2009 Vienna - European Society of Human Genetics

Cancer genetics
P06.018
Expression of Fibroblast Growth Factor Receptor-1 in tumors of
mexican females
S. Avilés1 , N. García2 , L. Baiza1 , D. Arenas2 , E. Olvera1 , G. Martínez1 , F. Salamanca1
;
1 2 National Autonomous University of Mexico, Mexico City, Mexico, IMSS Pediatry
Hospital, Mexico City, Mexico.
Expression of Fibroblast Growth Factor Receptor-1 in tumors of Mexican
females.
In Mexico, breast cancer is the second leading cause of cancer death
in women 30 to 54 years and ranks as the leading cause of mortality
from malignant neoplasms among women. Fibroblast growth factors
are a family of ligands that signal through receptor tyrosine kinase,
has been linked to processes such as proliferation, differentiation, cell
migration, angiogenesis and its inappropriate expression has been implicated
in breast cancer. It is believed that these receptors are linked
to the progression to the independence of steroids in breast cancer. It
has been shown that the expression of FGFR1 is essential in mammary
development and breast cancer, and the FGFR1 gene shows increased
levels of mRNA and proteins. Therefore, the aim of this study
is to assess the level of FGFR-1 expression in mammary tumors from
Mexican women by RT- PCR and Real Time RT-PCR . The tissues
were obtained from the Hospital de Oncología CMN of S-XXI. 15 tumors
were used in sporadic stage II and III breast cancer, 5 unaffected
breast tissues and cultured cell lines MCF-7, MDA-MB-231, MCF10A
as a positive control. First we found that cell lines of breast cancer expressed
higher levels of FGFR-1 than the cell line of normal mammary
epithelium. Similarly, the tumors expressed higher levels of FGFR-1
than unaffected breast tissue. We conclude that FGFR-1 is associated
with disease progression and can be used as a tool for diagnosis,
prognosis and treatment of breast cancer.
P06.019
characterization of an Oncogene candidate, UsP32, on 17q23
A. Sapmaz 1,2 , S. Akhavantabasi 1 , E. M. Petty 3 , A. E. Erson 1 ;
1 Department of Biological Sciences, Middle East Technical University, Ankara,
Turkey, 2 Department of Biological Science, University of Yuzuncu Yil, Van, Turkey,
3 University of Michigan, Ann Arbor, MI, United States.
Breast cancer is one of the most common malignancies affecting women.
The lifetime risk of any woman getting breast cancer is about 1 in 8.
Gene amplification is a common mechanism of oncogene activation in
cancers. Previous studies identified the chromosomal band 17q23 as
a frequent site of gene amplification in breast cancer. Amplification and
overexpression of oncogene candidates in this region are to be likely
important for breast cancer. USP32, a predicted ubiquitin specific protease
on 17q23, is one of the oncogene candidates. We hypothesized
that overexpression of USP32 may contribute to breast tumorigenesis
as a protein taking part in protein degradation pathways. We detected
amplification and overexpression of USP32 in MCF7 and BT474 breast
cancer cell lines. Presence of Cys-His domain suggests that USP32
functions as a deubiquitinating enzyme. To experimentally confirm this,
we sub-cloned three different fragments containing functional domains
of USP32 into a GST fusion vector. These constructs were tested in
vivo for deubiquitination activity and we demonstrated that this protein
is indeed a ubiquitin specific protease. To understand the physiological
role of this protein inside mammalian cells, we performed localization
and co-localization experiments for full length and partial fragments
of USP32 by generating USP32-GFP fusions. For further localization
studies, we used Fluorescent Protease Protection assay which suggested
that USP32 could be a membrane bound protein. Further characterization
of USP32 will help us understand the role of this protein in
the cell and in mammary tumorigenesis.
P06.020
integration of the Fluidigm technology into a high throughput
genotyping laboratory
C. Luccarini 1 , L. Smith 2 , Y. Yi 2 ;
1 Department of Oncology, University of Cambridge, Centre for Genetic Epidemiology,
Strangeways Research Laboratory, Cambridge, United Kingdom,
2 Fluidigm Corporation, South San Francisco, CA, United States.
The Centre for Genetic Epidemiology is using high-throughput SNP
genotyping to identify and verify genetic variants that underlie susceptibility
to various cancers. Cancers that are being investigated in-
clude breast, ovarian, colorectal, prostate, and melanoma. The Centre
has recently integrated the Fluidigm® technology into its core, high
throughput, genotyping laboratory.
Starting with an initial pilot experiment to demonstrate accurate SNP
calling, 384 DNA samples were genotyped using 48 TaqMan® assays.
These genotypes were compared with those previously obtained using
conventional genotyping with the same TaqMan assay. Further work
confirmed that the Fluidigm EP1 system meets high throughput needs,
which can be further scaled up easily, when needed, and provides a
fast and efficient workflow. The overall process flow was configured so
as to handle large sample numbers, including automated liquid handling
with associated sample tracking and data QC. The first production
experiment, using the 96.96 dynamic arrays and the EP1 instrument,
genotyped 96 SNP assays across 1200 endometrial cancer samples,
generating over 115,000 genotypes. The Centre plans to use the system
in genotyping studies involving thousands of samples, studies that
were previously less feasible due to workflow and cost constraints.
P06.021
Expression and prognostic significance of cell cycle regulatory
genes cDKN1A, TP , CDK , CDKN in breast and colon cancer
D. Macic 1 , L. Kapur 1 , J. Ramic 1 , N. Lojo-Kadric 1 , N. Obralic 2 , K. Bajrovic 1,2 ;
1 Institute for Genetic Engineering and Biotechnology, Sarajevo, Bosnia and
Herzegovina, 2 Institut for Oncology, KCUS, Sarajevo, Bosnia and Herzegovina,
Sarajevo, Bosnia and Herzegovina.
Aim of this study was detection of alterations in expression of cell cycle
control genes: CDKN1A TP53, CDK4 and CDKN2 in breast and colon
cancer patients.
CDKN1A encodes protein p21 which binds to and inhibits the activity
of CDK4 complex and thus regulates transition of cell trough G1
phase of the cell cycle. CDKN1A gene is under direct control of tumor
suppressor gene TP53 which induces G1 phase arrest in response to
a variety of stress. Mutations may destroy the normal function of p53
as a transcription factor and induction of cell arrest or apoptosis may
be reduced. This study included 100 breast and colon cancer affected
individuals. Genetic material was extracted from bioptic tissue specimen.
To analyze effects of mutations on expression of tested genes,
TP53 was subjected to mutational analysis using RFLP. Level of expression
of CDKN1A, TP53, CDK4 and CDKN2 was determined using
SYBR-green based real time PCR.
All relative quantity values of TP53 and CDK4 were normalized to
mRNA level of beta-actin and their relative expression was calculated
using REST®software.
To test hypothesis that alteration in sequence and expressions of tested
genes may have a prognostic significance, experimentally obtained
data were correlated to patohistological findings.
P06.022
investigation of the mitochondrial DNA deletions in patients with
chronic cervicitis and cervical cancer and of the correlations
between mtDNA deletion and pathological diagnosis
A. Tatar 1 , M. Kara 1 , B. Borekci 1 , S. Oztas 1 , A. F. Dagli 2 ;
1 Ataturk university, Erzurum, Turkey, 2 Firat university, Elazig, Turkey.
Mitochondrial DNA (mtDNA) is the specific DNA molecule within mitochondria
and susceptible to mutations because of a disability of DNA
repair mechanisms and more exposure to oxidative stress. The aim of
the present study was to investigate the mitochondrial DNA deletions
in the tissue of cervix uteri of the patients with chronic cervicitis and
cervical cancer and to explain the correlations between mtDNA deletion
and pathological diagnosis.
Tissue samples of cervix uteri were collected from paraffin blocks of
60 individuals in pathology archives; 20 patients with chronic cervicitis
(ChC group), 20 patients with cancer of cervix uteri (CaC group) and
20 patients, as control group, undergo an operation of uterotomy because
of other disorders. After mtDNA extraction, PCRs were made
using three different primer pairs; first primer pairs for a deletion of
4977 bp, the second primer pairs for negative control within the deletion
region and the third primer pairs for positive control out of the
deletion region.
We did not detect a deletion cervix uteri tissue of control group. However,
we determined a heteroplasmic 4977-bp deletion in ChC group.
The deletions were homoplasmic in CaC group.
It was suggested that overproduction of reactive oxygen species in
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