Increasing Wnt signaling in the bone marrow microenvironment inhibits the development of myeloma bone disease and reduces tumor burden in bone in vivo

There is increasing evidence to suggest that the Wnt signaling pathway plays a critical role in the pathogenesis of myeloma bone disease. In the present study, we determined whether increasing Wnt signaling within the bone marrow microenvironment in myeloma counteracts development of osteolytic bone disease. C57BL/KaLwRij mice were inoculated intravenously with murine 5TGM1 myeloma cells, resulting in tumor growth in bone and development of myeloma bone disease. Lithium chloride (LiCl) treatment activated Wnt signaling in osteoblasts, inhibited myeloma bone disease, and decreased tumor burden in bone, but increased tumor growth when 5TGM1 cells were inoculated subcutaneously. Abrogation of β-catenin activity and disruption of Wnt signaling in 5TGM1 cells by stable overexpression of a dominant-negative TCF4 prevented the LiCl-induced increase in subcutaneous growth but had no effect on LiCl-induced reduction in tumor burden within bone or on osteolysis in myeloma-bearing mice. Together, these data highlight the importance of the local microenvironment in the effect of Wnt signaling on the development of myeloma bone disease and demonstrate that, despite a direct effect to increase tumor growth at extraosseous sites, increasing Wnt signaling in the bone marrow microenvironment can prevent the development of myeloma bone disease and inhibit myeloma growth within bone in vivo.

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

Blood ◽

10.1182/blood.v110.11.812.812 ◽

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.

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

Blood ◽

10.1182/blood-2011-10-384784 ◽

2012 ◽

Vol 120 (7) ◽

pp. 1449-1457 ◽

Cited By ~ 42

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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Wnt3a signaling within bone inhibits multiple myeloma bone disease and tumor growth

Blood ◽

10.1182/blood-2007-10-120253 ◽

2008 ◽

Vol 112 (2) ◽

pp. 374-382 ◽

Cited By ~ 57

Author(s):

Ya-Wei Qiang ◽

John D. Shaughnessy ◽

Shmuel Yaccoby

Keyword(s):

Multiple Myeloma ◽

Wnt Signaling ◽

Bone Disease ◽

Tumor Burden ◽

Bone Homeostasis ◽

Mineral Density ◽

Myeloma Bone Disease ◽

Empty Vector

Abstract Canonical Wnt signaling is central to normal bone homeostasis, and secretion of Wnt signaling inhibitors by multiple myeloma (MM) cells contributes to MM-related bone resorption and disease progression. The aim of this study was to test the effect of Wnt3a on bone disease and growth of MM cells in vitro and in vivo. Although Wnt3a activated canonical signaling in the majority of MM cell lines and primary cells tested, Wnt3a had no effect on MM cell growth in vitro. Moreover, forced expression of Wnt3a in H929 MM cells conferred no growth advantage over empty vector-transfected cells in vitro or importantly when grown subcutaneously in severe combined immunodeficient (SCID) mice. Importantly, although H929 cells stably expressing an empty vector injected into human bone grew rapidly and induced a marked reduction in bone mineral density, bones engrafted with Wnt3a-expressing H929 cells were preserved, exhibited increased osteoblast-to-osteoclast ratios, and reduced tumor burden. Likewise, treatment of myelomatous SCID-hu mice, carrying primary disease, with recombinant Wnt3a stimulated bone formation and attenuated MM growth. These results provide further support of the potential anabolic and anti-MM effects of enhancing Wnt signaling in the bone.

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Inhibition of p38α MAPK Reduces Tumor Burden, Prevents the Development of Myeloma Bone Disease, and Increases Survival in the 5T2 and 5T33 Murine Models of Myeloma.

Blood ◽

10.1182/blood.v108.11.3436.3436 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3436-3436 ◽

Cited By ~ 7

Author(s):

Karin Vanderkerken ◽

Satya Medicherla ◽

Les Coulton ◽

Benjamin Van Camp ◽

Andy Protter ◽

...

Keyword(s):

Bone Disease ◽

Critical Role ◽

Disease Free Survival ◽

Myeloma Cell ◽

Bone Lesions ◽

Myeloma Cells ◽

Growth And Survival ◽

Myeloma Bone Disease ◽

Osteolytic Bone Disease

Abstract The bone microenvironment plays a critical role in supporting the growth and survival of myeloma cells and the development of osteolytic bone disease. Signalling through p38 α MAPK mediates synthesis of myeloma cell survival factors by stromal cells; whereas, inhibiting p38 α MAPK reduces myeloma cell proliferation and inhibits osteoclast formation in vitro. However, it is unclear whether p38 α MAPK inhibition will prevent the growth and survival of myeloma cells and the bone disease in vivo. The aim of this study was to determine whether SCIO-469, a selective p38 α MAPK inhibitor, would inhibit myeloma growth and prevent the development of bone disease in the 5TMM syngeneic models of myeloma. Treatment of 5TMM cells, in vitro, with SCIO-469 resulted in a clear inhibition of p38 phosphorylation, as assessed by Western blotting and an inhibition up to 35% of stromal cell induced 5T33MM proliferation. Injection of 5T2MM murine myeloma cells into C57Bl/KaLwRij mice resulted in the growth of myeloma in bone and the development of bone disease characterized by increased osteoclast surface (p<0.05), a reduction in cancellous bone (p<0.01) and the presence of osteolytic bone lesions on x-ray (p<0.01). Treatment of 5T2MM-bearing mice with SCIO-469 (150mg/kg in the diet, therapeutical treatment from paraprotein detection) resulted in a 42% decrease in serum paraprotein and prevented development of osteolytic lesions (p<0.01). Injection of 5T33MM cells into C57Bl/KaLwRij mice also resulted in the development of myeloma but not associated bone disease. Treatment of 5T33MM-bearing mice from the time of tumor cell injection with SCIO-469 resulted in a decrease in serum paraprotein (8.8+/−1.4g/dl to 0.04+/− 0.03g/dl, p<0.001) and a reduction in the proportion of tumor cells in the bone marrow (67 +/− 8.1% to 1.09 +/− 0.58%, p<0.001). Kaplan-Meier analysis demonstrated an increase in disease-free survival (veh=27.5 days vs 96 days, p<0.001) after treatment of the mice with SCIO-469. These data demonstrate that targeting p38 α MAPK with SCIO-469 is associated with an anti-myeloma effect, which indirectly prevents the development of myeloma bone disease.

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Induction of CXCL1 in Osteoblasts by Myeloma Cells Promotes Migration of Osteoclast Precursors

Blood ◽

10.1182/blood.v120.21.441.441 ◽

2012 ◽

Vol 120 (21) ◽

pp. 441-441

Author(s):

Martin F. Kaiser ◽

Ulrike Heider ◽

Maren Mieth ◽

Jozef Zustin ◽

Andrea Kuehnl ◽

...

Keyword(s):

Bone Marrow ◽

Healthy Volunteers ◽

Bone Disease ◽

Bone Marrow Microenvironment ◽

Bone Microenvironment ◽

Bone Marrow Biopsies ◽

Myeloma Cells ◽

Myeloma Bone Disease ◽

Immunomagnetic Sorting

Abstract Abstract 441 Introduction Multiple myeloma (MM) causes a dysbalance in the bone microenvironment between bone building osteoblasts and bone resorbing osteoclasts (OCs), with an increase in OC recruitment, differentiation and activation, leading to myeloma bone disease (MBD). Presence of MBD has a major impact on the quality of life of MM patients and novel treatment approaches for MBD are urgently needed. Several factors have been identified that play a role in this process, e.g. receptor activator of NF-kB ligand (RANKL). However, the pathomechanism of increased osteoclast recruitment and activation is not completely understood. Here, we investigated the role of the chemokine CXCL1 and its receptor CXCR2 in the bone microenvironment in MM. Material and Methods Serum samples from 52 patients with newly diagnosed MM and from 22 healthy volunteers were assayed using a CXCL1 ELISA. Primary human mesenchymal stem cells (hMSCs) were cultured from bone marrow aspirates and primary human differentiated osteoblasts (hOBs) were cultured from trabecular bone fragments, both from healthy volunteers. Osteoclast precursors (pre-OCs) were generated by immunomagnetic sorting of CD14-positive cells from the peripheral blood of healthy volunteers. Human myeloma cell lines (HMCLs) U-266, RPMI-8226 and LP-1 and primary bone marrow myeloma cells (pMMCs) selected using CD138 immunomagnetic sorting were used for the experiments. Co-cultures of HMCLs and pMMCs with hMSCs or hOBs were performed using 0.45 μm transwell inserts, allowing for the exchange of soluble mediators. Migration assays were performed using 8 μm transwell inserts and human recombinant CXCL1. Immunohistochemistry was performed on paraffin-embedded bone marrow biopsies from MM patients using an anti-CXCR2 monoclonal antibody. All experimental procedures involving patient material were approved by the local ethics committee and conducted after informed consent was obtained. Results CXCL1 serum levels were found to be significantly higher in MM patients than in healthy individuals (193.4 pg/mL vs. 137 pg/mL, respectively, p<0.05), indicating a role for CXCL1 in MM pathophysiology. We went on to investigate the role of CXCL1 in MBD and performed co-cultures of HMCLs and pMMCs with hMSCs or hOBs. Baseline CXCL1 expression was absent in HMCLs and low or absent in hMSCs or hOBs at baseline. RNA expression as well as protein excretion by hMSCs and hOBs were induced after co-culture with myeloma cells. For example, pMMCs from different individuals led to a mean 154-fold upregulation of CXCL1 mRNA levels in hMSCs and to a mean upregulation of CXCL1 protein in cell culture supernatants from <31.5 pg/mL at baseline to 2140 pg/mL after co-cultures. In order to investigate the potential function of elevated CXCL1 levels in the bone marrow microenvironment, the expression of CXCR2, the receptor for CXCL1, was analyzed. Pre-OCs as well as a majority of pMMCs expressed CXCR2 mRNA. CXCR2 protein expression in pMMCs was verified using immunohistochemistry on MM bone marrow biopsies. Human recombinant CXCL1 significantly increased pre-OC cell migration in a dose-dependent manner. For example, 50 ng/mL or 100 ng/mL of CXCL1 increased mean pre-OC migration along a CXCL1 gradient 2.5-fold and 5.6-fold over baseline, respectively. In addition, mean pMMC migration was increased 3.8-fold compared to baseline along a 100 ng/mL gradient of recombinant CXCL1. The osteoclastogenic capacity of the migrated pre-OCs was confirmed by TRAP expression after stimulation with RANKL and M-CSF. Conclusion We describe here a novel role for the chemokine CXCL1 in myeloma bone disease. We demonstrate that CXCL1 is induced in hMSCs and hOBs by co-culture with MM cells. CXCL1 leads to chemoattraction of both pre-OCs and pMMCs. These effects could lead to co-localization of OCs and MM cells in the bone marrow microenvironment and contribute to the tumor-promoting interaction between these cell types. Our data indicate the CXCL1-CXCR2 axis as a therapeutic target in myeloma bone disease. Disclosures: No relevant conflicts of interest to declare.

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The EphrinB2/EphB4 Axis Is Dysregulated in Osteoprogenitors from Myeloma Patients and Its Activation by EphrinB2-Fc or EhpB4-Fc Affects Myeloma Bone Disease and Tumor Growth in Vivo

Blood ◽

10.1182/blood.v112.11.844.844 ◽

2008 ◽

Vol 112 (11) ◽

pp. 844-844

Author(s):

Angela Pennisi ◽

Wen Ling ◽

Xin Li ◽

Jianmei Chen ◽

Sharmin Khan ◽

...

Keyword(s):

Tumor Growth ◽

Osteogenic Differentiation ◽

Bone Disease ◽

Plasma Cells ◽

Bone Lesions ◽

Reverse Signaling ◽

Myeloma Bone Disease ◽

Bidirectional Signaling ◽

Healthy Donors

Abstract Induction of osteolytic bone lesions in myeloma (MM) is caused by an uncoupling of osteoclastic bone resorption and osteoblastic bone formation. Recent studies indicate that in addition to role in cell adhesion, repulsion and neovascularization, bidirectional signaling between the cell surface molecules EphrinB2 and EphB4 also mediates the coupling between osteoblasts and osteoblasts. While mesenchymal stem cells (MSCs) and osteoblasts express the ligand EphrinB2 land its receptor, EphB4, osteoclasts and their precursors mainly express EphrinB2. Forward signaling in MSCs promotes osteogenic differentiation and reverse signaling in osteoclast precursors inhibits their differentiation. The aims of the study were to investigate whether the EphrinB2/Eph4 axis is dysregulated in MM osteoprogenitors and whether activation of this axis in myelomatous bone by EphrinB2-Fc or EphB4-Fc affects MM bone disease, angiogenesis and tumor growth. MSCs were generated from bone marrow of healthy donors (n=5) and patients with MM (n=13). Gene expression was determined by qRT-PCR. MSCs from MM patients had reduced expression of EphrinB2 (EFNB2) by 61±6% (p<0.02) and EphB4 by 60±10% (p<0.02) than expression levels of these molecules in MSCs from healthy donors. Expression of other EFN and EPH B genes were detected and similarly expressed in patients and donors MSCs. Differentiation of MSCs from MM patients into osteoblasts resulted in upregulation of EFNB2 and downregulation of EPHB4. MM cell lines and primary MM plasma cells expressed low to undetectable levels of this family of genes. We exploited our SCID-hu system for primary MM to study the consequences of activation of forward signaling by EphrinB2-Fc or reverse signaling by EphB4-Fc on MM-induced bone disease and MM growth. Twelve SCID-hu mice were engrafted with MM cells from a patient with active MM. Upon detection of MM growth (by human Ig ELISA) and bone disease (radiographically), hosts were locally treated with Fc (control), EphrinB2-Fc or EPHB4 (4 mice/group) for 4 weeks using Alzet pump that continually released 0.11 μg/hour of each compound. While in Fc-treated hosts BMD of the implanted bone was reduced by 8±3% from pretreatment levels, it was increased by EphrinB2-Fc and EPhB4-Fc by 15±8% (p<0.03 vs. Fc) and 2±1% (p<0.02 vs. Fc) from pretreatment levels, respectively. At experiment’s end levels of human Ig in mice sera were increased by 308±99% and 244±86% from pretreatment levels in Fc- and EphrinB2- Fc groups, respectively, while were reduced by 92±1% (p<0.02 vs. Fc) from pretreatment levels in EphB4-Fc group. In myelomatous bones, EphB4-Fc and EphrinB2-Fc increased the numbers of osteoblasts by >3 folds (p<0.004) while EphB4-Fc, but not EphrinB2-Fc, reduced osteoclast numbers by 5 folds (p<0.01 vs. Fc group). The numbers of CD34-reactive neovessels were reduced by 2 folds following treatment with EphB4-Fc (p<0.03) and were increased by 2.5 folds following treatment with EphrinB2-Fc (p<0.05). Our study suggests that downregulation of EphrinB2 and EhpB4 in MSCs from MM patients contributes to their impaired osteogenic differentiation and that treatment with EphrinB2-Fc or EphB4-Fc helps restore coupling of bone remodeling in myelomatous bones. The results also indicate that EphB4-Fc treatment is an effective approach to simultaneously inhibit MM and its associated bone disease.

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Hijacking the Niche: The Role of Stromal Osteopontin in the Induction of Leukemic Dormancy within the Bone Marrow Microenvironment

Blood ◽

10.1182/blood.v118.21.754.754 ◽

2011 ◽

Vol 118 (21) ◽

pp. 754-754

Author(s):

Benjamin Boyerinas ◽

Ali Ekrem Yesilkanal ◽

Andrea Pontier ◽

Dorothy A. Sipkins

Keyword(s):

Bone Marrow ◽

Cell Line ◽

In Vivo Imaging ◽

Tumor Burden ◽

Bone Marrow Microenvironment ◽

Leukemic Cells ◽

Hematopoietic Stem ◽

Bone Marrow Biopsies ◽

Stromal Microenvironment

Abstract Abstract 754 Introduction: Acute lymphoblastic leukemia (ALL) is a treatable malignancy where initial induction chemotherapy achieves clinical remission in the majority of patients. Relapsed disease, however, occurs in many patients and is significantly more difficult to treat. The majority of relapsed cases are a result of minimal residual disease (MRD) that persists within the bone marrow (BM) after initial chemotherapy. Our evolving knowledge of the importance of the host microenvironment in tumor progression suggests that the stromal microenvironment can protect leukemic cells from chemotherapeutic assault, and that inhibiting the supportive relationship between leukemic blasts and the bone marrow microenvironment (BMM) will provide novel therapeutic opportunities. We therefore aimed to identify and characterize novel stromal signaling mechanisms that retain and support blasts within the malignant BMM. Our preliminary data suggest that osteopontin (OPN), normally secreted by osteoblasts within the marrow, is one such signaling chemokine that is highly upregulated in the leukemic niche. OPN has well-defined roles in both solid tumor metastasis and normal hematopoietic stem cell function within the BMM. Specifically, OPN expression at the endosteal bone surface functions to recruit hematopoietic progenitors to bone where they are induced to become quiescent and maintain long term repopulating potential. We hypothesized that a similar relationship exists between leukemia and OPN resulting in a quiescent population of chemoresistant leukemic blasts at the BM endosteum. Here, we demonstrate that stromal OPN negatively regulates leukemia cell proliferation in the BMM. Methods: A GFP expressing clone of the pre-B ALL cell line Nalm-6 (10 × 106 cells) was engrafted into SCID hosts (6-8 weeks old) via tail vein injection. In vivo imaging was accomplished in live anesthetized mice by reflecting the scalp and imaging the calvarial marrow compartment using real-time multi-photon confocal microscopy. OPN expression in the malignant marrow was imaged by injecting engrafted mice with fluorescently conjugated anti-OPN antibodies 18hrs prior to imaging. For OPN neutralizing experiments, engrafted mice were injected with a cocktail of anti-mouse and anti-human OPN antibodies at a dose of 3 mg/kg. Results: Using PCR, Western blot and ELISA assays, we show that the ALL cell line Nalm-6 expresses OPN and secretes large quantities of OPN into conditioned media. Flow cytometric analysis demonstrates that Nalm-6 also express the cell surface OPN receptors VLA-4 and VLA-5. Furthermore, Nalm-6 cells specifically adhere to OPN in vitro via specific engagement of these integrin receptors. In vivo imaging demonstrates that OPN expression in the BM increases as leukemia progresses and that OPN is highly expressed adjacent to areas of high tumor burden. Specifically, a significant amount of OPN is detected in bony tunnels surrounding the vasculature at the invading tumor front. Using Q-PCR and western analysis, we demonstrate that both host-derived and leukemia-derived OPN are upregulated in malignant BM. In vivo inhibition of the OPN signaling axis in the Nalm-6 xenograft model using neutralizing antibodies directed at both human and murine OPN increased overall tumor burden two-fold as measured by flow cytometry and in vivo imaging (p=0.02, N=7) while simultaneously increasing the Ki-67 positive proliferative tumor population (p=0.029, N=4). Furthermore, IHC analysis of a panel of diagnostic bone marrow biopsies from a diverse cohort of ALL patients demonstrated high OPN expression in the marrow of these patients. Conclusion: Leukemic blasts that have hijacked normal stromal interactions to become quiescent may represent a major source of MRD and patient relapse in ALL. Our data demonstrate that the interaction of leukemic blasts with OPN in the stromal microenvironment reduces the number of cycling blasts and constrains tumor proliferation within the marrow. Current investigations are aimed at combining OPN neutralization with an in vivo model of MRD to determine whether OPN neutralization induces cycling of quiescent blasts, ultimately rendering them sensitive to chemotherapy. The ultimate goal of this work is the development of clinically relevant therapies designed to render leukemic cells more susceptible to chemotherapy by disengaging them from protective interactions with the BM microenvironment. Disclosures: No relevant conflicts of interest to declare.

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Multiple Myeloma and Bone Marrow Microenvironment Immunohistochemical Study of the Expression of 15 Proteins Related to Myeloma Bone Disease

Blood ◽

10.1182/blood.v126.23.5318.5318 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5318-5318 ◽

Cited By ~ 1

Author(s):

Patrik Flodr ◽

Pavla Latalova ◽

Petra Pusciznova ◽

Tomas Pika ◽

Jaroslav Bacovsky ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Bone Disease ◽

Conflicts Of Interest ◽

Activin A ◽

Annexin A2 ◽

Bone Marrow Microenvironment ◽

Therapeutic Approaches ◽

Variable Expression ◽

Myeloma Bone Disease

Abstract Objective: Neoplastic milieu is an integral part of all malignant diseases including multiple myeloma and plays variable role in their development, retention/adhesivity, resistency or sensitivity to therapeutic approach, homing and also paraneoplastic manifestations. Relatively genetically stable milieu may play an important role in new specific molecular therapeutic approaches and therefore should be contextually studied with neoplastic cells as complex neoplastic tissues. The expressions of 15 proteins with close relation to the development of myeloma bone disease (MBD) were analysed in consecutive multiple myeloma specimens. Methods: Bone marrow trephine biopsy specimens (n=57) with multiple myeloma were included in our prospective study. FFPE tissues were processed in app. 5microm sections and placed on charged slides. The indirect immunohistochemical staining was applicated after antigen retrieval and commercial primary antibodies were used for the detection of observed proteins. Standard secondary antibody and ABC method were included in visualisation. We analysed the expressions of MIP1alfa, Annexin A2, TRAP, DKK-1, RANK, RANKL, OPG, Sclerostin, Activin A, NFkappaB proteins (p50, p52, p65), p62 (sequestosome 1), MMP9 and RUNX2. Results: Bone marrow multiple myeloma specimens showed variable positivity of MIP1alfa in 60% (cut-off point 20%), Annexin A2 in 42% (myeloma cells, cut-off point 30%) and in 74% (stromal cells, cut-off point 5%), TRAP in 28% (cut-off point 5%), DKK-1 in 23% (cut-off point 30%), RANK in 53% (cut-off point 30%), RANKL in 70%, OPG in 39% (cut-off point 5%), Sclerostin in 95% (cut-off point 90%), Activin A in 35% (cut-off point 30%), cytoplasmic positivity of p50 in 5% (cut-off point 10%), p52 in 86% (cut-off point 10%), p62 in 91% (cut-off point 10%), p65 in 89% (cut-off point 10%), positivity of MMP9 in 22% (cut-off point 30%) and positivity of RUNX2 in 56% (cut-off point 30%). Conclusion: Our study showed variable expression of proteins related to MBD in multiple myeloma and its bone marrow microenvironment that imply biological heterogeneity, different development and stromal plasticity in this complex hemato-oncological disease. The exact and contextual knowledge of the engaged signaling pathways may suggest more specific or tailored therapeutic approaches (e.g. anti-RANKL, anti-DKK-1, anti-Sclerostin, anti-Activin A). Supported by the grant NT 14393. Disclosures No relevant conflicts of interest to declare.

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CYR61/CCN1 overexpression in the myeloma microenvironment is associated with superior survival and reduced bone disease

Blood ◽

10.1182/blood-2014-02-555813 ◽

2014 ◽

Vol 124 (13) ◽

pp. 2051-2060 ◽

Cited By ~ 16

Author(s):

Sarah K. Johnson ◽

James P. Stewart ◽

Rakesh Bam ◽

Pingping Qu ◽

Bart Barlogie ◽

...

Keyword(s):

Bone Marrow ◽

Tumor Growth ◽

Bone Disease ◽

Therapeutic Target ◽

Potential Therapeutic Target ◽

Myeloma Bone Disease ◽

Key Points ◽

Asymptomatic Disease

Key Points CYR61/CCN1 is a bone marrow microenvironmental biomarker for myeloma progression and for transformation of MGUS and asymptomatic disease to overt myeloma. CCN1 reduces myeloma bone disease and tumor growth and is a potential therapeutic target for myeloma.

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Targeting aberrant DNA methylation in mesenchymal stromal cells as a treatment for myeloma bone disease

Nature Communications ◽

10.1038/s41467-020-20715-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Antonio Garcia-Gomez ◽

Tianlu Li ◽

Carlos de la Calle-Fabregat ◽

Javier Rodríguez-Ubreva ◽

Laura Ciudad ◽

...

Keyword(s):

Dna Methylation ◽

Bone Marrow ◽

Mesenchymal Stromal Cells ◽

Bone Disease ◽

Stromal Cells ◽

Tumor Burden ◽

Dual Inhibitor ◽

Aberrant Expression ◽

Myeloma Bone Disease

AbstractMultiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD.

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