2008 Barcelona - European Society of Human Genetics

Cancer genetics
P04.197
mutation in siRNA target sequence can impair RNAi mediated
inhibition of E A gene expression in HEK 293
H. Vosgha, M. Behmanesh, M. Sadeghizadeh;
Tarbiat Modares University, Tehran, Islamic Republic of Iran.
RNA interference (RNAi) has emerged as an effective method for silencing
gene expression in eukaryotic cells . It has tremendous potential
as both a research tool and a therapeutic strategy . The key player
in RNAi is small RNA (~ 22nt) termed siRNA . So in this report we used
the E1A specific siRNA coding plasmid under U6 snRNA promoter to
suppress E1A gene expression . Then these constructs were transfected
into the HEK 293 cancerous and successfully transfected cells colonies
were selected based on Neomycin antibiotic resistance . Changes
in E1A gene expression were analysis using RT-PCR technique . Final
findings showed no obvious difference in E1A gene expression level
in suppression and control groups upon transfection with constructed
plasmids . In order to deduce the rationale behind no suppression of
the E1A gene expression, we analyzed the PCR amplified sequence
of the siRNA target region of the E1A gene using sequencing technique.
The findings illustrated certain mutations in this region. It has
been established previously that in RNAi process, occurrence of any
mutation in mRNA sequence of target gene at the siRNA binding site
might cause impaired interference in gene expression . Therefore even
a single mutation in mRNA sequence cause inhibition of interference .
P04.198
Novel somatic mutations in the s100A2 gene in non-small cell
lung carcinoma (NscLc)
M. Strazisar, D. Glavac, T. Rott;
Faculty of Medicine, Ljubljana, Slovenia.
Contrary to the recent hypothesis that S100A2 is a tumour suppressor,
no somatic mutations have yet been identified. We therefore screened
90 non-small cell lung carcinoma (NSCLC) samples, initially for mutations
in S100A2 and then also for mutations in P53 and K-RAS genes .
Alterations were detected in 46 .7 % of squamous lung cancer (SCC)
samples, but we detected only one novel tumour specific mutation,
Q23X in squamous carcinoma . We detected four polymorphisms, two
of them published for the first time (144+109 C/G and 297+75A/G) and
two already published: S62N, in coding region and related to squamous
cell carcinoma, and 297+17T/C . In one tumour with the S62N
polymorphism, P53 and K-RAS genes were also mutated, while two
tumours with the Q23X mutation have a P53 but no K-RAS mutation .
Expression profiles of hTERT and COX-2 revealed no significant correlation
with tumours having also the S100A2 alterations . To the best
of our knowledge, this is the first report describing alterations in the
S100A2 gene proving the relation between polymorphic changes in
predominantly squamous lung cancer (SCC) .
P04.199
Molecular cytogenetic characterization of paraffin-embedded
salivary gland tumors by comparative Genomic Hybridization
G. Floridia 1 , F. Censi 1 , M. Foschini 2 , V. Falbo 1 , D. Taruscio 1 ;
1 Istituto Superiore di Sanità , Dept.Cell Biology and Neuroscience, Roma, Italy,
2 Section of Pathology, University of Bologna, Bellaria Hospital, Bologna, Italy.
Salivary gland tumours (SGTs) are rare tumors of the neck and head
with an overall incidence in the Western world of approximately 2 .5-
3/100 .000/year . SGTs are remarkable for their histopathologic and
biologic diversity; they include benign and malignant tumors of epithelial,
mesenchymal and lymphoid origin . The study of molecular
pathogenesis of SGTs is a challenging task because of the rarity and
histopathological diversity of these malignancies . Comparative Genomic
Hybridization metaphase-based was performed in 10 paraffine
embedded Adenoid Cystic Carcinoma samples (ACC) . Heterogeneity
was detected and gains predominated over losses; no recurrent
anomaly was observed . However 3q29, 5q35, 16q24 and 21q22 gains,
detected in our study, have been reported and described in literature
as ACC loci . The correlation of CGH results with clinical-pathological
data and a comparison with literature data will be discussed .
This work has been funded in the frame of “Programma di collaborazione
ISS-NIH , Area Malattie Rare” Fasc .526/B and Fasc .7GR1 .
P04.200
A case of synovial sarcoma of the pericardium diagnosed by
FisH on FNA material
I. Trigo1 , A. Hernandez2 , M. Vargas1 , M. Diaz2 , J. Rios2 , H. Galera-Ruiz2 , R.
Gonzalez-Campora2 ;
1 2 Unidad de Genética., Sevilla, Spain, Dpt of Pathology, Sevilla, Spain.
Case report
We present a case of 40 year-old woman, without any previous interesting
medical history, who presented disnea, cough and fever over
several weeks . Thoracic MR revealed a left posterolateral paracardial
mass of possible pericardium origin . The cytologic study on material
obtained by transesophagic FNA was performed and the tumour was
surgically removed . Morphologic diagnosis was a malignant spindle
cell tumour consistent with synovial sarcoma (immunohistochemistry
profile: EMA, bcl-2,CD-99 and CK 19 positive. S-100, CD-34 and
caldesmon negative) . SYT gene rearrangement was confirmed by
FISH techniques, verifying the localization at SSX2 gene .
The synovial sarcoma is an uncommon mesenquimal tumour with
variable epithelial differentiation and represents 5% of cardiac sarcomas
and less than 0 .1 of all cardiac tumours . It is characterized by
t (X;18)(p11;q11), which is present in its four histological types . The
microscopic diagnosis is very difficult and the immunochemical techniques
are helpful but not conclusive . Consequently other ancillary
techniques, such as FISH analysis, are primordial to precise the definitive
diagnosis of this entity characterized by the SYT gene rearrangement
to SSX2 gene . In the literature review only 18 cases of heart
synovial sarcoma have been described and only one of them (biphasic
type) was diagnosed by FNA material without FISH contribution . To our
knowledge no other FISH studies on cytopathologic material of synovial
sarcoma of the pericardium have been reported in the literature .
P04.201
Detection of human telomerase gene (TERC) amplification in
cervical neoplasia: A reterospective study of 79 patients with
normal smears or mild or moderate dyskaryosis
R. E. Crookes1 , M. Dyson1 , J. H. F. Smith2 , E. Maltby1 ;
1 2 NHS Foundation Trust, Sheffield, United Kingdom, Royal Hallamshire Hospital,
Sheffield, United Kingdom.
The inclusion of a genetic marker of disease progression for cervical
carcinoma along side the histological assessment of Pap smear slides
could dramatically reduce the number of diagnostic colposcopic procedures
currently performed and increase the sensitivity and specificity
of cervical screening programmes .
Recent CGH studies (Heselmeyer-Haddad et al ., 2003) indicated the
involvement of extra copies of 3q and hence the human telomerase
gene (TERC) at 3q26, in invasive cervical carcinoma . Their retrospective
study of 59 cervical smears showed that gains of TERC could
predict progression from lower grade smear abnormality (mild or moderate
dyskaryosis) to CIN3 and invasive carcinoma .
We present the results of retrospective study, using the same TERC
probe kit, on a selection of 79 patients with negative, mild or moderate
dyskaryosis that later progressed to CIN3/cervical cancer, or regressed
to negative. In the cohort of patients classified as cytologically
negative that subsequently developed CIN 3, 28 .5% were positive for
TERC gain. In the cohort of patients classified as mild or moderate that
progressed to CIN3/cervical carcinoma, 60% and 82 .4% respectively
showed gains of TERC . In the cohort patients classed as negative,
mild or moderate dyskaryosis that regressed or remained negative 30
out of 33 patients were negative for TERC gains . This concurs with
previous studies which have proposed that the acquisition of TERC is
an important event in the progression of cervical dysplasia to cervical
cancer . The results demonstrate the potential use of TERC as an early
prognostic detection of disease progression .
P04.202
Effects of somatic mutations in tP53 on expression of genes
involved in cell cycle arrest
D. Macic 1 , L. Kapur 1 , J. Ramic 1 , N. Lojo-Kadric 1 , N. Obralic 2 , T. Ceric 2 , S.
Beslija 2 , K. Bajrovic 1 ;
1 Institute for Genetic Engineering and Biotechnology, Sarajevo, Bosnia and
Herzegovina, 2 Institute of Oncology, Sarajevo, Bosnia and Herzegovina.
The TP53, tumor suppressor gene, is a critical regulator of cell division
and its inactivation at the gene or protein level contributes to onco-