Genetic characterization of skull base chondrosarcoma and chordoma

Research Project

Project/Area Number	26861166
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Neurosurgery
Research Institution	Keio University
Principal Investigator	Kitamura Yohei 慶應義塾大学, 医学部, 共同研究員 (30445382)
Project Period (FY)	2014-04-01 – 2016-03-31
Project Status	Completed (Fiscal Year 2015)
Budget Amount *help	¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000) Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000) Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Keywords	頭蓋底軟骨肉腫 / 脊索腫 / IDH1/2 / brachyuryタンパク質 / 軟骨肉腫 / brachyura / 遺伝子異常 / brachyury
Outline of Final Research Achievements	Although chondrosarcomas rarely arise in the skull base, chondrosarcomas and chordomas are the two major malignant bone neoplasms occurring at this location. The distinction of these two tumors is important, but it is occasionally problematic because of radiological and histological overlap. We analyzed seven skull base chondrosarcoma specimens for chromosomal copy number alterations (CNAs), isocitrate dehydrogenase (IDH)1/2 mutations and brachyury expression. We detected CNAs in six of the seven cases, including chromosomal gains of 8q21.1, 19. Mutation of IDH1 was found with a high frequency, of which R132S was most frequently mutated. Immunohistochemical staining for brachyury was negative in all cases. To the best of our knowledge, this is the first whole-genome study of an SBSC case series. Our findings suggest that these tumors are molecularly consistent with a subset of conventional central chondrosarcomas and different from skull base chordomas.