2002 Fiscal Year Final Research Report Summary
Molecular Genetic Study of Intracranial Germ Cell Tumors
| Project/Area Number |
13671461
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Saitama Medical School |
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Principal Investigator |
MATSUTANI Masao Saitama Medical School, Dept. of Neurosurgery, Professor, 医学部, 教授 (90010454)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIKAWA Ryo Saitama Med. Schl, Dept. of Neurosurgery, Assoc. Prof., 医学部, 助教授 (90237678)
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| Project Period (FY) |
2001 – 2002
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| Keywords | germ cell tumor / FISH |
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| Research Abstract |
Twenty-five primary intracranial germ cell tumors (11 germinomas, 5 teratomas, 5 mixed teratomas-germinomas, 1 mixed choriocarcinoma-teratoma, 1 yolk sac tumor, 1 mixed yolk sac tumor-teratoma, and 1 embryonal carcinoma; from 24 males and 1 female) were studied by fluorescence in situ hybridization with probes to the X and Y chromosomes, chromosome 12p, the CDKN2A/p16 gene, and chromosome 13q-loci previously noted to be altered in either intracranial or systemic germ cell tumors. An increased number of X chromosomes, typically one extra copy, was observed in 23/25 cases (92%), with methylation-sensitive PCR demonstrating that the additional X chromosomes were hypomethylated in 13 of 16 (81%) studied tumors. * cases (20%) had increased copy numbers of 12p (including tumors with isochromosome 12p), and three (12%) had 13q loss. No tumors had CDKN2A/p16 deletion or mutation, and 16 of 25 (64%) were positive for p16 expression by immunohistochemistry. Genetic alterations such as isochromosome 12p, 13q loss and CDKN2A/p16 are therefore not common in intracranial germ cell tumors. However, gains of hypomethylated, active X chromosomes occur in nearly all intracranial germ cell tumors, regardless of histological subtype. Along with the observed male predominance of intracranial germ cell tumors and the predisposition in Klinefelter syndrome patients for these lesions, the data argue strongly that sex chromosome aberrations, rather than isochromosome 12p, are integral to intracranial germ cell tumorigenesis.
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Research Products
(2 results)
