2009 Vienna - European Society of Human Genetics

Cancer genetics
P06.125
Identification of a recurrent BRCA1 mutation in a north-eastern
Romanian population
L. Negura 1 , E. Carasevici 1 , A. Negura 2 , N. Uhrhammer 3 , Y. J. Bignon 3,4 ;
1 ”Gr. T. Popa” University of Medicine and Pharmacy, Iasi, Romania, 2 University “Alexandru
Ioan Cuza”, Iasi, Romania, 3 Centre d’Oncologie Moleculaire “Jean Perrin”,
Clermont-Ferrand, France, 4 Universite Auvergne, Clermont-Ferrand, France.
Introduction: We started the first characterization of hereditary breast
and ovarian cancer risk in north-eastern Romania, searching for mutations
in the cancer predisposition genes BRCA1 and BRCA2 in highrisk
families.
Patients and methods: We identified and recruited 15 hereditary breast
and ovarian cancer (HBOC) families, with at least 3 cases of epithelial
breast or ovarian cancer within the same family line. All patients
agreed by written informed consent. DNA was extracted from peripheral
blood. The entire coding sequence of both genes was analysed
using amplification and Sanger sequencing. BRCA1 was screened for
large deletions and duplications by MLPA. Multiplex-PCR was used to
screen for certain mutations recurring in different populations.
Results: We observed a recurring BRCA1 mutation in exon 20,
c.5266dupC. This mutation was found in two different HBOC families,
with different breast/ovarian cancer familial history and without any apparent
degree of relatedness.
The C duplication at position 5266 from initiator ATG creates a stop
codon at position 5484, truncating the BRCA1 protein upstream of the
C-terminal BRCT domain. This domain is responsible for molecular
interactions with BRCA2 and p53, and is involved in transcriptional activation.
Its deletion can be considered responsible for functional loss
of the BRCA1 tumour suppressor in cancer cases.
Conclusions: This outcome, the first one in Romania, could open the
way for a population study to determine the frequency of c.5266dupC
in the Romanian population, and for an eventual founder effect. This
could also develop in Romania the oncogenetic approach and followup
of BRCA mutations bearers.
P06.126
DNA-methylation changes in metastatic breast cancer
M. Hofner1 , K. Vierlinger1 , A. Kriegner1 , C. Nöhammer1 , C. Bichler2 , D. Kandioler2
, C. Fürhauser3 , C. Singer3 , A. Weinhäusel1 ;
1Austrian Research Centers GmbH - ARC, Molecular Medicine, Seibersdorf,
Austria, 2Medical University of Vienna, Department of Surgery, Vienna, Austria,
3Medical University of Vienna, Department of Obstetrics and Gynaecology,
Vienna, Austria.
Aberrant DNA methylation is an early event during neoplastic transformation.
Thus DNA methylation changes might be potent tumormarkers
for diagnosis and specific methylation patterns might also be used for
classification and prediction of disease outcome as well as for the development
of metastases.
To investigate methylation changes on a genome-wide scale we established
a specific amplification protocol based on methylation-sensitive
restriction digestion. This amplification does enrich the methylated
DNA and enables whole genome methylation screenings.
We used this protocol for analysing the DNA methylation status from
primary tumors of breast cancer patients with vs. without metastases
(10y follow up) on Agilent 244k human CpG island microarrays covering
27 800 CpG-islands.
From those chip-experiments we defined a group of potential marker
genes exhibiting significantly different methylation patterns between
both patient groups and performed KEGG pathway analyses. There
we found enriched numbers of these genes belonging to cellular pathways
associated with angiogenesis and metastasis.
P06.127
the survey of gene mutations in P53 gene in patients of
malignant breast cancer by PcR-sscP method.
M. Mirzaei Abbasabadi;
Medical University of Rafsanjan, Rafsanjan, Islamic Republic of Iran.
Background: Mutations in the p53 tumor suppressor gene are the most
common genetic alterations in human malignancies. These Mutations
founded 40-50% in breast carcinomas. In the present study, we analyzed
P53 gene mutations (exon 5-9) by PCR-SSCP method in 56
women patients of breast cancer.
Materials and methods: DNA extraction from samples (formalin-fixed
and paraffin-embedded or fresh tissue samples) of breast cancer patients
were done by standard Phenol chloroform method and stored
in -20º c .For mutation detection, exons 5-9 amplified by polymerase
chain reaction (PCR) and then specific electrophoresis (single-strand
conformational polymorphism SSCP).
Results: Abnormal movement of PCR products band in SSCP gel that
stained with silver nitrate reported as mutation. We found three mutations
(one in exon 5, one in exon 8 and one in exon 9) in patients.
Discussion: p53 Mutational analysis by PCR/SSCP method deserves
to be critically studied as a diagnostic criterion in patients with indeterminate
or suspicious cytology. Validation studies should be performed
to test p53 mutations, as molecular diagnostic markers in breast cytology
specimens Detection of P53 gene mutations can be helpful in pre
diagnosis and prevention of breast cancer and so in treatment. These
mutations occur in normal or benign breast tissue but resolutions of
this role in the pathogenesis of breast cancer will require long-term
follow-up studies.
P06.128
Evaluation of epigenetic changes in timP3, GstP1, BRcA1,
E cadherin and P16 genes in breast cancer tumors and it‘s
relation with grade of tumors
S. Alizadeh Shargh 1,2 , M. Mohaddes Ardebili 1 , M. Sakizli 3 , J. Gharesouran 1 ;
1 Department of Medical Genetics, Faculty of Medicine, University of Medical
Sciences, Tabriz, Islamic Republic of Iran, 2 Islamic Azad University, Chalus,
Islamic Republic of Iran, 3 9 eylul university, medical genetics department president,
Izmir, Turkey.
Epigenetic changes in breast cancer often occur and mostly happen in
promoter’s CpG islands that affects the genes expression state (mostly
tumor suppressor genes),in this study we performed the evaluation of
these alterations in GSTP1,P16,BRCA1,E-cadherin and TIMP3 genes
for methylation pattern and it’s relation with kind and garade of tumor
.Total 100 sample: 50 braest cancer patient with different kind of tumors
selected and 50 control tissue was obtained from same patient
and breast (adjacent area of tumor tissue) after pathological diagnosis,
and we performed bisulfite sequencing, immunohistochemistry and
western blotting methods for evaluation of promoter methylation pattern,
gene presence and expression statues respectively. Data analyses
will perform with cox-regretion statistical methods with (p