An unusual loss of EGFR gene copy in glioblastoma multiforme in a child: a case report and analysis of a successfully derived HGG-02 cell line.
OBJECTIVE
The aim of this study was to perform a detailed cytogenetic and molecular genetic analysis of a tumor taken from a 14.5-year-old boy with glioblastoma multiforme who showed an atypical clinical course.


METHODS
Formalin-fixed, paraffin embedded tumor tissue and the corresponding HGG-02 cell line derived from this tumor were analyzed using fluorescence in situ hybridization (FISH), G-banding, multiplex ligation-dependent probe amplification (MLPA), functional analysis of separated alleles in yeast (FASAY), immunohistochemistry (IHC), and immunocytochemistry (ICC).


RESULTS
Mutation of the p53 gene and hypermethylation of the MLH1 gene were detected by FASAY and MLPA, respectively. Cytogenetic analysis showed a polyploid karyotype with extensive heterogeneity in chromosome number. Using FISH, we identified a very unusual genetic change - a loss of EGFR gene copy in both the tumor tissue and the HGG-02 cell line. In accordance with the cytogenetic findings, IHC and ICC did not demonstrate overexpression of EGFR in the tumor tissue or HGG-02 cells.


CONCLUSIONS
Despite his very poor prognosis, the patient experienced 34 months of event-free survival after surgery and adjuvant radiotherapy and chemotherapy. The detected loss of the EGFR gene copy may contribute to the unusual biological features of this tumor, but the forthcoming detailed expression analysis of cancer regulatory pathways is necessary to better understand this tumor phenotype.
Veselska
Renata
R
Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 611 37, Brno, Czech Republic. veselska@sci.muni.cz
Skoda
Jan
J
Loja
Tomas
T
Zitterbart
Karel
K
Pavelka
Zdenek
Z
Smardova
Jana
J
Valaskova
Iveta
I
Hermanova
Marketa
M
Sterba
Jaroslav
J
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000293:Adolescent; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D045744:Cell Line, Tumor; D018450:Disease Progression; D066246:ErbB Receptors / Q000235:genetics*; D018628:Gene Dosage; D016158:Genes, p53; D005909:Glioblastoma / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D006801:Humans; D008297:Male; D000070957:MutL Protein Homolog 1; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D016896:Treatment Outcome
D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C512478:EGFR protein, human; D066246:ErbB Receptors; D000070957:MutL Protein Homolog 1