Loss of chromosome 22 and proliferative potential in ependymomas
Maria Debiec-Rychter1, Wojciech Biernat, Krzysztof Zakrzewski
1Department of Molecular Pathology and Neuropathology, Medical University of Lódź, Lódź, Poland.
Abstract:
Fluorescence in situ hybridisation (FISH) analysis using total chromosome 22 painting and locus specific 22q11.2 (bcr locus) probes was performed on sections from archival paraffin-embedded tumours obtained from 28 patients diagnosed with either ependymoma, WHO grade 11 (18 cases) or anaplastic ependymoma, WHO grade 111 (10 cases). The Ki-67 labelling index (LI) analysis was carried out in parallel to estimate the tumours' proliferative potential. Loss of chromosome 22 was revealed in eleven (39%) ependymomas, seven (39%) WHO grade II and four (40%) anaplastic variants. Concurrent cytogenetic analysis was performed on 11 tumours to confirm the loss of chromosome 22 in four cases; clones with a loss of chromosome 22, which was identified by FISH, were not detected by standard cytogenetics in two samples. The loss of chromosome 22 was restricted either to the tumours' site or to sex or age of the patients studied. The Ki-67 LI ranged from 0.1 to 32.0% (mean 4.3%). Low-grade tumours significantly showed a lower mean Ki-67 LI than those classified as anaplastic tumours (3.1% and 6.4%, respectively). Additionally, the mean Ki-67 LI for ependymomas with a loss of chromosome 22 was significantly lower than that for tumours with chromosome 22 disomy (1.6% and 6.0%, respectively, p = 0.05), indicating that loss of chromosome 22 may be associated with the subset of ependymomas characterised by low proliferative capacities.
More Related Videos
08:22A Novel Strategy Combining Array-CGH, Whole-exome Sequencing and In Utero Electroporation in Rodents to Identify Causative Genes for Brain Malformations
Published on: December 1, 2017
09:33Genetic Profiling and Genome-Scale Dropout Screening to Identify Therapeutic Targets in Mouse Models of Malignant Peripheral Nerve Sheath Tumor
Published on: August 25, 2023
Related Concept Videos
02:23Abnormal Proliferation
01:12Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:20The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:12Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...