2009 Vienna - European Society of Human Genetics

Cancer genetics
P06.053
search for alternative genetic defects in families suggestive
of the Li-Fraumeni syndrome with no identified missense
mutations in the tP53 gene
K. Prochazkova 1 , A. Finkova 1 , M. Trkova 2 , V. Krutilkova 2 , A. Puchmajerová 1 , Z.
Sedlacek 1 ;
1 Department of Biology and Medical Genetics, Charles University 2nd Faculty
of Medicine and University Hospital Motol, Prague, Czech Republic, 2 Gennet,
Prague, Czech Republic.
Li-Fraumeni syndrome (LFS) is a disorder characterised by autosomal
dominant predisposition to a broad spectrum of cancers. Most LFS
patients carry missense germline mutations in the tumour suppressor
gene TP53. Such mutations can be found in about 70 % of families
conforming to stringent criteria of LFS, and in about 20 % of families
conforming to less strict Li-Fraumeni - like (LFL) or Chompret criteria.
Most mutations are located in the middle part of the TP53 gene encoding
the DNA-binding domain (exons 5 - 9), and often only these exons
are analysed in routine TP53 testing.
In search for the genetic basis of cancer predisposition in families
suggestive of LFS but with no identified TP53 mutations in exons 5
- 9 we focused primarily on other defects possibly affecting the TP53
gene function. First, we completed the analysis of all TP53 exons by
sequencing also the outer exons (26 families). Second, we used the
MLPA method to exclude single- or multiexon deletions in the TP53
gene (7 families). Third, we applied bisulphite sequencing to analyse
possible epigenetic silencing of one of the alleles of the TP53 gene by
promoter methylation (14 families). Finally, we searched members of
several families for mutations in the CHEK2 and SNF5 genes, which
have also been associated with LFS in several rare families published
in literature. However, none of these efforts revealed any molecular
defects which could be responsible for hereditary cancer predisposition
in the families analysed. Supported by grants MSM0021620813
and MZO00064203.
P06.054
Association between manganese superoxide dismutase
gene polymorphism (Ala-9Val) and cutaneous squamous cell
carcinoma risk
R. Cocoş 1 , L. Bohîlţea 1 , F. Raicu 1,2 , D. Neagoş 1 , E. Paune-Buşe 3 , O. Coman 1,4 ,
R. Creţu 1 , I. Nicolae 4 ;
1 “Carol Davila”University of Medicine and Pharmacy, Bucharest, Romania,
2 Francisc I Rainer Institute of Anthropology Romanian Academy, Bucharest,
Romania, 3 University of Bucharest, Faculty of Biology, Bucharest, Romania,
4 Centre of Dermatovenerology, Dermato-venerological Hospital “Prof.
S.Longhin”, Bucharest, Romania.
Superoxide dismutase play an important role in the detoxification of
superoxide radicals thereby protecting cells from damage induced
by free radicals. One of the several metabolic pathways involved in
carcinogenesis is the polymorphism in the mitochondrial targeting
sequence (MTS) Val-9Ala of the MnSOD gene which influences the
transfer and acumulation of the MnSOD enzyme into the mitochondria.
Thus, the goal of this study was to find a relationship between MnSOD
Val-9Ala polymorphism and squamous cell carcinoma (SCC) risk. A
study of 91 patients with squamous cell carcinoma and 58 normal subjects
was performed. The MnSOD MTS genetic polymorphism was
determined by polymerase chain reaction-restriction fragment lenght
polymorphism technique using NgoMIV and automated sequencing.
No significant difference was found in cutaneous squamous cell carcinoma
susceptibility in the subjects with Ala/Ala and Val/Ala genotype
compared with Val/Val genotype (Odds ratio, 1.49; 95% confidence
interval, 0.73-2.76; p= 0.3735). These data suggest no correlation
between MnSOD Ala-Ala and MnSOD Val-9Ala genotypes and squamous
cell carcinoma (SCC) risk.
P06.055
correlation of mDR1 c3435t polymorphism and expression in
iranian breast cancer patients
m. taheri 1,2 , F. Mahjoubi 1 , R. Omranipour 3 ;
1 National institute of Genetic Engineering & Biotechnology, Tehran, Islamic
Republic of Iran, 2 Zahedan University of Medical science, Zahedan, Islamic
Republic of Iran, 3 Cancer Institute of Imam Khomeini hospital, Tehran, Islamic
Republic of Iran.
Multidrug resistant (MDR) is one of the problems in treatment of cancer
patients by chemotherapy. One of the mechanisms responsible for
drug resistance is over-expression of ABC-transporter genes such as
MDR1.MDR1 encodes p-glycoprotein (p-gp), a transmembrane glycoprotein
that transports many hydrophobic substrates and anti-cancer
drugs from cell. Polymorphism in MDR1 gene may affect the expression
level of the Pgp and subsequently can result to drug resistance.
In this study we investigated the possible association between MDR1
gene C3435T polymorphism and MDR1 expression in Iranian breast
cancer patients.
DNA and RNA were extracted from tumor and blood cells. For cDNA
synthesis, 1 mg of total RNA from each sample was used to synthesize
first-strand cDNA. Evaluation of the expression level of MDR1 was
performed by Real-Time Quantitative PCR and PCR-RFLP was used
for the detection of C3435T single nucleotide polymorphism.
A statistically significance in MDR1 expression was observed when
samples from breast cancer patients were compared with healthy individual.
We observed no difference in frequency of C3435T polymorphism
between breast cancer patients and healthy controls. Clinicopathological
parameters of patients with breast cancer were compared
for C3435T polymorphism. These data suggest that a number of other
factors in addition to gene polymorphisms, e.g., gene amplification,
promoter demethylation might be responsible for MDR1 over-expression
in these patients.
P06.056
Establishment of study Group of multiple Endocrine Neoplasia
in Japan (mEN consortium of Japan)
A. Sakurai 1 , S. Uchino 2 , S. Suzuki 3 , M. Imamura 4 , MEN Consortium of Japan;
1 Shinshu University School of Medicine, Matsumoto, Japan, 2 Noguchi Thyroid
Clinic & Hospital Foundation, Beppu, Japan, 3 Fukushima Medical University,
Fukushima, Japan, 4 Osaka Saiseikai Noe Hospital, Osaka, Japan.
Multiple endocrine neoplasia (MEN) is a rare hereditary syndrome
characterized by neoplastic disorder of endocrine organs. MEN is subdivided
into MEN1 and MEN2, and the latter includes MEN2A, MEN2B
and familial medullary thyroid carcinoma. MEN1 and MEN2 are caused
by germline mutations of the responsible genes, MEN1 and RET, respectively,
and mutations can be identified in most patients. Clinical
guideline for diagnosis and management of MEN has been published
in 2001, and that is widely accepted as a “golden standard”. However,
its contents are not based on reliable evidences. Efforts to establish
clinical evidence are currently ongoing in Europe, USA and other regions
of the world. In Asian countries including Japan, such efforts
have not been initiated. Also, some have claimed that clinical courses
of Japanese (Asian) patients may not be the same as that of Caucasian
patients, which is not verified. To construct a reliable database of
Japanese patients with MEN, we established a study group of MEN
and named it “MEN Consortium of Japan”. Each participant deposits
anonymized clinical data of patients and those are cumulated in data
handling center. Participants can freely extract clinical data from database
for analysis from various respects. This database also enables
long-term follow-up of patients even if they move from one hospital to
another. As of February 2009, 21 major institutions have joined this
Consortium and additional 20-30 institutions are expected to join in
near future. This consortium will help clarify current status of diagnosis
and clinical management of MEN in Japan.
P06.057
methyl-binding domain (mBD) protein based isolation of
methylated DNA from human serum
M. Wielscher, M. Hofner, C. Nöhammer, A. Weinhäusel;
Austrian Research Centers GmbH, 2444 Seibersdorf, Austria.
DNA methylation testing of serum-DNA for minimal invasive testing of
cancerous disease is of great diagnostic interest. Isolation of cell-free
DNA from human serum is a big challenge because only nanogram
amounts of DNA are present in one ml of serum.
In this work we tested the MBD-protein to isolate and enrich methylated
DNA already during the DNA isolation step. Selective binding of
cell-free serum DNA onto immobilised MBD directly in the serum would
enable favorable concentrations of DNA for further analysis.
In addition DNA binding under native conditions preserves proteins for
additional proteomic or immunological analyses.