Vascular Endothelial Growth Factor Expression in CD138+/CD19- and CD138+/CD19+ Plasma Cells in Monoclonal Gammopathies and Impact on Multiple Myeloma Prognosis

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5342-5342
Author(s):  
Catarina Geraldes ◽  
Ana Cristina Gonçalves ◽  
Raquel Alves ◽  
Emília Cortesão ◽  
Maria Leticia Ribeiro ◽  
...  

Abstract INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent angiogenic peptide with biologic effects that include regulation of extracellular matrix remodeling and inflammatory cytokine generation with an important role in the bone marrow microenvironment of multiple myeloma (MM). Angiogenesis is enhanced in the bone marrow of MM patients in parallel with tumor progression. Myeloma and stromal cells secrete angiogenic factors that include VEGF. Previous studies showed heterogeneity in the expression of VEGF between plasma cells (PCs) from the same MM patient. However, no clear association with expression levels, phenotypic subtypes of PCs and prognosis was demonstrated. MATHERIALS AND METHODS: Bone marrow PCs from 128 patients with monoclonal gammopathies, 60 patients with newly diagnosed symptomatic MM and 68 with monoclonal gammopathy of uncertain significance (MGUS) and also from 11 non-neoplastic controls (Ctr) were analysed between April 2010 and July 2013. We evaluated the expression of cytoplasmic VEGF with monoclonal antibodies by flow cytometry in the two populations of PCs, identified by gating CD138+/CD19- (clonal PCs) and CD138+/CD19+ (non-clonal PCs). The results are presented as percentage of PCs expressing VEGF and as expression levels of VEGF in mean intensity of fluorescence (MIF). The effects of VEGF expression on progression-free survival (PFS) and overall survival (OS) were analysed. For statistical analysis, software IBM SPSS Statistics v22 was used. Survival was estimated according to the Kaplan-Meier method. RESULTS: In our cohort of patients, median age was 70 (39-86) years, 52% were male. We found increased expression levels of VEGF in CD138+/CD19- PCs from MM (80 ± 7,5 MIF) compared to MGUS patients (61,7 ± 6,2 MIF) (p=0,011), as well as superior to CD138+/CD19+ PCs expression (39,92 ± 1,74 MIF) in both populations of patients (p<0,001 and p=0,02, respectively). No diferences were observed in the expression levels of VEGF in CD138+/CD19+ PCs from MM (39,92 ± 1,74 MIF), MGUS patients (41,18 ± 1,92 MIF) and controls (32,8±1,5 MIF). However, the percentage of CD138+/CD19+ expressing VEGF was significantly higher in MGUS (39,4±4%) and in MM patients (46,7±4,5%) compared to Ctr (13,5±0,5%)(p=0,019 and p=0,003, respectively). In MM patients, we also found an association between increased VEGF expression levels in CD138+/CD19- PCs (superior or equal to 175 MIF) and inferior PFS (p=0,002) and OS (p=0,003), irrespective of first line therapy (bortezomib-based regimens for fit patients or alkylating-based treatments for unfit patients). Interestingly, we also observed an incresed percentage of CD138+/CD19+ PCs (higher or equal to 21%) expressing VEGF in MM patients with a more favorable PFS (p= 0,04) and OS (p=0,008). CONCLUSIONS: The results of our investigation showed that CD138+/CD19- and CD138+/CD19+ PCs have diferences in what concerns VEGF expression, not only in MM patients, but also in MGUS patients. The increased expression of VEGF in clonal PCs from MM compared to MGUS patients evidences the relevance of VEGF in myelomagenesis. We also demonstrated a negative prognostic impact of an increased VEGF expression in CD138+/CD19- PCs, highlighting the role of VEGF in the survival and maintenance of clonal PCs and as a predictor of outcome in MM progression. The association between the percentage of CD138+/CD19+ PCs and survival supports the suggestion that these cells may not be neutral players in the complex pathogenesis of MM. The results of our study should be further investigated in larger series of patients. Disclosures Geraldes: Celgene: Employment, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees.

2011 ◽  
Vol 64 (3) ◽  
pp. 226-231 ◽  
Author(s):  
Leonardo Boiocchi ◽  
Claudia Vener ◽  
Federica Savi ◽  
Emanuela Bonoldi ◽  
Alessia Moro ◽  
...  

AimsThe authors investigated vascular endothelial growth factor receptor 1 (VEGFR-1) protein expression in a series of Philadelphia chromosome-negative myeloproliferative neoplasms (Ph- MPNs) and its correlations with microvessel density (MVD) and vascular endothelial growth factor (VEGF).Methods83 bone marrow biopsies of Ph- MPNs patients, including 27 essential thrombocythaemia (ET), 21 polycythaemia vera (PV) and 35 primary myelofibrosis (PMF), and 10 normal controls (NCs) were investigated by immunohistochemistry.ResultsPatients with PV and PMF showed an increased MVD (PV: 20.1±10.6; PMF: 25.8±6.5) compared with those with ET or NCs (ET: 10.4±4.6; NCs: 7±3.4). VEGFR-1 expression was increased in Ph- MPNs, particularly in PV and PMF (NCs: 0.07±0.03; ET: 0.15±0.09; PV: 0.31±0.2; PMF: 0.31±0.04). VEGF expression parallelled VEGFR-1 and resulted increased in Ph- MPNs (NCs: 0.08±0.04; ET: 0.13±0.06; PV: 0.29±0.2; PMF: 0.31±0.15) and higher in post-polycythaemic myelofibrosis and in the fibrotic stage of PMF than in the non-fibrotic phases of both diseases. VEGFR-1 protein expression correlated with MVD and VEGF expression in Ph- MPNs. VEGFR-1 and VEGF were expressed by the same bone marrow populations: megakaryocytes, macrophages and immature myeloid precursors showed a moderate to strong immunostaining intensity in both Ph- MPNs and NCs. The erythroid precursors were not immunoreactive.ConclusionsVEGFR-1 and VEGF were increased and co-localised in megakaryocytes, macrophages and myeloid precursors of Ph- MPNs. This finding supports the hypothesis of a VEGF/VEGFR-1 autocrine loop in the neoplastic cells of Ph- MPNs.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 133-133 ◽  
Author(s):  
Patricia Maiso ◽  
AbdelKareem Azab ◽  
Yang Liu ◽  
Yong Zhang ◽  
Feda Azab ◽  
...  

Abstract Abstract 133 Introduction: Mammalian target of rapamycin (mTOR) is a downstream serine/threonine kinase of the PI3K/Akt pathway that integrates signals from the tumor microenvironment such as cytokines and growth factors, nutrients and stresses to regulate multiple cellular processes, including translation, autophagy, metabolism, growth, motility and survival. Mechanistically, mTOR operates in two distinct multi-protein complexes, TORC1 and TORC2. Activation of TORC1 leads to the phosphorylation of p70S6 kinase and 4E-BP1, while activation of TORC2 regulates phosphorylation of Akt and other AGC kinases. In multiple myeloma (MM), PI3K/Akt plays an essential role enhancing cell growth and survival and is activated by the loss of the tumor suppressor gene PTEN and by the bone marrow microenvironment. Rapamycin analogues such as RAD001 and CCI-779 have been tested in clinical trials in MM. Their efficacy as single agents is modest, but when used in combination, they show higher responses. However, total inhibition of Akt and 4E-BP1 signaling requires inactivation of both complexes TORC1 and TORC2. Consequently, there is a need for novel inhibitors that can target mTOR in both signaling complexes. In this study we have evaluated the role of TORC1 and TORC2 in MM and the activity and mechanism of action of INK128, a novel, potent, selective and orally active small molecule TORC1/2 kinase inhibitor. Methods: Nine different MM cell lines and BM samples from MM patients were used in the study. The mechanism of action was investigated by MTT, Annexin V, cell cycle analysis, Western-blotting and siRNA assays. For the in vivo analyses, Luc+/GFP+ MM.1S cells (2 × 106/mouse) were injected into the tail vein of 30 SCID mice and tumor progression was detected by bioluminescence imaging. Nanofluidic proteomic immunoassays were performed in selected tumors. Results: To examine activation of the mTOR pathway in MM, we performed kinase activity assays and protein analyses of mTOR complexes and its downstream targets in nine MM cell lines. We found mTOR, Akt, pS6R and 4E-BP1 are constitutively activated in all cell lines tested independently of the status of Deptor, PTEN, and PI3K. All cell lines expressed either Raptor, Rictor or both; excepting H929 and U266LR7 which were negative for both of them. Moreover, primary plasma cells from several MM patients highly expressed pS6R while normal cells were negative for this protein. We found that INK128 and rapamycin effectively suppressed phosphorylation of p6SR, but only INK128 was able to decrease phosphorylation of 4E-BP1. We observed that INK128 fully suppressed cell viability in a dose and time dependent manner, but rapamycin reached a plateau in efficacy at ± 60%. The IC50 of INK128 was in the range of 7.5–30 nM in the eight cell lines tested. Similar results were observed in freshly isolated plasma cells from MM patients. Besides the induction of apoptosis and cell cycle arrest, INK128 was more potent than rapamycin to induce autophagy, and only INK128 was able to induce PARP and Caspases 3, 8 and 9 cleavage. In the bone marrow microenvironment context, INK128 inhibited the proliferation of MM cells and decreased the p4E-BP1 induction. Importantly, treatment with rapamycin under such conditions did not affect cell proliferation. INK128 also showed a significantly greater effect inhibiting cell adhesion to fibronectin OPM2 MM1S, BMSCs and HUVECs compared to rapamycin. These results were confirmed in vivo. Oral daily treatment of NK128 (1.0 mg/kg) decreased tumor growth and improved survival of mice implanted with MM1S. Conclusion: Dual inhibition of TORC1 and TORC2 represent a new and promising approach in the treatment of MM and its microenvironment. The ability of INK128 to inhibit both TORC1 and TORC2 strongly supports the potential use of this compound in MM patients. Disclosures: Anderson: Millennium Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Ghobrial:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4030-4030
Author(s):  
Nicola S. Fracchiolla ◽  
aleria Ferla ◽  
Umberto Gianelli ◽  
Claudia Vener ◽  
Federica Savi ◽  
...  

Abstract Abstract 4030 INTRODUCTION: An increased bone marrow angiogenesis might be involved in the pathophysiology of a number of haematological malignancies, including myelodysplasia (MDS). Many angiogenic factors have been investigated in MDS, and vascular endothelial growth factor (VEGF) and its significance has been evaluated the most. VEGF mediates its biological effects by binding to two transmembrane tyrosine kinase receptors, VEGFR-1 and VEGFR-2. The VEGF/receptor signaling system is involved in the regulation of two fundamental processes: the formation of blood vessels (angiogenesis) and of blood cells (hematopoiesis). VEGF regulates the two processes by different mechanisms: hematopoietic stem cell survival and repopulation mainly via an autocrin loop, and angiogenesis via a paracrine loop. PATIENTS: The study population included 79 patients (pts) (48 men and 31 women; median age, 70 years). The patients were given a diagnosis of 10 RA, 6 RARS, 17 RCMD, 7 5q-syndrome, 25 RAEB-1 e 14 RAEB-2 according to the WHO classification (2008). In agreement with the International Prognostic Scoring System (IPSS), 28 pts were graded as Low, 28 as Int-1, 17 as Int-2 and 6 as High. According to the WHO classification based prognostic scoring system (WPSS), 14 pts were graded as Very Low, 17 as Low, 11 as Int, 25 as High and 12 Very High. The leukemic evolution occurred in 23 pts. The median leukemia free survival (LFS) was 825 days. Exitus occurred in 49 pts. The median overall survival (OS) was 902 days. We included in the study 20 controls (NC). METHODS: The MicroVessel Density (MVD) was evaluated through CD34 immuno-histochemical reactivity. Each BMB was first totally scanned at low magnification (10×) in order to identify 5 “hot spot” zones and then examined at high magnification (40×). MVD was estimated by hot-spot “method” (MVD-HS) by counting all of the positive-endothelial cells. Lumens were required to consider a structure as microvessel. Sinusoid-like structures, with the exception of arterioles, were also included in the count. To avoid any bias related to BMB cellularity, we calculated a VEGF expression index (VEGFi), defined as the cellularity of the BMBs multiplied by the fraction of VEGF positive cells and expressed as a number between 0 and 1 [(% of BMB cellularity × %VEGF-positive cells)/10⋀4]. Two VEGFi expression classes, respectively Low and High (L-VEGFi and H-VEGFi), were determined considering as cut-off level the mean VEGF(i) expression value + 2 standard deviations. RESULTS: MVD-HS analysis showed increased levels in MDS in comparison to NCs (p=.009). MVD did not differ among IPSS and WPSS categories. MVD did not predicted leukemia free and overall survival (LFS and OS). VEGF expression in bone marrow cells was found as a weak cytoplasmic granular protein expression in proeritroblasts; normoblasts were not immunoreactive. In the myeloid lineage VEGF expression was more intense in immature cells. The macrophages and megakaryocytes showed a granular weak cytoplasmic positivity. The plasmacells showed an intense granular cytoplasmic positivity. VEGFi expression was evenly distributed among the different IPSS and WPSS categories and was higher in MDS in comparison to NCs (p=.006). L-VEGFi MDS pts presented a significant lower transfusional need in the first years from diagnosis (p=.02). We observed that L-VEGFi MDS pts had a longer LFS compared with H-VEGFi ones (p=.006). Moreover, L-VEGFi MDS pts had a significant better OS compared to H-VEGFi pts (p=.03). At multivariate analysis IPSS and WPSS, as expected, predicted OS (p<0.0001). Interestingly, VEGFi at diagnosis maintained its significant prognostic role on LFS also in multivariate analysis(p=.02), together with IPSS and WPSS (p=.002 and .001). CONCLUSIONS: We show that in MDS pts at diagnosis bone marrow VEGFi evaluation predicts OS and LFS. The influence of VEGFi on LFS is retained also in multivariate analysis in a model including IPSS and WPSS. This finding is even more interesting considering that IPSS and WPSS are multiparametric score systems, and that WPSS necessitates the quantification of the transfusional need in the first months from diagnosis, while VEGFi is a single immunohistochemical parameter evaluated on BMB specimens at diagnosis. Further studies are warranted to confirm the prognostic role of VEGFi in this disease setting and its clinical implications. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5331-5331
Author(s):  
Ryosuke Shirasaki ◽  
Takuji Matsuo ◽  
Yoko Oka ◽  
Jun Ooi ◽  
Naoki Shirafuji

Abstract Background We previously reported that when adult human dermal fibroblasts were cultured with interleukin (IL)-1-b, vascular endothelial growth factor (VEGF)-A was produced significantly (54th ASH). And, when antihuman VEGF-A neutralizing antibody (VEGF-A Ab) was added to the cultures, CD138 (Syndecan-1) expressed significantly. CD138 is a member of cell-surface transmembrane haparan sulfate proteoglycans, and expresses in plasma cells from multiple myeloma (MM) cases. Membrane-anchoring CD138 shows a better prognosis in an immunodeficiency murine transplantation model in vivo; however, when extra-domain of CD138 is digested by heparanase to be shed from the cell-surface, MM cells invade to various kinds of tissues, and the patients show poor prognosis. Aims To validate a biological implication of inhibition of VEGF-A-signaling in MM cells, we observed effects of VEGF-A Ab to bone marrow cells from MM patients. Cell-proliferations as well as morphological changes were also observed time-dependently. Materials and Methods Institutional ethical committee approved our study, and bone marrow cells were obtained from the informed MM patients as well as normal individuals. Cells were separated with gravity-sedimentation method, and the prepared mononuclear cells were cultured with or without VEGF-A Ab, and the expression of specific genes was analyzed. Results Twenty MM patients were eligible, in which three showed significant poor prognosis, and worsened after underwent intensive chemotherapy or allogeneic hematopoietic stem cells transplantation. Thirteen out of twenty expressed CD138, and when cells were cultured with VEGF-A Ab for four days, CD138-expression increased significantly in all cases. Four did not express CD138; however, CD138-expression was observed after 4 day’s culture with VEGF-A Ab. In three progressed cases CD138-expression decreased in accordance with the disease-progression; however, when VEGF-A Ab was added to the cell-cultures, CD138 was induced to express. Heparanase-expression was observed in 10 cases out of 20, which were down-regulated when VEGF-A Ab was added to the cultures. In contrast, in bone marrow cells from seven normal individuals CD138-expression was very low, which was down-regulated with the addition of VEGF-A Ab. Heparanase-expression was not observed in these normal cells, and were induced to be observed in four out of seven when VEGF-A Ab was added to the cultures. Discussion Expression of CD138 is induced in fibroblast by the addition of fibroblast growth factor-2, and in keratinocytes by epidermal growth factor and keratinocyte growth factor; however, an induction of CD138 by the VEGF-A Ab has not been reported. Several cytokines including VEGF-A influence plasma cell-proliferation; however, little is reported on cytokine-suppression therapy. Inhibition of the signaling of VEGF receptors by the chemicals including solafenib is not specific for VEGF-A. Currently we validate the efficacy of the inhibition of VEGF-A-signaling to MM cells and their environmental cells using RNA interference. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 311-311 ◽  
Author(s):  
Laurie Herviou ◽  
Alboukadel Kassambara ◽  
Stephanie Boireau ◽  
Nicolas Robert ◽  
Guilhem Requirand ◽  
...  

Abstract Multiple Myeloma is a B cell neoplasia characterized by the accumulation of clonal plasma cells within the bone marrow.Epigenetics is characterized by a wide range of changes that are reversible and orchestrate gene expression. Recent studies have shown that epigenetic modifications play a role in multiple myeloma (MM) by silencing various cancer-related genes. We investigated the epigenetic genes differentially expressed between normal bone marrow plasma cells (BMPC ; N=5) and MM plasma cells from patients (N=206). Using SAM (Significance Analysis of Microarrays) analysis, only 12 genes significantly differentially expressed between BMPC and MM cells (ratio > 2 and FDR (false discovery rate) < 5%) were identified, including the EZH2 histone methyltransferase. EZH2, the enzymatic subunit of Polycomb Repressive Complex 2, is a histone methyltransferases able to repress gene expression by catalyzing H3K27me3 histone mark. EZH2 overexpression has been associated with numerous hematological malignancies, including MM. We thus studied EZH2 role in MM physiopathology and drug resistance. EZH2 expression was analyzed in normal bone marrow plasma cells (BMPCs; N=5), primary myeloma cells from newly diagnosed patients (MMCs; N=206) and human myeloma cell lines (HMCLs; N=40) using Affymetrix microarrays. EZH2 gene is significantly overexpressed in MMCs of patients (median 574, range 105 - 4562) compared to normal BMPCs (median = 432; range: 314 - 563) (P < 0.01). The expression is even higher in HMCLs (median 4481, range 581 - 8455) compared to primary MMCs or BMPCs (P < 0.001). High EZH2 expression is associated with a poor prognosis in 3 independent cohorts of newly diagnosed patients (Heidelberg-Montpellier cohort - N=206, UAMS-TT2 cohort - N=345 and UAMS-TT3 cohort - N =158). Furthermore, GSEA analysis of patients with high EZH2 expression highlighted a significant enrichment of genes involved in cell cycle, downregulated in mature plasma cells vs plasmablasts, and EZH2 targets. Specific EZH2 inhibition by EPZ-6438 EZH2 inhibitor induced a significant decrease of global H3K27me3 in all the HMCLs tested (P < 0.01) and inhibited MM cell growth in 5 out of the 6 HMCLs tested. The inhibitory effect of EZH2 inhibitor on MM cell growth appeared at day 6 suggesting that it is mediated by epigenetic reprogramming. To confirm that EZH2 is also required for the survival of primary MMCs from patients, primary MM cells (n = 17 patients) co-cultured with their bone marrow microenvironment and recombinant IL-6 were treated with EPZ-6438. As identified in HMCLs, EZH2 inhibition significantly reduced the median number of viable myeloma cells by 35% (P = 0.004) from a subset of patients (n=9) while the other group (n=8) was resistant. Of interest, EPZ-6438 induced a significant global H3K27me3 decrease in both groups of patient. RNA sequencing of 6 HMCLs treated with EPZ-6438 combined with H3K27me3 ChIP analyses allowed us to create an EZ GEP-based score able to predict HMCLs and primary MM cells sensitivity to EZH2 inhibitors. We also observed a synergy between EPZ-6438 and Lenalidomide, a conventional drug used for MM treatment. More interestingly, pretreatment of myeloma cells with EPZ-6438 significantly re-sensitize drug-resistant MM cells to Lenalidomide. Investigating the effect of EPZ-6438/Lenalidomide combination in MMC, we identified that IKZF1, IRF4 and MYC protein levels were significantly more inhibited by the combination treatment (65.5%, 63.9% and 14.8% respectively) compared with Lenalidomide (51.5%, 43% and 2.2%) or EPZ-6438 (45.2%, 38.7% and 6.2%) alone. Clinical trials are ongoing with EZH2 inhibitors in lymphoma and could be promising for a subgroup of MM patients in combination with IMiDs. Furthermore, the EZ score enables identification of MM patients with an adverse prognosis and who could benefit from treatment with EZH2 inhibitors. Disclosures Goldschmidt: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium: Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Hose:EngMab: Research Funding; Takeda: Other: Travel grant; Sanofi: Research Funding.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4543-4543
Author(s):  
Lejla Zahiragic ◽  
Christoph Schliemann ◽  
Ralf Bieker ◽  
Wolfgang E. Berdel ◽  
Rolf M. Mesters

Abstract Angiogenesis is required for tumor growth and metastasis and is an attractive target for cancer therapy. Because of its pivotal role in tumorassociated angiogenesis across a wide range of malignancies, vascular endothelial growth factor-A (VEGF-A) has emerged as a central therapeutic target in cancer. Neoangiogenesis has been shown to play an important role in the pathogenesis of AML (Padro et al., Blood 2000) and antiangiogenic therapy could constitute a novel strategy for its treatment (Mesters et al., Blood 2001). Autocrine and paracrine secretion of vascular endothelial growth factor (VEGF) in the bone marrow may promote proliferation and survival of leukemic blasts (Fiedler et al., Blood 1997). This concept represented the rationale for the therapeutic application of bevacizumab (BV), a recombinant humanised monoclonal antibody against VEGF, in patients with advanced AML after failure of standard treatment. Nine patients (median age 63 years; range 46–81 years) with relapsed and/or refractory AML not judged medically fit for further intensive chemotherapy were enrolled in this study. All patients received at least one cycle of BV (10 mg/kg body weight), 5 patients received 2 cycles (days 1 and 14) and 2 patients a 3rd cycle (day 35). Treatment was well tolerated, without treatment-related side effects. Two patients had to be withdrawn from drug administration after cycle one due to progressive disease. After treatment with BV none of the patients fulfilled the criteria of a partial response, defined as the clearance of at least 50 % marrow blasts accompanied by increases in platelet counts and haemoglobin values. The level of VEGF expression in the bone marrow determined by immunohistochemistry significantly decreased during treatment with BV (before BV treatment: median of 3.78 arbitrary units (AU) [range 1.5–5.8 AU]; after BV treatment: median of 2.57 AU [range 1.3–5.0 AU]; Wilcoxon test, P&lt;0.05). In contrast, VEGFR-2 expression by leukemic blasts and bone marrow microvessel density did not change significantly. In conclusion, single agent BV has no significant antileukemic activity in relapsed and/or refractory AML.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 951-951 ◽  
Author(s):  
Abdel Kareem Azab ◽  
Phong Quang ◽  
Feda Azab ◽  
Costas M Pitsillides ◽  
John T Patton ◽  
...  

Abstract Abstract 951 INTRODUCTION: Multiple Myeloma (MM) is characterized by widespread disease at diagnosis with the presence of multiple lytic lesions and disseminated involvement of the bone marrow (BM), implying that the progression of MM involves a continuous re-circulation of the MM cells in the peripheral blood and re-entrance into the BM. Selectins are adhesion molecules expressed by activated endothelium of venules and leukocytes, and are involved in the primary interaction of lymphocytes with the endothelium of blood vessels. The binding of selectins serves as a biologic brake, making leukocyte quickly decelerate by rolling on endothelial cells, as the first step of extravasation. In this study, we have investigated the role of selectins and their ligands in the regulation of homing of MM Cells to the BM and the therapeutic implications of this role. METHODS AND RESULTS: We have used flow cytometry to characterize the expression of E, L and P-selectins and their ligands on MM cell lines, patient samples and on plasma cells from normal subjects. We found that all MM cell lines and patient samples showed high expression of L and P, but little of no E-selectin. While normal plasma cells showed low expression of all selectins and ligands.(give numbers) A pan-selectin inhibitor GMI-1070 (GlycoMimetics Inc., Gaithersburg, MD) inhibited the interaction of recombinant selectins with the selectin-ligands on the MM cells in a dose response manner. We have tested the role of the selectins and their ligands on the adhesion of MM cells to endothelial cells and found that MM cells adhered preferentially to endothelial cells expressing P-selectin compared to control endothelial cells and endothelial cells expressing E-selectin (p<0.05). Moreover, we found that blockade of P-selectin on endothelial cells reduced their interaction with MM cells (p<0.01), while blockade of E and L-selectin did not show any effect. Treating endothelial cells with GMI-1070 mimicked the effect of blocking P-selectin. Moreover, we found that treating endothelial cells with the chemokine stroma cell-derived factor-1-alpha (SDF1) increased their expression of P but not E or L-selectin detected by flow cytometry. Neither the blockade of each of the selectins and their ligands nor the GMI-1070 inhibited the trans-well chemotaxis of MM cells towards SDF1-alpha. However, blockade of P-selectin (p<0.001) on endothelial cells by GMI-1070 inhibited the trans-endothelial chemotaxis of MM cells towards SDF1-alpha. Both adhesion to endothelial cells and activation with recombinant P-selectin induced phosphorylation of cell adhesion related molecules including FAK, SRC, Cadherins, Cofilin, AKT and GSK3. GMI-1070 decreased the activation of cell adhesion molecules induced by both recombinant P-selectin and endothelial cells. Using in vivo flow cytometry we found that both anti P-selectin antibody and GMI-1070 prevented the extravasation of MM cells out of blood vessels into the bone marrow in mice. Moreover, we found that, in a co-culture system, endothelial cells protected MM cells from bortezomib induced apoptosis, an effect which was reversed by using GMI-1070, showing synergistic effect with bortezomib. CONCLUSION: In summary, we showed that P-selectin ligand is highly expressed in MM cells compared to normal plasma cells, and that it plays a major role in homing of MM cells to the BM, an effect which was inhibited by the pan-selectin inhibitor GMI-1070. This provides a basis for testing the effect of selectin inhibition on tumor initiation and tumor response to therapeutic agents such as bortezomib. Moreover, it provides a basis for future clinical trials for prevention of MM metastasis and increasing efficacy of existing therapies by using selectin inhibitors for the treatment of myeloma. Disclosures: Patton: GlycoMimetics, Inc: Employment. Smith:GlycoMimetics, Inc: Employment. Sarkar:GlycoMimetics, Inc: Employment. Anderson:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Magnani:GlycoMimetics, Inc.: Employment. Ghobrial:Millennium: Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.


2021 ◽  
Vol 11 ◽  
Author(s):  
Gilberto Gastelum ◽  
Mysore Veena ◽  
Kylee Lyons ◽  
Christopher Lamb ◽  
Nicole Jacobs ◽  
...  

Multiple myeloma (MM) is an incurable cancer arising from malignant plasma cells that engraft in the bone marrow (BM). The physiology of these cancer cells within the BM microenvironment (TME) plays a critical role in MM development. These processes may be similar to what has been observed in the TME of other (non-hematological) solid tumors. It has been long reported that within the BM, vascular endothelial growth factor (VEGF), increased angiogenesis and microvessel density, and activation of hypoxia-induced transcription factors (HIF) are correlated with MM progression but despite a great deal of effort and some modest preclinical success the overall clinical efficacy of using anti-angiogenic and hypoxia-targeting strategies, has been limited. This review will explore the hypothesis that the TME of MM engrafted in the BM is distinctly different from non-hematological-derived solid tumors calling into question how effective these strategies may be against MM. We further identify other hypoxia-mediated effectors, such as hypoxia-mediated acidification of the TME, oxygen-dependent metabolic changes, and the generation of reactive oxygen species (ROS), that may prove to be more effective targets against MM.


Sign in / Sign up

Export Citation Format

Share Document