Haematologica 2003 - Supplements

and 10 months after start of therapy, whereas 2 patients relapsed
after 4 and 6 months. One patient had stable disease, 2 progressed
during treatment, and 1 patient is too early to evaluate. The most
common side effect reported was grade 2 fatigue. One patient had
WHO grade 4 thrombocytopenia/neutropenia and grade 3
infection. However, this individual had a 99 % bone marrow
infiltration with plasmablastic myeloma cells. Treatment resulted
in a reduction of Bcl-2 protein expression levels in peripheral
blood lymphocytes (mean reduction on days 4 and 7 was 23 %
and 18 % for T cells and 43 % and 30 % for B cells, respectively)
and circulating myeloma cells (mean reduction on days 4 and 7
was 18 % and 17 %, respectively) as determined by flow
cytometry.
Conclusion: These data indicate that G3139 can successfully
downregulate Bcl-2 in vivo in myeloma cells and may be of value
for the treatment of refractory multiple myeloma. This trial
continues to enroll patients.
399
Metabolism of a cholesterol-rich microemulsion (LDE)
in patients with multiple myeloma and a preliminary
clinical study of LDE as drug vehicle for the treatment
of the disease.
Vania T. M. Hungria1, Maria C. Latrilha2, Débora G.
Rodrigues2, Sergio P. Bydlowski3, Carlos S. Chiattone1,
Raul C. Maranhão2.
1- Hematology and Hemotherapy Section, Santa Casa Medical
School, São Paulo, Brazil; 2- Lipid Metabolism Laboratory, Heart
Institute (INCOR), University of São Paulo Medical School
Hospital, São Paulo, Brazil; 3- Department of Hematology,
University of São Paulo Medical School Hospital, São Paulo, Brazil
Purpose: Previously, we showed that cholesterol-rich microemulsions
that binds to LDL receptors have the ability to concentrate in acute
myeloid leukemia cells and in ovarian and breast carcinomas. Thus,
LDE may be used as vehicle of drugs directed against neoplastic
cells. Indeed, we subsequently showed that when carmustine was
associated with LDE the toxicity of the drug was pronouncedly
reduced in patients with advanced cancers. The present study aimed
to verify whether LDE may be taken-up by multiple myeloma cells
and whether multiple myeloma patients may be responsive to
treatment with LDE associated with carmustine. Methods: 131
consecutive recently diagnosed volunteer multiple myeloma patients
classified as clinical stage IIIA had their plasma lipid profile
determined. LDE plasma kinetics were performed in 14 of them. The
uptake of LDE by a multiple myeloma cell lineage was evaluated.
Finally, an exploratory clinical study of LDE-carmustine (carmustine
dose: 180 mg/m2 body surface every 4 weeks) was performed in 7
untreated multiple myeloma patients. Results: LDL cholesterol was
smaller in the 131 multiple myeloma patients than in the healthy
controls and the fractional clearance rate (FCR, in min-1) was twice
greater in the 14 multiple myeloma patients than in 14 paired control
healthy subjects. Moreover, entry of LDE was shown to be mediated
by LDL receptors in the multiple myeloma cells. Taken together,
those data indicate that LDE may target multiple myeloma. The
exploratory clinical study showed that gammaglobulin decreased 10-
70% (36%) after 3 cycles and 25-75% (44%) after 6 cycles.
Furthermore, there was amelioration of the symptoms in all patients.
Cholesterol concentration increased post-treatment, suggesting that
the treatment resulted in at least partial destruction of neoplastic cells
with receptor upregulation. Side effects of the treatment were
negligible. Conclusion: Because it targets multiple myeloma and
when associated with an antineoplastic agent it produces therapeutic
responses in patients with lesser side-effects, LDE has potential for
use as drug vehicle in the treatment of the disease.
400
Gliotoxin (GLT) and dehydroxymethylepoxyquinomicin
(DHMEQ) induce apoptosis in multiple myeloma (MM)
cells by causing endoplasmic reticulum (ER) stress.
Hiro Tatetsu, Miki Nakamura, Takashi Sonoki, Hiroaki
Mitsuya and Hiroyuki Hata
Department of Internal Medicine II, Kumamoto University School of
Medicine
Introduction: Proteasome inhibitors (PI) have been reported to be
useful in the treatment of MM. One of the mechanisms of PI
action is thought to increase the amount of IκB, thereby
decreasing NF-κB migration of NF-kB to nucleus, indicating that
PI serves as NF-κB inhibitors. Considering that NF-κB represents
a key molecule in B cell lineage, we asked whether PI and NF-κB
inhibitors induced apoptosis in MM cells.
Materials and Methods: A proteasome inhibitor, GLT, and two
NF-κB inhibitors, BAY11-7082 (an IκB phosphorylation
inhibitor) and DHMEQ (an inhibitor of NF-κB nuclear
translocation; a gift from K. Umezawa) were employed.
Apoptosis occurring in an MM cell line, U266, was examined
using May-Giemsa staining and Annexin V/PI staining. Profiles
of IκB, phosphorylated-IκB, XBP-1, BiP/GRP78 and caspase 12
were also examined using western blot.
Results: All three agents used induced apoptosis in U266 cells,
among which GLT was the most potent apoptosis-inducer and
IκB phosphorylation-potentiator, followed by BAY11-7082 and
DHMEQ. When U266 cells were treated with GLT or DHMEQ,
the cleavage of Caspase-12 was readily seen, a salient feature of
endoplasmic reticulum (ER) stress, whereas other indicators
employed showed no changes as determined using western blot.
Conclusions: The present data suggest that proteasome inhibitors
and NF-κB inhibitors could induce apoptosis in MM cells
through causing ER stress. The data might explain how such
agents exert their clinically favorable effects in patients with
MM. (This work was supported in part by International Myeloma
Foundation)
401
Inhibition of Multiple Myeloma Cell Growth and Bone
Resorption By Silence TRAF6 mRNA
Haiming Chen, Hank H. Yang, Kim Burkhardt, Guangxu Li,
Robert Lieberman, Daocheng Zhu, Xinmin Yan, Robert
Vesico B., and James R. Berenson.
Hematology and Oncology, Cedars-Sinai Medical Center, UCLA
School of Medicine, Los Angeles, California, USA
Although recently advances in the management of Multiple
myeloma (MM) include the use of high-dose chemotherapy
followed by autologous or allogeneic transplantation of
hematopoietic stem cells, the patients can be prolonged survival
to 4-5 years. Myeloma remains incurable. However, RNA
interference (RNAi) is emerging as one of the most promising
RNA-based treatments. RNAi is the process of sequence specific,
post-transcriptional gene silencing, initiated by complementary
double strand RNA (dsRNA). RNAi can be used to interfere with
the expression and action of targeted genes involved in tumor
genesis. RNAi can also used to silence the genes that are
involving in the promotion of MM cell growth and proliferation,
and the biological function of osteoclast cells. Our previous
studies showed that increased DNA-binding activity of the
transcription factor nuclear factor kappa B (NF-kB) is associated
with enhanced tumor cell survival in MM. Tumor necrosis factor
receptor-associated factor6 (TRAF6) is essential for the
activation of NF-kB signaling in plasma cells and the Jun NH2-
S266