- Email: [email protected]
B563 Anti-DKK1 mAb (BHQ880) as a Potential Therapeutic Agent for Multiple Myeloma
XII International Myeloma Workshop maturational stage (immature, naive and memory B-cells, and lymphoplasmocytes-plasmablasts) and the isotype of the B-cell receptor (IgM, IgG, and IgA). Results: B-cell distribution shows statistically significant age-related differences consistent with a decreasing number of circulating memory cells and lymphoplasmocytes with age. Interestingly, in all groups of MG patients, the absolute number of circulating lymphoplasmocytes is increased (P < .05), particularly among malignant conditions (MM and PCL; P < .001). Moreover, among MGUS a positive correlation was found between the amount of the serum monoclonal component (MC) and the number of circulating lymphoplasmacytes (R2 = 0.67; P = .02). In turn, among IgG MM patients (but not IgA MM), the serum concentration of monoclonal component showed a direct correlation with the number of circulating memory B-cells (R2 = –0.52; P = .04). Conclusion: Although aging induces a decrease of circulating memory B-cells and lymphoplasmocytes, the number of these cells in MG patients seems to be increased, particularly among the malignant diagnostic subgroups of the disease.
unposphorylated (active form) b-catenin protein expression, while it downregulated NF-KB activity, which is the prime mechanism mediating IL-6 secretion by BMSC. Interestingly, we also observed in vivo inhibition of MM cell growth by BHQ880 treatment in the SCID-hu murine model with both high and low tumor burden. These results confirm DKK1 as an important therapeutic target in myeloma and provide the rationale for clinical evaluation of BHQ880 to improve bone disease and to inhibit MM growth.
B564 Various Growth Factors Regulate Mesenchymal Stem Cell Differentiation Derived Human Multiple Myeloma C Lee,1 KS Ahn,1 EK Bae,2 J Park,3 BS Kim,4 SM Bang,5 I Kim,6 C Park,7 DS Lee,8 S Park,9 BK Kim,10 SS Yoon,11 Korean Multiple Myeloma Working Party 1
Korea University, College of Medicine, Department of Pathology,
Medical Research Center; 2Han Yang University, College of Medicine, Department of Biomedical Science; 3Seoul National
B563
University, College of Medicine, Cancer Research Institute;
Anti-DKK1 mAb (BHQ880) as a Potential Therapeutic Agent for Multiple Myeloma
4
Seoul National University Boramae Hospital, Internal Medicine;
5
Seoul National University Bundang Hospital, Internal Medicine;
M Fulciniti,1 S Vallet,1 S Ettenberg,2 X Shen,3 N Raje,1 P Tassone,4 T Hideshima,1 P Nanjappa,1 R Prabhala,1 KC Anderson,1 D Stover,2 NC Munshi1
6
1
Pathology; 9Seoul National University Hospital, Internal Medicine
2
Dana-Farber Cancer Institute; Novartis Institutes for Biomedical 3
4
Seoul National University Hospital, Internal Medicine and
Clinical Research Institute; 7Seoul National University Hospital, Microbiology; 8Seoul National University Hospital, Clinical
Research; Beth Israel Deaconess Medical Center; University
and Clinical Research Institute; 10Seoul National University Hospital,
“Magna Græcia” of Catanzaro
Internal Medicine and Clinical Research Institute; 11Seoul National University Hospital, Internal Medicine and Clinical Research Institute
Decreased activity of osteoblasts (OB) contributes to osteolytic lesions in multiple myeloma (MM). The production of the soluble Wnt inhibitor Dickkopf-1 (DKK1) by MM cells inhibits osteoblast activity and its serum level correlates with focal bone lesions in MM. Therefore, we have evaluated bone anabolic effects of a human DKK1 neutralizing antibody (BHQ880) in MM in the context of the BM microenvironment. We first analyzed the effects of BHQ880 on OB differentiation. BHQ880 was able to increase differentiation of mesenchymal stem cells (MSCs) to OB and reduce IL-6 levels following OB differentiation in vitro. While OB activity in MSCs was reduced in the presence of MM cells, treatment with BHQ880 restored OB activity, overcoming the negative effect of MM cells on osteoblastogenesis. To evaluate the in vivo activity of BHQ880, we used a SCID-hu murine model of human Myeloma, in which MM cells are injected in implanted fetal human bone. In this model, BHQ880 treatment for one month lead to significant increases in OB number and serum human osteocalcin level compared to mice injected with isotype control antibody. These effects also correlated with increased trabecular bone. Next, we evaluated the effect of BHQ880 on myeloma cell growth and survival. Although there was no direct effect of BHQ880 on MM cell growth, it induced significant growth inhibitory effect on a panel of human MM cells in presence of BM stromal cells (BMSC). The growth inhibitory effect of BHQ880 was associated with inhibition of BMSC/MM cell adhesion and production of IL-6. In BMSC we observed that BHQ880 upregulated
Introduction: Along with the progression of multiple myeloma (MM), myeloma-induced bone destruction is the result of an increased function of osteoclasts, which is not accompanied by a comparable increase of osteoblast activity. Various growth factors are involved in MM progression and an individual factor differentially affects the balance between osteoblasts and osteoclasts. Recent studies suggested that MM cells interact with bone marrow stromal cells and their secreted cytokines, have influence on osteocyte formation. However, it is still unknown whether multipotent human mesenchymal stem cells (hMSC) obtained from MM patients differentiate to either osteoblast or osteoclast by exposure to various growth factors or cytokines. Materials and Methods: To investigate growth factors affecting osteocytic differentiation of mesenchymal stem cells, morphology of hMSC and osteocytic differentiation related genes (Oct4, RUNX2, COL1A1, ALPL and osteoclastic factors - MIP-1, RANKL, OPG) were examined using immunostain, RT-PCR and western blot after treatment with various growth factors in hMSC. In addition, osteocytic differentiation of hMSC was examined after co-culture with MM cells. Results: Among various growth factors, BMPs stimulated osteoblastic differentiation. In contrast, TGF-1b, IL-6, and IL-3 stimulated osteoclastic differentiation. With the treatment of hMSC with BMPs, hMSC differentiated to osteoblast and NF-kB activation was decreased. Blockage of BMP signaling pathway reduced formation of osteoblastic cells. In our
Clinical Lymphoma & Myeloma Supplement February 2009
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unposphorylated (active form) b-catenin protein expression, while it downregulated NF-KB activity, which is the prime mechanism mediating IL-6 secretion by BMSC. Interestingly, we also observed in vivo inhibition of MM cell growth by BHQ880 treatment in the SCID-hu murine model with both high and low tumor burden. These results confirm DKK1 as an important therapeutic target in myeloma and provide the rationale for clinical evaluation of BHQ880 to improve bone disease and to inhibit MM growth.
B564 Various Growth Factors Regulate Mesenchymal Stem Cell Differentiation Derived Human Multiple Myeloma C Lee,1 KS Ahn,1 EK Bae,2 J Park,3 BS Kim,4 SM Bang,5 I Kim,6 C Park,7 DS Lee,8 S Park,9 BK Kim,10 SS Yoon,11 Korean Multiple Myeloma Working Party 1
Korea University, College of Medicine, Department of Pathology,
Medical Research Center; 2Han Yang University, College of Medicine, Department of Biomedical Science; 3Seoul National
B563
University, College of Medicine, Cancer Research Institute;
Anti-DKK1 mAb (BHQ880) as a Potential Therapeutic Agent for Multiple Myeloma
4
Seoul National University Boramae Hospital, Internal Medicine;
5
Seoul National University Bundang Hospital, Internal Medicine;
M Fulciniti,1 S Vallet,1 S Ettenberg,2 X Shen,3 N Raje,1 P Tassone,4 T Hideshima,1 P Nanjappa,1 R Prabhala,1 KC Anderson,1 D Stover,2 NC Munshi1
6
1
Pathology; 9Seoul National University Hospital, Internal Medicine
2
Dana-Farber Cancer Institute; Novartis Institutes for Biomedical 3
4
Seoul National University Hospital, Internal Medicine and
Clinical Research Institute; 7Seoul National University Hospital, Microbiology; 8Seoul National University Hospital, Clinical
Research; Beth Israel Deaconess Medical Center; University
and Clinical Research Institute; 10Seoul National University Hospital,
“Magna Græcia” of Catanzaro
Internal Medicine and Clinical Research Institute; 11Seoul National University Hospital, Internal Medicine and Clinical Research Institute
Decreased activity of osteoblasts (OB) contributes to osteolytic lesions in multiple myeloma (MM). The production of the soluble Wnt inhibitor Dickkopf-1 (DKK1) by MM cells inhibits osteoblast activity and its serum level correlates with focal bone lesions in MM. Therefore, we have evaluated bone anabolic effects of a human DKK1 neutralizing antibody (BHQ880) in MM in the context of the BM microenvironment. We first analyzed the effects of BHQ880 on OB differentiation. BHQ880 was able to increase differentiation of mesenchymal stem cells (MSCs) to OB and reduce IL-6 levels following OB differentiation in vitro. While OB activity in MSCs was reduced in the presence of MM cells, treatment with BHQ880 restored OB activity, overcoming the negative effect of MM cells on osteoblastogenesis. To evaluate the in vivo activity of BHQ880, we used a SCID-hu murine model of human Myeloma, in which MM cells are injected in implanted fetal human bone. In this model, BHQ880 treatment for one month lead to significant increases in OB number and serum human osteocalcin level compared to mice injected with isotype control antibody. These effects also correlated with increased trabecular bone. Next, we evaluated the effect of BHQ880 on myeloma cell growth and survival. Although there was no direct effect of BHQ880 on MM cell growth, it induced significant growth inhibitory effect on a panel of human MM cells in presence of BM stromal cells (BMSC). The growth inhibitory effect of BHQ880 was associated with inhibition of BMSC/MM cell adhesion and production of IL-6. In BMSC we observed that BHQ880 upregulated
Introduction: Along with the progression of multiple myeloma (MM), myeloma-induced bone destruction is the result of an increased function of osteoclasts, which is not accompanied by a comparable increase of osteoblast activity. Various growth factors are involved in MM progression and an individual factor differentially affects the balance between osteoblasts and osteoclasts. Recent studies suggested that MM cells interact with bone marrow stromal cells and their secreted cytokines, have influence on osteocyte formation. However, it is still unknown whether multipotent human mesenchymal stem cells (hMSC) obtained from MM patients differentiate to either osteoblast or osteoclast by exposure to various growth factors or cytokines. Materials and Methods: To investigate growth factors affecting osteocytic differentiation of mesenchymal stem cells, morphology of hMSC and osteocytic differentiation related genes (Oct4, RUNX2, COL1A1, ALPL and osteoclastic factors - MIP-1, RANKL, OPG) were examined using immunostain, RT-PCR and western blot after treatment with various growth factors in hMSC. In addition, osteocytic differentiation of hMSC was examined after co-culture with MM cells. Results: Among various growth factors, BMPs stimulated osteoblastic differentiation. In contrast, TGF-1b, IL-6, and IL-3 stimulated osteoclastic differentiation. With the treatment of hMSC with BMPs, hMSC differentiated to osteoblast and NF-kB activation was decreased. Blockage of BMP signaling pathway reduced formation of osteoblastic cells. In our
Clinical Lymphoma & Myeloma Supplement February 2009
•
S151