scholarly journals An Improved Animal Model of Multiple Myeloma Bone Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-31
Author(s):  
Syed Mehdi ◽  
Maurizio Zangari ◽  
Donghoon Yong
Keyword(s):  
Multiple Myeloma ◽  
Lumbar Spine ◽  
Bone Disease ◽  
Therapeutic Effects ◽  
Myeloma Cells ◽  
Tail Vein ◽  
Significant Difference ◽  
Osteolytic Bone Disease ◽  
Nsg Mouse

Multiple myeloma (MM) is a plasma cell malignancy that represents an accumulation of terminally differentiated monoclonal plasma cells (PCs) in the bone marrow (BM), accompanied by increased osteoclasts and decreased osteoblasts in areas adjacent to myeloma cells, leading to MM associated bone disease (MMBD). Osteolytic bone disease is one of the defining features of MM. During the disease, over 90% of patients are developing MMBD. Many of MM animal models have been developed and enable us to interrogate the mechanisms of MM tumorigenesis. Most MMBD models were derived by intratibial injection of myeloma cells. In these models, osteolysis occurs locally at the site where myeloma cells were injected. Mouse myeloma cells, 5TGM1 transplanting C57BL/KaLwRij mouse via the tail vein develops and shows MMBD features close to human MMBD. Even in this model, the MMBD levels on each mouse are widely varied. Lack of appropriate in vivo MMBD model hampers our understanding of the disease and developing therapy. We try to establish a murine model for MMBD to study its pathophysiology and test a novel treatment. 1x106 luciferase-expressing 5TGM1 (5TGM1-Luc) cells were injected into 8-12 week old NOD SCID gamma mouse (NSG) and C57BL/KaLwRij mouse via the tail vein. Myeloma progression was weekly assessed by in vivo bioluminescence (BL) imaging using IVIS-200 (Perkin Elmer). Mice were sacrificed when they showed endpoint signals such as significant weight loss, hindlimb paralysis, etc.. At postmortem, the micro-computer tomography (micro-CT) was performed for bone histo-morphometric analyses using micro CT400, Scano medical, Inc. The median survival was 56 days in NSG, while 42 days in C57BL/KaLwRij. In vivo BL image analysis showed that myeloma slowly develops in NSG mouse in comparison to C57BL/KaLwRij mouse. Histomorphic analyses found that severe osteolytic lesions occur at the lumbar spine in NSG mouse compared to C57BL/KaLwRij mouse, but no significant difference at the femur of both strains. At the lumbar spine, trabecular thickness (p < 0.0004) and trabecular space (p < 0.0014) were significantly increased in NSG mouse compared to C57BL/KaLwRij mouse. On the contrary, trabecular number (p < 0.0002) and bone volume density (p < 0.0005) were significantly decreased in NSG mouse compared to C57BL/KaLwRij mouse. In conclusion, we found that the systemic 5TGM1 injected NSG mouse slowly progresses myeloma and develops more severe MMBD than C57BL/KaLwRij model. This model will serve a better MMBD model to evaluate the therapeutic effects of MMBD targeted drugs. Disclosures No relevant conflicts of interest to declare.

scholarly journals Increased circulating LDL cholesterol increases myeloma tumour burden in vivo

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Beatriz Gamez
Keyword(s):  
Bone Disease ◽  
Dietary Intervention ◽  
Dietary Cholesterol ◽  
Cholesterol Diet ◽  
Tumour Burden ◽  
Benign Condition ◽  
Myeloma Cells ◽  
Osteolytic Bone Disease

Gámez B., Morris EV., Olechnowicz S., Sowman, A., Turner, C. and Edwards CM.   Multiple myeloma (MM) is a fatal malignancy characterized by an expansion of malignant plasma cells in the bone marrow (BM) and associated with osteolytic bone disease. MM is preceded by the benign condition, monoclonal gammopathy of undetermined significance (MGUS). Understanding MGUS progression and development of MM bone disease is key for patient management. We and others have previously demonstrated that diet-induced obesity promotes myeloma progression, but the mechanisms underlying this remain unknown. The aim of the current study was to determine the effect of dietary cholesterol on MM development. A 2% cholesterol diet was used to increase circulating LDL in mice. Mice were randomly distributed to either a) cholesterol diet 4 weeks prior to 5TGM1 MM inoculation (pretreatment) or b) cholesterol diet 4 weeks prior to MM inoculation and continued for the entire experiment (continuous). Mice on the continuous cholesterol diet had increased tumour burden, associated with an increase in lipid droplet content of MM cells. No differences in tumour burden were seen in those mice where cholesterol diet was halted at time of MM inoculation. In vitro, myeloma cells cultured with delipidated FBS had a 50% reduction in viability after 72 hours. Rich cholesterol content lipoproteins (LDL) but not VLDL could restore MM cell viability, suggesting that cholesterol is responsible for this lipid-depletion effect. Taken together, our results show that high cholesterol promotes myeloma and results in a higher lipid content in myeloma cells, ultimately increasing BM tumour burden. Pretreatment with a cholesterol diet did not alter disease progression suggesting a direct pro-tumourigenic effect of cholesterol. These results demonstrate both the detrimental effect of cholesterol on myeloma progression and the potential for dietary intervention approaches.

What Is Important Factor of Bone Disease in Multiple Myeloma?.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4855-4855
Author(s):  
Shoso Munemasa ◽  
Akira Sakai ◽  
Yoshiko Okikawa ◽  
Yoshiaki Kuroda ◽  
Yuta Katayama ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cyclin D1 ◽  
Bone Disease ◽  
Tissue Growth ◽  
Good Survival ◽  
Bone Lesions ◽  
Rt Pcr ◽  
Myeloma Cells ◽  
Significant Difference ◽  
Chromosome 13Q

Abstract New International Prognostic Index (IPI) staging system of multiple myeloma (MM) is a combination of the level of serum β2-microglobulin and serum albumin. Particularly, good survival (median survival >5 years) is associated with absence of chromosome 13q deletion. Recently, correlations between molecular subtypes and prognosis have been identified as a good prognosis with t(11;14) and a poor prognosis with t(4;14) and t(14;16) besides chromosome 13 abnormalities. We have reported that some MM cases with cyclin D1 overexpression detected by competitive RT-PCR were not caused by t(11;14)(q13;q32) or extra copies of 11q13 (In J Oncol, in press). A recent report revealed that subtypes of MM cases with the translocation of cyclin D showed a close correlation with bone disease and high level of DKK1. We also have been studing about the correlation between bone disease and bone morphogenetic protein (BMP) 2, or connective tissue growth factor (CTGF) that is supposed to inhibit the VEGF binding to its receptor or modulate cell signaling by BMP. First, we analyzed IPI staging in 91 MM cases, and then analyzed the relation between IPI staging and existence of cyclin D1 overexpression, or t(11;14)(q13;q32) and extra copies of 11q13. Competitive RT-PCR was performed in 77 cases, and cyclin D1 overexpression was detected in 40/77 (52%). Deletion of chromosome 13q was detected in 32/87 (37%), and t(11;14)(q13;q32) or extra copies of 11q13 was detected in 11/50 (22%) and 7/50 (14%), respectively. There were no significant differences of those factors among IPI staging. And we analyzed the scale of bone lesion by bone x-ray in 81 cases. We could not detect the relation between bone disease and cyclin D1 overexpression or translocation of 11q13. Furthermore, we analyzed the expression of BMP2 and CTGF by quantitative real time-PCR in purified myeloma cells or in bone marrow mononuclear cells (BMMNC) reduced myeloma cells less than 5%. We have gotten results that MM cases have a tendency to show higher CTGF expression in BMMNC compared with that of normal BM, but there was no significant difference of BMP2 expression in BMMNC between them. And there was no correlation between cyclin D1 overexpression and BMP2 or CTGF expression. So far a cause of bone lesions in MM is supposed to be the activity of osteoclast, however, our preliminary examination by TRAP staining revealed that osteoclast differentiation from BMMNC in MM cases by adding M-CSF (25 ng/ml) and RANKL (50 ng/ml) decreased compared with that in normal BM, and osteoblast diffentiation also decreased in MM by cytochemical staining for alkaline phosphatase (AP). We guess that both osteoclast and osteobalst differentiation are suppressed in MM and CTGF is a candidate for the suppressor of osteoblast differentiation. We will be able to show the result of AP activity of osteoblast and the effect of recombinant CTGF on osteoblast in meeting.

In-Vitro and in-Vivo Synergistic Effect of Melphalan and Dual DNA Repair Inhibition in Multiple Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3301-3301
Author(s):  
Pritesh R. Patel ◽  
Annie L. Oh ◽  
Vitalyi Senyuk ◽  
Dolores Mahmud ◽  
Nadim Mahmud ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Dna Repair ◽  
Combination Index ◽  
Fold Increase ◽  
High Dose ◽  
Myeloma Cells ◽  
Synergistic Cytotoxicity ◽  
Significant Difference

Abstract High dose melphalan is commonly used in patients with multiple myeloma (MM). Resistance to melphalan has been linked to the ability to repair DNA damage. To test whether DNA repair inhibitors overcome resistance to melphalan and and also have a direct anti-MM effect, we tested MM cell lines RPMI8226 and U266 in-vitro and in-vivo, using a NOD/SCID/ gamma null (NSG) xenograft model. RPMI8226 and U266 cells were initially treated in-vitro with the PARP inhibitor ABT-888. Using a proliferative assay, myeloma cells appeared sensitive to ABT-888 with low GI50 values (8.7μM for RPMI8226 cells, 49μM for U266 cells) and increased γH2AX foci, which persisted at 24 hours after treatment. This was confirmed in methycellulose colony assay where ABT-888 treatment reduced RPMI8226 colonies by 35% (p=0.002). Next we showed synergistic cytotoxicity between ABT-888 and melphalan. In both RPMI8226 and U266 cells strong synergy was displayed with a combination index (CI) less than 1 in proliferative assays (CI 0.5 and 0.3 at 50% proliferation respectively). Combination ABT-888 and melphalan treated cells underwent accelerated senescence compared to cells treated by melphalan alone (27% versus 51% βGal+ staining at 24 hours, p=0.02). This was confirmed by upregulation of senescence related genes p16 (1.6 fold increase) and p21 (1.5 fold increase). We did not find significant difference in apoptosis by Annexin V/ PI staining. Given that increased non-homologous end joining (NHEJ) activity has been shown to lead to resistance to melphalan, we tested whether an inhibitor of NHEJ could be synergistic with PARP inhibition and melphalan. Treatment with the DNA-PK inhibitor NU7026 at 10μM in addition to ABT-888 at 4μM resulted in 46% reduction in proliferation in RPMI8226 cells and 52% in U266 cells. When used in combination with melphalan chemotherapy, the dual DNA repair inhibitor therapy showed marked synergy in RPMI8226 cells with a combination index of 0.39. Finally we tested the ability of the combination of ABT-888 and melphalan to treat myeloma in-vivo. NSG mice were injected via tail vein with 5x106 RPMI8226 cells. Control (untreated) mice subsequently developed myeloma infiltrating the marrow, spleen and axial skeleton, with hind limb paralysis occurring at a median of 42 days. Treated mice received intraperitoneal injections of ABT-888 (3 times a week), or melphalan (weekly) or a combination of both agents starting on day 28 post-injection of MM cells for a total of 3 weeks. Using ABT-888, melphalan and a combination of both agents, median survival of mice was progressively prolonged (44 vs. 67 vs. 107 days, respectively) (p=0.02). Here we show that PARP and DNA-PK inhibition synergizes with melphalan in myeloma cells lines, providing a rationale for the addition of these agents to conditioning chemotherapy. In addition, we also show a direct anti-myeloma activity of these agents without the use of alkylator chemotherapy. Disclosures No relevant conflicts of interest to declare.

scholarly journals An Improved Animal Model of Multiple Myeloma Bone Disease

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4277
Author(s):  
Syed Hassan Mehdi ◽  
Carol A Morris ◽  
Jung Ae Lee ◽  
Donghoon Yoon
Keyword(s):  
Multiple Myeloma ◽  
Bone Disease ◽  
Plasma Cells ◽  
Bone Lesions ◽  
Myeloma Bone Disease ◽  
Nsg Mice ◽  
Morphometric Analyses ◽  
Imaging Results ◽  
Nsg Mouse

Multiple myeloma (MM) is a plasma cell malignancy that causes an accumulation of terminally differentiated monoclonal plasma cells in the bone marrow, accompanied by multiple myeloma bone disease (MMBD). MM animal models have been developed and enable to interrogate the mechanism of MM tumorigenesis. However, these models demonstrate little or no evidence of MMBD. We try to establish the MMBD model with severe bone lesions and easily accessible MM progression. 1 × 106 luciferase-expressing 5TGM1 cells were injected into 8–12 week-old NOD SCID gamma mouse (NSG) and C57BL/KaLwRij mouse via the tail vein. Myeloma progression was assessed weekly via in vivo bioluminescence (BL) imaging using IVIS-200. The spine and femur/tibia were extracted and scanned by the micro-computer tomography for bone histo-morphometric analyses at the postmortem. The median survivals were 56 days in NSG while 44.5 days in C57BL/KaLwRij agreed with the BL imaging results. Histomorphic and DEXA analyses demonstrated that NSG mice have severe bone resorption that occurred at the lumbar spine but no significance at the femur compared to C57BL/KaLwRij mice. Based on these, we conclude that the systemic 5TGM1 injected NSG mouse slowly progresses myeloma and develops more severe MMBD than the C57BL/KaLwRij model.

Targeting CCR1 for the Treatment of Osteolytic Bone Disease in Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2503-2503
Author(s):  
Sonia Vallet ◽  
Noopur Raje ◽  
MariaTeresa Fulciniti ◽  
Kenji Ishitsuka ◽  
Teru Hideshima ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Clinical Trials ◽  
Bone Disease ◽  
Cell Number ◽  
In Vivo Studies ◽  
Protective Effects ◽  
Osteolytic Bone Disease

Abstract Osteolytic bone disease (OBD) is a frequent complication of multiple myeloma (MM), affecting 70 to 80% of the patients. OBD is characterized by imbalanced bone remodeling, due to decreased osteoblast (OB) number and increased osteoclast (OC) formation and activity. MM cells secrete osteoclastogenic factors, such as receptor activator of nuclear factor kappa B ligand (RANKL) and CCL3. In turn, OC support MM cell proliferation and survival, thus promoting a positive feedback that exacerbates bone resorption. Chemokines modulate osteoclastogenesis and promote MM cell proliferation, in particular CCL3 and its receptor CCR1 play an important role in mediating OBD in MM. MLN3897 (Millennium Pharmaceuticals, Cambridge) is a novel small molecule specific antagonist of human CCR1 (IC50 0.8 nM). It has a favorable toxicity profile in healthy volunteers and is currently undergoing phase II clinical trials in rheumatoid arthritis and multiple sclerosis. Here we evaluate the effects of MLN3897 on OC function and activity, as well as OC-MM cell interactions. Our in vitro data demonstrates a dual mechanism of action for MLN3897: it inhibits osteoclastogenesis and also overcomes the protective effects conferred by OC on MM cells. Our data further shows inhibition of OC formation and function by 40 and 70%, respectively, following MLN3897 treatment. This is mediated via inhibition of the fusion process and is accompanied by downregulation of pERK and c-fos signaling. To analyze its effect on MM cells, we verified CCR1 and CCR5 expression levels on MM1.S (15% and 3.6%) and OPM1 (3.8 and 0.7%). Our data show that OC secrete high levels of CCL3 which triggers MM cell migration; and that MLN3897 abrogates these effects by inhibiting the PI3K/Akt pathway. Moreover, MLN3897 overcomes the proliferative advantage conferred by OC on MM cells, as demonstrated in INA6, MM1.S and MM patient derived primary cells. OC induced MM cell proliferation is mediated by adhesion and cytokine secretion, and MLN3897 abrogates both MM cell-to-OC adhesion and interleukin-6 (IL6) secretion by OC in a co-culture system, thereby resulting in decreased MM cell survival and proliferation. To confirm these in vitro results, in vivo studies in a SCID-hu mouse model are underway. Implanted SCID-Hu INA-6 bearing mice are treated with twice daily oral MLN3897 for 3 weeks. The evaluation of osteolytic lesions and OC, OB and endothelial cell number; and tumor burden will be presented. Our in vitro results therefore show novel biologic sequelae of CCL3 and its inhibition on both osteoclastogenesis and MM cell growth. Our in vivo experiments will further validate the role of CCR1 in a human BM microenvironment-MM model, providing the framework for clinical trials of MLN3897 for the treatment of OBD in MM.

scholarly journals Antibody-based inhibition of DKK1 suppresses tumor-induced bone resorption and multiple myeloma growth in vivo

Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 2106-2111 ◽  
Author(s):  
Shmuel Yaccoby ◽  
Wen Ling ◽  
Fenghuang Zhan ◽  
Ronald Walker ◽  
Bart Barlogie ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Resorption ◽  
Bone Disease ◽  
Neutralizing Antibodies ◽  
Experimental Period ◽  
Mineral Density ◽  
Osteolytic Bone Disease ◽  
Important Regulator ◽  
Dickkopf 1

Abstract Dickkopf-1 (DKK1), a soluble inhibitor of Wnt signaling secreted by multiple myeloma (MM) cells contributes to osteolytic bone disease by inhibiting the differentiation of osteoblasts. In this study, we tested the effect of anti-DKK1 therapy on bone metabolism and tumor growth in a SCID-rab system. SCID-rab mice were engrafted with primary MM cells expressing varying levels of DKK1 from 11 patients and treated with control and DKK1-neutralizing antibodies for 4 to 6 weeks. Whereas bone mineral density (BMD) of the implanted myelomatous bone in control mice was reduced during the experimental period, the BMD in mice treated with anti-DKK1 increased from pretreatment levels (P < .001). Histologic examination revealed that myelomatous bones of anti-DKK1–treated mice had increased numbers of osteocalcin-expressing osteoblasts and reduced number of multinucleated TRAP-expressing osteoclasts. The bone anabolic effect of anti-DKK1 was associated with reduced MM burden (P < .04). Anti-DKK1 also significantly increased BMD of the implanted bone and murine femur in nonmyelomatous SCID-rab mice, suggesting that DKK1 is physiologically an important regulator of bone remodeling in adults. We conclude that DKK1 is a key player in MM bone disease and that blocking DKK1 activity in myelomatous bones reduces osteolytic bone resorption, increases bone formation, and helps control MM growth.

scholarly journals Increased circulating LDL cholesterol increases myeloma tumour burden in vivo

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Beatriz Gamez
Keyword(s):  
Bone Disease ◽  
Dietary Intervention ◽  
Dietary Cholesterol ◽  
Cholesterol Diet ◽  
Tumour Burden ◽  
Benign Condition ◽  
Myeloma Cells ◽  
Osteolytic Bone Disease

Gámez B., Morris EV., Olechnowicz S., Sowman, A., Turner, C. and Edwards CM. Multiple myeloma (MM) is a fatal malignancy characterized by an expansion of malignantplasma cells in the bone marrow (BM) and associated with osteolytic bone disease. MM ispreceded by the benign condition, monoclonal gammopathy of undetermined significance(MGUS). Understanding MGUS progression and development of MM bone disease is key forpatient management. We and others have previously demonstrated that diet-induced obesitypromotes myeloma progression, but the mechanisms underlying this remain unknown. The aimof the current study was to determine the effect of dietary cholesterol on MM development. A2% cholesterol diet was used to increase circulating LDL in mice. Mice were randomlydistributed to either a) cholesterol diet 4 weeks prior to 5TGM1 MM inoculation (pretreatment)or b) cholesterol diet 4 weeks prior to MM inoculation and continued for the entire experiment(continuous). Mice on the continuous cholesterol diet had increased tumour burden, associatedwith an increase in lipid droplet content of MM cells. No differences in tumour burden wereseen in those mice where cholesterol diet was halted at time of MM inoculation. In vitro,myeloma cells cultured with delipidated FBS had a 50% reduction in viability after 72 hours. Richcholesterol content lipoproteins (LDL) but not VLDL could restore MM cell viability, suggestingthat cholesterol is responsible for this lipid-depletion effect. Taken together, our results showthat high cholesterol promotes myeloma and results in a higher lipid content in myeloma cells,ultimately increasing BM tumour burden. Pretreatment with a cholesterol diet did not alterdisease progression suggesting a direct pro-tumourigenic effect of cholesterol. These resultsdemonstrate both the detrimental effect of cholesterol on myeloma progression and thepotential for dietary intervention approaches.  

Targeting Wnt Signaling in Myeloma In Vivo; Differential Effects on Tumor Burden and Myeloma Bone Disease.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 812-812
Author(s):  
Claire M. Edwards ◽  
James R. Edwards ◽  
Seint T. Lwin ◽  
Gregory R. Mundy
Keyword(s):  
Bone Marrow ◽  
Wnt Signaling ◽  
Bone Disease ◽  
Tumor Burden ◽  
Bone Microenvironment ◽  
Myeloma Cells ◽  
Myeloma Bone Disease ◽  
Osteolytic Bone Disease

Abstract Multiple myeloma is characterized by uncontrolled proliferation of myeloma cells within the bone marrow and the development of a severe osteolytic bone disease. In addition to a well characterized increase in osteoclastic bone resorption, myeloma bone disease is associated with a reduction in bone formation. Osteoblast differentiation and bone formation are regulated in vivo by canonical Wnt signaling and activation of β-catenin. Therefore increasing Wnt signaling in the bone microenvironment in multiple myeloma may prevent the development of myeloma bone disease. In support of this, we have previously demonstrated that activation of Wnt signaling with lithium chloride (LiCl) in the 5TGM1 murine model of myeloma reduces tumor burden and osteolytic bone disease. However, we also found that LiCl treatment increased subcutaneous (s.c.) tumor growth. This suggests that the reduction in tumor burden within the bone microenvironment may be an indirect effect mediated through the effects of LiCl to prevent myeloma bone disease. The aim of the current study was to determine the effect of specific molecular blockade of Wnt signaling in myeloma cells in vivo. 5TGM1-GFP myeloma cells were transfected by electroporation with either myc-tagged dominant negative TCF4 (DNTCF4) or pcDNA. Following stable selection by culture in G418, expression of DNTCF4 was confirmed by western blot for myc. No difference was found in the growth rates of 5TGM1-pcDNA or 5TGM1-DNTCF4 in vitro. Treatment with LiCl or Wnt3A had no significant effect on cell viability in vitro, but significantly increased β-catenin activity, as measured by TOPFLASH activity in 5TGM1-pcDNA cells. This increase was not observed in 5TGM1-DNTCF4, confirming that expression of DNTCF4 blocked Wnt signaling induced by LiCl in 5TGM1 myeloma cells. C57Bl/KaLwRij mice were inoculated with 5TGM1-pcDNA or 5TGM1-DNTCF4 cells by either intravenous (i.v.) or s.c. injection. Mice were treated from time of tumor cell inoculation with 200mg/kg/day LiCl or vehicle control (d.H20) by oral gavage for 28 days. I.v. inoculation of myeloma cells resulted in a significant increase in serum IgG2bκ concentrations and the proportion of GFP-positive cells in the bone marrow. A significant reduction in trabecular bone volume was also observed. MicroCT analysis of the tibia demonstrated that LiCl significantly increased trabecular bone volume in both 5TGM1-pcDNA and 5TGM1-DNTCF4 myeloma-bearing mice. LiCl significantly decreased serum IgG2bκ concentrations in both 5TGM1-pcDNA and 5TGM1-DNTCF4 myeloma-bearing mice, with a greater effect in 5TGM1-DNTCF4 myeloma-bearing mice. FACS analysis of GFP-positive cells demonstrated that LiCl significantly reduced tumor burden in the bone marrow in both 5TGM1-pcDNA and 5TGM1-DNTCF4 myeloma-bearing mice. However, following s.c inoculation, LiCl significantly increased s.c. tumor volume of 5TGM1-pcDNA tumors, but had no effect on 5TGM1-DNTCF4 s.c. tumor volume. Taken together these results demonstrate that the effect of increasing Wnt signaling in myeloma is dependent upon the microenvironment. By specific inhibition of β-catenin activity in myeloma cells combined with systemic stimulation of the Wnt signaling pathway, our results suggest that increasing Wnt signaling in myeloma in vivo has dual effects; firstly to enhance myeloma growth directly, and secondly to enhance osteoblast differentiation and thus indirectly reduce tumor burden in bone, highlighting the importance of the bone marrow microenvironment in regulating myeloma growth and survival.

Osteoclast Gene Expression Profiling in Multiple Myeloma

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2735-2735
Author(s):  
Jerome Moreaux ◽  
Dirk Hose ◽  
Thierry Rème ◽  
Philippe Moine ◽  
Karène Mahtouk ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Bone Resorption ◽  
Bone Disease ◽  
Plasma Cells ◽  
Osteoclastic Bone Resorption ◽  
Myeloma Cells ◽  
Myeloma Bone Disease ◽  
Osteolytic Bone Disease

Abstract Multiple myeloma (MM) is a fatal hematologic malignancy associated with clonal expansion of malignant plasma cells within the bone marrow and the development of a destructive osteolytic bone disease. The principal cellular mechanisms involved in the development of myeloma bone disease are an increase in osteoclastic bone resorption, and a reduction in bone formation. Myeloma cells (MMC) are found in close association with sites of active bone resorption, and the interactions between myeloma cells and other cells within the specialized bone marrow microenvironment are essential, both for tumor growth and the development of myeloma bone disease. In order to investigate the gene expression profile (GEP) of osteoclastic cells, we compare GEP of osteoclastic cells (7 samples) with normal B cells (7 samples), normal bone marrow plasma cells (7 samples), bone marrow stromal cells (5 samples), bone marrow CD3 cells (5 samples), CD14 cells (7 samples), CD15 cells (7 samples), CD34 cells (7 samples) and primary MMC (123 samples). Using SAM analysis, a set of 552 genes was overexpressed in osteoclasts compared to others cell subpopulations with a FDR ≤ 1% and a ratio ≥ 2. Osteoclasts specifically overexpressed genes coding for chemokines (CCL2, CCL7, CCL8, CCL13, CCL18, CXCL5 and CCL23) and MMC growth factors (IGF-1, APRIL and IL-10). Anti- IGF-1 receptor and TACI-Fc inhibit MMC growth induced by osteoclasts. Among the chemokines overexpressed by osteoclasts, the majority of them have a common receptor: CCR2 expressed by MMC. Anti-CCR2 MoAb inhibits migration of the CCR2+ HMCL in response to osteoclasts. Expression data of purified MMC were analyzed by supervised clustering of group with higher (CCR2high) versus lower (CCR2low) CCR2 expression level. Patients in the CCR2high group are characterized by a higher bone disease. A set of 176 genes was differentially expressed between CCR2high and CCR2low MMC. CCR2high displayed a gene signature linked to the dependency of MMC on the interactions with the BM osteoclastic subpopulation and the osteoclastic bone resorption. Taken together, our findings suggest addition of chemokine antagonists to current treatment regimens for MM should result in better therapeutic responses because of the loss of both the protective effect of the bone marrow environment on the MMC and the osteoclastic cells activity.

scholarly journals CCR1 blockade reduces tumor burden and osteolysis in vivo in a mouse model of myeloma bone disease

Blood ◽  
2012 ◽  
Vol 120 (7) ◽  
pp. 1449-1457 ◽  
Author(s):  
Daniel J. Dairaghi ◽  
Babatunde O. Oyajobi ◽  
Anjana Gupta ◽  
Brandon McCluskey ◽  
Shichang Miao ◽  
...  
Keyword(s):  
Bone Disease ◽  
Tumor Burden ◽  
Comparable Efficacy ◽  
Therapeutic Effects ◽  
Myeloma Bone Disease ◽  
Osteoclast Precursors ◽  
Osteolytic Bone Disease ◽  
Ccr1 Antagonist ◽  
Further Development

Abstract The chemokine CCL3/MIP-1α is a risk factor in the outcome of multiple myeloma (MM), particularly in the development of osteolytic bone disease. This chemokine, highly overexpressed by MM cells, can signal mainly through 2 receptors, CCR1 and CCR5, only 1 of which (CCR1) is responsive to CCL3 in human and mouse osteoclast precursors. CCR1 activation leads to the formation of osteolytic lesions and facilitates tumor growth. Here we show that formation of mature osteoclasts is blocked by the highly potent and selective CCR1 antagonist CCX721, an analog of the clinical compound CCX354. We also show that doses of CCX721 selected to completely inhibit CCR1 produce a profound decrease in tumor burden and osteolytic damage in the murine 5TGM1 model of MM bone disease. Similar effects were observed when the antagonist was used prophylactically or therapeutically, with comparable efficacy to that of zoledronic acid. 5TGM1 cells were shown to express minimal levels of CCR1 while secreting high levels of CCL3, suggesting that the therapeutic effects of CCX721 result from CCR1 inhibition on non-MM cells, most likely osteoclasts and osteoclast precursors. These results provide a strong rationale for further development of CCR1 antagonists for the treatment of MM and associated osteolytic bone disease.

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