2009 Vienna - European Society of Human Genetics

Cancer genetics
chronic inflammation may cause oxidative damage of mtDNA. In addition,
we suggest that mtDNA deletions may be predisposing or accelerator
factor on malign transformation of cells of cervix uteri.
P06.023
Nucloestemin is highly expressed in gastric adenocarcinoma
and its gene expression knock-down caused a G1 arrest in AGs
cell line
M. H. Asadi 1 , S. J. Mowla 1 , F. Fathi 2 , B. Nikkho 2 , F. Sheikh Esmaili 2 ;
1 Department of Genetics, Faculty of Basic Sciences, Tarbiat Modares University,
Tehran, Islamic Republic of Iran, 2 Faculty of Medicine, Kurdistan University
of Medical Sciences, Sanandaj, Islamic Republic of Iran.
Nucleostemin (NS) is a nucleolar protein, primarily hypothesized to
be a novel regulator of stem cell self-renewal, where it binds to P53
and hence regulates cell cycle. It is now believed that NS is also expressed
in some highly proliferating cells of adult tissues including several
cancer cell lines and tissues. However, molecular links between
NS and stem-cell self-renewal, embryogenesis and/or tumorigenesis
are not well understood. We have previously shown that NS is highly
expressed in rat bone marrow stromal stem cells (BMSCs) and the
expression is shut off upon induction of differentiation. Knocking-down
the expression of NS in rBMSCs suggests an apparently P53-independent
role for it in these cells. Moreover, NS knock-down in different
bladder cancer cell lines demonstrated a cell-type dependent function
of NS in arresting cell proliferation in either G1 or G2/M phases of
cell-cycle. Here, we have evaluated the potential expression of NS
in 40 tumor/non-tumor biopsies of the patients with gastric cancer.
Moreover, we have assessed the effects of the NS knock-down on
cell proliferation of the AGS cell line, using RNAi strategy. Our data
revealed that NS is highly expressed in gastric adoenocarsinoma, but
not in apparently normal tissues obtained from the margin of same patients.
The data suggest that NS is potentially a suitable tumor marker
for diagnosis, grading and molecular classification of gastric adoenocarsinoma.
Furthermore, NS knock-down in the AGS cell line caused a
G1 cell cycle arrest in the cells, confirming its causative role in gastric
tumorigenesis.
P06.024
targeting cancer stem cells via Oct4 promoter-derived
construct
R. Najafi, M. Sadeghizadeh, S. J. Mowla;
Department of Genetics, Faculty of Basic Sciences, Tehran, Islamic Republic
of Iran.
Despite significant improvements in cancer therapy, tumor recurrence
is frequent and can be due to a variety of mechanisms, including the
evolution of resistance and tumor metastasis. Cancer stem cells are a
subclass of cancer cells possessing parts of properties of normal stem
cells. The existence of these malignant stem cells has been proven
for hematological as well as some solid tumors. These kinds of cells
have a high capacity of proliferation and are not targeted by standard
therapy thus play a critical role in tumor recurrence, resistance to radio-
and chemotherapy. The Octamer-binding transcription factor 4
gene (OCT4), encodes a POU-domain transcription factor which plays
a critical role in maintaining pluripotency and self-renewal of ES cells.
OCT4 expression has also been detected in adult stem cells as well as
a variety of cancer cells and cell lines e.g. the bladder 5637 cell line.
In this study, the OCT-4 promoter was cloned into the pGL3-control
reporter vector encoding the Luciferase gene, followed by transfection
of the resultant construct into the 5637 bladder cell line. OCT-4
promoter-driven Luciferase gene expression was further detected in
the 5637 bladder cell line which suggests the activity of the OCT-4
promoter in these cells. Our data indicate that OCT4 can be chosen as
a therapeutic target, as well as a novel tumor biological and prognostic
marker which could decrease the toxicity of cancer therapy to normal
tissues.
P06.025
Expression of DDX3Y in testicular germ cell tumours (tGcts) - a
model system for the study of DDX Y male germ line function
B. Gueler 1 , S. Brask Sonne 2 , S. Buse 3 , J. Zimmer 1 , N. Graem 4 , M. Hohenfellner
3 , E. Rajpert-De Meyts 2 , P. H. Vogt 1 ;
1 Section Molecular Genetics and Fertility Disorders, University Hospital of
Women, Heidelberg, Germany, 2 University Department of Growth and Re-
production, Rigshospitalet, Copenhagen, Denmark, 3 Department of Urology,
University of Heidelberg, Heidelberg, Germany, 4 Department of Pathology,
Rigshospitalet, Copenhagen, Denmark.
DDX3Y is a DEAD-box-RNA-helicase located on the Y-chromosome.
It has a functional counterpart on the X-chromosome, DDX3X, and
both are involved in translational control of downstream genes and
control of G1/S-progression during cell-cycle. While DDX3Y protein is
exclusively expressed in the male germ-line, predominantly in spermatogonia,
the DDX3X protein is found also in somatic cells, but in
the male germ-line only translated in spermatids. Since the deletion of
DDX3Y results in pre-meiotic spermatogenic disruption, an essential
role of DDX3Y in spermatogenesis is assumed. Our purpose was to
examine if the mechanisms for translational regulation of DDX3Y transcripts
might be associated with male germ-cell differentiation. Testicular
germ-cell tumours (TGCTs) are derived from different stages of
germ-cell maturation and therefore provide a model-system for such
germ-cell-differentiation studies. Consequently, we used a TGCT sample
panel including the pre-invasive carcinoma in situ (CIS) to investigate
the expression of DDX3Y protein in these specimens. Our results
revealed strong DDX3Y expression in CIS cells but a heterogeneous
pattern in other TGCT cell types. The strong CIS expression is marking
their high proliferative activity and clearly designates DDX3Y as a
novel marker for these tumour precursor cells. Overt tumours showed
only a small and variable number of DDX3Y expressing cells. An abundant
expression in seminomas compared to non-seminomas points to
reduction of DDX3Y expression during tumour-progression. Our results
indicate a successive vanishing of the spermatogonia cell type
character of these tumour cells and suggest that the spermatogonia
specific DDX3Y translation is indeed controlled by germ-cell specific
trans-factors.
P06.026
From human papillomaviruses & cervical carcinoma to HPV
detection
D. Konvalinka, J. Dvořáčková, D. Marková, M. Uvírová, J. Šimová, I. Urbanovská;
CGB laboratoř a.s., Ostrava, Czech Republic.
Human papillomaviruses (HPV) are double-stranded DNA viruses,
invading mucosal or cutaneous epithelium. More than 100 different
types of HPV are already known.
With respect to the oncogenic potential, HPV are divided into “highrisk”(HR)
and “low-risk”(LR) types. HR HPV invade ano-genital and
oropharyngeal regions of the human body and cause one of the most
serious and the second most frequent cancer in women: cervical carcinoma.
HPV DNA carries information for proteins of an early (E-proteins)
and a late (L-proteins) infection phase. Most serious is the interaction
of E6- and E7-proteins with the human p53 and pRb proteins,
respectively, leading to malignant transformation of infected cells.
Within this presentation we would like to draw your attention to relations
between cervical carcinoma, HPV infection and detection. HPV
detection can be performed by different techniques: indirect detection,
showing us presence of altered tissues or cells. The most widely used
technique, but not the most sensitive one, is gynaecological cytology.
Direct detection, manifesting presence of HPV, uses (among others)
most sensitive molecular biology techniques, and makes HPV DNA
testing possible. We have tested 380 patients. 88 patients (23.1 %)
were found to be HPV DNA positive.
Use of the HPV DNA test allows detection of HPV infection with high
sensitivity and specificity. Such result can more efficiently specify unclear
outcomes of other screening methods, such as cytology. HPV
DNA test has been already incorporated into routine screening within
several countries. This test can be used for pre-vaccination (e.g. before
vaccination against HPV) examination too.
P06.027
Genome-wide discovery of copy number variations in cancer
patients using sOLiD sequencing
X. Xu 1 , B. B. Tuch 1 , M. Muller 1 , C. Barbacioru 1 , C. Bormann-Chung 1 , C. Monighetti
1 , J. Brockman 2 , J. Schageman 2 , J. Gu 2 , S. Kuersten 2 , R. Setterquist 2 ,
Y. Sun 1 , C. Xiao 3 , H. Peckham 3 , R. K. Gottimukkala 1 , A. Bashir 4 , V. Bafna 4 , R.
Laborde 5 , E. Moore 5 , J. Kasperbauer 5 , M. Barker 1 , A. Siddiqui 1 , F. Hyland 1 , D. I.
Smith 5 , F. M. De La Vega 1 ;
1 Applied Biosystems, Foster City, CA, United States, 2 Applied Biosystems,