#666 Molecular cytogenetic studies of pediatric ependymomas

Kramer, Deborah; Wentz, Erica; Parmiter, Annette H.; Biegel, Jaclyn A.; Cohen, Ann

doi:10.1097/00043426-199611000-00105

Cited by 24 publications

(45 citation statements)

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“…If the changes suggestive of intermediate ploidy are discounted, loss of 22q is the most frequent genetic abnormality in our series of ependymomas, occurring in 26% of ependymomas, which is in line with data from other CGH studies (Reardon et al, 1999;Hirose et al, 2001;Ward et al, 2001). However, the frequency of loss of 22q in ependymomas varies greatly (up to 71%) in previous studies that have used a variety of methods (Ransom et al, 1992;Neumann et al, 1993;Kramer et al, 1998;Vagner-Capodano et al, 1999;Zheng et al, 2000). This variability is likely to reflect ascertainment bias, because the frequency of loss of 22 in ependymomas varies according to histological variant, anatomic site, and age of the patient.…”

Section: Genetics and Genomicssupporting

confidence: 88%

Genetic abnormalities detected in ependymomas by comparative genomic hybridisation

et al. 2002

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Using comparative genomic hybridisation, we have analysed genetic imbalance in a series of 86 ependymomas from children and adults. Tumours were derived from intracranial and spinal sites, and classified histologically as classic, anaplastic or myxopapillary. Ependymomas showing a balanced profile were significantly (P50.0005) more frequent in children than adults. Profiles suggesting intermediate ploidy were common (44% of all tumours), and found more often (P50.0005) in tumours from adults and the spinal region. Loss of 22q was the most common specific abnormality, occurring in 50% of spinal (medullary) ependymomas and 26% of tumours overall. Genetic profiles combining loss of 22q with other specific abnormalities -gain of 1q, loss of 6q, loss of 10q/10, loss of 13, loss of 14q/14 -varied according to site and histology. In particular, we showed that classic ependymomas from within the cranium and spine have distinct genetic profiles. Classic and anaplastic ependymomas with gain of 1q tended to occur in the posterior fossa of children and to behave aggressively. Our extensive data on ependymomas demonstrate significant associations between genetic aberrations and clinicopathological variables, and represent a starting point for further biological and clinical studies.

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Section: Genetics and Genomicssupporting

confidence: 88%

Genetic abnormalities detected in ependymomas by comparative genomic hybridisation

et al. 2002

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“…It is also possible that the number of deletions is underestimated by the FISH technique (eg, small deletions or relative RB deletions in an extensively polyploid tumor). However, our frequencies of 9p and 13q losses are similar to those previously reported using other techniques 11,14,24,[32][33][34] and there appears to be no clear suggestion of a prognostic association based on the available data thus far. Therefore, it is probable that genes other than p16 and RB may be targeted by the 9p and 13q deletions in ependymomas.…”

Section: Discussionsupporting

confidence: 83%

“…11,21,24,[31][32][33][34] Based on the recent finding of CGH detectable losses in high-grade examples, it was suggested that the RB pathway may be specifically targeted in the process of tumor progression. 24 In contrast, our larger study similarly identified a subset of ependymomas with 9p or 13q deletions by FISH, but there were no obvious associations with tumor grade, location, patients age, recurrences, or death.…”

Section: Discussionmentioning

confidence: 99%

9p21 and 13q14 dosages in ependymomas. A clinicopathologic study of 101 cases

et al. 2004

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Ependymomas are glial neoplasms whose clinical behavior is difficult to predict based on histology alone. Recently, a comparative genomic hybridization study identified frequent chromosome 9p and 13q losses in anaplastic ependymomas, suggesting that p16 and RB alterations may be involved in tumor progression. In order to test this hypothesis further, 101 myxopapillary, conventional, and anaplastic ependymomas (51 spinal and 50 intracranial tumors) were tested for RB and p16 deletions using fluorescence in situ hybridization. Clinical follow-up, ranging from 2 to 198 months (median 46 months), was obtained in 90 cases (91%). RB and p16 deletions were seen in 22 of 92 (24%) and 22 of 89 (25%) informative cases, respectively. Polysomies were more frequent in the grade I and II spinal tumors, consistent with prior reports of increased aneuploidy in such cases. No significant genetic associations were seen with tumor grade, recurrence, or death, suggesting that 9p and 13q deletions do not play a prominent role in the malignant progression of ependymomas, as has been implicated in other glioma subtypes.

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“…Furthermore, up to 50% of tumors appear karyotypically normal. To date, the most common chromosomal aberrations reported are deletions or rearrangements of 6q, 17, and 22, although all are present in only Ͻ30% of cases (Kramer et al, 1998;Mazewski et al, 1999;Reardon et al, 1999). Recent comparative genomic hybridization (CGH) 4 studies have also demonstrated gain of 1q to be present in a subset of ependymomas, and our laboratory has also reported high-copy-number amplifi cation at 1q24-31 in three cases (Carter et al, 2002;Dyer et al, 2002;Ward et al, 2001).…”

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confidence: 87%

Microarray analysis of pediatric ependymoma identifies a cluster of 112 candidate genes including four transcripts at 22q12.1-q13.3

Suárez-Merino¹,

Hubank²,

Révész³

et al. 2005

Neuro-Oncol

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Ependymomas are glial cell-derived tumors characterized by varying degrees of chromosomal abnormalities and variability in clinical behavior. Cytogenetic analysis of pediatric ependymoma has failed to identify consistent patterns of abnormalities, with the exception of monosomy of 22 or structural abnormalities of 22q. In this study, a total of 19 pediatric ependymoma samples were used in a series of expression profi ling, quantitative real-time PCR (Q-PCR), and loss of heterozygosity experiments to identify candidate genes involved in the development of this type of pediatric malignancy. 12,627 genes analyzed, a subset of 112 genes emerged as being abnormally expressed when compared to three normal brain controls. Genes with increased expression included the oncogene WNT5A; the p53 homologue p63; and several cell cycle, cell adhesion, and proliferation genes. Underexpressed genes comprised the NF2 interacting gene SCHIP-1 and the adenomatous polyposis coli (APC)-associated gene EB1 among others. We validated the abnormal expression of six of these genes by Q-PCR. The subset of differentially expressed genes also included four underexpressed transcripts mapping to 22q12.3-13.3. By Q-PCR we show that one of these genes, 7 CBX7 (22q13.1), was deleted in 55% of cases. Other genes mapping to cytogenetic hot spots included two overexpressed and three underexpressed genes mapping to 1q31-41 and 6q21-q24.3, respectively. These genes represent candidate genes involved in ependymoma tumorigenesis. To the authors' knowledge, this is the fi rst time microarray analysis and Q-PCR have been linked to identify heterozygous/homozygous deletions.- Neuro-Oncology 7, 20-31, 2005 (Posted to Neuro-Oncology [serial online], Doc. y 04-059, December 6, 2004

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#666 Molecular cytogenetic studies of pediatric ependymomas

Cited by 24 publications

References 0 publications

Genetic abnormalities detected in ependymomas by comparative genomic hybridisation

Genetic abnormalities detected in ependymomas by comparative genomic hybridisation

9p21 and 13q14 dosages in ependymomas. A clinicopathologic study of 101 cases

Microarray analysis of pediatric ependymoma identifies a cluster of 112 candidate genes including four transcripts at 22q12.1-q13.3

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