12th Congress of the European Hematology ... - Haematologica

1230
ASSOCIATION OF HEPARANASE GENE (HPSE) SINGLE NUCLEOTIDE POLYMORPHISMS
WITH HEMATOLOGICAL MALIGNANCIES
O. Ostrovsky, 1 M. Korostishevsky, 2 I. Levite, 1 M. Leiba, 1 H. Galski, 1
I. Vlodavsky, 3 A. Nagler 1
1 Chaim Sheba Medical Center, RAMAT GAN, Israel; 2 Tel Aviv University, TEL
AVIV, Israel; 3 Technion, HAIFA, Israel
Heparanase, endo-β-D-glucuronidase, degrades heparan sulfate (HS)
glycosaminoglycans-the principal polysaccharide component of the
basement membrane and extracellular matrix (ECM). Cleavage of HS
disassembles the basement membrane structure and releases HS-bound
bioactive angiogenic and growth-promoting mediators. Heparanase
activity plays a decisive role in fundamental biological processes associated
with remodeling of the ECM, such as cancer metastasis, angiogenesis
and inflammation. In the hematopoietic system, heparanase is
thought to be associated with normal differentiation and function of
myeloid cells and platelets. We investigated heparanase polymorphisms
in patients with acute myeloid leukemia (AML), myelodysplastic syndrome
(MDS), acute lymphoblastic leukemia (ALL), chronic myeloid
leukemia (CML), Hodgkin’s disease (HD), and multiple myeloma (MM).
Statistically significant correlation was found between rs11099592 and
rs6535455 SNPs of the heparanase (HPSE) gene and ALL (χ21df=4.96,
p=0.026). Genotype frequency comparisons revealed a significant association
with rs4693602 (χ22df=7.276, p=0.026) in MM patients and
rs4364254 (χ22df=6.226, p=0.044) in AML patients. Examination of
HPSE gene mRNA expression by real-time RT-PCR indicated a significant
low expression level of the HPSE gene in ALL patients and a high
expression level in MM and AML patients, compared to healthy controls.
These data suggest that alterations in HPSE gene are an important determinant
in the pathogenesis of these hematological malignancies.
1231
WITHDRAWN
1232
ABVD CHEMOTHERAPY EFECTS ON HUMAN GENOME IN HODGKIN DISEASE
M.V. Teleanu, 1 A.D. Moicean, 1 D. Usurelu, 1 D. Cimponeriu2 1 2 Fundeni Clinical Institution, BUCHAREST, Romania; Institute of Human
Genetics, BUCHAREST, Romania
Background. Chemotherapy has an important mutant effect on human
genome. Human chromosomal aberration seems to be an important cancer-associate
biomarker. ABVD as first line chemotherapy cures most of
Hodgkin disease patients. Material and methods: We have studied peripheral
blood lymphocytes from 18 samples obtained from patients with
Hodgkin disease receiving chemotherapy ABVD. To asses the cytogenetic
damage rate we looked for chromosomal aberrations on metaphases
chromosomes at cumulative doses of chemotherapy. For molecular
changes we evaluate the epigenetic effects e.g. hipo/hypermethylation
under ABVD regimen of the human genes. In vitro analysis were performed
on peripheral blood cultures from healthy nonsmoker volunteer
donor treated with increasing doses of doxorubicin (0.025×10 –6 M,
0.05×10 –6 M, 0.1×10 –6 M, 0.25×10 –6 M). Results: We had found an evidence
for a direct link between chromosomal aberrations and the number of
therapy cycles. The most frequent identified aberration were the PCD
(premature centromere divisions) and the chromosomal fusions (14.6-
26.3% and 10,7-16.9%, respectively). A global imbalance of the methylation
pattern was identified with a hypermethylation tendency. Further
studies should clarify the epigenetic changes of this chemotherapy
regimen.
1233
OVEREXPRESSION OF HOCT1 AT 6 MONTHS IS RELATED TO MAJOR MOLECULAR
RESPONSE TO MESYLATE IMATINIB TREATMENT
M. Bendit, 1 L. Nardinelli, 2 T.F.B. Martins, 2 M.F.Y. Novaes, 2
M.C. Mello, 2 P.E. Dorliac-Llacer, 2 W.M. Lima, 2 R.R. Giorgi, 2
D.A.F. Chamone, 2 I. Bendit2 1 University of Sao Paulo, SAO PAULO, Brazil; 2 Medical School-University of
Sao Paulo, SAO PAULO, Brazil
Background. Some studies have shown that human organic cation
transporter 1 (hOCT1) is responsible for the influx of imatinib in CML
cells, and therefore might determine the intracellular levels and hence the
response to imatinib. Although newly diagnosed CML patients have a
12 th Congress of the European Hematology Association
90% of event free progression at the end of 5 years of follow-up, there
is still a small number of patients that failed to achieve a major cytogenetic
response (MCR) at 6 months and/or a complete cytogenetic
response at 12 months (CCR). Resistance to imatinib is getting a major
concern and some of the mechanisms have already been elucidate as the
presence of mutations in the ABL kinase domain, overexpression due
BCR-ABL gene amplification, and the presence the ABC transporters
proteins involved in drug efflux across the cell membrane. Methods. We
decided to study the expression of hOCT1 in a cohort of 44 CML (35
CP; 7 AP; 2 BC) patients treated with imatinib as a front line therapy.
Mononuclear cells collected at different time as diagnosis, 3, and 6
months (mo) after initiated treatment with imatinib were assayed for
hOCT1 expression by quantitative real-time polymerase reaction (PCR)
and normalized for Abl expression. Results. Patients were defined as
responder if they achieved a Major Molecular Response (3 log reduction
of BCR-ABL from the standardised baseline) at 6 mo of treatment with
imatinib. Among the 44 patients that enter in the study 34 patients were
eligible for the analysis at 6 mo, 6 patients have been treated for less than
6 mo, 2 were withdraw from the study because hepatic toxicity grade
3, and 2 died with progressive disease. There was no statistical significance
among the median levels of hOCT1 expression at diagnosis, 3
and 6 months. Overexpression was considered when the levels of
hOCT1 were higher than the median value of the patients at diagnosis.
The presence of hOCT1 overexpression at diagnosis did not interfere
with the molecular response at 3 and 6 mo, but when hOCT1 expression
at 6 mo was compared with the molecular response at the same
period, a statistical difference was noted between the 21/34 responders
and 13/34 nonresponders (Kruskal-Wallis test, p=0.016). Conclusion.
Besides others had published before (Crossman et als, 2005) that low
levels of expression of hOCT1 at diagnosis may be related to fail in
achieving a cytogenetic response, in the present study, we could not
conclude that either the presence or absence of overexpression of
hOCT1 at diagnosis is a good predictor of molecular to imatinib response
after 3 and 6 mo of treatment. On the other hand, the presence of overexpression
of hOCT1 is related to a MMR at 6 months of treatment,
although some responders (5/21) did not present overexpression of
hOCT1, and 4/13 no responders expressed levels of hOCT1 above the
median. We can postulate that at the end of 12 mo of treatment those 4
patients that show expression of hOCT1 could achieve a MMR.
1234
ANAGRELIDE CORRECTS THE ENDOTHELIAL FUNCTION IN PATIENTS WITH ESSENTIAL
THROMBOCYTHEMIA
E. Cacciola, E. Di Francesco, F. Pezzella, R. Giustolisi, R. Cacciola
Institute of Hematology, CATANIA, Italy
The essential thrombocythemia (ET) may be complicated by microand
macrovascular thrombosis. The microthrombosis is platelet-associated
and it is reversed by antiplatelets whereas the macrothrombosis is
probably platelet coagulant-associated and it is antiplatelet orphan. Anagrelide
(ANA) is a platelet lowering drug that inhibits platelet aggregation.
Therefore, we evaluated platelet factor 4 (PF4), marker of platelet
activation, prothrombin fragment 1+2 (F1+2) and thrombin antithrombin
complex (TAT), markers of coagulant activation, TFPI (tissue factor
pathway inhibitor), tissue factor (TF) and von Willebrand factor (vWF),
indicators of micro- and macrovascular activation, respectively, in 19 ET
patients (12 males and 7 females, mean age 51 years) who fulfilled PVSG.
All patients were on antiplatelets either aspirin (10 patients) or indobufen
(7 patients) and ticlopidine (2 patients). Their mean duration of disease
was 7 years. ANA was administered in dose of 0.5 mg/day, with increases
of 0.5 mg/day every 7 days until the platelets decreased below
500×109 /L and with a average maintenance dosage of 2.1 mg/day.
Platelets, PF4, F1+2, TAT, TFPI, TF and vWF were measured before
cytoreduction and to complete response defined as platelets < 500×109 /L.
Platelets were measured by automated analyser. PF4, F1+2, TAT, TFPI,
TF and vWF were assayed by ELISA. Before ANA all patients had
marked platelets (1057±349×109 /L) and high PF4 (121±43 IU/mL vs
5.5±2.6 IU/mL) (p< .0001), TFPI (159±68 ng/mL vs 100±14 ng/mL) (p
0.001) and TF (247±184 pg/mL vs 4.8±2.5 pg/mL) (p