European Human Genetics Conference 2007 June 16 – 19, 2007 ...

Cancer genetics
and cytoplasmic domains of lymphocyte triggering moieties.The most
important problem of this type of immunotherapy is scFv, because of
its poor solubility and stability, the big size and unstable linker. Part
of the humoral immune response of camels and lamas is based on
heavy-chain antibodies where the light chain is totally absent. These
unique antibody isotypes interact with the antigen by virtue of only one
single variable domain, referred to as VHH. VHH have these unique
features:
1) Solubility and stability
2) Specificity and binding to their antigen with nanomolar affinity
3) Recognizing unique conformational epitopes that are currently out
of reach for conventional antibodies
4) Homology to human VH sequences that causes VHH is not immunogene
for human
We are developing a new construct which expresses a CR containing
VHH instead of scFv. This construct might provide opportunities to
develop a new generation of T cell therapy that hope to solve some of
the problems of T_cell therapy.
P0621. A novel approach for the determination of T-cell clonality
using microarray
O. A. Gra 1 , J. V. Sidorova 2 , E. A. Nikitin 2 , A. B. Sudarikov 2 , A. S. Zasedatelev 1 ,
T. V. Nasedkina 1 ;
1 Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Moscow,
Russian Federation, 2 Hematology Research Center, Russian Academy of
Medical Sciences, Moscow, Russian Federation.
T-cell lymphomas account for 15-20% of all lymphoid malignancies in
Western countries. Determination of T-cell clonality has important for
the differential diagnosis between malignant and non malignant T-cell
proliferation.
We developed a new method for the post-PCR analysis of TCR-γ rearrangements
using hybridization on oligonucleotide microchip. The
TCR-γ has become a favorite target for T-cell clonality assays because
the γ-chain undergoes rearrangement before the α- and β-chains and,
consequently, is rearranged in all lymphocytes.
The microchip contains oligonucleotide probes for all variable (V) and
joining (J) gene segments involved in rearrangements of the TCR-γ
locus. To estimate the accuracy of the method, we examined 49 samples
of patients with lymphoproliferative disorders and 47 samples of
normal donors. The results of hybridization on the microchip displayed
100% coincidence with the results obtained by other methods. The
sensitivity of the method is sufficient to determine 10% of clonal cells
in the sample.
Furthermore this biochip has been used for determination of the of Vγ
and Jγ genes frequencies. Among the Vγ gene segments, those of
family 1 were most commonly used (total frequency 62%), while the
lowest frequency (3.5 %) was observed for the family 4 gene segment
Vγ11. As for the Jγ gene segments, the Jγ1 and Jγ2 gene segments
are most commonly used in clonal rearrangements: their frequency
was 81.6% in the total rearrangements with the Jγ gene segments.
The results demonstrate the principal possibility of detecting T-cell
clonality in patients with T-cell lymphoid malignancies by hybridization
on the microchip.
P0622. “Familial and sporadic Thyroid Tumors: new variants
in candidate genes and their relevance for the oncocytic
phenotype.”
E. Bonora, C. Evangelisti, L. Pennisi, G. Romeo;
Unit of Medical Genetics, Bologna, Italy.
Familial Non-Medullary Thyroid Cancer (fNMTC) is associated with
some of the highest familial recurrence among all cancers. Inheritance
patterns indicate that fNMTC is transmitted as an autosomal dominant
trait with reduced penetrance, but a multigenic inheritance is not
excluded. TCO (Thyroid tumor with Cell Oxyphilia), a predisposing
locus for recurrence of oxyphilic/oncocytic tumors, characterized by
the presence of oncocytic cell, rich in mitochondria, was previously
mapped to the 19p13.2 region.
In order to identify the TCO gene, genes on chromosome 19p13.2
were analyzed in patients of the families contributing to linkage. We
screened 9 genes with a role in tumor development and/or mitochondrial
functions: MUC16, DNMT1, ICAM1, EIFS4, MBD3L1, SMARCA4,
ILF3, TYK2, ZNF358. We identified new variants in the coding region
of MUC16, a member of the mucin family and highly expressed in thy-
1 2
roid tumors. Haplotype analysis and functional study of these variants
is currently ongoing and results will be presented.
In parallel, we previously identified disruptive mutations in a panel
of sporadic oncocytic thyroid tumors in genes of complex I subunits
encoded by mitochondrial DNA. These changes correlated with the
biochemical defects identified in oncocytic neoplasia. However, the
mutations do not account for all the cases of thyroid oncocytic tumors,
suggesting that other nuclear changes might be involved. We are currently
screening nuclear genes encoding for the complex I subunits
and for PolG, the mitochondrial polymerase. Results of the screening
will be presented.
P0623. Tumor necrosis factor gene -308 (G→A) polymorphism
and risk of Non-Hodgkin lymphoma
A. R. Nestorovic 1 , M. Radojkovic 2 , B. Ristic 2 , M. Stankovic 1 , M. Andjelic 3 , D.
Radojkovic 1 ;
1 Institute of molecular genetics and genetic engineering, Belgrade, Serbia,
2 Clinic of Internal medicine, Clinical Center Dr. Dragisa Misovic, Belgrade,
Serbia, 3 Department of Pulmonology, University Clinical Centar Zvezdara, Belgrade,
Serbia.
Common genetic variants in inflammatory response genes can affect
the risk of developing Non-Hodgkin lymphoma (NHL). The tumor necrosis
factor (TNF) is central in proinflammatory response and therefore
represents a strong candidate for mediating the risk of developing
immunologicaly related malignant disease. Recent data have suggested
that TNF -308 (G →A) polymorphism might be associated with
increased risk of NHL. Genotype AA is associated with higher serum
levels of soluble TNF.
This study investigated the potential influence of TNF -308 polymorphism
on the etiology on NHL in Serbian population. A total of 48 NHL
patients and two control groups consisting of 102 diabetes patients
and 120 healthy blood donors were included in the analysis. All subject
were genotyped for TNF -308(G→A) by PCR-RFLP analysis. One of
48 patients (2%) was homozygous (AA), and 13 of 48 patients (27
%) were heterozygous (GA). In control group consisted of diabetes
patients, 3 of 102 (3%) were homozygous and 28 of 102 (27%) were
heterozygous and in healthy blood donors control group, two of 120
(2%) were homozygous and 30 of 120 (25%) were heterozygous. Our
study found no association between TNF-308 polymorphism and risk
of NHL:the differences in allelic and genotype distribution was not
statistically significant among tested groups. However, hypothesis on
involvement of TNF -308 polymorphism in NHL deserves further investigation
on a larger cohort of patients. In future studies additional
polymorphisms within the TNF gene and inflammatory response genes
should be taken into consideration
P0624. TP53 mutation frequency analysis in breast cancer
against other carcinoma types
D. Macic 1 , L. Kapur 1 , J. Ramic 1 , N. Pojskic 1 , N. Obralic 2 , S. Beslija 2 , N. Bilalovic
3 , K. Bajrovic 1 ;
1 Institute for Genetic Engineering and Biotechnology, Sarajevo, Bosnia and
Herzegovina, 2 Institute of Oncology, KCUS, Sarajevo, Bosnia and Herzegovina,
3 Institute of Pathology, KCUS, Sarajevo, Bosnia and Herzegovina.
The aim of this study was to compare occurrence of somatic mutations
at codons 248 and 273 of TP53 gene in patients with breast cancer to
patients diagnosed with other types of cancer.
TP53 is a tumor suppressor gene involved in control of cell division
and mutations in the gene are considered to represent the most common
genetic alteration in human cancers. These mutations may damage
the normal function of TP53 as a transcription factor and the induction
of repair or apoptosis may be diminished. Consequently, genetic
alterations may accumulate in the cell.
Codons 248 and 273 are positioned at DNA binding domain of TP53
gene and mutation that are to be tested are single base substitution
A>G in exons 7 and 8. As a result amino acid sequence is changed
from Arg-Gln and Arg-His respectively.
This study included 100 subjects, half of which are breast cancer affected
individuals and rest are patients with other cancers. Genetic
material was extracted from bioptic tissue specimen. Mutations occurrence
in TP53 (codons 248 and 273) was determined by PCR analysis
using single strand conformation polymorphism and restriction enzyme
digestion. Pathohistological findings obtained from clinic were correlated
with molecular alterations. Genetic data were evaluated in respect