High GRP78 (78-kDa Glucose-Regulated Protein) Expression Predicts for a Favorable Clinical Outcome in Patients with Multiple Myeloma and May be a Potentially Useful Therapeutic Target in the Treatment of Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4206-4206 ◽  
Author(s):  
Hang Quach ◽  
Daniel North ◽  
Susanna Freddi ◽  
Shuh Y Tan ◽  
Lenny Straszkowski ◽  
...  

Abstract Background: GRP78 (78-kDa glucose-regulated protein) is a molecular chaperone that is upregulated during cellular stress. It has been well demonstrated that GRP78 upregulation is associated with chemoresistance and metastasis in solid tumours. GRP78 has not been widely explored in multiple myeloma (MM), however, we and others have shown that GRP78 is much more overexpressed in myeloma cell lines compared to other cell lines. To assess the clinical relevance of GRP78 overexpression in MM, we investigated the association of plasma cell GRP78 expression on primary bone marrow (BM) trephines to clinical outcome in patients with MM, and correlate this finding to concurrent in vitro studies to investigate the potential usefulness of targeting GRP78 for the treatment of MM. Method: The degree of GRP78 expression within CD138+ plasma cells was assessed by immunohistochemistry (IHC) on archived bone marrow trephines of patients with newly diagnosed MM, who underwent autologous stem cell transplant (ASCT) at St.Vincent's Hospital Melbourne. Independent assessment of GRP78 was performed by 3 hematopathologists, who underwent initial calibration. The degree of GRP78 expression within plasma cells was assigned as low, medium or high. Clinical data was abstracted from medical records of the corresponding patients with respect to baseline demographics, treatment-response, progression free survival (PFS), time to next treatment (TTNT) and overall survival (OS). The association GRP78 expression to each of these clinical parameters was assessed using Kaplan-Meier product limit method and the Mantel-Cox logrank test. In vitro, GRP78 expression was also quantified in various myeloma cell lines by RT-PCR and western blot. The association of GRP78 expression to MM-cell survival and drug resistance was assessed in vitro. The impact of GRP78 inhibition on reversal of drug resistance and myeloma-cell viability was investigated. Result: Between the years 2000 to 2014, a total of 243 patients with newly diagnosed MM underwent ASCT as part of initial therapy, and were included in the study. Baseline bone marrow trephine was available for CD138 and GRP78 staining for 91 patients. Of these, 20, 42 and 34% of patients had low, medium and high expression of GRP78 within BM plasma cells, respectively. Low GRP78 expression was associated with a shorter PFS (HR 2.4, p=0.0006) and shorter TTNT (HR 2.5, p=0.008) compared to intermediate or high GRP78 expression. No significant difference was seen in OS. High GRP78 correlated with a higher probability of achieving CR (p=0.03). In vitro, inhibition of GRP78 resulted in decreased myeloma cell viability, and sensitized myeloma cells to various antimyeloma agents. As a result, synergistic anti-myeloma activity was seen when GRP78 inhibition was combined with melphalan (synergy quotient (SQ) 1.2), dexamethasone (SQ 1.97) and especially bortezomib (SQ 2.06). Conclusion: In contrast to what is reported for solid tumours in the literature, higher GRP78 expression appeared to predict for a more favorable clinical outcome in patients with MM. In vitro, GRP78 inhibition resulted in significant anti-myeloma effects and increased the antimyeloma activity of various agents especially bortezomib. Together, these findings suggest that GRP78 is potentially a useful biomarker and therapeutic target that warrants further investigation in patients with MM. Disclosures Quach: Celgene Corp, ONYX, Janssen, Takeda, Novartis, BMS: Honoraria, Research Funding.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1419-1419
Author(s):  
Soraya Wuilleme-Toumi ◽  
Nelly Robillard ◽  
Patricia Gomez-Bougie ◽  
Philippe Moreau ◽  
Steven Le Gouill ◽  
...  

Abstract Multiple Myeloma (MM) is a fatal malignancy of B-cell origin characterized by the accumulation of plasma cells within the bone marrow. The expression of the pro-survival members of the Bcl-2 family has been shown to be a key process in the survival of myeloma cells. More particularly, Mcl-1 expression turned out to be critical for their survival. Indeed, knockdown of Mcl-1 by antisenses induces apoptosis in myeloma cells. Finally, Mcl-1 was found to be the only anti-apoptotic Bcl-2 family member which level of expression was modified by cytokine treatment of myeloma cells. For these reasons, we have evaluated the expression of Mcl-1 in vivo in normal, reactive and malignant plasma cells (PC) i.e., myeloma cells from 55 patients with MM and 20 human myeloma cell lines using flow cytometry. We show that Mcl-1 is overexpressed in MM in comparison with normal bone marrow PC. Forty-seven percent of patients with MM at diagnosis (p=.017) and 80% at relapse (p=.014 for comparison with diagnosis) overexpress Mcl-1. Of note, only myeloma cell lines but not reactive plasmocytoses have abnormal Mcl-1 expression, although both plasmocyte expansion entities share similar high proliferation rates (>20%). Of interest, Bcl-2 as opposed to Mcl-1, does not discriminate malignant from normal PC. This shows that the overexpression of Mcl-1 is clearly related to malignancy rather than to proliferation. It will be important to know whether the overexpression of Mcl-1 is related to an abnormal response to cytokines like Interleukin-6 or to mutations of the promoter of the Mcl-1 gene as already described in B chronic lymphocytic leukemia. Finally, level of Mcl-1 expression is related to disease severity, the highest values being correlated with the shortest event-free survival (p=.01). In conclusion, Mcl-1 which has been shown to be essential for the survival of human myeloma cells in vitro is overexpressed in vivo in MM and correlates with disease severity. Mcl-1 represents a major therapeutical target in MM.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2701-2701
Author(s):  
Anja Seckinger ◽  
Tobias Meißner ◽  
Jérôme Moreaux ◽  
Hartmut Goldschmidt ◽  
Axel Benner ◽  
...  

Abstract BACKGROUND: Pathogenesis of multiple myeloma is partly attributed to an aberrant expression of proliferation-, pro-angiogenic and bone-metabolism modifying factors by malignant plasma-cells. AIM. Given the long and variable time-span from first diagnosis of early-stage plasma-cell dyscrasias to overt myeloma and the low proliferation rate of malignant plasma-cells, we hypothesize these to concomitantly express a novel class of anti-proliferative factors of potential prognostic relevance. Here, bone morphogenic proteins (BMPs) represent possible candidates, as they inhibit proliferation, stimulate bone formation, and have an impact on the survival of cancer patients. PATIENTS AND METHODS. We assessed expression of BMPs and its receptors by Affymetrix DNA-microarrays (n=434) including CD138-purified primary myeloma-cell-samples, normal bone-marrow plasma-cell-samples, polyclonal plasmoblasts-samples, human myeloma-cell-lines (HMCL), and whole bone-marrow. Presence and differential gene expression was determined by PANP-algorithm and empirical Bayes statistics. Event-free (EFS) and overall survival (OAS) were investigated for the 168 patients undergoing high-dose chemotherapy (HM-group) using Cox’s proportional hazard model. Findings were validated using the same strategy on an independent group of 345 patients from the Arkansas-group. For validation, quantitative real-time PCR and flow cytometry were performed. In vitro induction of angiogenesis was assessed using the AngioKit-assay. Effect of BMP6 on proliferation of HMCL was assessed by 3H-thymidine uptake. RESULTS. BMP6 is the only BMP expressed by normal- (13/14 samples) and malignant plasma-cells (228/233 samples). It is significantly lower expressed in proliferating non-malignant plasmablastic cells and human myeloma cell-lines. In vitro, BMP6 significantly inhibits proliferation of myeloma-cell-lines with an IC50 ranged from 0.08–2.15μg/ml, survival of primary myeloma-cells, and in vitro tubule formation down to the level of the negative control. High BMP6-expression in malignant plasma cells delineates significantly superior overall-survival for patients undergoing high-dose chemotherapy in both independent series of patients (n=168, P=.02 and n=345, P=.03, respectively, see below). CONCLUSION. With BMP6 we report for the first time the autocrine expression of a prognostically relevant anti-angiogenic and anti-proliferative factor and its receptors by normal and malignant plasma-cells. Figure Figure


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4462-4462
Author(s):  
Xiu Ly Song ◽  
Raphaël Szalat ◽  
Alexis Talbot ◽  
HaiVu Nguyen ◽  
Mehmet K. Samur ◽  
...  

Abstract In Multiple Myeloma (MM), the t(4;14) translocation is associated with a poor outcome. However, beside this translocation, the genetic events which determine the adverse evolution of the disease and the resistance to treatments remain elusive. In this study we performed whole exome or RNA sequencing analysis of samples from 65 newly diagnosed t(4;14) MM. We found that NRAS, KRAS, MAPK and FGFR3 are frequently mutated (12%, 9%, 13.8%, and 20% respectively). Overall, the FGFR3/RAS/BRAF/MAPK genes were mutated in 36 cases (54%). There was a negative correlation between mutations in FGFR3 and those occurring in NRAS, KRAS and BRAF as expected from the mutually exclusive occurrence of mutations in these genes. In addition to alterations in TP53 and DIS3, we found marked elevated frequency of mutations in PRKD2 (10.7%), ATM/ATR (10.7%) and MYCBP2 (7.6%), reduced frequency in FAM46C (1.5%) and no mutation in TRAF3 and CCND1. Mutations in ATM/ATR were strongly associated with the MB4-2 breakpoint (Bp) (p = 1.62 10-4) and significantly correlated with mutations affecting genes coding for members of the MAPK family. We observed a positive correlation between non-silent mutations in PRKD2 and the MB4-1 or MB4-3 Bp (p = 1.3 10-2). Of note, PRKD2 mutations are exclusively found in 3 t(4;14) MM cell lines and among the 84 MM sequenced by Bolli et al. (1), none of the non t(4;14) patient were mutated in PRKD2, indicating that this genetic lesion is associated with t(4;14) MM. In the NCI-H929 t(4;14) MM cell line, which is mutated for PRKD2, encoding the PKD2 serine/threonine kinase, we observed elevated levels of phosphorylated PKD2. Furthermore, inhibition of PKD, decreased PKD2 phosphorylation and triggered reduced proliferation and apoptosis of MM cell lines and fresh plasma cells from patients in vitro. These results define a specific mutational landscape for t(4;14) MM and identify PKD2 as a potential therapeutic target in MM patients. Altogether, these results define a specific mutational landscape for t(4;14) MM and identify PKD2 as a potential therapeutic target in MM patients. Reference 1. Bolli, N., Avet-Loiseau, H., Wedge, D.C., Van Loo, P., Alexandrov, L.B., Martincorena, I., Dawson, K.J., Iorio, F., Nik-Zainal, S., Bignell, G.R., et al. (2014). Heterogeneity of genomic evolution and mutational profiles in multiple myeloma. Nat Commun 5, 2997. Disclosures Munshi: Janssen: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Amgen: Consultancy; Merck: Consultancy; Pfizer: Consultancy; Oncopep: Patents & Royalties.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3820-3820
Author(s):  
Yi Tao ◽  
Zhimin Gu ◽  
Ye Yang ◽  
Hongwei Xu ◽  
Xiaojing Hu ◽  
...  

Abstract Background We have recently established that increased chromosomal instability (CIN) signature is linked to drug resistance and poor outcome in multiple myeloma (MM) and other cancers. Thyroid Hormone Receptor Interactor 13 (Trip13), one of the 56 drug-resistant genes, plays a key role in chromosomal recombination and structure development during meiosis and has been reported to be increased in some malignancies including lung cancer, prostate cancer and breast cancer. In this study, we investigated how important Trip13 is in myelomagenesis and progression. Materials and Methods Gene expression profiling (GEP) was analyzed on plasma cells from 22 healthy donors, 44 patients with monoclonal gammopathy of undetermined significance (MGUS), 351 patients with newly diagnosed multiple myeloma, and 9 human myeloma cell lines, as well as on 36 sequential samples at diagnosis, pre-1st, pre-2nd and post-2nd autologous stem cell transplantation (ASCT). Over-expression and knock-down experiments of Trip13 were performed on myeloma cell lines by lentivirus transfection. Cell viability was assessed by trypan exclusion assay. Western blots were used to detect the expression of Trip13, P31 comet, caspase-8, caspase-9, caspase-3 and PARP, and checkpoint related proteins MAD2 and CDC20 in Trip13 overexpressed or Trip13 shRNA-transfected myeloma cells. Results Sequential GEP samples showed that Trip13 expression increased in 8 of 9 patients after chemotherapy and ASCT compared to the samples at diagnosis strongly suggesting that increased Trip13 is associated with drug resistance. Trip13 was already significantly increased in MGUS patients, newly diagnosed MM patients and MM cell lines compared with normal plasma cells. Furthermore, Trip13 was significantly higher in high-risk MMs than in low-risk MMs and increased Trip13 was linked to an inferior event-free survival (EFS) (p<0.01) and overall survival (OS) (p<0.01) in 351 newly diagnosed MMs. In contrast, the Trip13-interacting gene P31 comet was down-regulated in high-risk MMs and high expression of P31 was associated with good outcome. Interestingly, patients with high Trip13 and low P31 comet have the worst outcome compared to patients with only one of these, suggesting the interaction of Trip 13 and p31 has a synergistic effect on MM progression. Transfection of Trip13 into ARP1 and OCI-My5 cells significantly increased cell proliferation, while knock-down Trip13 in OCI-My5, H929, RPMI8226 cells inhibited cell growth and induced MM cell apoptosis with increases of cleaved caspase-8, caspase-9, caspase-3 and PARP. Mechanistic studies showed that Trip13 over-expression decreased P31comet and MAD2 expression by western blotting, but increased CDC20. Conclusions The association of increased Trip13 and decreased p31 is a good biomarker for MM drug resistance and poor prognosis. Our results also show Trip13 and P31 comet could be potential targets to overcome drug resistance in MM. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1944-1944 ◽  
Author(s):  
David J Dilillo ◽  
Kara Olson ◽  
Katja Mohrs ◽  
T. Craig Meagher ◽  
Kevin Bray ◽  
...  

Abstract Improving therapies for multiple myeloma (MM) remains a high medical need because of the significant morbidity and mortality of the disease. Targeted immunotherapies represent a promising opportunity to fill this clinical need. B cell maturation antigen (BCMA) is an attractive cell-surface target for MM due to its consistent expression on MM patient malignant plasma cells and expression limited in normal tissue primarily to plasma cells. Redirection of a patient's T cells to recognize tumors by CD3-binding bispecific molecules or through the generation of chimeric antigen receptor (CAR) T cells, has shown preliminary evidence of clinical activity. Bispecific antibodies concurrently engage a tumor antigen on cancer cells and the CD3 signaling machinery on T cells, bringing the tumor cell and T cell into proximity and facilitating T cell activation and tumor cell killing. By contrast, CAR T cell therapy involves re-infusion of the patient's own T cells after ex vivo engineering to express CARs targeting tumor antigens and triggering T cell signaling. Here we describe the generation of REGN5458, a human bispecific antibody that binds to BCMA and CD3. In vitro, REGN5458 efficiently activates T cells and induces polyclonal T cell killing of myeloma cell lines with a range of BCMA cell-surface densities, and also induces cytotoxicity of primary human plasma cells. Similar to gamma-sectretase inhibitors, incubation of myeloma cell lines with REGN5458 increased surface levels of BCMA. In xenogenic studies, after BCMAhigh NCI-H929 and BCMAlow MOLP-8 MM cells were co-implanted with PBMC and grown subcutaneously in immunodeficient NOD/SCID/L2Rgamma-deficient (NSG) mice, REGN5458 doses as low as 0.4 mg/kg significantly suppressed the growth of both tumors. Using aggressive, systemic xenogenic tumor models, in which NSG mice were engrafted with PBMC and intravenously injected with BCMAhigh OPM-2 cells or BCMAlow MOLP-8 cells expressing luciferase, REGN5458 reduced tumor burden and suppressed tumor growth at doses as low as 0.4 mg/kg. In immunocompetent mice genetically engineered to express human CD3, REGN5458 inhibited the growth of syngeneic murine tumors expressing human BCMA at doses as low as 0.04 mg/kg. Finally, as REGN5458 binds to cynomolgus CD3 and BCMA and mediates cytotoxicity of primary cynomolgus plasma cells, the pharmacology of REGN5458 was evaluated in cynomolgus monkeys. REGN5458 administration was well-tolerated, resulting in a mild inflammatory response characterized by transiently increased CRP and serum cytokines. Importantly, REGN5458 treatment led to the depletion of BCMA+ plasma cells in the bone marrow, demonstrating cytotoxic activity in non-human primates. The anti-tumor efficacy of REGN5458 was compared to BCMA-specific CAR T cells using 2nd generation CAR lentiviral constructs containing a single-chain variable fragment binding domain from REGN5458's BCMA binding arm and 4-1BB and CD3z signaling domains. Human PBMC-derived T cells were transduced to express this CAR and expanded. Both REGN5458 and the BCMA CAR T cells demonstrated similar targeted cytotoxicity of myeloma cell lines and primary patient blasts in vitro, and were capable of clearing established systemic OPM-2-luciferase myeloma tumors in NSG mice, but with different kinetics: treatment with REGN5458 resulted in rapid clearance of tumors within 4 days, whereas treatment with BCMA CAR T cells allowed tumors to continue to grow for 10-14 days following injection before rapidly inducing tumor clearance. Thus, REGN5458 exerts its therapeutic effect rapidly after injection, using effector T cells that are already in place. In contrast, BCMA CAR T cells require time to traffic to the tumor site and expand, before exerting anti-tumor effects. Collectively, these data demonstrate the potent pre-clinical anti-tumor activity of REGN5458 that is comparable to that of CAR T cells, and provide a strong rationale for clinical testing of REGN5458 in patients with MM. Disclosures Dilillo: Regeneron Pharmaceuticals: Employment. Olson:Regeneron Pharmaceuticals: Employment. Mohrs:Regeneron Pharmaceuticals: Employment. Meagher:Regeneron Pharmaceuticals: Employment. Bray:Regeneron Pharmaceuticals: Employment. Sineshchekova:Regeneron Pharmaceuticals: Employment. Startz:Regeneron Pharmaceuticals: Employment. Retter:Regeneron Pharmaceuticals: Employment. Godin:Regeneron Pharmaceuticals: Employment. Delfino:Regeneron Pharmaceuticals: Employment. Lin:Regeneron Pharmaceuticals: Employment. Smith:Regeneron Pharmaceuticals: Employment. Thurston:Regeneron Pharmaceuticals: Employment. Kirshner:Regeneron Pharmaceuticals: Employment.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1008-1008
Author(s):  
Tyler Moser-Katz ◽  
Catherine M. Gavile ◽  
Benjamin G Barwick ◽  
Sagar Lonial ◽  
Lawrence H. Boise

Abstract Multiple myeloma is the second most common hematological malignancy in the U.S. with an estimated 30,700 new diagnoses in 2018. It is a clonal disease of plasma cells that, despite recent therapeutic advances, remains incurable. Myeloma cells retain numerous characteristics of normal plasma cells including reliance on survival signals in the bone marrow for long term viability. However, malignant transformation of plasma cells imparts the ability to proliferate, causing harmful bone lesions in patients, and in advanced stages independence of the bone-marrow microenvironment. Therefore, we are investigating the molecular mechanisms of myeloma cell survival that allow them to become extramedullary. We identified syntenin-1 (SDCBP) as a protein involved in myeloma cell survival and a potential therapeutic target. Syntenin-1 is an adapter protein that has been shown to regulate surface expression of several transmembrane proteins by binding with membrane phospholipids and mediating vesicular trafficking of proteins throughout the cell. Syntenin-1 regulates the surface expression of CD138, a plasma/myeloma cell marker. Syntenin-1 has been shown to regulate apoptosis in numerous cancer cell lines including breast cancer, glioma, and pancreatic cancer but its role in multiple myeloma survival has not been studied. To determine if syntenin-1 expression has an effect on myeloma cell survival, we utilized the CoMMpass dataset (IA12), a longitudinal study of myeloma patients that includes transcriptomic analysis throughout treatment. We found that patients with the highest expression of syntenin-1 mRNA (top quartile) had significantly worse overall survival, progression-free survival, and a shorter response duration than those in the bottom quartile of expression. To determine if syntenin-1 has a role in myeloma cell survival, we used short hairpin RNA to knock down syntenin-1 (shsyn) in RPMI 8226 and MM1.s myeloma cell lines. We then determined the amount of cell death using Annexin-V staining flow cytometry four days following lentiviral infection. We found increased cell death in syntenin-1-silenced cells compared to our empty vector control in both RPMI 8226 (control=42.17%, shsyn=71.53%, p=0.04) and MM1.s cell lines (control=8.57%, shsyn=29.9%, p=0.04) suggesting that syntenin-1 is important for myeloma cell survival. Syntenin-1 contains two PDZ domains that allow it to bind to receptor proteins via their corresponding PDZ-binding motifs. We therefore wanted to look at correlation of syntenin-1 expression with CD138 and CD86, two PDZ-binding domain containing proteins expressed on the surface of myeloma cells. Using the CoMMpass dataset, we found patients with high expression of syntenin-1 had a median expression of CD86 that was twice as high as the total population (P<0.0001) while syntenin-1-low patients expressed CD86 at levels that were half as much as the population (P<0.0001). In contrast, there was no clear relationship between syntenin-1 and CD138 mRNA expression. Indeed if one takes into account all patients, there is a positive correlation between CD86 and syntenin-1 expression (r=0.228, P<0.0001) while there is a negative correlation between CD138 and syntenin-1 (r=-0.1923, P<0.0001). The correlation with CD86 but not CD138 suggests a previously undescribed role for syntenin-1 in myeloma cells. Our lab has previously shown that expression of CD86 is necessary for myeloma cell survival, and signals via its cytoplasmic domain to confer drug resistance. Silencing syntenin-1 results in a decrease in CD86 surface expression. However, there is no change in CD86 transcript or total cellular CD86 protein levels in our shsyn treated cells. Moreover, knockdown of CD86 resulted in increased protein expression and transcript levels of syntenin-1. Taken together, these data suggest that syntenin-1 may regulate CD86 expression on the cell surface. Our data supports a novel role for syntenin-1 in myeloma cell viability and as a potential regulator of CD86 surface expression. The role of syntenin-1 has not previously been explored in multiple myeloma and determining its molecular function is warranted as it may be an attractive target for therapeutic treatment of the disease. Disclosures Lonial: Amgen: Research Funding. Boise:AstraZeneca: Honoraria; Abbvie: Consultancy.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 499-499
Author(s):  
Xenofon Papanikolaou ◽  
Caleb K. Stein ◽  
Ricky D Edmondson ◽  
Veronica Macleod ◽  
Ruslana Tytarenko ◽  
...  

Abstract The proteasome inhibitor Bortezomib (Bz), the first agent of a new class of drugs in Multiple Myeloma (MM), has shown remarkable activity and forms an integral part of modern MM treatment. Nevertheless, resistance to Bz eventually develops in a significant proportion of patients, with adverse effects on survival. Numerous publications have addressed this issue through in vitro developed models of acquired Bz resistance (BzR). However the results were quite different in each publication, none of the produced Bz myeloma cell lines was provably stable, no common mechanism of resistance could be demonstrated, and hence were of minimal relevance to the clinical setting. In order to address these issues an effort was made for the development of an in vitro model of acquired BzR that would resemble the clinical reality in the most accurate way. Two myeloma cell lines were used, one resembling a multisensitive (JJN3) and the other a multiresistant (U266) drug behavior, that were both sensitive to Bz. An at least 20 fold increase in the 48h Bz IC50 was noted for both cell lines. The increase in the IC50 was able to be verified a year after culturing the cell lines in normal medium thus ensuring a stable resistance phenotype. To delineate the molecular mechanisms that underlie the development of BzR a combined genetic/Gene Expression Profile (GEP) and functional/Proteomics approach was used with emphasis in the common elements of both cell lines. The hypothesis was that if certain pathways are activated in the cells that actually produce the phenotype of BzR they must fulfil two important criteria: 1) They must be present in all the levels of the BzR, 2) The gene changes have to be verified in the level of the gene encoded proteins thus securing their functional importance. GEP of the naïve cell lines along with the GEP of the Bz resistant cells at different levels of BzR (5-fold, 10-fold, 20-fold) were used. The statistical analysis revealed 100 gene probes common in both cell lines that achieved their highest change as soon as BzR was established and remained stable at that level for all later versions (P<0.1, q<0.1) and 115 gene probes common in both cell lines that their change was proportional to the level of BzR (P<0.001, q <0.005). The proteomics analysis of the Bz resistant cell lines at their latest level of resistance (20-fold) revealed 262 proteins common in both cell lines that were up-regulated and 263 common in both cell lines that were down-regulated (change >10% to be considered significant). The intersection of the list of the common genes with the list of the common proteins revealed 47 gene-proteins all but one novel in MM. They can be grouped in distinct biological categories with the most prominent ones being the ROS/Mitochondrial Factor category comprising of 10 gene-proteins, the E3 Ubiquitin Pathway 6 genes-proteins and Translation Regulation 5 genes-proteins. Even more importantly 30 of them have profound survival implications in MM -all of them novel in MM- both for Overall Survival (OS) and Progression Free Survival (PFS) in both Bz (TT3) and non Bz (TT2) containing protocols implying that myeloma cells apply both Bz specific and non-specific mechanisms to acquire BzR. Based on these 30 genes-proteins a GEP risk score (GEP-30) was constructed that was able to achieve remarkable statistical power in both Bz containing and non containing trials of both newly diagnosed (TT2 with and without thalidomide i.e. TT2+ and TT2-, TT3a, TT3b, HOVON, MRC IX, Figure 1A,B,C) and relapsed MM (TT6 , OS: NR vs 1.52 yr P<0.00001, PFS: NR vs 1.13 yr P<0.00001 for low and high risk) Figure 1. KM plots for OS and PFS of GEP-30 for newly diagnosed MM Figure 1. KM plots for OS and PFS of GEP-30 for newly diagnosed MM Figure 1B. Figure 1B. Figure 1C. Figure 1C. Disclosures Stein: University of Arkansas for Medical Sciences: Employment. Barlogie:University of Arkansas for Medical Sciences: Employment. Epstein:University of Arkansas for Medical Sciences: Employment. Heuck:Janssen: Other: Advisory Board; Celgene: Consultancy; Millenium: Other: Advisory Board; Foundation Medicine: Honoraria; University of Arkansas for Medical Sciences: Employment.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5080-5080
Author(s):  
Shankaranarayana Paneesha ◽  
Raghu Adya ◽  
Hemali Khanji ◽  
Ed Leung ◽  
C. Vijayasekar ◽  
...  

Abstract Multiple myeloma is a clonal lymphoproliferative disorder characterised by the proliferation of plasma cells in the bone marrow. Inspite of good initial response, it is associated with universal relapse. We hypothesise this is due to sanctuary provided to myeloma cells by the endothelium. Matrix metalloproteinases (MMPs) are shown play a role in cell growth, invasion, angiogenesis, metastasis and bone degradation. We show here the protection offered by endothelial cells to human myeloma cell lines in in-vitro co-culture with upregulation of MMP-2 & 9 and the role of GM6001 MMP inhibitor (Ilomastat) in overcoming this protection. Human myeloma cell lines (H929, RPMI 8226, U266 & JJN3) with or without endothelial cells (human umbilical vein endothelial cells and EaHy 926 cell line) in-vitro co-culture were treated with melphalan, dexamethasone, arsenic trioxide and Ilomastat. Cytotoxicity/proliferation were assessed by the alamarBlue™ assay (Serotec) and validated by Annexin V-FITC apoptosis detection Kit (Calbiochem) and BrDU proliferation assay (BD Pharmingen™). Gelatin Zymography was used to demonstrate activity of MMP-2 & 9 in the supernatant. MMP-2 and 9 mRNA expression was quantified by Real Time Quantitative PCR (ROCHE). Co-culture of human myeloma cell lines with endothelial cells lead to increase in the proliferation of myeloma cell lines and also protected them from the cytotoxicity of chemotherapeutic agents. MMP-2 & 9 activity was upregulated by the co-culture. MMP-2 mRNA expression in human myeloma cell lines increased following 4 hr co-culture. Treatments with Ilomastat lead to the suppression of proliferation in co-culture in a dose dependent manner, associated with a reduction of MMP-2 and 9 activity. Our study shows endothelial cells offer protection to human myeloma cell lines in the presence of cytotoxic agents. This may result in the sanctuary of myeloma cells in bone marrow leading to ultimate relapse of disease. Our study also demonstrates the upregulation of MMP-2 and 9 by co-culture and increased cytotoxicity achieved by the inhibition of MMPs. Further studies are needed to determine the exact role of MMPs in myeloma biology as MMP inhibition may be an interesting therapeutic target and help in averting relapse in multiple myeloma.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1664-1664
Author(s):  
Jayakumar R Nair ◽  
Louise M Carlson ◽  
Noreen Ersing ◽  
Asher Alban Chanan-Khan ◽  
Kelvin P. Lee

Abstract Multiple myeloma (MM) is an incurable neoplasia of terminally differentiated plasma cells in the bone marrow. Essential interactions of MM cells with host bone marrow stromal cells (BMSC) induce growth factors essential for MM progression and pathogenesis, as well as induce an immunosuppressive environment that inhibits endogenous and therapeutically-induced immune responses against the MM cells. However, despite their importance, little is known about the identity of these BMSC cells or the molecular basis of their interaction with myeloma cells. A potential MM surface protein that could be involved in these interactions is CD28, based on its known pro-survival role in T cells. Clinical studies have shown that expression of CD28 in multiple myeloma highly correlates (p=0.006) with myeloma disease progression. Moreover, CD28+ MM cells invariably express the CD28 ligand CD86. A survival role for MM-CD28 might involve interactions with cellular partners that express the B7 (CD80/CD86) ligands. Potential candidates would include CD86+ myeloma cells themselves or B7+ dendritic cells (DC) that are known to be closely associated with myeloma cells in the patient bone marrow. When myeloma-myeloma interactions were disrupted by using the high affinity CD80/CD86 blocker CTLA4Ig (Abatacept®), increased sensitivity to arsenic trioxide (ATO) and melphalan (MEL) was observed in all the three MM cell lines U266, RPMI8226 and MM1S. For U266 viability was 93% in media alone, 84% with CTLA4Ig (100 μg/ml) alone, 86% with 2 μM ATO alone and was significantly reduced to 36% with CTLA4Ig + ATO. Similar drops in viability were observed with 25 μM MEL in combination with CTLA4Ig (33% as opposed to 71–74 % with CTLA4Ig or MEL alone). Our data suggests that this does not involve the downregulation of anti-apoptotic proteins Bcl-2, Bcl-xL or Mcl-1, commonly associated with drug resistance in myeloma. In the second part of the study, we demonstrate that myeloma cell lines or primary CD138+ myeloma cells can enhance via direct contact the ability of human monocyte derived immature DC to produce the immunosuppressive tryptophan depleting enzyme indoleamine 2,3 dioxygenase (IDO, as estimated by kynurenine (Kyn) (a tryptophan catabolite) levels in the supernatant) and also the pro-plasma cell survival cytokine IL-6. In co-cultures of IFNg treated immature DCs with either MM cell lines or with primary CD138+ myeloma cells from patient BM aspirates, the activity of IDO was enhanced ~ 2–8 fold (81 mM kyn with U266 and 20–43mM with primary cells) over that observed in control IFNg-treated DCs (9.7 mM Kyn). Western analysis also demonstrated increased IDO expression relative to IFNg activated DC controls. Blocking MM-CD28 with (Fab)2 fragments of anti-hCD28 mAb 9.3 downregulated IDO activity (9.3 mM) close to that of control, demonstrating the involvement of MM-CD28 in these interactions. We also demonstrated a significant up-regulation of the pro-myeloma survival cytokine IL-6 when immature DCs were co-cultured with CD28+ MM1S (90–300 pg/ml), a 4–9 fold increase over that of DC only control (25 – 35 pg/ml). This was further enhanced when immature DCs cultured with IL-10 (+ GM-CSF + IL-4) was used in co-cultures with MM-1S (800 – 1300 pg/ml), or with primary CD138+ myeloma cells from patient bone marrow aspirates (128–1142 pg/ml). In conclusion, our data demonstrates that blocking myeloma-CD28 - myeloma-CD86 “autocrine” interaction can enhance drug cytotoxicity, while interactions with DCs produce the essential growth cytokines IL-6 and immunosuppressive enzyme IDO with potential implications in MM survival and immune escape. Use of clinically approved agents (e.g. Abatacept®) to block myeloma-CD28 binding to its B7 ligands (increase chemotherapeutic efficacy), 1-MT to inhibit IDO and targeting DCs in the microenvironment to disrupt the tumor microenvironment could be viable therapeutic strategies for the future treatment of multiple myeloma.


Blood ◽  
1995 ◽  
Vol 85 (12) ◽  
pp. 3704-3712 ◽  
Author(s):  
N Huang ◽  
MM Kawano ◽  
MS Mahmoud ◽  
K Mihara ◽  
T Tsujimoto ◽  
...  

The mature myeloma cells express very late antigen 5 (VLA-5) and MPC-1 antigens on their surface and adhere to bone marrow (BM) stromal cells more tightly than the VLA-5-MPC-1-immature myeloma cells in vitro. The VLA-5 and MPC-1 antigens possibly function as two of the molecules responsible for interaction of mature myeloma cells with BM stromal cells. However, the immature myeloma cells do interact with BM stromal cells, and it is unclear which adhesion molecules mediate their interaction. In this study, we found that both immature and mature myeloma cells expressed CD21, an adhesion molecule known to bind to CD23. CD21 was also detected on normal plasma cells. To evaluate the role of CD21 expression on myeloma cells, two myeloma cell lines, NOP-2 (VLA-5-MPC-1-) and KMS-5 (VLA-5+MPC-1+), were used as representatives of immature and mature myeloma cell types, respectively, and an adhesion assay was performed between the myeloma cell lines and BM stromal cells. Antibody-blocking results showed that adhesion of the mature type KMS-5 to KM102, a human BM-derived stromal cell line, or to short-term cultured BM primary stromal cells was inhibited by monoclonal antibodies (MoAbs) against CD21, VLA-5, and MPC-1, and inhibition of adhesion of the immature type NOP-2 to KM102 by the anti-CD21 MoAb was observed as well. Furthermore, CD23 was detected on KM102. Treatment of KM102 with an anti-CD23 MoAb also inhibited adhesion of either KMS-5 or NOP-2 to KM102. Therefore, we propose that CD21 expressed on myeloma cells likely functions as a molecule responsible for the interaction of immature myeloma cells as well as mature myeloma cells with BM stromal cells, and CD23 may be the ligand on the stromal cells for the CD21-mediated adhesion.


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