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

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1801-1801
Author(s):  
Johannes Drach ◽  
Astrid Slany ◽  
Thomas Mohr ◽  
Johannes Griss ◽  
Christoph C Zielinski ◽  
...  

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.

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2880-2880
Author(s):  
Prashant Ramesh Tembhare ◽  
Constance Yuan ◽  
Neha Korde ◽  
Irina Maric ◽  
Katherine Calvo ◽  
...  

Abstract Abstract 2880 Background: The percent abnormal plasma cells (aPC) as determined by flow cytometry (FC) has been shown to be an independent risk factor for progression from myeloma precursor disease (monoclonal gammopathy of uncertain significance, MGUS; smoldering multiple myeloma, SMM) to multiple myeloma (MM). However, differentiation of aPCs from normal PCs (nPCs) in these patients is challenging. MM cell lines are know to underexpress the tetraspanin proteins (e.g. CD81, CD82) in comparison to nPCs. Although CD81, a nonglycosylated tetraspanin, is robustly expressed on the surface of nPCs, little information is available regarding its expression in the aPCs of MM, SMM and MGUS. In this study we evaluate the expression of CD81 in conjunction with CD19, CD45 and CD56 in bone marrow aPCs and nPCs from patients with MM, SMM and MGUS. Methods: Bone marrow aspirates from 41 patients (9 MGUS, 22 SMM, 7 MM, 3 non-neoplastic with clinical suspicion of MGUS) were analyzed with 8-color multiparametric FC using a panel of antibodies (CD138, CD38, CD19, CD20, CD27, CD28, CD45, CD56, CD81, CD13, CD14, CD16, CD3, CD34 and intracellular kappa & lambda light chains). The pattern of surface antigen and intracellular light chain expression was utilized to determine the percent aPC (defined as monoclonal with aberrant antigen expression) and percent nPC (defined as polyclonal with normal antigen expression). In all cases the pattern of antigen expression was evaluated in the aPCs; additionally, in cases with greater than 5% nPCs (19/41 patients: 8 MGUS, 8 SMM and 3 non-neoplastic) the pattern of antigen expression was evaluated in the nPCs. The ability to detect clonal aPC by evaluation of FC pattern of antigen expression was determined and compared for CD19, CD45, CD56 and CD81. We also examined the sensitivity and specificity of the CD19 and CD81 combination verses the conventional combination of CD19, CD56 and CD45 (Perez-Persona et al, Blood 2007) for the detection of clonal aPC. Results: CD81 was strongly expressed by nPC (average mean fluorescent intensity (MFI): 11500, standard deviation (SD): 5061, range: 5347–21657) in contrast to aPC with abnormally weak expression (average MFI: 1487, SD: 887, range: 647–4311). CD81 was a highly reliable marker for the detection of clonal PC; with 90% sensitivity and 100% specificity. It was the most specific and second most sensitive marker in our study (Table 1). CD81 was equally sensitive in detection of aPCs in MGUS, SMM and MM. Evaluation of the combined pattern of expression of CD19 and CD81 resulted in 100% sensitivity and 100% specificity for detection of aPC, which is greater than the conventional combination of CD19, CD56 and CD45, yielding 100% sensitivity but 90% specificity, for diagnostic evaluation of aPC. Conclusions: CD81 is a highly reliable marker in the detection of abnormal plasma cells in MM, SMM and MGUS. The combined approach of CD19 and CD81 is superior to other conventional marker combinations (i.e. CD19, CD45, and CD56) in terms of detection of clonal plasma cells and may replace their use in the clinical evaluation of bone marrow aspirates for plasma cell processes. Furthermore, it should help widening the applicability of minimal residual disease testing in MM. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 133 (23) ◽  
pp. 2484-2494 ◽  
Author(s):  
Tarek H. Mouhieddine ◽  
Lachelle D. Weeks ◽  
Irene M. Ghobrial

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma cell dyscrasia that consistently precedes multiple myeloma (MM) with a 1% risk of progression per year. Recent advances have improved understanding of the complex genetic and immunologic factors that permit progression from the aberrant plasma cell clone to MGUS and overt MM. Additional evidence supports bidirectional interaction of MGUS cells with surrounding cells in the bone marrow niche that regulates malignant transformation. However, there are no robust prognostic biomarkers. Herein we review the current body of literature on the biology of MGUS and provide a rationale for the improved identification of high-risk MGUS patients who may be appropriate for novel clinical interventions to prevent progression or eradicate premalignant clones prior to the development of overt MM.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Michael G. Alexandrakis ◽  
Parascevi Roussou ◽  
Constantina A. Pappa ◽  
Ippokratis Messaritakis ◽  
Athina Xekalou ◽  
...  

In multiple myeloma, there are many factors influencing the growth of the malignant clone in direct and indirect manners. BAFF is a growth factor for myeloma cells. The aim of the study was to measure its circulating levels in 54 pretreatment patients, along with serum levels of other proliferation markers, such as interleukins-6, -10, and -15, CRP, and beta-2 microglobulin, as well as bone marrow plasma cell infiltration and expression of Ki-67 PI, in various stages of the disease and after effective treatment in 28 of them. Serum levels of the previously mentioned factors were measured by ELISA, whereas bone marrow plasma cell infiltration and Ki-67 expression were estimated immunohistochemically. All measured parameters were higher in pretreated myeloma patients compared to healthy population and were also increasing with the progression of the disease. They all also decreased after effective therapy. Furthermore, all pretreatment values correlated to each other. BAFF seems to be an important growth factor for myeloma plasma cells. Measuring its serum levels, along with the previously mentioned cytokines, may provide important information regarding the degree of myeloma cells’ proliferation. Therefore, they all could be used as markers of proliferation and disease activity.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1783-1783
Author(s):  
Julie Abraham ◽  
Estelle Desport ◽  
Benoit Marin ◽  
Sebastien Bender ◽  
Corinne Lacombe ◽  
...  

Abstract Abstract 1783 Poster Board I-809 Purpose Hepatocyte Growth Factor (HGF) is a pro-angiogenic cytokine and a mitogenic, motogenic and morphogenic factor involved in tumor growth. Previous studies have shown that HGF is secreted by plasma cells in multiple myeloma and that HGF serum levels are higher in patients with multiple myeloma and correlate with disease activity. A previous study reported that serum HGF levels were significantly higher in patients with AL amyloidosis compared to patients with multiple myeloma (Iwasaki et al. Br J Haematol. 2002;116:796-802). A preliminary study of 18 AA and AL amyloidosis patients (Shikano et al, Intern Med. 2000;39:715-9) suggested that measurement of HGF might be useful for the diagnosis of amyloidosis. To determine whether HGF may be used as a relevant diagnosis marker and prognosis factor in AL amyloidosis, we have measured HGF serum levels in patients with AL amyloidosis and patients with plasma cell dyscrasia without amyloidosis. Patients and Methods Two groups of patients were included; patients with biopsy proven AL amyloidosis and patients with plasma cell dyscrasia (MGUS, multiple myeloma, POEMS) without amyloidosis as controls. Levels of HGF were measured by ELISA at diagnosis in the two groups, before any treatment (Quantikine® R&D Systems). Clinical features were recorded for AL patients. A Receiver Operating Characteristic curve (ROC) analysis was performed to assess the diagnostic accuracy of HGF for identification of amyloidosis cases among patients with monoclonal gammopathy. The area under the ROC curve (AUC) which can be interpreted as the probability that a randomly chosen amyloidosis patient has a test result greater than that of a randomly chosen non-amyloidosis patient, was calculated with its 95% confidence interval (95%CI). The ROC curve was also used to determine the best threshold for HGF. Using this threshold, sensitivity and specificity were calculated. Survival analyses were performed for patients suffering from AL amyloidosis. Baseline time was time from first HGF assessment to death or censoring date. Univariate analysis were done using Kaplan Meier and Cox proportional hazard models. Results Sixty-nine AL amyloidosis patients diagnosed between 2004 and 2008 and 76 controls (56 patients with MGUS, 17 with multiple myeloma, three with POEMS) were included. The median age was 61 (32-90) for AL patients and 60 (39-86) for controls. Median creatinine levels were respectively 86μmol/l (39-500) and 79μmol/l (44-317); 57 AL patients (82.6%) had renal involvement and 40 had (57.9%) cardiac disease. Monoclonal protein isotype was lambda in 69.6% of AL patients and kappa in 30.4%. HGF serum levels were significantly higher in patients with AL amyloidosis: 11.2ng/ml (0.5-200.4) compared with controls: 1.5ng/ml (0.8-8.2), p<0.0001 (healthy controls 0.9 ng/ml). HGF levels at diagnosis seemed to be discriminant with area under the ROC curve at 0.896 IC95% [0.834-0.94] p=0.0001. The threshold value of 2.4ng/ml conferred the best sensitivity : 82.6% IC95% [71.6-90.7] and specificity : 89.5% IC95% [80.3-95.3] for the diagnosis of AL amyloidosis. Patients were treated mainly by conventional chemotherapy (M-Dex), 65 % of AL patients were alive after a median follow up of 18 months. Univariate analysis showed a relative risk of mortality of 1.70 in AL patients with HGF levels upper than 11ng/ml, compared to those with HGF levels under 11 ng/l who showed a trend for better survival (p=0.22). Conclusion This study confirms that HGF levels are elevated in patients with AL amyloidosis, significantly higher than in patients with other plasma cell disorders. A threshold value of 2.4ng/ml confers a good sensitivity (80%) and specificity (90%) to suggest AL amyloidosis. HGF measurement may be used in patients with plasma cell dyscrasia to determine which patient should be considered for a biopsy. We found a trend towards reduced survival in patients with the highest levels of HGF. This, and the usefulness of HGF measurement in predicting clinical responses should be confirmed on larger studies. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1875-1875 ◽  
Author(s):  
Jawad Z. Sheqwara ◽  
Mohammad Alhyari ◽  
Shannon Keating ◽  
Philip Kuriakose

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is the most common form of plasma cell dyscrasia, with a prevalence of 3% in the general population above age of fifty. MGUS has a malignant evolution rate of 1% per year. Large longitudinal studies have suggested that virtually all patients diagnosed with multiple myeloma (MM) had a preceding MGUS, with 75 % having detectible Monoclonal (M) protein ≥8 years prior to diagnosis. It is important to identify the features at diagnosis that can predict neoplastic transformation to MM. Purpose We identified 239 patients at our institute in whom MGUS was diagnosed between 2000 and 2010. The presenting clinico-hematologic features were correlated with the frequency of evolution into MM to identify early predictors of evolution. The primary end point was progression to MM. Results The patients' mean age was 70.7 years. The Male/Female ratio was 0.7. The mean concentration of the M component (MC) was 0.7 g/dL. IgG was the most frequent MC (77%), followed by IgA (13%). The median ratio of MC protein to total protein was 0.5. Single or multiple background polyclonal (PC) suppression was noted in 36% of patients. PC suppression of 50% or more was noted in 20.1% of patients, 49.8% had < 50% and 30.1% had no suppression. Mean bone marrow plasma cell percentage was 4.5 percent and mean hemoglobin was 12.4 g/dL. Eighteen of the 239 patients with MGUS progressed into MM over ten years of follow up. Univariate comparisons of all variables between those who progressed and those who did not, showed that the initial concentration of the serum M protein, ratio of M protein to the total protein, number of PC gamma globulins suppressed, degree of PC suppression and IgM gamma globulin suppression were statistically significant risk factors that correlated with progression into MM. Fourteen out of eighteen patients with progressive disease had either PC suppression or background IgM suppression. Conclusions Monoclonal protein concentration, ratio of M protein to the total protein and abnormal serum free light chain ratio are simple variables that have been shown in multiple previous studies to predict the progression of MGUS into MM. In our study, we additionally found that number of PC suppressed, degree of suppression and IgM suppression are also key risk factors that can predict progression. We believe that these variables can be potentially applied into an approach that uses a detailed risk stratification system to predict which cases of MGUS will progress into MM and to provide more intensive monitoring for patients more likely to progress. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3133-3133 ◽  
Author(s):  
Carlos Fernández de Larrea ◽  
Adriana Zingone ◽  
Elisabet E. Manasanch ◽  
Neha Korde ◽  
Peter Wu ◽  
...  

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.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5338-5338
Author(s):  
Finella MC Brito-Babapulle ◽  
Tanya Cranfield ◽  
Robert B Corser ◽  
Helen Dignum ◽  
Christopher James ◽  
...  

Abstract Mouse eosinophils have been shown in 2011 to be required for the maintenance of long lasting plasma cells in the bone marrow and in maintaining the bone marrow plasma cell microenvironment. Human eosinophils have been shown by Wong et al to support multiple myeloma cell proliferation via a mechanism independent of IL6. We looked at bone marrow biopsies taken from patients who had a paraprotein and in whom a diagnosis of multiple myeloma was suspected. These samples were taken solely for the purposes of diagnosisng multiple myeloma and were retrospectively reviewed from the point of view of degree of eosinophil infiltration and its correlation with tumour load, bone lytic lesions, plasma cell morphology, whether blastic, crystalline inclusions, Mott cells, flame cells and or lymphoplasmacytoid. There were no cases of IGD or E myeloma or osteosclerotic myeloma.Nonsecretory myeloma and cases of light chain myeloma with or without amyloid were included in the series. Biopsies were not performed from osteolytic lesion unless biopsy was necessary to make a diagnosis of myeloma. Myeloma was diagnosed when plasma cell infiltrate was greater than 10% on bone marrow aspirate with a paraprotein and or lytic lesions. Eosinophil infiltration did not correlate with any of the tumour clinicopathological markers but showed an inverse correlation with degree of plasmacytosis. Eosinophils were hardly ever found in marrow aspirates that had over 70% plasma cells. They were usually found in trephine sections of bone marrow in areas where there was Grade I/II fibrosis and were often found in close proximity to focal areas of plasma cell infiltration. Whether eosinophils play a role in preventing or maintaining malignant plasma cell recurrence is currently being studied. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4808-4808
Author(s):  
Shuang Geng ◽  
Jing Wang ◽  
Mingyi Chen ◽  
Wenming Wang ◽  
Yuhong Pang ◽  
...  

Abstract Extramedullary Plasmacytoma (EMP) is a minor yet devastating metastatic form of Multiple Myeloma (MM), shortening patients' survival from 10 years to 6 months on average. Genetic cause of EMP in MM is yet to be defined. Transcriptome difference between EMP+ patients and EMP- patients is studied here on single cell level by RNA Sequencing (RNA-Seq). We sorted CD38+CD138+ malignant plasma cells from bone marrow and peripheral blood samples by flow cytometry, then picked up single malignant plasma cell and performed single cell RNA-Seq with SmartSeq2 protocol followed by Tn5-based library preparation from bone marrow, peripheral blood and extramedullary tissue of EMP patients. From the single cell RNA-Seq results, in bone marrow we found differential gene expression between EMP+ and EMP- samples, such as CTAG2, STMN1 and RRM2. By comparing circulating malignant plasma cells in PBMC and malignant plasma cell from the sample EMP+ patient, we observed metastatic clone in blood with the same VDJ immunoglobulin heavy chain as in bone marrow. Several genes' expression of these metastatic cells are down-regulated than in bone marrow, such as PAGE2, GTSF1, DICER1. These genes may correlate with egress capability of MM cells into peripheral to become circulating plasma cells (cPCs), and EMP eventually. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4373-4373
Author(s):  
Sandro Bräunig ◽  
Dimitra Zacharaki ◽  
Hongzhe Li ◽  
Hooi Ching Lim ◽  
Stefan Lang ◽  
...  

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.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2823-2823 ◽  
Author(s):  
Tilmann Bochtler ◽  
Ute Hegenbart ◽  
Christiane Heiss ◽  
Axel Benner ◽  
Stephanie Pschowski-Zuck ◽  
...  

Abstract Abstract 2823 Poster Board II-799 AL amyloidosis (AL) is characterized by the deposition of amyloid fibrils in diverse tissues due to an underlying monoclonal plasma cell dyscrasia. In a previous study (Bochtler et al, Blood 2008) we have demonstrated that in AL cytogenetic aberrations were detectable in about 90% of patients (pts). Translocation t(11;14) proved to be the most frequent aberration in AL found in 45% of the pts. In this study we evaluated whether the concept of hyperdiploidy and non-hyperdiploidy as major pathogenetic pathways in monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) is also applicable to AL. Our study was based on the largest patient group tested for cytogenetics in AL thus far including 184 pts with AL - among them 21 pts with concomitant MM I. They were assessed for their ploidy status by interphase fluorescence in situ hybridization (FISH). 179 MGUS and MM I pts not requiring therapy served as controls. We used a well established score (Wuilleme et al, Leukemia 2005), which requires extra copies for at least two out of the three probes 5p15/5q35, 9q34 and 15q22 as criterion for hyperdiploidy. The hyperdiploidy frequency was very low in AL with 14% as compared to 32% in MGUS / MM I (p<0.001). Among AL pts those with a concomitant MM I displayed a higher hyperdiploidy frequency than those without (43% versus 10%, p<0.001) suggesting that chromosomal gains reflect progression of the monoclonal plasma cell clone. Addressing hyperdiploidy probes in detail, we could show that both in the 184 pts. with AL and 179 pts. with MGUS / MM I gains of 11q23, 17p13 and 19q13.3 closely clustered with the three hyperdiploidy defining probes 5p15/5q35, 9q34 and 15q22 (p'0.01 for all probes after adjusting for multiple testing). However, gain of 11q23 was also frequently detected in association with t(11;14). The group with gain of 11q23 subdivides into a t(11;14) positive and a hyperdiploidy positive subgroup in both the AL (p<0.001) and the MGUS / MM I (p<0.001) entities. As revealed by additional probes for 11p15 and 11cen, gain of 11q23 in hyperdiploid pts reflected a gain of the whole chromosome 11 in all tested pts (10 AL and 31 MGUS / MM I). On the contrary, gain of 11q23 in t(11;14) positive pts was merely due to the translocation involving chromosome 11 (with 25 out of 26 AL and 5 out of 7 MGUS / MM I pts displaying a normal diploid status for 11p15 and 11cen). Therefore, gain of 11q23 is a poor indicator of hyperdiploidy in AL, where t(11;14) frequencies are particularly high and hyperdiploidy frequencies are particularly low. Addressing the cytogenetic clustering of hyperdiploidy with other cytogenetic aberrations we observed a strong inverse association of hyperdiploidy with t(11;14) in both AL and MGUS / MM I (p<0.001 in both entities). Accordingly, both aberrations were allocated to branches separating from each other already at the root in the oncogenetic tree model (see figure 1). Del13q14/t(4;14) and IgH translocations with an unknown partner also separated as distinct branches early from the root. These similar clustering patterns of both AL and MGUS / MM I with 4 major cytogenetic groups suggests common pathogenetic mechanisms in both entities despite their differing hyperdiploidy and t(11;14) frequencies. Disclosures: No relevant conflicts of interest to declare.


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