10049-GGE-3 CHARACTERISTICS OF CHROMOSOMAL ABERRATIONS IN GLIOMAS AND THEIR IMPACT ON RECURRENCE

Abstract

Abstract INTRODUCTION Chromosome instability is the inability to evenly distribute sister chromatids during mitosis, which leads to chromosomal numerical/structural abnormalities and increases the genetic heterogeneity of the tumor. In this study, we investigated the association between chromosome aberration characteristics and recurrence in clinical specimens of gliomas using the Spectral Karyotyping. METHODS Chromosome karyotypes were analyzed for a total of 121 cells from 26 gliomas (Glioblastoma 14, PXA 3, Astrocytoma 5, Oligodendroglioma 3, Ependymoma 1, 18 primary cases and 8 recurrent cases) removed at our hospital. In addition, each case was quantitatively analyzed for numerical aberrations/ cell (AS: Aneuploidy score), structural abnormalities/ cell (SS: Structural abnormality score), and karyotype concordance rate between cells /case (HS: Heterogeneity Score) were quantitatively analyzed. RESULTS In the analysis of all cases, numerical aberrations in chromosomes X and 7 (21.5%/16.9%) and structural aberrations in chromosomes 1, 4, and 5 (>10.0%) were highly prevalent, with structural aberrations in large chromosomes and numerical aberrations in small chromosomes. On the other hand, quantitative analysis showed that the mean for the first occurrence (18 cases); AS: 2.22±0.94/ SS: 1.48±0.96/ HS: 22.2±7.41, and for the recurrence (8 cases); AS: 4.68±1.75/ SS: 7.50±1.44/ HS: 55.0±11.1, indicating that numerical and structural abnormalities were more common in the recurrent lesions The recurrent lesions showed more numerical and structural abnormalities and higher intra-tumor heterogeneity. In addition, in cases in which the primary/recurrent lesions were analyzed in pairs, the frequency of numerical and structural chromosomal abnormalities was higher in the recurrent lesions. DISCUSSION This study clarified the characteristics of chromosomal aberrations in each pathological classification of gliomas and suggested the involvement of chromosomal instability in the recurrence process. We look forward to further clarification of the pathogenesis of gliomas with a focus on chromosomal instability.