Haematologica 2003 - Supplements

PC-AI levels of MGUS and SMM patients with patients in PMM
phase did not bring any significant differences, the medians of
their values were very similar (PC-PI: M -1.8, 1.7 and 2.1%; PC-
AI: M-9.1, 10.8 and 9.0 %). The statistically significant
differences of PC-PI and PC-AI were found, if comparing
MGUS and SMM patients with group of AMM patients marked
by a higher level of the PC-PI (M-1.8 and 1.7 vs. 3.2 %, p- 0.000)
eventually by lower values of the PC-AI (M-9.1 and 10.8 vs. 4.8
%). In contrast to AMM patients, in the PMM phase significantly
lower PC-PI levels (M-2.1 vs. 3.2%, p- 0.000) and significantly
higher PC-AI values (M-9.1 vs. 4.8%, p-0.000) were found.
Conclusion. Our results supported the conception of usually
inverse relationship between the proliferative and apoptotic
activity of the plasma cell compartments of patients with MGUS,
smoldering and overt/symptomatic forms of MM. The patients
with MGUS, SMM and PMM phases have usually low
proliferative and high apoptotic level, whereas patients in the
AMM phase have usually high proliferative and low apoptotic
level. These results suggest that not only proliferative but also
apoptotic properties of myeloma cells are important from the
point of view of clinical and laboratory manifestation of MM.
089
Aberrant methylation of tumor suppressor genes in
patients with Multiple Myeloma and Monoclonal
Gammopathy of Undetermined significance
Sonja Seidl, Jutta Ackermann, Hannes Kaufmann,
Christoph C. Zielinski, Johannes Drach and Sabine
Zöchbauer-Müller
Clinical Division of Oncology, University Hospital, Vienna, Austria
Aberrant methylation (referred to as methylation) of normally
unmethylated CpG islands in the promotor region of tumor
suppressor genes (TSGs) has been associated with transcriptional
inactivation of these genes in human cancer. So far, several genes
have been identified which are frequently methylated in
malignant diseases. However, only little is known about
methylation of these genes in patients with multiple myeloma
(MM), plasma cell leukemia (PCL) or monoclonal gammopathy
of undetermined significance (MGUS). Thus, we investigated the
frequency of methylation of the genes p16, TIMP-3, p15, CDH1,
DAPK, p73, RASSF1A, p14, MGMT and RARbeta in bone
marrow aspirates from patients with MM (N = 109), PCL (N=7)
and from patients with MGUS (N = 29) by methylation specific
PCR. Methylation of the genes p16, TIMP-3, p15, CDH1, DAPK,
p73, RASSF1A, p14, MGMT and RARbeta was detected in 34%,
27%, 26%, 24%, 20%, 17%, 16%, 7%, 5%, and 0% in MM
patients, respectively. Aberrant methylation of at least one of the
genes was detected in 77% of MM patients. The frequency of
methylation in PCL was similar to MM patients in the case of
TIMP-3, p15, DAPK, p73, RASSF1A, p14, MGMT and
RARbeta but was higher in the case of p16 (57%) and CDH1
(57%). In MGUS patients, the frequency of methylation was
similar to MM patients for most of the genes. However, the
frequency of p15 methylation was lower. Interestingly,
methylation of CDH1 was not found in any of the MGUS patients
(P = 0,004). We also analysed bone marrow specimens from
healthy bone marrow donors and patients with localized non-
Hodgkin’s lymphomas. However, we did not observe methylation
of any of these genes in control specimens. The methylation
results will be compared with clinical characteristics as well as
specific chromosomal alterations from these patients. In
conclusion, our data demonstrate that methylation of several
genes is a frequent event in patients with MM. Methylation of
CDH1 was not detected in MGUS patients, but in MM patients
and in an even higher percentage in patients with PCL suggesting
that CDH1 methylation is an indicator of disease progression in
this hematologic malignancy.
090
Bcl-2 and poly-ADP-ribosyl polymerasis expression in
plasma cells of MGUS and multiple myeloma patients:
a comparative study
V. Scudla, Z. Kolar, J. Bacovsky, M. Vytrasova
3rd Department of Internal Medicine and Department of Pathology,
Faculty Hospital, Palacky University, Olomouc, Czech Republic
Background. Multiple myeloma (MM) is a plasma cell
malignancy, in which different proliferative activity and
resistance to apoptosis of plasma cells play an important role in
pathophysiology and clinical manifestation of this disease. Bcl-2
oncoprotein plays a very important role in hemopoietic cells by
preventing apoptosis. Disregulation of this process may be
important for oncogenesis due to illegitimate cell survival and
increase in the chances for cells to acquire additional gene defects
that promote aberrant growth and proliferation. The real clinical
impact of bcl-2 or PARP (poly-ADP-ribosyl polymerasis)
expression in monoclonal gammopathies is not adequately known
in this time. Aims. The aims of this study was the
contemporaneous measurement of the bcl-2 (i), bcl-2 (m), PARP
and Ki-67 expression intensity in plasma cells and correlations of
these markers in the patients with MGUS (n-10), smoldering
multiple myeloma (S-MM, n-11), patients evaluated at the time
of MM diagnosis (D-MM, n-45) and in the various phases of the
disease (R-MM, n-25). Methods. Immunoenzymatic methods
were applied using McAb against bcl-2 protein (i and m), PARP
and Ki-67 while the intensity of protein expression was assessed
by the semiquantitative histomorphometry method (LUCIA M
system, Prague) in the bone marrow biopsy samples. Data were
analyzed and the groups compared using Pearson’s and ANOVA
tests. Results. The intensity of bcl-2 (i) expression in plasma cells
was weak and statistically insignificant in all four analyzed
groups. The intensity expression of the bcl-2 (m) was also weak
in patients with MGUS, S-MM and R-MM but high in D-MM
patients, with statistical significance in comparison of MGUS, S-
MM and R-MM vs D-MM (p- 0.011, 0.008 and 0.001). The
intensity of PARP expression was significantly different in
comparison of MGUS, S-MM and R-MM vs D-MM patients (p-
0.018, 0.000 and 0.000). There was observed a statistically
significant correlation of the bcl-2(i) vs bcl-2(m) plasma cells
activity in the situation of MGUS (p < 0.05), S-MM ( p < 0.001)
and R-MM (p < 0.001) but no significant difference in D-MM.
The significant relationship was also observed in comparison of
bcl-2(m) vs PARP myeloma cells expression in the R-MM but
not in the case of MGUS, S-MM and D-MM. There was no
correlation of bcl-2(i), bcl-2(m) and PARP expression in
comparison of Ki-67 proliferative rate of plasma cells in all four
evaluated groups. Conclusion. There was demonstrated that the
expression activity of bcl-2 (m) and PARP in plasma cells in
overt form of MM (D-MM and R-MM) is statistic significantly
higher than in MGUS or S-MM. Bcl-2(m) may play a significant
role in the pathogenesis of malignant gammopathies, extending
the survival of myeloma cells by protecting them from apoptosis
and increasing the chance for cells to acquire new additional gene
defect.
Supported by grant of IGA MH CR.
S128