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

1376
RESVERATROL INDUCED P53 MEDIATED APOPTOSIS BY SIGNAL TRANSDUCTION
PATHWAYS VIA RUNX3 AND PIK3CA GENE EXPRESSIONS IN LEUKEMIA CELL LINES
G. Saydam, 1 C. Biray-Avci, 2 F. Sahin, 3 S. Numanoglu, 2 S. Yilmaz, 2
Z.O. Dogan, 2 F. Avcu, 4 A.U. Ural, 4 G. Saydam, 3 C. Gunduz 2
1 Ege University Hospital, BORNOVA IZMIR; 2 Ege University Hospital, Medical
Biology, BORNOVA IZMIR; 3 Ege University Hospital, Hematology, BOR-
NOVA IZMIR; 4 GATA, ANKARA, Turkey
Background. Resveratrol (3,5,4’-trihydroxy-trans-stilbene), a phytoalexin
present in grapes and other food products, has been suggested as a
potential cancer chemo-preventive agent based on its striking inhibitory
effects on diverse cellular events associated with tumor initiation,
promotion, and progression. Aims. The aim of the study is to determine
the activation profiles of p53 (tumor antigen p53), RUNX3 (Runt-related
transcription factor 3), which are tumor suppressor genes and EGFR
(Epidermal growth factor receptor), PIK3CA (phosphoinositide-3-kinase,
catalytic, α polypeptide), which are oncogenes in leukemia. To investigate
the role of gene expressions PIK3CA, Runx3, p53 and EGFR in
resveratrol-induced apoptosis of leukemia cells, we performed cytotoxicity,
apoptosis and expression analysis, respectively. Methods. We determined
IC50 values of resveratrol in these cell lines. ARH-77(human multiple
myeloma), CCRF-CEM (Acute T-lymphoblastic leukemia), HL-60
(Human premyelocytic) and K-562 (Human eritroleukemia) cell lines
grown in RPMI-1640 medium. Cytotoxic assays and determination of
IC50 dose of resveratrol in leukemia cells were performed by using Trypan
blue dye exclusion and XTT assay as indicated in manufacturers’
instructions. Acridine orange/Ethidium bromide dye technique was used
to evaluate apoptosis. Gene expressions were examined in leukemia
cells by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR).
Results. Cytotoxic effects of resveratrol in ARH-77, CCRF-CEM, HL-60
and K-562 were detected in dose and time dependent manner with the
IC50 doses of 10 µM, 0.1 µM, 5 µM and 100 µM respectively. Acridine
Orange / Ethidium bromide method have shown remarkable apoptosis
at 72nd hour in resveratrol treated cells. Although HL-60 is known as an
EGFR negative cell line, we also found no EGFR expression in other
leukemia cell lines. P53 expression was found to be induced in ARH-77
and HL-60 and reduced in CCRF-CEM and none in K-562 cell lines.
Except ARH-77, MDM2 expression showed antagonist expression when
compared to p53 expression in others. All cell lines exhibited down-regulation
of PIK3CA expression in IC50 doses of resveratrol. RUNX3
expression was up-regulated in K-562 while the others were presenting
reduced expression. Conclusion. Our data indicate that resveratrol induced
apoptosis by p53-dependent signal transduction pathways in leukemia
cell lines positive for p53 expression, and by using downstream pathways
interacting each other and effecting some apoptotic pathways in
p53 negative cells.
1377
NO INTRINSIC DEFECT OF BONE MARROW ERYTHROID CELLS IN CHRONIC
LYMPHOCYTIC LEUKEMIA
O. Tsopra, 1 P. Ziros, 1 E. Lagadinou, 1 E. Thanopoulou, 1 A. Spyridonidis, 1
L. Phearson, 1 M. Angelopoulou, 2 G. Pangalis, 2 N. Zoumbos1 1 2 University Hospital of Patras, RION, PATRAS; Laikon University Hospital of
Athens, ATHENS, Greece
Background. The pathogenesis of anemia in chronic lymphocytic
leukemia (CLL) at diagnosis is multifactorial and it may be due to
autoimmune hemolysis, deficiency of erythropoietic co-factors, blood
loss, pure red blood cell aplasia or hypersplenism. If none of the above
causes exist (anemia of unknown origin), bone marrow (BM) infiltration
by malignant cells is often considered to be responsible for anemia. However,
it is reported that BM infiltration does not correlate with low hemoglobin
levels in CLL, as patients with extensive BM involvement are not
always anemic, whereas others without extended BM disease present
with anemia. Aims. We investigated whether intrinsic defects of BM erythroid
cells may be implicated in the development of anemia of
unknown origin in CLL. Methods. BM samples from 15 newly diagnosed
CLL patients with anemia of unknown origin (Hb