Transcriptome Alterations of Isolated Primary Bone Marrow Endothelial Cells Provide Insigt to MGUS and Multiple Myeloma Pathobiology

Multiple myeloma (MM) is characterized by an abnormal clonal expansion of plasma cells in the bone marrow, production of monoclonal immunoglobulins and finally organ damage (CRAB). The premalignant precursor of MM is Monoclonal gammopathy of undetermined significance (MGUS) and one percent of all MGUS patients progress to MM yearly. The bone marrow microenvironment is thought to play an important role in plasma cell growth, migration, and survival mainly via cytokine secretion and cell-cell interactions. Endothelial cells (ECs) are a major component in the bone marrow microenvironment, they regulate trafficking and homing of hematopoietic progenitor and stem cells. In MM increased bone marrow angiogenesis and recruitment of endothelial progenitors to the bone marrow niche has been reported. However, the specific EC contribution to myelomagenesis is not yet known. This study therefore aimed to investigate transcriptome alterations in prospectively isolated bone marrow ECs from MGUS and MM patients to identify possible disease-stage related changes. We isolated primary ECs from MGUS and MM patients undergoing diagnostic bone marrow aspirations and age-matched healthy donors by FACS. RNA from Lin- CD45- CD71- CD235a- CD271- CD31+ cells of MGUS (n=4) and MM (n=7) patients and healthy donors (n=6) was extracted. Sequencing was done using the Illumina® NextSeq 500/550 High Output Kit v2.5 (300 cycles). Gene expression analysis was performed in R. Differential gene expression analysis (DEseq2) identified 1,507 genes with p adjusted values below 1e-2 that were significantly differentially expressed between the three groups. Hierarchical clustering was done following Ward's method (ward.D2). Unsupervised clustering on the data showed that one MGUS-EC sample clustered with the healthy controls, and that one healthy control sample clustered with the MGUS samples. We therefore decided to restrict the analysis to those samples that clearly clustered separately, to be able to better depict the MGUS-, MM- and healthy EC specific profiles. Further clustering of differential expressed genes into 8 clusters revealed two especially interesting expression patterns. One cluster (#4) contained 102 genes that where higher expressed in the healthy controls with lower expression in MGUS and lowest expression in MM Samples. These genes thus reflect the downregulation during progression from a healthy bone marrow microenvironment to a reduced expression MGUS and further downregulation in MM. Another cluster (#6) showed the opposite pattern, with 105 genes being low or not expressed in healthy controls while the expression was higher in MGUS and highest in MM. Gene sets where further analyzed in the Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.8. Cluster 4 showed a high number of downregulated transmembrane genes. Six genes of the major histocompatibility complex conserved site where identified might indicate a possible immunomodulating effect in disease progression. Furthermore, within cluster 4 we identified a cluster of genes involved in cell adhesion and receptor binding. Cluster 6 most strikingly showed a group of 6 genes of the melanoma-associated antigen (MAGE) gene family that were upregulated with disease progression. MAGE genes which belong to the cancer-testis group of germline genes have previously been reported in MM, as being involved in tumorigenesis, and plasma cell MAGE expression has been associated with chemotherapy resistance. Furthermore, cluster 6 contained a high number of extracellular matrix genes, and genes for proteins having an extracellular region, respectively, hinting towards a differential microenvironment composition upon MM development. Taken together RNA sequencing analysis of prospectively isolated bone marrow endothelial cells identified genes that were specifically upregulated/suppressed in MM-ECs compared to MGUS-ECs and healthy donor-ECs. These genes thus represent potential gene candidates involved in the disruption of normal microenvironment function, thus leading to disease development and progression. Accordingly, studies are underway to investigate selected transcriptional deregulation EC-MM microenvironmental functions in the context of the disease. Disclosures No relevant conflicts of interest to declare.

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P-077: Bone marrow microenvironment analysis of exosomal microRNAs in multiple myeloma, extramedullary disease and plasma cell leukemia

Clinical Lymphoma Myeloma & Leukemia ◽

10.1016/s2152-2650(21)02211-4 ◽

2021 ◽

Vol 21 ◽

pp. S81

Author(s):

Jana Gregorova ◽

Monika Vlachova ◽

Lenka Radova ◽

Lucie Brozova ◽

Renata Bezdekova ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Bone Marrow Microenvironment ◽

Plasma Cell Leukemia ◽

Cell Leukemia ◽

Extramedullary Disease

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Levels of CEACAM6 in Peripheral Blood Are Elevated in Patients with Plasma Cell Disorders: A Potential New Diagnostic Marker and a New Therapeutic Target?

Disease Markers ◽

10.1155/2019/1806034 ◽

2019 ◽

Vol 2019 ◽

pp. 1-6

Author(s):

N. Steiner ◽

R. Hajek ◽

D. Nachbaur ◽

B. Borjan ◽

S. Sevcikova ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Adhesion Molecule ◽

Peripheral Blood ◽

Therapeutic Target ◽

Plasma Levels ◽

Diagnostic Marker ◽

Healthy Controls ◽

Plasma Cell Disorders

Introduction. The prognosis of multiple myeloma is still unfavorable due to inherent characteristics of the disease and the often-delayed diagnosis due to widespread and unspecific symptoms such as back pain and fatigue. Therefore, a simple diagnostic blood test would be helpful to speed up the diagnostic procedure in such patients (pts.). Here, we evaluated the diagnostic value of plasma levels of carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) in the peripheral blood and bone marrow of pts. with plasma cell disorders and in healthy controls. Materials and Methods. Immunoreactive CEACAM6 was determined in the peripheral blood and bone marrow (n=95/100) of pts. with monoclonal gammopathy of unknown significance (MGUS: 28/37), newly diagnosed multiple myeloma (NDMM: 42/40), and relapsed/refractory multiple myeloma (RRMM: 25/23) by sandwich ELISA. Results. Median CEACAM6 levels in the peripheral blood of pts. with plasma cell disorders were significantly higher than those of healthy controls (healthy controls: 15.2 pg/ml (12.1-17.1); MGUS: 19.0 pg/ml (16.4-22.5); NDMM: 18.0 pg/ml (13.4-21.2); and RRMM: 18.9 pg/ml (15.2-21.5); p<0.001). Plasma levels of CEACAM6 discriminated healthy subjects from MGUS/NDMM pts. (AUC=0.71, 95% CI: 0.6-0.8); i.e., a CEACAM6 level>17.3 pg/ml has an 82% (95% CI: 70-90) predictive probability for the identification of MGUS or NDMM. Moreover, CEACAM6 levels in the bone marrow were significantly higher in RRMM pts. than in NDMM pts. (p=0.04), suggesting a role of this molecule in disease progression. Conclusion. CEACAM6 plasma levels can noninvasively identify pts. with a plasma cell disorder and should be evaluated prospectively as a potential diagnostic marker. Moreover, due to high CEACAM6 levels in the bone marrow in RRMM pts., this adhesion molecule might be a therapeutic target in multiple myeloma pts.

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The Disease-Related Bone Marrow Microenvironment Alters Hematopoietic Stem and Progenitor Function in Multiple Myeloma Patients

Blood ◽

10.1182/blood.v118.21.2898.2898 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2898-2898

Author(s):

Ingmar Bruns ◽

Ron-Patrick Cadeddu ◽

Ines Brückmann ◽

Sebastian Buest ◽

Julia Fröbel ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Progenitor Cells ◽

Bone Marrow Microenvironment ◽

Tgf Beta ◽

Hematopoietic Stem ◽

Healthy Donors ◽

Stem And Progenitor Cells ◽

Related Bone Marrow

Abstract Abstract 2898 Multiple myeloma (MM) patients often suffer from hematopoietic impairment already at the time of diagnosis with anemia as the prevailing symptom. Given the overt affection of the bone marrow in MM patients by the invasion of malignant plasma cells, we hypothesized that hematopoietic insufficiency in these patients may originate from a functional impairment of hematopoietic stem and progenitor cells. Quantitative analysis of BM CD34+ HSPC cell subsets from MM patients and age-matched healthy donors showed a significant decline of all HSPC subsets including hematopoietic stem cells, common myeloid and lymphoid progenitors, granulocyte-macrophage progenitors and megakaryocyte-erythrocyte progenitors in MM patients. The greatest diminution was observed in megakaryocyte-erythrocyte progenitors (MEP) which were 4.9-fold reduced in comparison to healthy donors. Transcriptional analyses of CD34+ HSPC subsets revealed a significant deregulation of signaling pathways that was particularly striking for TGF beta signaling and suggested increased activation of this signaling pathway. Immunhistochemical staining of phosphorylated smad2, the downstream mediator of TGF receptor I kinase activation, in bone marrow sections and immunoblotting of purified CD34+ HSPC of MM patients confirmed the overactivation of TGF beta signaling. On a functional level, we observed significantly reduced long-term self-renewal and clonogenic growth, particularly of the erythroid precursors BFU-E and CFU-E, in CD34+ HSPC of MM patients which could be restored by inhibition of TGF beta signaling. Proliferation and cell cycle analyses revealed a significantly decreased proliferation activity in CD34+ HSPC and, particularly, MEP. Again, this was reversible after inhibition of TGF beta signaling. In addition, the transcriptional analyses showed disturbance of pathways involved in the adhesion and migration of HSPC and the gene encoding for the principal hyaluronan receptor CD44 throughout the HSPC subsets. This was corroborated by immunofluorescence imaging of CD44 on HSPC subsets showing a marked downregulation in the patients' cells. In line, the adhesion of CD34+ HSPC subsets to hyaluronan and their migration towards SDF-1 was significantly inhibited. Subsequent xenotransplantation of CD34+ HSPC from MM patients and healthy donors into myeloma-free recipients revealed even increased long-term engraftment of CD34+ HSPC obtained from MM patients and normal differentiation capacities suggesting that the observed functional alterations in fact depend on the MM-related bone marrow microenvironment. Our data show that hematopoietic impairment in patients with multiple myeloma originates, at least in part, from functional alterations of hematopoietic stem and progenitor cells. These alterations seem to depend on the disease-related changes of the bone marrow microenvironment. Currently, experiments are underway to elucidate in more detail the role of the microenvironment and the responsible structures for the impairment of HSPC in MM patients. These data will be presented. Disclosures: Kobbe: Celgene: Consultancy, Research Funding; Ortho Biotec: Consultancy.

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Aberrant Expression Of miRNA and mRNA Of Cell Cycle and Adhesion-Related Genes In Bone Marrow Stroma Cells Derived From Patients With Multiple Myeloma

Blood ◽

10.1182/blood.v122.21.3149.3149 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3149-3149 ◽

Cited By ~ 3

Author(s):

Rimma Berenstein ◽

Blau Igor Wolfgang ◽

Axel Nogai ◽

Marlies Wächter ◽

Antonio Pezzutto ◽

...

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Multiple Myeloma ◽

Bone Marrow ◽

Genetic Alterations ◽

Bone Marrow Stroma ◽

Aberrant Expression ◽

Healthy Donors ◽

Marrow Stroma ◽

Bone Marrow Stroma Cells

Abstract Multiple myeloma (MM) is a B-cell malignancy characterized by accumulation of malignant plasma cells (PC) within the bone marrow. The bone marrow microenvironment such as bone marrow stroma cells (BMSC) supports MM disease progression, resistance to chemotherapy, protects the tumor cells against apoptosis and causes osteolytic bone disease and angiogenesis. The aim of this study was to identify constitutive genetic alterations in BMSC derived from patients with MM (MM-BMSC) in comparison to BMSC from healthy donors. For BMSC selection, mononuclear cells were isolated from fresh bone marrow aspirates and were further expanded in cell culture. We studied 25 MM patients and 5 healthy donors. Senescence status was determined in passage 1 of cell cultures. MM-BSMC displayed a considerably higher percentage of senescence cells (p<0,05). We investigated the expression of cell cycle and adhesion-associated genes (CCNE1, CCND1, CDKN1B, VCAM, ICAM, IKK-alpha) in BMSC (passage 4) using SYBR-Green Real-Time PCR and relative quantification by linear regression. A downregulation of CCNE1 (p=0,05), CDKN1B (p=0,29), and an upregulation of CCND1 (p=0,05), VCAM-1 (p=0,33), ICAM-1 (p=0,33), and IKK-alpha (p=0,05) was demonstrated. Furthermore, the expression profile of miRNAs, targeting the analyzed mRNA genes or correlating with senescence, was studied (miR-16, miR-221, miR-126, miR-223, miR-485-5p and miR-519d). For miRNA detection treatment with Poly(A)-Polymerase and cDNA-Synthesis with a Poly(T)VN-Adaptor primer were carried out following an amplification with an universal reverse primer corresponding to the adaptor sequence and a miRNA-specific primer. miR-16, miR-223, miR-485-5p and miR-519d were significantly upregulated, (p=0,02; p=0,004; p=0,02; and p=0,002, respectively), whereas miR-221 and miR-126 showed no considerable differences to BMSC obtained from healthy donors. Next we investigated incubation of immunmodulatory drug Lenalidomid in BMSC cultures. Cells were treated with 10 µM Lenalidomid over 72 hours and expression was normalized to a 0,01 % DMSO control. Significant difference in gene expression were visible for ICAM-1 (p=0,01). For CDKN1B (p=0,16) and VCAM-1 (p=0,12) we demonstrated changes in gene expression. Our results indicate aberrant expression of cell cycle and adhesion-related genes, such as CCNE1, CCND1 and CDKN1B VCAM-1, ICAM-1 and IKK-alpha in MM-BMSC as compared with healthy donors. Furthermore, we found significant upregulation of miR-16, miR-223, miR-485-5p and miR-519d. Further investigation are needed to determine molecular mechanisms in MM-BMSC and PC interaction that lead to constitutive changes in BMSC characteristics and gene expression patterns. Disclosures: No relevant conflicts of interest to declare.

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Plasma Circulating Proteasomes As Biomarkers Along Natural History Of Asymptomatic Monoclonal Gammopathies

Blood ◽

10.1182/blood.v122.21.3133.3133 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3133-3133 ◽

Cited By ~ 1

Author(s):

Carlos Fernández de Larrea ◽

Adriana Zingone ◽

Elisabet E. Manasanch ◽

Neha Korde ◽

Peter Wu ◽

...

Keyword(s):

Risk Factors ◽

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Mayo Clinic ◽

M Protein ◽

Current Time ◽

Monoclonal Gammopathies ◽

Chymotrypsin Activity ◽

Healthy Donors

Abstract Background Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic plasma cell dyscrasias with a heterogeneous probability to progress to symptomatic multiple myeloma (MM). Reliable markers for progression to MM are vital to advance the understanding of myeloma precursor disease and for the development of intervention trials designed to delay/prevent MM. The Mayo Clinic and Spanish PETHEMA have proposed models to stratify patient risk based on clinical parameters. At the current time, no molecular biomarkers have been established to determine risk of transformation. Based on the fact that MM tumor cells are highly sensitive to proteasome inhibition and that circulating proteasomes (cProt) have been detected in the blood of MM patients, we conducted a prospective clinical study designed to characterize patterns of cProt in peripheral blood from MGUS, SMM and MM patients. Patients and Methods Ninety two patients diagnosed with asymptomatic monoclonal gammopathies (39 MGUS and 53 SMM; median age 63 years; 46M/47F) were studied. This group was compared to normal sera from healthy donors (n=6) and untreated patients with recent diagnosed MM (n=38). Initial baseline demographics, clinical and laboratory data were collected. MGUS patients were classified according to Mayo Clinic risk score (M-protein, monoclonal isotype and serum FLC), while SMM could be stratified according to PETHEMA (malignant bone marrow plasma cell (BMPC) percentage and immunoparesis) and Mayo system (BMPC infiltration, serum M-protein and serum FLC). Plasma and bone marrow supernatant samples were collected at diagnosis and frozen to -80ºC. In 58 MGUS and SMM cases, sequential plasma samples at 6 months and 1 year were also analyzed. Chymotrypsin-like, caspase-like, and trypsin-like activities from cProt were assayed by continuously monitoring the production of 7-amino-4-methylcoumarin (AMC) from fluorogenic peptides by plasma. Briefly, samples were activated with SDS (for chymotrypsin-like and caspase-like) or 10% Tween-20 (for trypsin-like). The reaction wells contained 30 μL assay buffer (25 mmol/L HEPES), 10 μL activated sample, and 10 μL of the prospective fluorogenic peptide-AMC substrate. To measure the fluorescence release of free AMC with time, the SpectraMax M5 (Molecular Devices) instrument was used with a read interval of 1 min during 30 min at 37ºC. All samples were performed by triplicate. Enzymatic activities were quantified (pmol AMC/s/mL plasma) by generating a standard curve of AMC. Results MGUS patients had zero (38.5%), one (41%) or two risk factors (20.5%) according to the Mayo Clinic model. In contrast, 49% of the patients with SMM were classified as high-risk according to the PETHEMA model, versus 69.8% with 2 or 3 risk factors in the Mayo Clinic model. Chymotrypsin activity levels in plasma were statistically correlated with serum M-protein concentration and total IgG concentration (p<0.001). Chymotrypsin-like activity was differentially expressed in plasma across the different groups of patients (p=0.009; Figure 1). Particularly, SMM and MM showed higher levels than healthy controls and MGUS patients. In SMM, patients with highest-risk of transformation showed a higher levels of this chymotrypsin-like activity than the other groups (p=0.02). When only IgG SMM and MGUS patients were considered, a correlation with immunoparesis (reduction of IgM and IgA), BMPC infiltration, relative lower hemoglobin levels and higher FLC ratio (p<0.05) was observed. Caspase-like activity was also associated with diagnosis, showing higher levels in symptomatic and SMM patients than healthy donors and MGUS (p=0.016) (Figure 2) and correlated with IgG and serum M-protein (p=0.01 and p=0.006). In contrast, trypsin-like levels were negatively correlated along the spectrum of tumoral mass in the four groups (p=0.004) (Figure 3). Bone marrow supernatant chymotrypsin activity was higher in symptomatic MM than MGUS patients (p=0.004), with a trend for caspase. Conclusion Chymotrypsin-and caspase-like activity of circulating proteasome in asymptomatic gammopathies is related to tumoral mass and immunoparesis degree. MGUS patients are close to healthy individuals, with SMM not so different than symptomatic patients. Prognostic significance of these findings after longer follow-up is warranted. Disclosures: No relevant conflicts of interest to declare.

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Angiogenesis in Multiple Myeloma (MM): Angiogenic Switch or Reflexion of Plasma Cell Number? A Gene Expression Based Survey in Primary Myeloma Cells and the Bone Marrow Microenvironment.

Blood ◽

10.1182/blood.v108.11.3405.3405 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3405-3405

Author(s):

Dirk Hose ◽

John DeVos ◽

Christiane Heiß ◽

Jean-Francois Rossi ◽

Angela Rösen-Wolff ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Plasma Cell ◽

Empirical Bayes ◽

Plasma Cells ◽

De Novo ◽

Cell Number ◽

Bone Marrow Microenvironment ◽

Myeloma Cells ◽

Angiogenic Switch

Abstract BACKGROUND. Angiogenesis is a hallmark of active multiple myeloma. However, two etiologic hypotheses have been proposed: an angiogenic switch (i.e. differential or de novo expression of pro/antiangiogenic genes in MM), and, alternatively an effect of increased plasma cell number. AIM of this study was to investigate the angiogenic signature of multiple myeloma cells (MMC), normal bone marrow plasma cells (BMPC), the bone marrow microenvironment (BMME) and cellular subfractions therein. PATIENTS AND METHODS. 128 newly diagnosed MM-patients (65 training (TG) / 63 independent validation group (VG)) and 14 normal donors (ND) were included. Bone marrow aspirates were CD138-purified by activated magnetic cell sorting. Whole bone marrow (n=49) and FACSAria sorted subfractions thereof (n=5) were investigated. RNA was in-vitro transcribed and hybridised to Affymetrix HG U133 A+B GeneChip (TG) and HG U133 2.0 plus arrays (VG). Expression data were gcrma-normalised and the empirical Bayes algorithm used. p-Values were adjusted using the Benjamini-Hochberg method (Bioconductor). iFISH was performed on purified MM-cells using probesets for chromosomes 1q21, 9q34, 11q23, 11q13, 13q14, 15q22, 17p13, 19q13, 22q11 and the translocations t(4;14) and t(11;14). HGF expression was verified by real time RT-PCR and western blotting. Based on Medline review, we established a list of 89 pro- and 56 antiangiogenic genes and investigated their expression according to the stage of disease: BMPC vs. MGUS, SD stage I (asymptomatic myeloma) vs. SD stage II/III (symptomatic myeloma requiring therapy). RESULTS. BMPC express pro- (e.g. VEGFA) and antiangiogenic genes (e.g. TIMP2). Only one pro-angiogenic gene (hepatocyte growth factor, HGF) is significantly overexpressed in MMC compared to BMPC. HGF has previously been linked with myeloma progression and induction of angiogenesis. Six antiangiogenic genes (TIMP2, SERPINF1, COL18A1, PF4, THBS1, CXCL14) are downregulated in MMC compared with BMPC. Compared to healthy donors, the BMME of MM shows a significant downregulation of PLAU (urokinase, antiangiogenic) and upregulation of TNF(proangiogenic). CONCLUSION. Upregulation of HGF-expression, downregulation of TIMP2, SERPINF1, COLA18A1, PF4, THBS1 and CXCL14 expression in MMC as well as downregulation of PLAU and upregulation of TNFα in the BMME seem to indicate an “angiogenic switch”. However, given the relatively low number of differentially expressed genes (7/145) and the expression of angiogenic genes by BMPC, an effect caused by an increasing number of plasma cells might be evenly important.

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Secretome Analyses of Primary Bone Marrow Fibroblasts Isolated From MGUS and Multiple Myeloma Show a Stepwise Occurrence of Alterations.

Blood ◽

10.1182/blood.v114.22.1801.1801 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1801-1801

Author(s):

Johannes Drach ◽

Astrid Slany ◽

Thomas Mohr ◽

Johannes Griss ◽

Christoph C Zielinski ◽

...

Keyword(s):

Multiple Myeloma ◽

Bone Marrow ◽

Growth Factor ◽

Plasma Cell ◽

Conflicts Of Interest ◽

Cell Clone ◽

Serum Levels ◽

Plasma Cell Dyscrasia ◽

Healthy Donors ◽

Bone Marrow Fibroblasts

Abstract Abstract 1801 Poster Board I-827 The microenvironment of tumor cells in the bone marrow was demonstrated to contribute to tumor promotion and survival. The role of bone marrow fibroblasts (BMFs) in supporting the malignant plasma cell clone in multiple myeloma (MM) has been established, but it remains unclear to which extent the BM microenvironment in general and BMFs in particular are involved in the progression of monoclonal gammopathy of undetermined significance (MGUS) to MM. Therefore we performed proteomics studies on the secretome of BMFs isolated from healthy donors, patients suffering from MGUS and patients suffering from MM. Compared to normal background, BMFs derived from MGUS secreted elevated levels of proteins indicating mitogenic activity and moderate inflammation. These proteins included periostin, IL-6, CXCL5 and CSF-1. Insulin-like growth factor II, which is normally not expressed by normal BMFs, was secreted by BMF cells derived from MGUS as well as from MM. In addition to those and other proteins, BMF cells derived from MM were found to specifically secrete stem cell growth factor, MMP-28 and stanniocalcin-1. These data indicate a step-wise alteration of BMF secretion activity related to the stage of the underlying plasma cell dyscrasia. Therefore BMF might support the progression from MGUS to MM. In order to correlate the secretion performance of BMF with blood serum levels of candidate marker proteins, Luminex assays are employed. Based upon these results, it is our aim to identify serum biomarkers which allow to assess the functional state of BMF and thus the risk for the progression of MGUS to MM. Disclosures No relevant conflicts of interest to declare.

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A Novel Role For Histone Deacetylase 11 (HDAC11) In Plasma Cell Differentation and Survival

Blood ◽

10.1182/blood.v122.21.1907.1907 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1907-1907

Author(s):

Eva Sahakian ◽

Jason B. Brayer ◽

John Powers ◽

Mark Meads ◽

Allison Distler ◽

...

Keyword(s):

Gene Expression ◽

Multiple Myeloma ◽

Bone Marrow ◽

B Cells ◽

Plasma Cell ◽

Research Funding ◽

Plasma Cells ◽

Myeloma Cells ◽

Peripheral Blood Plasma

Abstract The role of HDACs in cellular biology, initially limited to their effects upon histones, is now appreciated to encompass more complex regulatory functions that are dependent on their tissue expression, cellular compartment distribution, and the stage of cellular differentiation. Recently, our group has demonstrated that the newest member of the HDAC family of enzymes, HDAC11, is an important regulator of IL-10 gene expression in myeloid cells (Villagra A Nat Immunol. 2009). The role of this specific HDAC in B-cell development and differentiation is however unknown. To answer this question, we have utilized a HDAC11 promoter-driven eGFP reporter transgenic mice (TgHDAC11-eGFP) which allows the monitoring of the dynamic changes in HDAC11 gene expression/promoter activity in B-cells at different maturation stages (Heinz, N Nat. Rev. Neuroscience 2001). First, common lymphoid progenitors are devoid of HDAC11 transcriptional activation as indicated by eGFP expression. In the bone marrow, expression of eGFP moderately increases in Pro-B-cells and transitions to the Pre- and Immature B-cells respectively. Expression of eGFP doubles in the B-1 stage of differentiation in the periphery. Of note, examination of both the bone marrow and peripheral blood plasma cell compartment demonstrated increased expression of eGFP/HDAC11 mRNA at the steady-state. These results were confirmed in plasma cells isolated from normal human subjects in which HDAC11 mRNA expression was demonstrated. Strikingly, analysis of primary human multiple myeloma cells demonstrated a significantly higher HDAC11 mRNA expression in malignant cells as compared to normal plasma cells. Similar results were observed in 4/5 myeloma cell lines suggesting that perhaps HDAC11 expression might provide survival advantage to malignant plasma cells. Support to this hypothesis was further provided by studies in HDAC11KO mice in which we observed a 50% decrease in plasma cells in both the bone marrow and peripheral blood plasma cell compartments relative to wild-type mice. Taken together, we have unveiled a previously unknown role for HDAC11 in plasma cell differentiation and survival. The additional demonstration that HDAC11 is overexpressed in primary human myeloma cells provide the framework for specifically targeting this HDAC in multiple myeloma. Disclosures: Alsina: Millennium: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Baz:Celgene Corporation: Research Funding; Millenium: Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Karyopharm: Research Funding; Sanofi: Research Funding.

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