2008 Barcelona - European Society of Human Genetics

Cancer genetics
P04.162
HER-2/neu Amplification in Paraffin Embedded Tissue Sections
of meningioma Patients
O. Ozer 1 , F. I. Sahin 1 , F. Aydemir 2 , O. Ozen 3 , Z. Yilmaz 1 , N. Altinors 2 ;
1 Baskent University Faculty of Medicine Department of Medical Genetics,
Ankara, Turkey, 2 Baskent University Faculty of Medicine Department of Neurosurgery,
Ankara, Turkey, 3 Baskent University Faculty of Medicine Department of
Pathology, Ankara, Turkey.
Meningiomas arise from the meningoendothelial cells and are one of
the most common tumors of the central nervous system . About 90%
of meningiomas are benign. They are histologically classified as benign
(Grade1), atypical (Grade2) and anaplastic (Grade3) according to
World Health Organization (WHO) 2007 classification of brain tumors,
which also correlates with disease prognosis . Numerical and structural
chromosome abnormalities have been reported in meningiomas .
HER-2/neu gene is located on 17q11 .2-q12 chromosome region and
encodes an epidermal growth factor receptor . HER-2/neu gene amplification
and/or over expression have been detected in some human
cancers and studied most widely in breast carcinomas . Previous studies
have shown the importance of HER-2/neu gene amplification on
the prognosis of meningioma cases . In this study, we aimed to detect
HER-2/neu gene copy number in archive materials of 55 meningioma
patients by fluorescent in situ hybridization (FISH) . The patients included
in the study have been operated in the neurosurgery department of
our hospital between 1999 and 2002. Tissue samples were classified
histologically according to WHO 2007 guidelines . We found HER-2/
neu gene amplification in 7 (12,73%) patients. Another 2 patients had
only one signal for the HER2-neu region. We confirmed this finding
by a second hybridization with chromosome 17p13 .1 (p53) probe . According
to our results, HER-2/neu amplification could be regarded as
an additional genetic factor playing role in meningioma pathogenesis
together with known chromosomal abnormalities .
P04.163
methylenetetrahydrofolate reductase gene (mtHFR) 677c>t
polymorphism in serbian oral squamous cell carcinoma and
basal cell carcinoma patients
R. Milicevic1 , B. Ilic2 , D. Jelovac2 , J. Milosevic3 , T. Damnjanovic4 , M. Vukadinovic2
, V. Konstantinovic2 , J. Milasin2 ;
1 2 3 Pediatric Clinic, Nis, Serbia, School of Dentistry, Belgrade, Serbia, School of
Denistry, Belgrade, Serbia, 4School of Medicine, Belgrade, Serbia.
Enzyme methylenetetrahydrofolate reductase (MTHFR) regulates intracellular
folate metabolism through conversion of 5,10-methylenetetrahydrofolate
to 5-methyltetrahydrofolate, which in turn play an important
role in cancerogenesis because of its involvement in DNA methylation
and nucleotide synthesis . A common genetic polymorphism in the
MTHFR gene - C677T is associated with thermolability and decreased
enzyme activity . Reduced MTHFR activity may decrease the methylation
of homocysteine to methionine, resulting in DNA hypomethylation .
The contribution of MTHFR polymorphisms to the susceptibility to various
types of cancer is controversial . We investigated a possible association
of MTHFR polymorphisms 677C>T
and increased risk for oral squamous cell carcinoma (OSCCs) and
basal cell carcinoma (BCCs) .
PCR- RFLP analysis of the MTHFR gene was performed on DNA obtained
from 40 SCC and 35 BCC patients and 400 healthy individuals
. The following genotype frequencies were found: 25% (CC), 67 .5%
(CT) and 7 .5% (TT) in squamous cell carcinomas; 34 .3% (CC), 57 .2%
(CT) and 8 .5% (TT) in basal cell carcinoma patients . Genotypes in
controls were: 40% (CC), 46 (CT)% and 14% (TT) . A statistically significant
difference (p