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

Cancer genetics
ously defined for different rearrangements in AML patients, and other
ones have been reported to be loci of some genes which take place in
hematopoiesis. Possible effects of these new cytogenetic findings on
prognosis of AML will be discussed.
P0495. Case report of a rare AF9-MLL fusion gene in pediatric
acute megakaryoblastic leukemia
A. Divane 1 , M. Baka 2 , M. Varvoutsi 2 , A. Pourtsidis 2 , D. Bouhoutsou 2 , D. Doganis
2 , K. Koronioti 1 , S. Velaeti 1 , H. Kosmidis 2 ;
1 Department of Cytogenetics, Locus Medicus, Diagnostic Centre, Athens,
Greece, 2 Department of Oncology, Aglaia Kyriakou Childrens Hospital, Athens,
Greece.
It is known that structural abnormalities involving the mixed -lineage
leukemia (MLL) gene on 11q23 have been associated with hematologic
malignancies.
In acute myelogenous leukemia (AML) the MLL gene fuses to more
than 30 different partner genes. To the best of our knowledge only
few cases of AML-M7 have been associated with MLL rearrangement.
We herein report a rare case of pediatric AML-M7 with translocation
t(9;11)(p22;q23) leading to the AF9/MLL fusion gene.
An 18-month old girl presented with anaemia and thrombocytopenia.
In repeated bone marrow (BM) examinations, patient exhibited cytopenia
and 15-25% infiltration with blast cells. Immunophenotyping
revealed blast positivity for CD41, CD42b and CD61 and the leukemia
was therefore classified as M7 according to FAB classification.
Cytogenetic analysis of BM showed normal karyotype. FISH analysis
was performed using the LSI MLL dual color break apart rearrangement
probe (Vysis) at 11q23. 27,5% of analysed nuclei contained a
MLL rearrangement. Patient was treated as per the BFM98 protocol for
AML . Analysis at a later time and when patient achieved clinical and
hematological remission, showed 4,2% positive nuclei while investigation
of metaphases spreads revealed that the translocation involved
the short arm of chromosome 9 (9p22) and the chromosome 11 at
band q23. Chromosome 9 was hybridized, simultaneously with probe
for ABL gene (9q34), as a marker.
The patient continued chemotherapy according to protocol and she is
candidate for allogeneic bone marrow transplantation.
P0496. Mutation analysis of the APC and MYH genes in Spanish
patients with Familial Adenomatous Polyposis
C. Ruiz-Ponte, N. Gomez-Fernandez, C. Fernandez-Rozadilla, A. Vega, A.
Carracedo;
Grupo de Medicina Xenómica USC, FPGMX-SERGAS, Santiago de Compostela,
Spain.
Familial adenomatous polyposis (FAP) is an autosomal dominant inherited
syndrome caused by germline mutations in the adenomatous
polyposis coli (APC) gene. However, germline mutations in APC cannot
be identified in about 20-30% of patients with classical FAP and up
to 90% of those with attenuated phenotype (AFAP). Recently, germline
mutations in the base-excision-repair gene, MYH, have been associated
with some APC negative FAP and AFAP patients.
Thirty-four unrelated patients with a clinical diagnosis of multiple polyposis
(15-100 colorectal adenomas) or classical FAP (>100 colorectal
adenomas) were analysed for germline APC mutations. Patients without
APC detected mutations were investigated for MYH mutations.
Eighteen families (54%) carried point mutations or large rearrangements
in the APC gene. p.R805X and p.R216X mutations were found
twice in unrelated patients. Phenotypic heterogeneity was observed for
the R805X, associated with either AFAP or FAP, suggesting that modifier
genes or environment could modulate FAP phenotype. Two new
unclassified variants p.I1055M and p.R1171C were also identified.
Three biallelic (20%) and two monoallelic (14%) MYH germline mutation
carriers were identified in 4 AFAP and 1 FAP families APC
negative. The two most frequent germline mutations (p.Y165C and
p.G382D) were observed as well as new genetic variants for which
control populations studies were performed.
In this study 20% of the APC negative patients were found to be biallelic
MYH germline mutation carriers. Therefore, MYH analysis is
recommended for all APC negative families even if a recessive inheritance
is not confirmed. However, mutations in MYH can not explain all
cases of FAP.
P0497. Analysis of APC tumor suppressor gene promoter
methylation status in adenocacinoma of stomach and in serum
M. Alivand 1,2 , F. Ratgar jazii 3 , M. Zare 3,4 ;
1 National Institute of Genetic Engineering and Biotechnology of Iran, Tehran,
Islamic Republic of Iran, 2 Khatam University, Tehran-ferdous blv., Islamic Republic
of Iran, 3 National Institute of Genetic Engineering and Biotechnology of
Iran, tehran, Islamic Republic of Iran, 4 khatam university, Tehran-ferdous blv.,
Islamic Republic of Iran.
Adenocarcinoma of stomach has a high mortality rate . Its incidence
rate in Ira is high. Often, the cancer is diagnosed when its is already
advanced and has spread to other tissues, which makes treatment difficult.
In order to early diagnose the disease attention is focused to the
promoter methylation status of tumor suppressor genes. By applying
Methylation Specific PCR(MSP) we studied the methylation status of
the Adenomatous polyposis coli(APC) tumor suppressor gene in this
type of cancer . MSP analysis of APC was done due to the fact that promoter
methylation is an important way of APC inactivation. Our study
indicates methylation of APC promoter in %66.6 of tissue samples. We
further extended our study on to serum of such patients and our results
indicate that MSP could be applicable to the serum which clinically is
important for diagnosis and evaluation of treatment strategy.
P0498. The coumarins and furanocoumarins induced apoptosis
and inhibit proliferation in human leukemic cells
A. Bogucka-Kocka, D. H. Smolarz, J. Kocki;
Medical University, Lublin, Poland.
Coumarins and furanocoumarins are plant compounds exhibiting anticancer
activities. A series of 15 coumarins and furocoumarins have
been evaluated for anticancer activity in vitro on 6 human leukemic cell
lines: HL-60, J45.01, Eol-1, 1301, U261, and ML1.
The cell cultures were stimulated with coumarin derivatives in various
concentrations. As a negative control the cells were incubated without
compounds. The cell growth was measured by using tetrazolium bromide
(MTT) assay. Coumarins and furanocoumarins induced apoptosis
in cells as indicated by dose- and time-dependent (1) cytochrome c
release, (2) caspase activation, (3) DNA fragmentation, and (4) reduction
of expression of anti-apoptotic genes: BCL-2, MCL-1 and BCL-xL.
Genes expression activity were detected by using real-time quantitative
reverse transcription-polymerase chain reaction. After leukemic
cells were treated with coumarins and furanocoumarins, the expression
of BCL-2, MCL-1 and BCL-xL mRNAs decreased.
Our studies show the influence of coumarins: xanthotoxin, o,o-dimetyl-fraxetin,
heraclenine and phelopterine on apoptosis process in human
lymphocytes in vitro. The compounds showed very good activity
against different leukemic cell lines. Supported by grant of Polish State
Committee of Scientific Research No 2 PO5F 04928.
P0499. Alterations in ATP2A2 gene in correlation with colon and
lung cancer
M. Ravnik-Glavač1 , B. Korošec1 , D. Glavač2 ;
1Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Slovenia,
2Department of Molecular Genetics, Faculty of Medicine, University of Ljubljana,
Ljubljana, Slovenia.
Sarco/endoplasmic reticulum calcium transport ATPases (SERCAtype
calcium pumps), proteins that accumulate calcium in the ER, play
an important role in numerous signaling pathways controlling tumor
growth, differentiation and cell death. Reports that SERCA2 haploinsufficient
mice often developed cancer prompted us to study the involvement
of the ATP2A2 gene in human cancer development. We
found 13 novel different alterations of the ATP2A2 gene in 27 of 416 alleles
of patients with two different types of cancer. Changes in ATP2A2
were statistically significantly more common in patients with colon (p
< 0.0001, OR = 25.3) as well as lung (p = 0.046; OR = 8.05) cancer.
We found two missense mutations, two intronic deletions, an intronic
insertion and 8 single nucleotide alterations, of which two were in the
coding region, three in the intronic and three in the promoter region.
We were able to detect lost or reduced expression of ATP2A2 in all patients
with alterations in the promoter region, as well as in patients with
a combination of gene alterations. Our results suggest that germline
alterations of ATP2A2 may predispose to lung and colon cancer and
that an impaired ATP2A2 gene might be involved, directly or indirectly,
as an early event in carcinogenesis.
1