Increased M2 Macrophages and Higher Levels Of The Tribble Family Member Trib1 In Monocytes Are Associated With Progressive Disease In Multiple Myeloma (MM) Patients

Abstract Macrophages consist of two subgroups, M1 and M2. M1 macrophages are pro-inflammatory cells against bacterial and viral infections whereas M2 macrophages are anti-inflammatory and associated with tumor progression. The mammalian tribble (Trib) family of genes, Trib1, Trib2 and Trib3, encode pseudokinase proteins that have important roles in monocyte/macrophage proliferation, differentiation, and apoptosis. Trib1 is a critical factor that induces M2 macrophage differentiation in the bone marrow (BM). First, we investigated the proportion of M1 and M2 macrophages in BM mononuclear cells (MCs) from multiple myeloma (MM) patients with progressive disease or in remission using flow cytometric analysis. The percentage of M2 (CD36+/CD86-) macrophages in BM was significantly increased in MM patients with progressive disease (n=15) compared to those in remission (n=5; P<0.05) whereas there was no difference in the percentage of M1 (CD86+/CD14+) macrophages in BM derived from MM patients with progressive disease compared to those in remission. Using immunohistochemical (IHC) analysis, the proportion of M2 macrophages was also determined in MM BM biopsies from patients with progressive disease and remission. The samples were cut into five-micrometer sections and double stained with two antibodies following a standard IHC protocol. IHC demonstrated that the percentage of M2 macrophages (CD36+/CD14+) was markedly increased in BM sections from MM patients with progressive disease compared to those in remission. In contrast, the percentage of M1 (CD86+/CD14+) macrophages was not different among those patients with progressive disease compared to those in remission. Next, we analyzed Trib1, Trib2 and Trib3 gene expression in BMMCs obtained from MM patients with progressive disease or in remission. RT-PCR results showed Trib1 expression levels were much higher among patients with progressive disease compared to those in remission. In contrast, the expression Trib2 and Trib3 was not related to the MM patient's clinical status. To determine whether MM tumor cells affected monocyte/macrophage differentiation and Trib gene expression, we co-cultured fresh MM tumor cells with purified healthy human monocytes. BMMCs from MM patients were co-cultured with human monocytes from normal subjects using Transwell plates and the percentage of M1 and M2 macrophages was determined using flow cytometric analysis following 2, 5 and 7 days of culture. The percentage of M2 cells increased whereas the proportion of M1 cells decreased. Gene expression of Trib1, Trib2 and Trib3 was analyzed using RT-PCR following 2, 5, and 7 days of co-culture. The expression of Trib 1 increased during the 7 days of co-culture whereas the expression of Trib2 and Trib3 did not change. Moreover, when direct cell-to-cell contact occurred between the MM cells and the monocytes, the percentage of M2 macrophages (CD36+) markedly increased after 7 days of incubation. We have shown that MM cells induce monocytes to increase Trib1 gene expression, which stimulates M2 differentiation in monocytes. M2 cells, in turn, induce tumor progression, providing a positive feedback loop on Trib1 expression, monocyte differentiation and tumor cell growth. Overall, we propose that Trib1 may be considered as a potential novel therapeutic target for the treatment of MM. Disclosures: No relevant conflicts of interest to declare.

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Increased M2 Macrophages in Multiple Myeloma Patients with Progressive Disease and Down-Regulated Polarization with the JAK2 Inhibitor Ruxolitinib

Blood ◽

10.1182/blood.v124.21.4106.4106 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4106-4106 ◽

Cited By ~ 2

Author(s):

Haiming Chen ◽

Eric Sanchez ◽

Mingjie Li ◽

Cathy Wang ◽

Abby Gillespie ◽

...

Keyword(s):

Gene Expression ◽

Tumor Cells ◽

Progressive Disease ◽

Flow Cytometric Analysis ◽

Human Monocytes ◽

M2 Macrophages ◽

Jak2 Inhibitor ◽

Flow Cytometric ◽

M2 Polarization ◽

M1 And M2 Macrophages

Abstract Introduction: Macrophages polarize into pro-inflammatory M1 or alternative M2 states with distinct phenotypes and physiological functions. M2 cells promote tumor growth and metastasis through secretion of growth factors. However, crosstalk between tumor cells and macrophages in the development of M2 polarization has not been well demonstrated. We evaluated the proportion of M2 macrophages in bone marrow (BM) from patients (pts) with multiple myeloma (MM), the effects of MM cells on M1 and M2 differentiation, and the role of Trib1 in M2 differentiation in MM BM. Since the JAK-STAT signaling pathway plays key roles in the cell growth and differentiation of macrophages, we evaluated the effects of the JAK2 inhibitor ruxolitinib (RUX) on M2 polarization in MM. Methods: Using immunofluorescence (IFC) analysis, we determined the proportion of M1 and M2 macrophages in BM biopsies from MM pts with progressive disease and in remission. The BM biopsy samples were stained with antibodies directed against human iNOS and CD86 for M1 and arginase 1(ARG1) and CD36 for M2 cells, following a standard IFC protocol. Monocyte/macrophage phenotypes for M1 and M2 subtypes in mononuclear cells isolated from MM BM aspirates were also examined using flow cytometric analysis with these same antibodies. Human monocytes isolated from normal subjects or the THP1 monocyte cell line were co-cultured with MM cell lines or primary MM tumor cells with or without exposure to low concentrations (IC20) of ruxolitinib (RUX) using Transwell plates. The percentage of M1 and M2 macrophages was determined using flow cytometric analysis. Total RNA was extracted from monocytes followed the manufacturer’s directions. Quantitation PCR were measured with TaqMan technology performed in an OneStepPlus instrument. Results: IFC demonstrated that the percentage of M2 macrophages (CD36+/ARG1+) was markedly increased in BM sections from MM pts with progressive disease compared with those pts in remission. The flow cytometric data also showed the percentage of M2 (CD36+/ ARG1+) macrophages in BM was significantly increased in MM patients with progressive disease (n=20) compared to those in remission (n=9; P=0.005) whereas there was no significant difference in the percentage of M1 (CD86+/iNOS+) macrophages in BM derived from MM patients with progressive disease compared to those in remission. The results of both RT-PCR and Quantitation PCR showed Trib1 gene expression levels were higher among patients with progressive disease compared to those in remission. In contrast, the gene expression of Trib2 and Trib3 was not related to the MM patient’s clinical status. To determine whether MM tumor cells affected monocyte/macrophage differentiation and Trib gene expression, we co-cultured MM cell lines or fresh MM tumor cells with purified healthy human monocytes using Transwell plates. The percentage of M2 cells markedly increased whereas the proportion of M1 cells decreased. The expression of Trib1 increased during the 7 days of co-culture whereas there was no change in the expression of Trib2 and Trib3. Moreover, when direct cell-to-cell contact occurred between the MM cells and the monocytes, the percentage of M2 macrophages markedly increased after 7 days of incubation. It has been reported that Trib-1 mediated regulation of the MAPK/ERK pathway in a murine model and the Ras/Raf-1/MEK1/ERK cascade culminates in up-regulated expression of the gene encoding STAT3 whereas recruitment and activation of tyrosine kinase JAK-2 phosphorylates it. Thus, we investigated the effects of the JAK2 inhibitor RUX on M2 differentiation induced with MM tumor cells. The percentage of M2 cells was decreased when the monocytes that were co-cultured with MM tumor cells were treated with a low concentration (IC20) of RUX. Trib1 gene expression of the monocytes treated with RUX was also reduced comparing to the cells untreated with JAK2 inhibitor. Conclusion: Our results show that MM cells induce monocytes to become M2 macrophages and increase Trib1 gene expression providing a positive feedback loop on Trib1 expression, monocyte differentiation and tumor cell growth. M2 cells are present at high levels in BM derived from MM pts with progressive disease compared to those in remission. Notably, the JAK2 inhibitor RUX shows inhibition of both M2 macrophage polarization and Trib1 gene expression in MM, and these results suggest this drug may be effective for treating MM. Disclosures No relevant conflicts of interest to declare.

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Increased Alternative Macrophage-2 (M2) Polarization with Trib1 Gene over Expression in Myeloma Patients with Progressive Disease and Jak2 Inhibitors Reduce M2 Polarization

Blood ◽

10.1182/blood.v126.23.1011.1011 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1011-1011 ◽

Cited By ~ 1

Author(s):

Haiming Chen ◽

Mingjie Li ◽

Eric Sanchez ◽

Abigail Gillespie ◽

Cathy Wang ◽

...

Keyword(s):

Gene Expression ◽

Tumor Growth ◽

Tumor Cells ◽

Progressive Disease ◽

Scid Mice ◽

Human Monocytes ◽

M2 Macrophages ◽

Jak2 Inhibitor ◽

M2 Polarization ◽

M1 And M2 Macrophages

Abstract Introduction: The bone marrow (BM) microenvironment plays an important role in multiple myeloma (MM). The BM niche is composed of multiple cell types including macrophages. Macrophages polarize into pro-inflammatory macrophage-1 (M1) or alternative M2 states that promote tumor growth and metastasis. We evaluated the proportion of M2 macrophages in BM from MM pts either showing complete response (CR) or progressive disease (PD), the effects of MM cells on M1 and M2 differentiation, and the role of Trib1 in M2 differentiation in MM BM. Since the JAK-STAT signaling pathway plays key roles in macrophages, we also evaluated the effects of the JAK2 inhibitor ruxolitinib (RUX) on M2 polarization in MM. Methods: Using immunofluorescence (IFC), we determined the proportion of M1 and M2 macrophages in BM biopsies and aspirates from MM pts with PD or CR. The BM biopsy samples were stained with antibodies directed against human iNOS and CD86 for M1 and arginase 1(ARG1) and CD36 for M2 cells. MM BM aspirates were also examined using flow cytometric analysis (FCA). Human monocytes isolated from healthy subjects or the THP1 monocyte cell line were co-cultured with MM cell lines (RPMI8226 and U266) or primary MM tumor cells. The effects of RUX at low concentrations (IC20) on M2 polarization were determined. The percentages of M1 and M2 macrophages were determined using FCA. Total RNA was extracted from monocytes. Quantitative PCR was measured with TaqMan technology. For the in vivo studies, human MM tumors (LAGκ-2) were surgically implanted into the left superficial gluteal muscle of SCID mice and tumor volume measured on a weekly basis. Results: The proportion of M2 macrophages (CD36+/ARG1+) was markedly increased in BM biopsies or mononuclear cells from MM pts with PD compared with those in CR using IFC staining. FCA also showed the percentage of M2 macrophages in BM was significantly increased in MM pts with PD (n=25) compared to those in CR (n=10; P=0.005) whereas there was no difference in the percentage of M1 (CD86+/iNOS+) macrophages in BM derived from MM pts with PD compared to those in CR. Trib1 gene mRNA levels were higher among pts with PD compared to those in CR whereas the gene expression of Trib2 and Trib3 was not different. Next, we co-cultured MM cell lines (U266) or fresh MM BMMCs with purified healthy human monocytes for one week. The percentage of M2 cells markedly increased and the proportion of M1 cells decreased. Trib1 gene expression increased during co-culture whereas there was no change in expression of the other two Tribs. When direct cell-to-cell contact occurred between the MM tumor cells and the monocytes, the percentage of M2 macrophages markedly increased. We investigated the effects of the JAK2 inhibitor RUX on M2 differentiation induced with MM tumor cells. After exposure to a low concentration of RUX, the percentage of M2 cells decreased when the monocytes were co-cultured with MM tumor cells. Trib1 gene expression of the monocytes treated with RUX was also notably reduced compared with cells not treated with the JAK2 inhibitor. Using our human MM xenograft model LAGκ-2, RUX (1.5mg/kg) reduced tumor growth and decreased the proportion of M2 macrophages in the tumor tissue of MM tumor-bearing SCID mice. Conclusion: M2 cells are present at high levels in BM derived from MM pts with PD compared to those in CR, MM cells induce monocytes to become M2 macrophages and increase Trib1 gene expression. This induces monocyte differentiation into M2 macrophages that support MM tumor cell growth.. Notably, the JAK2 inhibitor RUX inhibits both M2 macrophage polarization and Trib1 gene expression in MM, and reduces tumor growth in SCID mice bearing human MM. These results suggest that RUX may be effective for treating MM pts. Disclosures No relevant conflicts of interest to declare.

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Circulating Tie2-Expressing Cells Are Increased in Multiple Myeloma Patients, Correlate with Serum Pleiotrophin Levels and May Develop from This Myeloma Angiogenic and Growth Factor.

Blood ◽

10.1182/blood.v106.11.2494.2494 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2494-2494

Author(s):

Haiming Chen ◽

Richard A. Campbell ◽

Melinda S. Gordon ◽

Steven J. Manyak ◽

Cathy Wang ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Growth Factor ◽

Peripheral Blood ◽

Serum Levels ◽

Angiogenic Factor ◽

Mrna Levels ◽

Human Monocytes ◽

Rt Pcr ◽

Control Subjects

Abstract Tie2, an endothelial cell-specific receptor kinase, plays an important role in tumor angiogenesis. This protein is essential to the development of embryonic vasculature as well as vascular growth and maintenance in adult tissues. Because of the increasing importance that angiogenesis has been shown to play in multiple myeloma (MM), we determined the number of Tie2-expressing cells in the peripheral blood (PB) of MM patients and its relationship to the serum levels and gene expression of a recently identified angiogenic factor, pleiotrophin (PTN). We have recently demonstrated that PTN is expressed and secreted by MM tumor cells, and serum levels of this protein are highly elevated in MM patients. We quantified the number of Tie2-positive cells in MM patients (n=15) and age-matched control subjects (n=10) using an immunohistochemical technique. Tie2-expressing cells were significantly elevated in the PB mononuclear cells (MCs) from MM patients compared to the normal controls (p<0.05). We also analyzed gene expression for Tie2 in these same samples using RT-PCR. The results showed that Tie2 mRNA was strongly expressed in the PBMCs from MM patients whereas control samples showed no or low expression of this gene. Serum levels of PTN were tested with ELISA, and PTN mRNA concentrations were quantified by RT-PCR in PBMCs from these same patients and control subjects. The results showed that serum levels of PTN correlated with the number of Tie2-expressing PBMCs in MM patients (R2=0.5778). PTN mRNA levels also correlated with Tie2 gene expression in PBMC samples. We further examined whether monocyte colony stimulating factor (mCSF), PTN and vascular endothelial growth factor (VEGF) may be capable of inducing Tie2 expression in highly purified human monocytes that lack Tie2 expression. Normal PB monocytes were purified using density centrifugation followed by anti-CD14 micro-bead affinity column selection. Although none of these three proteins alone or the combinations of either VEGF and mCSF or VEGF and PTN induced Tie2 gene expression in the monocytes following one week of incubation, the combination of PTN (100 nM) and mCSF (20 nM) led to expression of Tie2 in these cells. We quantified the proportion of cells expressing Tie2 in these samples with RT-PCR using serial dilutional analysis with B or T cells that lack Tie2 expression, and showed that approximately 0.1–1.0% of the monocytes expressed this gene following incubation with PTN and mCSF. Moreover, the addition of VEGF (20 ng/ml) to PTN and mCSF increased the proportion of cells expressing Tie2 (to >10%). Anti-PTN antibody blocked the induction of Tie2 gene expression in these monocytes by this cytokine combination. These results show that Tie2-expressing cells are elevated in the peripheral blood of MM patients, and correlate with PTN serum and PTN mRNA expression. PTN in combination with VEGF and mCSF induces Tie2 gene expression in a large proportion of circulating human monocytes. These results suggest that MM patients show increased numbers of vasculogenic progenitors in their circulation that may result from the presence of elevated levels of circulating angiogenic factors including PTN and VEGF.

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Gene Expression Profile of Circulating Myeloma Cells Reveals CD44 and CD97 (ADGRE5) Overexpression

Blood ◽

10.1182/blood.v128.22.5639.5639 ◽

2016 ◽

Vol 128 (22) ◽

pp. 5639-5639

Author(s):

Tereza Sevcikova ◽

Fedor Kryukov ◽

Lucie Brozova ◽

Jana Filipova ◽

Zuzana Kufova ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Bone Marrow ◽

Peripheral Blood ◽

Research Funding ◽

Plasma Cells ◽

Flow Cytometric Analysis ◽

Differentially Expressed ◽

Paired Samples ◽

Flow Cytometric

Abstract Introduction: Release of the aberrant plasma cells (PC) from the bone marrow (BM) and their presence in the peripheral blood (PB) is a maker of disease progression and worse survival in multiple myeloma (MM) (Nowakowski et al., 2005). Circulating plasma cells (cPCs) are able to survive without homing microenvironment, evade the original tumor and colonize other bone marrow niche. Detailed analysis of various surface proteins showed that cPCs display decreased levels of integrins, adhesion molecules N-CAM (CD56) and the stem cell factor receptor (Paiva et al., 2013). Comprehensive analysis of the genome-wide gene expression profiling that could provide deeper insight into the expression patterns of cPCs of MM is still lacking. Aims: To identify differentially expressed genes in paired samples of aberrant plasma cells from BM and PB and to describe potential biomarkers of cPCs in MM. Material and methods: Ten patients with multiple myeloma (seven new diagnoses and three relapses) have been included in the study after signing the informed consent form. Paired samples of aberrant plasma cells from bone marrow and peripheral blood were obtained from each patient. Aberrant plasma cells (aPCs) were sorted according to the immunophenotype as CD45dim/CD38+/CD19-/CD56-/+ cells. Gene expression profiling (GEP) was performed on paired samples using Affymetrix GeneChip Human Gene ST 1.0 array. RMA normalized data at gene level were analyzed using Wilcoxon paired test with Benjamini-Hochberg multiple testing correction. Results: The median infiltration of aberrant PC in the BM was 27.5% (range 1.1 - 93%) and 1.2% (range 0.19 - 2.8%) for cPCs in the PB. The median level of M-protein was 32.35 g/l (range 18.6 - 62.2 g/l). GEP analysis of paired BM and PB samples revealed 1001 significantly changed genes in cPCs (adjusted p-value<0.05). Gene ontology analysis did not reveal any significantly affected pathways. Nevertheless, two genes upregulated in cPCs, ADGRE5 and CD44, can be suggested as biologically relevant potential biomarkers of cPCs (Figure 1). Conclusion: The infiltration of aPCs in the bone marrow does not correlate with the amount of cPCs (p=0.16). Among differentially expressed genes, two surface markers upregulated in cPCs are of particular interest: CD44 and ADGRE5 (CD97). The CD44 antigen is a cell-surface glycoprotein involved in cell-cell interactions, cell adhesion and migration. Moreover, CD44 contribute to lenalidomide resistance in multiple myeloma (Bjorklund et al., 2014). CD97 is encoded by ADGRE5 gene and belongs to the EGF-TM7 subgroup of adhesion G-protein-coupled receptors. The expression of CD97 has been linked to invasive behavior in thyroid and colorectal cancer. Moreover, higher CD97 expression levels have been detected in 54% (208/385) of primary AML samples based on flow cytometric analysis (Wobus et al., 2015). Nevertheless, neither ADGRE5 nor CD97 expression were described in plasma cell dyscrasia previously. Thus, despite non-systemic changes of gene expression at the whole transcriptome level, cPCs in MM likely represent distinct biological entity with specific expression profile underlying advanced PC malignant transformation. To confirm the results, flow cytometric analysis on the bigger cohort will be performed. Acknowledgment: This study was supported by Institutional Development Plan of University of Ostrava (IRP201550) and The Ministry of Education, Youth and Sports (Specific university research of the Faculty of Medicine, University of Ostrava) project no. SGS03/LF/2015-2016, Ministry of Health Czech Republic RVO-FNOs/2014/17P and RVO-FNOs/2016/21. Figure 1 Genes of interest differentially expressed in the bone marrow (BM) versus peripheral blood (PB) aberrant plasma cells. Figure 1. Genes of interest differentially expressed in the bone marrow (BM) versus peripheral blood (PB) aberrant plasma cells. Disclosures Hajek: BMS: Honoraria; Onyx: Consultancy; Novartis: Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding.

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CD40 Ligand Stimulation of Multiple Myeloma Cells Results in Upregulation of Surface Expressed Heat Shock Proteins and Increased Antigenicity.

Blood ◽

10.1182/blood.v104.11.3351.3351 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3351-3351

Author(s):

Charles A. Gullo ◽

William Hwang ◽

Melvin Au ◽

Edward A. Greenfield ◽

Kenneth C. Anderson ◽

...

Keyword(s):

Multiple Myeloma ◽

Immune System ◽

Heat Shock ◽

Cell Membrane ◽

Heat Shock Proteins ◽

Flow Cytometric Analysis ◽

Cd40 Ligand ◽

Flow Cytometric ◽

Shock Proteins ◽

Stimulation Of

Abstract Effective immune-based therapies against the plasma cell malignancy, multiple myeloma (MM), are currently lacking. Identification of novel antigens (Ag) on the surface of MM cells to use as cellular targets for the destruction of cancer cells by the body’s immune system has been of great interest. We and others have demonstrated that CD40 stimulation of MM cells results in marked upregulation of membrane bound proteins such as Ku86. Using CD40 triggered MM cells as immunogens and hybridoma technology; we generated a monoclonal antibody (mAb), 6D11, that recognizes a CD40 induced cell membrane Ag on MM cells. This Ag is detectable on the surface of MM cells using indirect immunofluorescence flow cytometric analysis. Moreover, in Western immunoblotting assays, 6D11 mAb reacts with a 94 kDa protein, which is strongly associated with a 78 kDa protein. Using high performance liquid chromatography and protein microsequencing, we confirm that these proteins are the heat shock proteins (HSP), glucose-regulated peptide 94 (GRP94) and GRP78, respectively. These data were confirmed using co-immunprecipitation experiments. Furthermore, we demonstrate through indirect immunofluorescence flow cytometric analysis and quantitative real time reverse transcription polymerase chain reaction (RQ-PCR) that CD40 ligand (CD40L) stimulation of MM cells results in rapid upregulation of both GRP94 and GRP78. Since HSPs have been shown to play a role in both Ag presentation, as well as the intracellular transport of cellular Ags, it is tempting to speculate that cell membrane expression of tumor-specific peptides could also be induced via CD40 triggering. Accordingly, CD40 induced cell membrane HSP expression resulted in increased antigenicity as determined by increased co-stimulatory molecule expression on Ag presenting cells (APC) and by increased immunoreactivity in mixed lymphocyte reactions (MLR). This suggests that CD40 induced HSP expression may indeed result in increased recognition of MM cancer by the immune system. Our study therefore supports the development of CD40-based targeted cell therapies against MM.

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Peripheral Blood Cells from Multiple Myeloma Patients Show Increased Osteoclast and Decreased Osteoblast Gene Expression.

Blood ◽

10.1182/blood.v106.11.5098.5098 ◽

2005 ◽

Vol 106 (11) ◽

pp. 5098-5098

Author(s):

Melinda S. Gordon ◽

Ariana M. Berenson ◽

Charles B. Drucker ◽

Matthew Katz ◽

Hee Jin Lee ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Alkaline Phosphatase ◽

Bone Disease ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Bisphosphonate Treatment ◽

Rt Pcr ◽

Circulating Cells ◽

Osteolytic Bone Disease

Abstract Bone resorption leading to osteolytic bone disease is characteristic of multiple myeloma (MM). Recent studies show the presence of bone-resorbing osteoclasts and bone-forming osteoclasts in the circulation, and these cells may correlate with bone disease and change with anti-bone resorptive therapies. We have investigated whether there is an imbalance in the expression of osteoblast and osteoclast genes in the peripheral blood mononuclear cells (PBMCs) from MM patients relative to normal age-matched controls and the effect of bisphosphonate treatment on the expression of these genes. We analyzed the expression of a panel of osteoblast-related (bone alkaline phosphatase [bone AP], bone morphogenic protein 2 [BMP2], collagen I and osteocalcin) and osteoclast-related (b3 integrin, calcitonin, receptor for activation of nuclear factor kappa B [RANK] and tartrate-resistant alkaline phosphatase [TRAP]) genes by semi-quantitative RT-PCR on total RNA isolated from PBMCs obtained following density gradient separation. We demonstrated that the expression of the osteoblast-related gene BMP2 was reduced in eight of nine MM patients when compared with normal donors. In marked contrast, three osteoclast-related genes, b3 integrin, RANK and TRAP, were more highly expressed in all nine MM patients compared to the normal donors; only calcitonin expression was similar to the control subjects. Interestingly, patients receiving bisphosphonate treatment appeared to show increased osteoblast gene expression with higher amounts of bone AP, BMP2 and osteocalcin RNA compared to the patients not receiving anti-bone resorptive therapy. However, there was no alteration in the level of the RNA in any of the four osteoclast genes compared to patients not receiving anti-bone resorptive therapy. We are extending our analysis to a larger panel of MM patients in order to determine the relationship between these circulating cells and bone disease, overall clinical status and change in their levels with anti-bone resorptive therapy. In addition, we are also investigating whether there exist larger and smaller numbers of circulating osteoclasts and osteoblasts, respectively, in MM patients, or whether these circulating cells show alteration of their expression of these genes. Our semi-quantitative RT-PCR results are being correlated with immunohistochemical staining results from osteoblast and osteoclast markers obtained on PBMCs from MM and normal subjects. These studies provide evidence that the number of circulating osteoblasts and osteoclasts is altered in patients with MM, and also may suggest that bisphosphonate therapy may also be associated with changes in these cell populations.

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Proteomic Signature Predicting Achievement of Very Good Partial Response In Patients with Multiple Myeloma Based On Complementary Label-Free and iTRAQ Quantitative Proteome Analysis

Blood ◽

10.1182/blood.v116.21.1902.1902 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1902-1902

Author(s):

Dominik Dytfeld ◽

Malathi Kandarpa ◽

John R Strahler ◽

Dattatreya Mellacheruvu ◽

Suchitra Subramani ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Western Blot ◽

Differential Expression ◽

Proteomic Analysis ◽

Quantitative Proteomics ◽

Proteomic Profile ◽

Differentially Expressed Proteins ◽

Label Free ◽

Rt Pcr

Abstract Abstract 1902 Introduction: Multiple myeloma (MM) remains mostly incurable. Novel therapies have improved response rates, which are now reaching 100%. More importantly, number of recent studies showed that the depth of response, e.g. achievement of at least 90% reduction of the disease (≥VGPR) is associated with longer disease control. Therefore, improving VGPR rates and establishing predictors of VGPR to a given regimen may be an important clinical goal. High throughput quantitative proteomics may offer greater insight into the actual biology of the malignant cell than genome analysis and therefore, may be more useful in the development of personalized therapy. The objective of this study is to establish a proteomic signature predicting achievement of at least VGPR to initial treatment with bortezomib (Velcade®), pegylated liposomal doxorubicin, and dexamethasone (VDD). We previously reported preliminary proteomic profile of malignant plasma cells (PCs) obtained from a set of naïve MM pts enrolled in the VDD trial (Dytfeld et al., ASH 2009). Here we present the results of differential proteomic analysis of MM PCs of all available samples from the frontline VDD study (≥VGPR vs. <VGPR) using two independent and complementary quantitative proteomic platforms. We also compared the proteomic profile with gene expression data. Preliminary validation of the biomarkers of response prediction is presented. Methods: PCs were acquired from pre-treatment bone marrow specimens after obtaining informed consent from patients (pts), and were thereafter enriched with a RosetteSep® negative selection kit. Quantitative proteomic analysis of PCs from 17 naïve pts with MM from the VDD study was performed using iTRAQ approach in 8-plex variant. To increase confidence of analysis, label-free quantitative proteomics (LF) based on spectra counting was conducted on PCs from 12 pts. In iTRAQ experiments, proteins were processed with reagents according to the manufacturer's protocol followed by SCX fractionation and LC-MS/MS analysis (4800 Plus MALDI TOF/TOF). Peptides from the MM1S cell line were used as a reference. The data were analyzed using ProteinPilot™. For LF analysis, proteins were fractionated before trypsin digestion on Bis-Tris-Gel and subsequently run on LC-ESI-MS/MS on a linear trap mass spectrometer (LTQ Orbitrap). A database search was carried out using X!Tandem followed by Trans-proteomic Pipeline. At least 1.5-fold difference in expression in both platforms was used as a cut-off value. To correlate proteomics with gene expression of dysregulated proteins of interest, mRNA levels were analyzed by quantitative real time PCR (RT-PCR). Validation of proteomic findings on proteins of interest was performed using Western Blot. Results: We identified a total of 894 proteins in 3 iTRAQ experiments with high confidence (FDR<1%) and 1058 proteins by LF approach. Based on iTRAQ analysis, 20 proteins were found up-regulated in samples from pts with ≥VGPR (8 out of 17 pts) while 14 were down- regulated. Using LF approach, 284 proteins were elevated in the ≥VGPR group (6 out of 12 pts) while 315 proteins were down-regulated. Both iTRAQ and LF methods showed 15 differentially expressed proteins in common and 14 of them showed identical up or down trends. Interestingly, among differentially expressed proteins, there were proteins involved in proteasome activation (PSME1 and TXNL1), protection against oxidative stress (TXN and TXNDC5), glucose and cholesterol metabolism (TP1, APOA1 and ACAT1) and apoptosis (MX1). RT-PCR performed on a subset of genes confirmed the trend in differential expression between pts with ≥VGPR and <VGPR for TXNDC5 and PSME1. No change in mRNA expression levels was observed in TXN, APOA1, TPI1 and MX1while the trend in expression was reversed for ACAT1. Western blot analysis performed to date validated differential expression of PSME1. Conclusions: We present patient-derived proteomic characteristics of MM cells using two independent proteomic platforms. As a proof of concept, analysis of PCs obtained from pts enrolled in the frontline VDD study shows differential expression of 34 proteins in pts who achieved ≥VGPR vs. pts with <VGPR. Correlation with gene expression and further validation and functional analysis are in progress. This study was supported by a grant from the Multiple Myeloma Research Foundation. Disclosures: Jakubowiak: Millennium, Celgene, Bristol-Myers Squibb, Johnson & Johnson Ortho-Centocor: Honoraria; Millennium, Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Millennium, Celgene, Centocor-Ortho Biotech: Speakers Bureau.

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TRAF6 Dominant Negative Peptides Block Intracellular Signaling Resulting in Anti-Myeloma and Anti-Bone Resorptive Effects in Multiple Myeloma

Blood ◽

10.1182/blood.v118.21.2919.2919 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2919-2919

Author(s):

Mingjie Li ◽

Marissa P Dreyer ◽

Cameryn P Ahles ◽

David Ramirez ◽

Cydney M Nichols ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Cell Proliferation ◽

Tumor Cells ◽

Intracellular Signaling ◽

Conflicts Of Interest ◽

Cell Formation ◽

Osteoclast Formation ◽

Dominant Negative ◽

Rt Pcr

Abstract Abstract 2919 Tumor necrosis factor receptor-associated factor 6 (TRAF6) has been implicated in regulating the NF-kB and JNK signal transduction pathways; and, thus, is likely to promote tumor cell proliferation and osteoclast formation. We have previously reported inhibition of cell proliferation and increase of apoptosis in multiple myeloma (MM) cells through regulation of these intracellular pathways through silencing of TRAF6 C-domain mRNA. To determine TRAF6 protein expression in fresh MM tumor cells, we performed an immunofluorescence assay (IFA). The results showed that expression of this factor in tumor cells from bone marrow (BM) from MM patients with progressive disease is higher than in cells from patients with monoclonal gammopathies without disease progression or normal controls. We further examined the effects of TRAF6 negative dominant peptides on intracellular signaling pathways. Briefly, cells from the RPMI8226 or MM1s MM cell lines or primary MM BM samples were treated with or without TRAF6 inhibition peptide for 24 hours and then stimulated with either IGF1 (30ng/ml) or IL1 β (20ng/ml) for 30 minutes. The cells were lysed and Western blot analysis performed to determine protein phosphorylation and RT-PCR for gene expression. TRAF6 has been found to be an E3 ligase for Akt ubiquitination. We found that IGF1 increased the phosphorylation of AKT and treatment with TRAF6 inhibition peptide markedly decreased its phosphorylation compared to treatment with a control peptide in RPMI8226 and primary MM tumor cells. Downstream of AKT, C-Raf phosphorylation was also significantly reduced with treatment with TRAF6 inhibition peptide. Notably, cyclin D gene expression in MM tumor cells treated with TRAF6 inhibition peptide was reduced as determined with an RT-PCR. In contrast, the gene expression of mTOR was increased in RPMI8226 cells treated with TRAF6 inhibition peptide whereas there was no change in its expression in MM1s and primary MM tumor cells. It is quite possible that the increase in mTOR expression in RPMI8226 cells may act as a negative feedback which results from blockage of the ubiquitination of TRAF6. We further examined the effect of the TRAF6 inhibition peptide on NF-kB and JNK signaling as determined through evaluation of JUN kinase kinase (JNKK), which activates the MAP kinase homologues SAPK and JNK in response to IL-1 receptor stimulation. Phospho-NF-kB protein was reduced and phosphorylation of JNKK was clearly decreased with exposure to the TRAF6 inhibition peptide. We examined c-Jun, a component of the transcription factor complex AP-1, which binds and activates transcription at TRE/AP-1 elements. Total endogenous c-Jun is reduced following exposure of RPMI8226 cells to the TRAF6 inhibition peptide. Consistent with our past findings, TRAF6 inhibition peptide significantly inhibited osteoclast formation from CD14+ induced by RANKL and M-CSF with in a concentration dependent fashion whereas control peptides showed no effects on osteoclast formation. In addition, inhibition of the TRAF6 signaling blocked not only myeloma cell proliferation induced by AKT and NF-kB activation but also osteoclast cell formation mediated through transcription at TRE/AP-1 elements. The study has been extended to our SCID-hu murine model of human myeloma. Disclosures: No relevant conflicts of interest to declare.

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