authors.forename: Mariko
authors.initials: M
authors.lastname: Mine
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Shunichi
authors.initials: S
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012426:Russia; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf