Cytogenetic techniques were used to detect specific chromosomal losses and/or stuctural changes in 6 meningioma cell population of 11 meningioma patients. Polymorphic DNA markers were utilized to investigate the loss of constitutional
heterozygosity on
chromosomes 8.17 and 22 in 9 meningioma cell population of 11 meningioma patients.
As a result, 5 cases(M-2,4,5,9 and 10) represented 45, XX, -22 or 45, XY,-22 as stem line. In addition to chromosome 22, other chromosomes were lost randomly. In one case(M-3) normal karyotypic pattern was oberved. The 9q+ structural change was
also
noted in case M-2.
This structural change was thought to be the chromosomal involvement secondary to the loss of chromosome 22 in meningioma. Retentions of constitutional heterozygosity on chromosomes 8 and 17 were found in all cases. Loss of constitutional
hererozygosity
on chromosome 22 were found at Hind III RFLP of v-sis in cases M-1 and M-7, EcoR I RFLP of v-sis in case M-1, Bgl II RFLP of v sis case M-1, M-1, Xba I RFLP of v-sis in cases M-6, M-9 and M-11, and EcoRI RFLP of bcr in all cases. Rearrangement of
chromosome 22 in case M-1 was detected on the Xba I RFLP of v-sis as extra hand(3,14kb). The reduction to hemizygosity on chromosome 22 was one important step in tumorigenesis of meningioma. Monosomy 22 might operate at the primary level of tumor
initiation. Randomlosses of other chromosomes or structural changes as 9q+ were postulated to be related to tumor development.
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