Haematologica 2003 - Supplements

8. Mouse models for MM
P8.1
THE 5TMM MODEL: A USEFUL MODEL FOR THE
STUDY OF MULTIPLE MYELOMA
Karin Vanderkerken 1 , Kewal Asosingh 1 , Peter Croucher 2 ,
Hendrik De Raeve 3 , Els Van Valckenborgh 1 , Eline Menu 1 ,
Evy De Leenheer 1,2 , Angelo Willems 1 , Ivan Van Riet 1 and
Ben Van Camp 1
1
Department of Hematology and Immunology, Vrije Universiteit
Brussel (VUB), Brussels, Belgium; 2 Nuffield Department of
Orthopaedic Surgery, University of Oxford, Oxford, UK;
3
Department of Pathology, University of Antwerp (UIA), Antwerp,
Belgium
The 5TMM murine models of myeloma were initially developed
by J. Radl (1). Multiple myeloma (MM) developed spontaneously
in 0.5% of mice (of the inbred strain C57BL/KaLwRij ) older
than 2 years. The MM cells were localized in the BM of the mice
and the serum paraprotein concentration correlated well with the
development of the disease. The latter was associated with a
decreased concentration of normal polyclonal immunoglobulins.
The primary diseased BM was intravenously transplanted into
young syngeneic animals and by doing so several in vivo growing
5TMM lines were developed, each with its own characteristics.
The 5TMM model hereby belongs to the de novo myelomas and
its clinical characteristics resemble the human disease closely: the
tumor cells are located in the bone marrow, the serum paraprotein
concentration is a measure of disease development,
neovascularization is increased (this was determined for 5T2MM
and 5T33MM (2)) and in certain lines a clear osteolytic bone
disease develops. All the original 5TMM models are maintained
and propagated in vivo (3,4).
The 5T2MM model best represents human MM, with a moderate
growth and the development of osteolytic bone lesions. These
osteolytic lesions are associated with a decrease in cancellous
bone volume, decreased bone mineral density and increased
numbers of osteoclasts (5). The 5T33MM model has a more rapid
tumor take and in addition to the bone marrow, also grows in the
liver (6). For the 5T33MM model an in vitro, stroma independent
growing cell line, clonally identical to the in vivo line (7), has
been developed (8). Additional lines include the 5T7MM line
which is a model for smouldering MM while the 5T14MM line is
model for MM with osteosclerotic lesions.
The 5T2 and 5T33MM models have been extensively
characterized. Specific monoclonal antibodies have been raised
against the idiotype of both 5T2 and 5T33MM allowing the
detection, with great sensitivity, of the serum paraprotein by
ELISA and the specific staining of the tumor cells both by FACS
analysis and immunostaining of histological frozen sections (6).
The sequence analysis of the V H gene enables the detection of
cells by RT-PCR and Northern blot analysis (9).
The 5TMM models can be used for both in vitro and in vivo
experiments. The specific antibodies allow the separation of MM
cells by flow cytometry or with magnetic beads, generating pure
MM cell populations for further in vitro investigation. The
5TMM models generate a typical MM disease and different
methods are available to assess tumor load in the bone marrow,
serum paraprotein concentrations, bone marrow angiogenesis (by
measuring the microvessel density) and osteolytic bone lesions
(by a combination of radiography, densitometry and
histomorphometry). The investigation of these latter parameters
allow the use of the 5TMM models in a preclinical setting and
study the growth and biology of the myeloma cells in a complete
syngeneic microenvironment. Both, molecules targeting the MM
cells themselves and molecules targeting the bone marrow
microenvironment, can be studied. While the 5T33MM model
can be used to target both the microenvironment and the MM
cells themselves, the 5T2MM model can also be used to study the
myeloma associated bone disease.
The 5TMM models have now been used to unravel the
mechanisms of homing to the bone marrow (10) and in this in
vivo setting, the evaluation of possible therapies including DNA
vaccination (11), the use of biphosphonates (12,13) and the
blocking of the RANKL/RANK interaction (5,14).
Radl J et al. Idiopathic paraproteinemia. J Immunol. 1979; 122:
609-13.
Van Valckenborgh E et al. Br J Cancer 2002; 86: 796-802.
Radl J et al. Am J Pathol. 1988;132: 593-7.
Radl J. Immunol Today 1990; 11: 234-6.
Croucher PI et al. Blood 2001; 98: 3534-40.
Vanderkerken K et al. Br J Cancer 1997; 76: 451-60.
Asosingh K et al. Cancer Res 2000; 60, 3096-104.
Manning LS et al. Br J Cancer. 1992; 66:1088-93.
Zhu D et al..Immunology. 1998; 93 :162-70.
Vanderkerken K et al Immunological Reviews-in press
King CA et al. Nat Med. 1998; 4 :1281-6.
Radl J et al.Cancer. 1985, 55:1030-40.
Croucher PI et al. J Bone and Mineral Res, 2003, in press
Vanderkerken K et al. Cancer Research 2003; 63: 287-89
P8.2
MYELOMA BIOLOGY REVEALED BY THE SCID-HU
MODEL FOR PRIMARY HUMAN MYELOMA.
Joshua Epstein, D.Sc.
Myeloma Institute for Research and Therapy, Arkansas Cancer
Research Center, University of Arkansas for Medical Sciences,
4301 W. Markham #776, Little Rock, Arkansas, USA. Tel. (501)
686-5274. Fax (501) 686-6442. Email: EpsteinJoshua@uams.edu
The human bones of SCID-hu mice consistently support growth
of freshly obtained myeloma cells. Growth of the myeloma cells
is restricted to the human bones, and induces changes in the
human bone marrow microenvironment, most notably increase in
microvessel density, increased osteoclast activity and decrease in
osteoblast numbers. Growth of myeloma cells is also associated
with typical myeloma manifestations, the most dramatic of which
is osteolysis of the human bone. 1 By supporting the growth of
primary human myeloma cells in a human bone marrow
microenvironment, the SCID-hu model provides a platform for
studying important aspects of myeloma biology and therapy
previously beyond the power of our experimental models, among
them whether myeloma plasma cells are proliferative and the role
of the bone marrow microenvironment in the disease process.
Experiments in which myeloma plasma cells, purified from bone
marrow aspirates, were used demonstrated unequivocally that the
recognizable tumor cells of plasma cell morphology produce
myeloma in the SCID-hu model, with all its manifestations.
Moreover, myeloma cells recovered from one mouse could be
sequentially transferred from one SCID-hu mouse to another,
clearly demonstrating that myeloma plasma cells are or contain a
subpopulation of proliferative cells with self-renewal capacity. In
contrast, the myeloma plasma cell-depleted bone marrow and
blood specimens or purified B cells from myeloma patients did
not produce myeloma in SCID-hu mice. 2
In some experiments, myeloma cells were injected only into one
human bone of mice implanted with two, contralaterally placed
bones. As myeloma developed, plasma cells disseminated,
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