Angiogenesis in multiple myeloma

Targeting the bone marrow microenvironment in multiple myeloma

Multiple myeloma (MM) is characterized by clonal expansion of malignant plasma cells in the bone marrow (BM). Despite the significant advances in treatment, MM is still a fatal malignancy. This is mainly due to the supportive role of the BM microenvironment in differentiation, migration, proliferation, survival, and drug resistance of the malignant plasma cells. The BM microenvironment is composed of a cellular compartment (stromal cells, osteoblasts, osteoclasts, endothelial cells, and immune cells) and a non-cellular compartment. In this review, we discuss the interaction between the malignant plasma cell and the BM microenvironment and the strategy to target them.

The Cyclophilin A-CD147 complex promotes the proliferation and homing of multiple myeloma cells

B cell malignancies frequently colonize the bone marrow. The mechanisms responsible for this preferential homing are incompletely understood. Here we studied multiple myeloma (MM) as a model of a terminally differentiated B cell malignancy that selectively colonizes the bone marrow. We found that extracellular CyPA (eCyPA), secreted by bone marrow endothelial cells (BMECs), promoted the colonization and proliferation of MM cells in an in vivo scaffold system via binding to its receptor, CD147, on MM cells. The expression and secretion of eCyPA by BMECs was enhanced by BCL9, a Wnt-β-catenin transcriptional coactivator that is selectively expressed by these cells. eCyPA levels were higher in bone marrow serum than in peripheral blood in individuals with MM, and eCyPA-CD147 blockade suppressed MM colonization and tumor growth in the in vivo scaffold system. eCyPA also promoted the migration of chronic lymphocytic leukemia and lymphoplasmacytic lymphoma cells, two other B cell malignancies that colonize the bone marrow and express CD147. These findings suggest that eCyPA-CD147 signaling promotes the bone marrow homing of B cell malignancies and offer a compelling rationale for exploring this axis as a therapeutic target for these malignancies.

Targeting of multiple myeloma-related angiogenesis by miR-199a-5p mimics: in vitro and in vivo anti-tumor activity

Multiple myeloma (MM) cells induce relevant angiogenic effects within the human bone marrow milieu (huBMM) by the aberrant expression of angiogenic factors. Hypoxia triggers angiogenic events within the huBMM and the transcription factor hypoxia-inducible factor-1α (HIF-1α) is over-expressed by MM cells. Since synthetic miR-199a-5p mimics negatively regulates HIF-1α, we here investigated a miRNA-based therapeutic strategy against hypoxic MM cells. We indeed found that enforced expression of miR-199a-5p led to down-modulated expression of HIF-1α as well as of other pro-angiogenic factors such as VEGF-A, IL-8, and FGFb in hypoxic MM cells in vitro. Moreover, miR-199a-5p negatively affected MM cells migration, while it increased the adhesion of MM cells to bone marrow stromal cells (BMSCs) in hypoxic conditions. Furthermore, transfection of MM cells with miR-199a-5p significantly impaired also endothelial cells migration and down-regulated the expression of endothelial adhesion molecules such as VCAM-1 and ICAM-1. Finally, we identified a hypoxia/AKT/miR-199a-5p loop as a potential molecular mechanism responsible of miR-199a-5p down-regulation in hypoxic MM cells. Taken together our results indicate that miR-199a-5p has an important role for the pathogenesis of MM and support the hypothesis that targeting angiogenesis via a miRNA/HIF-1α pathway may represent a novel potential therapeutical approach for this still lethal disease.

A polysaccharide from mushroom Huaier retards human hepatocellular carcinoma growth, angiogenesis, and metastasis in nude mice

Mushroom Huaier has become a focus of interest in the treatment of hepatocellular carcinoma (HCC). Presently, we isolated and purified one polysaccharide from this mushroom. This study aimed to investigate the effects of SP1 on tumor growth and metastasis in a HCC xenograft model and explore its possible mechanism of action. Our results showed that SP1 not only significantly inhibited the proliferation of SMMC-7721 cells in vitro at the concentration ranging from 0 to 800 μg/ml but also suppressed the HCC tumor growth and metastatic nodules to the lung in SMMC-7721-bearing mice by oral administration at three doses of 30, 60, and 120 mg/kg. Concomitantly, immunohistochemistry analysis of tumor tissues identified that SP1 administration at three doses significantly inhibited the in vivo cancer cell proliferation and microvessel density (MVD) formation, evidenced by a low proliferating cell nuclear antigen (PCNA) and CD34 expression, but increased the percentage of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells. Keeping in line with this observation, SP1 treatment decreased serum matrix metalloproteinase (MMP) 2 and vascular endothelial growth factor (VEGF) levels, downregulated the protein expression of hypoxia-inducible factor (HIF)-1alpha, VEGF, MMP2, bcl-2, N-cadherin, signal transducer and activator of transcription 3 (STAT3), and metadherin (MTDH), and upregulated bax and NE-cadherin protein expression in tumor tissues. Taken together, our data suggest that SP1 appears to be a promising chemopreventive agent for the tumorigenesis and metastasis in patients with HCC, especially at advanced stages.

Angiopoietin-2 in Bone Marrow milieu promotes Multiple Myeloma-associated angiogenesis

Angiopoietin-2 (Ang-2) is involved in angiogenesis in both solid and hematological malignancies. In Multiple Myeloma (MM), serum Ang-2 correlates with disease progression and response to therapy. To address the patho-physiologic role of Ang-2 in MM associated angiogenesis, we used sera from patients with active MM, which contained significantly higher levels of the molecule, compared to those from patients with smoldering MM and Monoclonal Gammopathy of Undetermined Significance. MM Bone Marrow (BM) sera with high Ang-2 concentration specifically contributed to endothelial cell (EC) activation, while Ang-1 containing sera maintained EC stabilization. The functional dichotomy of Ang-1 and Ang-2 was confirmed by the triggering of distinctive signaling pathways down-stream the common Tie-2 receptor, i.e., the Akt or the ERK- phosphorylation pathway. Notably, Ang-2 but not VEGF serum levels correlated with BM micro-vessel density, further underscoring the key role of Ang-2 in angiogenesis. Western Blot, RT-PCR and immunocytochemistry identified MMEC as the major source of Ang-2, at variance with MM cells and CD14(+) BM monocytes. These data suggest that Ang-2 produced in the BM milieu may contribute to MM angiogenesis and suggest that the molecule can be further exploited both as angiogenesis biomarker and as a potential therapeutic target.

Stimulation of invariant natural killer T cells by α-Galactosylceramide activates the JAK-STAT pathway in endothelial cells and reduces angiogenesis in the 5T33 multiple myeloma model

Tumour pathogenesis in multiple myeloma (MM) correlates with a high vascular index. Therefore, targeting angiogenesis is an important therapeutic tool to reduce MM progression. This study aimed to investigate the role of invariant natural killer T (iNKT) cells in angiogenesis and the mechanisms behind the stimulation by α-Galactosylceramide (α-GalCer). We have previously found that α-GalCer could increase the survival of 5T33MM mice and here we demonstrate that α-GalCer reduces the microvessel density. We performed both in vivo and in vitro angiogenic assays to confirm this observation. We found that conditioned medium of α-GalCer stimulated iNKT cells reduced neovascularization in the chick chorioallantoic membrane and in matrigel plug assays. Moreover, we observed a reduction in proliferation, migration and network formation and an induction of apoptosis upon exposure of murine endothelial cell lines to this conditioned medium. We furthermore observed that the JAK-STAT signaling pathway was highly activated in endothelial cells in response to stimulated iNKT cells, indicating the possible role of IFN-γ in the anti-angiogenic process. In conclusion, these results highlight the possibility of recruiting iNKT cells to target MM and angiogenesis. This gives a rationale for combining immunotherapy with conventional anti-tumour treatments in view of increasing their therapeutic potential.

Biology and bioinformatics of myeloma cell

Multiple myeloma (MM) is a plasma cell disorder that occurs in about 10% of all hematologic cancers. The majority of patients (99%) are over 50 years of age when diagnosed. In the bone marrow (BM), stromal and hematopoietic stem cells (HSCs) are responsible for the production of blood cells. Therefore any destruction or/and changes within the BM undesirably impacts a wide range of hematopoiesis, causing diseases and influencing patient survival. In order to establish an effective therapeutic strategy, recognition of the biology and evaluation of bioinformatics models for myeloma cells are necessary to assist in determining suitable methods to cure or prevent disease complications in patients. This review presents the evaluation of molecular and cellular aspects of MM such as genetic translocation, genetic analysis, cell surface marker, transcription factors, and chemokine signaling pathways. It also briefly reviews some of the mechanisms involved in MM in order to develop a better understanding for use in future studies.

Value of whole body MRI and dynamic contrast enhanced MRI in the diagnosis, follow-up and evaluation of disease activity and extent in multiple myeloma

PURPOSE

To evaluate the significance of dynamic contrast enhanced MRI (DCE-MRI) and whole body MRI (WB-MRI) in the diagnosis, prognosis and assessment of therapy for patients with monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM).

MATERIALS AND METHODS

The retrospective study includes 219 patients providing 463 WB-MRI and DCE-MRI investigations for the subgroups MGUS (n=70), MM active disease (n=126; this includes 70 patients with new diagnosis of MM, according to the International Staging System (ISS): 41.4% ISS stage I, 20.0% ISS stage II, 7.1% ISS stage III, 31.4% insufficient for staging; and 56 patients with '(re-)active disease': 16.07% relapse, 32.14% progressive disease and 51.79% stable disease) and MM remission (n=23; 60.87% complete remission, 17.39% very good partial remission and 21.74% partial remission). Investigations of patients with hereditary multiple exostoses (n=5), neurofibromatosis (n=7) and healthy persons (n=9) were added as control subjects (n=21). WB-MRI evaluation was done by evaluating thirteen skeletal regions, providing a 'skeletal score'. DCE-MRI images of the spine, were analyzed with regions-of-interest and time-intensity-curves (TIC).

RESULTS

All TIC parameters can significantly differentiate between the predefined subgroups (p<0.001). One hundred days after autologous stem cell transplantation a 75% decrease of the slope wash-in value (p<0.001) can be seen. A cubic regression trend between 'skeletal score' and slope wash-in (adj.R(2)=0.412) could demonstrate a significant increase bone marrow perfusion if MM affects more than 10 skeletal regions (p<0.001), associated with a poorer prognosis (p<0.001).

CONCLUSION

DCE-MRI evaluation of the spine is useful for diagnosis of MM, follow-up after stem cell transplantation and evaluation of disease activity. A combined evaluation with WB-MRI and DCE-MRI provides additional micro-vascular information on the morphologic lesions and could help categorize patients with MM in two different groups to offer useful therapeutic and prognostic advise.

The hypoxia target adrenomedullin is aberrantly expressed in multiple myeloma and promotes angiogenesis

In multiple myeloma (MM), angiogenesis is strongly correlated to disease progression and unfavorable outcome, and may be promoted by bone marrow hypoxia. Employing gene-expression profiling, we here identified the pro-angiogenic factor adrenomedullin (AM) as the most highly upregulated gene in MM cells exposed to hypoxia. Malignant plasma cells from the majority of MM patients, belonging to distinct genetic subgroups, aberrantly express AM. Already under normoxic conditions, a subset of MM highly expressed and secreted AM, which could not be further enhanced by hypoxia or cobalt chloride-induced stabilization of hypoxia-inducible factor (HIF)1α. In line with this, expression of AM did not correlate with expression of a panel of established hypoxia-/HIF1α-target genes in MM patients. We demonstrate that MM-driven promotion of endothelial cell proliferation and tube formation is augmented by inducible expression of AM and strongly repressed by inhibition of endogenous and hypoxia-induced AM activity. Together, our results demonstrate that MM cells, both in a hypoxia-dependent and -independent fashion, aberrantly express and secrete AM, which can mediate MM-induced angiogenesis. Thus, AM secretion can be a major driving force for the angiogenic switch observed during MM evolution, which renders AM a putative target for MM therapy.

Tumor-associated macrophages as a prognostic parameter in multiple myeloma

The interaction between multiple myeloma (MM) cells and the bone marrow stroma constitutes the basis of myeloma pathogenesis and has led the way for the corresponding therapeutic strategies. The aim of this study is to evaluate tumor-associated macrophages (TAMs) which is an important element of bone marrow stroma and its prognostic relevance in newly diagnosed MM patients. We also wanted to determine the association between TAMs and microvessel density (MVD). Sixty-eight patients, who were diagnosed with MM at the Department of Hematology, Gazi University Hospital, between January 2000 and January 2011, were reviewed retrospectively. Tumor-associated macrophages were evaluated by staining with anti-CD68 and anti-CD163 monoclonal antibodies, and MVD was evaluated by factor VIII staining. Median age was 60 (range, 40-84) years with 36 males and 32 females. The number of both CD 68+ and CD 163+ cells had a negative impact on OS at 6 years (p = 0.013 vs. 0.036; p = 0.015 vs. 0.039) in univariate and multivariate analysis in which age, sex, ISS, the induction treatment, and response to induction treatment are included as variables. High-grade MVD was found to be associated with increased CD163+ cell count. In conclusion, TAMs seems to be a promising prognostic histopathological marker in newly diagnosed MM patients.

Novel renal replacement strategies for the elimination of serum free light chains in patients with kappa light chain nephropathy

Multiple myeloma (MM) is a malignancy with excessive production of monoclonal proteins. At disease presentation 30% of MM patients have significant renal impairment which may progress to renal failure requiring dialysis. Besides chemotherapy extracorporeal elimination procedures such as plasma exchange have been applied as adjuvant strategies to eliminate free light chains from circulating blood, however the efficacy was poor with older techniques. We report about a highly efficient method to eliminate serum free light chain (sFLC) using a newly designed protein leaking membrane in patients suffering from sFLC induced acute renal failure. The protein leaking membrane (HCO 1100) is characterized by increased pore size facilitating elimination of middle molecules such as sFLC kappa (22.5 kD). The HCO 1100 membrane was applied in a hemodialysis and hemodiafiltration mode and compared to standard procedures (high flux hemodialysis, hemodiafiltration and plasma exchange). Hemodiafiltration with the protein leaking membrane HCO 1100 was superior to all other extracorporeal replacement strategies in eliminating sFLC-kappa from circulating blood. A median blood reduction rate of 40.8% (range 13.9% - 66.4%) was achieved during hemodiafiltration. The corresponding peak clearance rate was 25 ml/min. Importantly, the poorest elimination rate was achieved by plasma exchange followed by standard high flux hemodialysis. Extracorporeal elimination strategies with the protein leaking membrane HCO 1100 may be a promising adjuvant treatment strategy for patients with sFLC nephropathy requiring dialysis. Hemodiafiltration and to lesser extend also hemodialysis with the HCO 1100 hemofilter are able to eliminate substantial amounts of sFLC kappa in MM patients.

Endothelial progenitor cells: current issues on characterization and challenging clinical applications

Since their discovery about a decade ago, endothelial precursor cells (EPC) have been subjected to intensive investigation. The vision to stimulate respectively suppress a key player of vasculogenesis opened a plethora of clinical applications. However, as research opened deeper insights into EPC biology, the enthusiasm of the pioneer era has been damped in favour of a more critical view. Recent research is focused on three major questions: The fact that the number of EPC in peripheral blood is exceedingly low has consistently raised suspicion whether these cells can plausibly have an impact on physiological or pathophysiological processes. Secondly, whereas the key role of EPC in tumourigenesis has been strongly emphasized by various groups in the past, recent publications are challenging this hypothesis. Thirdly, the lack of consensus on EPC-defining markers and standardized protocols for their detection have repeatedly led to difficulties concerning comparability between papers. In this current review, an overview on recent findings on EPC biology is given, their challenging clinical implications are discussed and the perplexity underlying the current controversial debate is illustrated.

Relapsed/Refractory multiple myeloma: defining refractory disease and identifying strategies to overcome resistance

Despite the development of more effective therapies for multiple myeloma (MM) over the past decade, nearly all patients will eventually experience disease relapse and require further therapy. Designing the next generation of therapies for relapsed and refractory disease will depend on understanding the complex molecular pathogenesis of MM and mechanisms of resistance. Oncogenomic studies have identified many potential therapeutic targets and have led to emerging models of the multistep molecular pathogenesis of MM. The key to overcoming resistance may depend on interrupting the complex interactions between MM cells and the bone microenvironment. Direct interaction between MM cells and bone marrow cells activates pleiotropic signaling pathways that mediate growth, survival, and migration of MM cells as well as resistance to chemotherapy (known as cell adhesion-mediated drug resistance). The bone marrow also secretes growth factors and cytokines that maintain MM cells and inhibit apoptosis. Therefore, successful therapeutic strategies must target not only the MM plasma cell but also the bone microenvironment. The benefit of immunomodulatory drugs such as thalidomide and lenalidomide and the proteasome inhibitor bortezomib in relapsed/refractory MM is related to their ability to target both. Novel agents and combination strategies are building on the success of these agents and targeting synergistic pathways.

Pentraxin 3 (PTX3) inhibits plasma cell/stromal cell cross-talk in the bone marrow of multiple myeloma patients

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that binds with high affinity and selectivity to fibroblast growth factor-2 (FGF2), thus inhibiting its pro-angiogenic activity. Here we investigated the effects of PTX3 on monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patient-derived bone marrow (BM) plasma cells (PCs), endothelial cells (ECs), and fibroblasts (FBs), and assessed whether PTX3 can modulate the cross-talk between PCs and those microenvironment cells. PTX3 and FGF2 expression was evaluated by ELISA. Functional studies, including cell viability, wound healing, chemotaxis, and Matrigel(®) assays, were performed on MGUS and MM ECs and FBs upon the PTX3 treatment. Through western blot PTX3-induced modulation in FGF2/FGF receptor signalling pathways was evaluated in MGUS and MM ECs and FBs through western blot. Co-cultures between MM ECs/FBs and human PC lines were used to evaluate possible PTX3 indirect effects on MM PCs. Adhesion molecules were studied by flow cytometry. PTX3 provides a direct time- and dose-dependent apoptotic effect on MM ECs and FBs, but not on either MM primary PCs or human PC lines. PTX3 inhibits migration of MM ECs and FBs in a dose-dependent manner, and impacts in vitro and in vivo FGF2-mediated MM angiogenesis. Co-cultures of PCs and ECs/FBs show that PTX3 treatment indirectly impairs PC viability and adhesion. We conclude that PTX3 is an anti-angiogenic factor in MM and behaves as a cytotoxic molecule on MM cells by inhibiting the cross-talk between PCs and ECs/FBs.

Total Saponin from Root of Actinidia valvata Dunn Inhibits Hepatoma 22 Growth and Metastasis In Vivo by Suppression Angiogenesis

The root of Actinidia valvata dunn has been widely used in the treatment of hepatocellular carcinoma (HCC), proved to be beneficial for a longer and better life in China. In present work, total saponin from root of Actinidia valvata Dunn (TSAVD) was extracted, and its effects on hepatoma H22-based mouse in vivo were observed. Primarily transplanted hypodermal hepatoma H22-based mice were used to observe TSAVD effect on tumor growth. The microvessel density (MVD), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) are characterized factors of angiogenesis, which were compared between TSAVD-treated and control groups. Antimetastasis effect on experimental pulmonary metastasis hepatoma mice was also observed in the study. The results demonstrated that TSAVD can effectively inhibit HCC growth and metastasis in vivo, inhibit the formation of microvessel, downregulate expressions of VEGF and bFGF, and retrain angiogenesis of hepatoma 22 which could be one of the reasons.

Intrinsic therapeutic applications of noble metal nanoparticles: past, present and future

Biomedical nanotechnology is an evolving field having enormous potential to positively impact the health care system. Important biomedical applications of nanotechnology that may have potential clinical applications include targeted drug delivery, detection/diagnosis and imaging. Basic understanding of how nanomaterials, the building blocks of nanotechnology, interact with the cells and their biological consequences are beginning to evolve. Noble metal nanoparticles such as gold, silver and platinum are particularly interesting due to their size and shape dependent unique optoelectronic properties. These noble metal nanoparticles, particularly of gold, have elicited a lot of interest for important biomedical applications because of their ease of synthesis, characterization and surface functionalization. Furthermore, recent investigations are demonstrating another promising application of these nanomaterials as self-therapeutics. To realize the potential promise of these unique inorganic nanomaterials for future clinical translation, it is of utmost importance to understand a few critical parameters; (i) how these nanomaterials interact with the cells at the molecular level; (ii) how their biodistribution and pharmacokinetics influenced by their surface and routes of administration; (iii) mechanism of their detoxification and clearance and (iv) their therapeutic efficacy in appropriate disease model. Thus in this critical review, we will discuss the various clinical applications of gold, silver and platinum nanoparticles with relevance to above parameters. We will also mention various routes of synthesis of these noble metal nanoparticles. However, before we discuss present research, we will also look into the past. We need to understand the discoveries made before us in order to further our knowledge and technological development (318 references).

Neovascular niche for human myeloma cells in immunodeficient mouse bone

The interaction with bone marrow (BM) plays a crucial role in pathophysiological features of multiple myeloma (MM), including cell proliferation, chemoresistance, and bone lesion progression. To characterize the MM-BM interactions, we utilized an in vivo experimental model for human MM in which a GFP-expressing human MM cell line is transplanted into NOG mice (the NOG-hMM model). Transplanted MM cells preferentially engrafted at the metaphyseal region of the BM endosteum and formed a complex with osteoblasts and osteoclasts. A subpopulation of MM cells expressed VE-cadherin after transplantation and formed endothelial-like structures in the BM. CD138⁺ myeloma cells in the BM were reduced by p53-dependent apoptosis following administration of the nitrogen mustard derivative bendamustine to mice in the NOG-hMM model. Bendamustine maintained the osteoblast lining on the bone surface and protected extracellular matrix structures. Furthermore, bendamustine suppressed the growth of osteoclasts and mesenchymal cells in the NOG-hMM model. Since VE-cadherin⁺ MM cells were chemoresistant, hypoxic, and HIF-2α-positive compared to the VE-cadherin⁻ population, VE-cadherin induction might depend on the oxygenation status. The NOG-hMM model described here is a useful system to analyze the dynamics of MM pathophysiology, interactions of MM cells with other cellular compartments, and the utility of novel anti-MM therapies.

Inhibition of tumor-induced angiogenesis and its mechanism by ardipusilloside I purified from Ardisia pusilla

The aim of this study was to evaluate the effects of ardipusilloside I isolated from Ardisia pusilla on tumor angiogenesis and its mechanism of action. The anti-angiogenic effect in vivo was evaluated on xenograft in the athymic mice model and the chicken chorioallantoic membrane (CAM) neovascularization model, the inhibition of growth in vitro was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and the mechanism was demonstrated through detecting microvessel density (MVD), vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR2) and P-VEGFR2 protein expressions, as well as mRNA expressions of VEGF and VEGFR2. The results showed that ardipusilloside I had a good inhibitory effect on A549 xenografted tumor growth, angiogenesis of CAM, and A549 cell growth. Compared to the negative control, MVD protein and mRNA expressions of VEGF and VEGFR were significantly inhibited by ardipusilloside I in a dose-dependent manner. These findings suggested that ardipusilloside I might be a promising candidate as angiogenesis inhibitors.

Biological aspects of angiogenesis in multiple myeloma

Multiple myeloma (MM) is a hematological malignancy characterized by the aberrant expansion of malignant plasma cells within the bone marrow (BM). One of the hallmarks of this disease is the close interaction between myeloma cells and neighboring cells within the BM. Angiogenesis, through the activation of endothelial cells, plays an essential role in MM biology. In the current review, we describe the angiogenesis process in MM by identifying the interacting cells, the pro- and anti-angiogenic cytokines modulated, and the extracellular matrix degrading proteases liable to participate in the pathophysiology. Finally, we highlight the impact of hypoxia (through hypoxia-inducible factor-1) and constitutive activation of nuclear factor-κB in this tumor-induced neo-vascularization.

Syndecan-1 promotes the angiogenic phenotype of multiple myeloma endothelial cells

Angiogenesis is considered a hallmark of multiple myeloma (MM) progression. In the present study, we evaluated the morphological and functional features of endothelial cells (ECs) derived from bone marrow (BM) of patients affected by MM (MMECs). We found that MMECs compared with normal BM ECs (BMECs) showed increased expression of syndecan-1. Silencing of syndecan-1 expression by RNA interference technique decreased in vitro EC survival, proliferation and organization in capillary-like structures. In vivo, in severe combined immunodeficient mice, syndecan-1 silencing inhibited MMEC organization into patent vessels. When overexpressed in human umbilical vein ECs and BMECs, syndecan-1 induced in vitro and in vivo angiogenic effects. Flow-cytometric analysis of MMECs silenced for syndecan-1 expression indicated a decreased membrane expression of vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2). Immunoprecipitation and confocal analysis showed colocalization of VEGFR-2 with syndecan-1. Absence of nuclear translocation of VEGFR-2 in syndecan-1-knockdown cells together with the shift from perinuclear localization to recycling compartments suggest a role of syndecan-1 in modulation of VEGFR-2 localization. This correlated with an in vitro decreased VEGF-induced invasion and motility. These results suggest that syndecan-1 may contribute to the highly angiogenic phenotype of MMECs by promoting EC proliferation, survival and modulating VEGF-VEGFR-2 signalling.

Targeting the tumor microenvironment: focus on angiogenesis

Tumorigenesis is a complex multistep process involving not only genetic and epigenetic changes in the tumor cell but also selective supportive conditions of the deregulated tumor microenvironment. One key compartment of the microenvironment is the vascular niche. The role of angiogenesis in solid tumors but also in hematologic malignancies is now well established. Research on angiogenesis in general, and vascular endothelial growth factor in particular, is a major focus in biomedicine and has led to the clinical approval of several antiangiogenic agents including thalidomide, bevacizumab, sorafenib, sunitinib, pazopanib, temesirolimus, and everolimus. Indeed, antiangiogenic agents have significantly changed treatment strategies in solid tumors (colorectal cancer, renal cell carcinoma, and breast cancer) and multiple myeloma. Here we illustrate important aspects in the interrelationship between tumor cells and the microenvironment leading to tumor progression, with focus on angiogenesis, and summarize derived targeted therapies.

Angiogenesis and multiple myeloma

The bone marrow microenvironment in multiple myeloma is characterized by an increased microvessel density. The production of pro-angiogenic molecules is increased and the production of angiogenic inhibitors is suppressed, leading to an "angiogenic switch". Here we present an overview of the role of angiogenesis in multiple myeloma, the pro-angiogenic factors produced by myeloma cells and the microenvironment, and the mechanisms involved in the myeloma-induced angiogenic switch. Current data suggest that the increased bone marrow angiogenesis in multiple myeloma is due to the aberrant expression of angiogenic factors by myeloma cells, the subsequent increase in pro-angiogenic activity of normal plasma cells as a result of myeloma cell angiogenic activity, and the increased number of plasma cells overall. Hypoxia also contributes to the angiogenic properties of the myeloma marrow microenvironment. The transcription factor hypoxia-inducible factor-1α is overexpressed by myeloma cells and affects their transcriptional and angiogenic profiles. In addition, potential roles of the tumor suppressor gene inhibitor of growth family member 4 and homeobox B7 have also been recently highlighted as repressors of angiogenesis and pro-angiogenic related genes, respectively. This complex pathogenetic model of myeloma-induced angiogenesis suggests that several pro-angiogenic molecules and related genes in myeloma cells and the microenvironment are potential therapeutic targets.

Prognostic value of bone marrow microvessel density and angiogenic cytokines in patients with multiple myeloma undergoing autologous stem cell transplant

Angiogenesis is important for the proliferation and metastasis of most malignant neoplasms including multiple myeloma (MM). The aim of this study was to evaluate the role of bone marrow angiogenesis and angiogenic cytokines in patients with MM prior to and after autologous stem cell transplant (ASCT). Twenty-nine patients with MM who underwent ASCT had serial samples of serum and bone marrow biopsies at diagnosis, prior to ASCT, and at the 3rd and 6th months post-transplant. Besides bone marrow microvessel density (MVD), serum angiogenic cytokines including vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) and markers of disease activity such as interleukin-6 (IL-6), IL-1β, C-reactive protein (CRP), β(2)-microglobulin, and bone marrow plasma cells (BMPCs) were also determined. Bone marrow MVD, serum levels of IL-6, CRP, and β(2)-microglobulin, and BMPCs decreased significantly from diagnosis to the 6th month post-transplant (p < 0.05). Serum FGF and IL-1β levels decreased significantly until 3 months post-transplant, however lost this significance at the 6th month. Serum VEGF levels did not vary significantly during follow-up. MVD, serum angiogenic cytokine levels, and parameters reflecting disease activity were similar in responders and non-responders to induction chemotherapy. Cytokines and MVD both at diagnosis and prior to transplant did not show any correlation with overall survival (OS) and progression-free survival (PFS) after a median follow-up of 55 months after transplant (p > 0.05). Our findings suggest that bone marrow MVD decreases significantly with ASCT in MM, however without an impact on OS and PFS.

Pathogenesis of myeloma

Multiple myeloma (MM) is a neoplasm of post-germinal center, terminally differentiated B cells. It is characterized by a multifocal proliferation of clonal, long-lived plasma cells within the bone marrow (BM) and associated skeletal destruction, serum monoclonal gammopathy, immune suppression, and end-organ sequelae. MM is preceded by an age-progressive premalignant condition termed monoclonal gammopathy of undetermined significance. Unlike the genomes of most hematological malignancies, and similar to those of solid-tissue neoplasms, MM genomes are typified by numerous structural and numerical chromosomal aberrations as well as mutations in a number of oncogenes and tumor-suppressor genes, some of which have been linked to disease pathogenesis and clinical behavior. Recent studies have also defined the importance of interactions between the MM cells and their BM microenvironment, dysregulation in signaling pathways and in a specialized subpopulation of cells within the tumor (termed myeloma cancer stem cells) for tumor cell growth and survival, and the development of resistance to therapy.

Reduction of matrix metalloproteinase-9 expression by culture filtrate of Paecilomyces farinosus J3

The aim of the present study was to investigate the anti-tumor effects of a culture filtrate of Paecilomyces farinosus J3. Various anti-tumor assays using B16 melanoma cells were carried out. Paecilomyces farinosus J3 significantly decreased the wound healing capability, invasiveness and angiogenic activity, which was confirmed by wound healing, human umbilical vein endothelial cell and invasion assays. Paecilomyces farinosus J3 strongly inhibited cell migration, tube formation and the angiogenic process in a concentration-dependent manner. Zymographic analysis also indicated a reduced expression of matrix metalloproteinase-9 (MMP-9), a 92-kDa gelatinase. Taken together, the results indicate that the anti-tumor activities of Paecilomyces farinosus J3 originate from the reduction of MMP-9 expression in B16F10 cells.

Angiopoietin-2: a potential novel diagnostic marker in multiple myeloma

BACKGROUND

Multiple myeloma (MM) was the first hematological malignancy in which a prognostic relevance of bone marrow (BM) angiogenesis was reported. Microenvironment formed by reactive oxygen species, growth factors and chemokines initiates the process of BM angiogenesis. Among the angiopoietins, angiopoietin-1 is involved in vessel stability, whereas angiopoietin-2 is involved in vessel sprouting.

DESIGN AND METHODS

Circulatory levels of angiopoietin-1, angiopoietin-2 and VEGF in 62 MM patients and 50 healthy controls were determined using ELISA.

RESULTS

Significant increase in VEGF and angiopoietin-2 level was observed in patients which correlated positively with the severity of the disease, whereas no alteration was observed in angiopoietin-1 levels.

CONCLUSION

Significant elevation in angiopoietin-2 and VEGF levels and their correlation with severity of the disease indicate their utility as potential tumor markers along with β(2)- microglobulin and might also suggest new therapeutic target for anticancer treatment.

SST0001, a chemically modified heparin, inhibits myeloma growth and angiogenesis via disruption of the heparanase/syndecan-1 axis

PURPOSE

Heparanase promotes myeloma growth, dissemination, and angiogenesis through modulation of the tumor microenvironment, thus highlighting the potential of therapeutically targeting this enzyme. SST0001, a nonanticoagulant heparin with antiheparanase activity, was examined for its inhibition of myeloma tumor growth in vivo and for its mechanism of action.

EXPERIMENTAL DESIGN

The ability of SST0001 to inhibit growth of myeloma tumors was assessed using multiple animal models and a diverse panel of human and murine myeloma cell lines. To investigate the mechanism of action of SST0001, pharmacodynamic markers of angiogenesis, heparanase activity, and pathways downstream of heparanase were monitored. The potential use of SST0001 as part of a combination therapy was also evaluated in vivo.

RESULTS

SST0001 effectively inhibited myeloma growth in vivo, even when confronted with an aggressively growing tumor within human bone. In addition, SST0001 treatment causes changes within tumors consistent with the compound's ability to inhibit heparanase, including downregulation of HGF, VEGF, and MMP-9 expression and suppressed angiogenesis. SST0001 also diminishes heparanase-induced shedding of syndecan-1, a heparan sulfate proteoglycan known to be a potent promoter of myeloma growth. SST0001 inhibited the heparanase-mediated degradation of syndecan-1 heparan sulfate chains, thus confirming the antiheparanase activity of this compound. In combination with dexamethasone, SST0001 blocked tumor growth in vivo presumably through dual targeting of the tumor and its microenvironment.

CONCLUSIONS

These results provide mechanistic insight into the antitumor action of SST0001 and validate its use as a novel therapeutic tool for treating multiple myeloma.

Angiogenic activity of mesenchymal stem cells in multiple myeloma

The pathophysiology of multiple myeloma-induced angiogenesis is complex and involves both direct production of angiogenic cytokines by plasma cells and their induction within the microenvironment. In this research, we investigated whether mesenchymal stem cells participated in inducing the angiogenic response in multiple myeloma, and explored the mechanism by which MSCs influence myeloma angiogenesis. We detected the concentration of angiogenic factors (bFGF, HGF, and VEGF) in the conditioned medium of mesenchymal stem cells and the capillary formation ability of mesenchymal stem cells in vitro. We found that conditioned medium of MSCs derived from MM significantly promoted the proliferation, chemotaxis, and capillary formation of human umbilical vein endothelial cells compared with that from normal donors. ELISA and RT-PCR were used to detect the mRNA and protein levels of angiogenic factors (bFGF, HGF, and VEGF) in the conditioned medium. We found that mRNA and protein levels of angiogenic factors were elevated in MSCs from multiple myeloma compared with normal donors.

Utility of flow cytometry immunophenotyping in multiple myeloma and other clonal plasma cell-related disorders

In recent years, multiparameter flow cytometry (MFC) immunophenotyping has become mandatory in the clinical management of hematological malignancies, both for diagnostic and monitoring purposes. Multiple myeloma (MM) and other clonal plasma cell-related (PC) disorders should be no exception to this paradigm, but incorporation of immunophenotypic studies in the management of patients with PC disorders is still far from being routinely established in many diagnostic flow cytometry laboratories. For clonal PC disorders, MFC is of clear and established clinical relevance in: (1) the differential diagnosis between MM and other PC-related disorders; (2) the identification of high-risk MGUS and smoldering MM; (3) minimal residual disease investigation after therapy; additionally it may also be useful for (4) the definition of prognosis-associated antigenic profiles; and (5) the identification of new therapeutic targets. In this article, we review the clinical value of MFC in the study of PC disorders, with specific emphasis in those areas where consensus exists on the need to incorporate MFC into routine evaluation of MM and other clonal PC-related disorders.

Bone marrow microenvironment in myelomagenesis: its potential role in early diagnosis

Multiple myeloma (MM) is the second most common hematological malignancy, with an overall survival of 4-6 years. It is always preceded by a premalignant stage called monoclonal gammopathy of unknown significance (MGUS). Importantly, at this time we lack reliable predictors to determine who will progress from MGUS to MM, and who will remain stable. The bone marrow microenvironment plays a key role in myelomagenesis (growth, survival and migration of malignant plasma cells). In the present review, we summarize and discuss our current understanding of the bone marrow microenvironment and its compartments in relation to myelomagenesis. Although it remains to be proven, we believe that an improved characterization of the cellular constituents, the extracellular matrix components and the soluble factors of the bone marrow could open up novel avenues to better understand underlying mechanisms of the transformation from MGUS to MM. Ultimately, this will lead to the development of early treatment of high-risk precursor disease aimed to delay/prevent MM.

Repression of multiple myeloma growth and preservation of bone with combined radiotherapy and anti-angiogenic agent

The effects of ionizing radiation, with or without the anti-angiogenic agent anginex (Ax), on multiple myeloma growth were tested in a SCID-rab mouse model. Mice carrying human multiple myeloma cell-containing pre-implanted bone grafts were treated weekly with various regimens for 8 weeks. Rapid multiple myeloma growth, assessed by bioluminescence intensity (IVIS), human lambda Ig light chain level in serum (ELISA), and the volume of bone grafts (caliper), was observed in untreated mice. Tumor burden in mice receiving combined therapy was reduced to 59% (by caliper), 43% (by ELISA), and 2% (by IVIS) of baseline values after 8 weeks of treatment. Ax or radiation alone slowed but did not stop tumor growth. Four weeks after the withdrawal of the treatments, tumor burden remained minimal in mice given Ax + radiation but increased noticeably in the other three groups. Multiple myeloma suppression by Ax + radiation was accompanied by a marked decrease in the number and activity of osteoclasts in bone grafts assessed by histology. Bone graft integrity was preserved by Ax + radiation but was lost in the other three groups, as assessed by microCT imaging and radiography. These results suggest that radiotherapy, when primed by anti-angiogenic agents, may be a potent therapy for focal multiple myeloma.

A survey of prognostic value of serum factors in multiple myeloma patients before treatment: macrophage-colony stimulating factor (M-CSF) is a powerful predictor of survival

Cytokines are involved in the pathogenesis of multiple myeloma (MM) and other cancers. The aim of this study was to evaluate a range of cytokines of diverse activity in patients with multiple myeloma for a possible prognostic value. Concentrations of the following cytokines and cytokine receptors were measured by ELISA in the sera of 64 untreated MM patients: IL-6, IL-8, IL-10, TNFα, sTNF R I and II, sIL-2Rα, IL-1ra, M-CSF, G-CSF, VEGF, and bFGF. Serum levels of sTNF RI, IL-6, and bFGF were elevated in over 50% of patients. There was an inverse relationship between sTNF RII, TNFα, IL-1ra, and albumin levels. There was no significant relationship between cytokines/cytokine receptors and other serum correlates of myeloma. In a univariate survival analysis, β2-microglobulin, LDH, sIL-2Rα, sTNF RI, and M-CSF were significant variables. In a multivariate analysis, only M-CSF and β2-microglobulin retained a significant influence on survival. Serum M-CSF may be considered another independent and clinically useful prognostic factor in multiple myeloma.

The molecular characterization and clinical management of multiple myeloma in the post-genome era

Cancer-causing mutations disrupt coordinated, precise programs of gene expression that govern cell growth and differentiation. Microarray-based gene-expression profiling (GEP) is a powerful tool to globally analyze these changes to study cancer biology and clinical behavior. Despite overwhelming genomic chaos in multiple myeloma (MM), expression patterns within tumor samples are remarkably stable and reproducible. Unique expression patterns associated with recurrent chromosomal translocations and ploidy changes defined molecular classes with differing clinical features and outcomes. Combined molecular techniques also dissected two distinct, reproducible forms of hyperdiploid disease and have molecularly defined MM with high risk for poor clinical outcome. GEP is now used to risk-stratify patients with newly diagnosed MM. Groups with high-risk features are evident in all GEP-defined MM classes, and GEP studies of serial samples showed that risk increases over time, with relapsed disease showing dramatic GEP shifts toward a signature of poor outcomes. This suggests a common mechanism of disease evolution and potentially reflects preferential expansion of therapy-resistant cells. Correlating GEP-defined disease class and risk with outcomes of therapeutic regimens reveals class-specific benefits for individual agents, as well as mechanistic insights into drug sensitivity and resistance. Here, we review modern genomics contributions to understanding MM pathogenesis, prognosis, and therapy.

Multiple myeloma

Multiple myeloma is characterised by clonal proliferation of malignant plasma cells, and mounting evidence indicates that the bone marrow microenvironment of tumour cells has a pivotal role in myeloma pathogenesis. This knowledge has already expanded treatment options for patients with multiple myeloma. Prototypic drugs thalidomide, bortezomib, and lenalidomide have each been approved for the treatment of this disease by targeting both multiple myeloma cells and the bone marrow microenvironment. Although benefit was first shown in relapsed and refractory disease, improved overall response, duration of response, and progression-free and overall survival can be achieved when these drugs are part of first-line regimens. This treatment framework promises to improve outcome not only for patients with multiple myeloma, but also with other haematological malignancies and solid tumours.

Induction of angiogenesis by normal and malignant plasma cells

Abundant bone marrow angiogenesis is present in almost all myeloma patients requiring therapy and correlated to treatment response and survival. We assessed the expression of 402 angiogenesis-associated genes by Affymetrix DNA microarrays in 466 samples, including CD138-purified myeloma cells (MMCs) from 300 previously untreated patients, in vivo microcirculation by dynamic contrast-enhanced magnetic resonance imaging, and in vitro angiogenesis (AngioKit-assay). Normal bone marrow plasma cells (BMPCs) express a median of 39 proangiogenic (eg, VEGFA, ADM, IGF-1) and 28 antiangiogenic genes (eg, TIMP1, TIMP2). Supernatants of BMPCs unlike those of memory B cells induce angiogenesis in vitro. MMCs do not show a significantly higher median number of expressed proangiogenic (45) or antiangiogenic (31) genes, but 97% of MMC samples aberrantly express at least one of the angiogenic factors HGF, IL-15, ANG, APRIL, CTGF, or TGFA. Supernatants of MMCs and human myeloma cell lines induce significantly higher in vitro angiogenesis compared with BMPCs. In conclusion, BMPCs express a surplus of proangiogenic over antiangiogenic genes transmitting to the ability to induce in vitro angiogenesis. Aberrant expression of proangiogenic and down-regulation of antiangiogenic genes by MMCs further increases the angiogenic stimulus, together leading to bone marrow angiogenesis at various degrees in all myeloma patients.

Reduction of serum IGF-I levels in patients affected with Monoclonal Gammopathies of undetermined significance or Multiple Myeloma. Comparison with bFGF, VEGF and K-ras gene mutation

Background

Serum levels of IGF-I in patients affected with multiple myeloma (MM) have been scarcely studied. The present study is aimed to explore this point comparing 55 healthy subjects, 71 monoclonal gammopaties of uncertain significance (MGUS) and 77 overt MM patients. In the same subjects, basic FGF and VEGF, have been detected. All three mediators were analyzed in function of K-ras mutation and melphalan response. Concerning IGF-I, two representative monitoring examples have also been added.

Methods

Cytokine determinations were performed by commercially available ELISA kits, while K12-ras mutation was investigated on genomic DNA isolated from bone marrow cell specimens by RFLP-PCR assay.

Results

Significant reductions of IGF-I levels were observed in MGUS and MM as compared with healthy controls. In addition, MM subjects showed significantly decreased serum IGF-I levels than MGUS. Conversely, increasing levels were observed for bFGF and VEGF, molecules significantly correlated. A multivariate analysis corrected for age and gender confirmed the significant difference only for IGF-I values (P = 0.01). K12-ras mutation was significantly associated with malignancy, response to therapy and with significantly increased serum bFGF levels.

Conclusion

IGF-I reduction in the transition: Controls→MGUS→MM and changes observed over time suggest that IGF-I should be furtherly studied in future clinical trials as a possible monitoring marker for MM.

Bone marrow microenvironment and the identification of new targets for myeloma therapy

The development of multiple myeloma (MM) is a complex multi-step process involving both early and late genetic changes in the tumor cell as well as selective supportive conditions by the bone marrow (BM) microenvironment. Indeed, it is now well established that MM cell-induced disruption of the BM homeostasis between the highly organized cellular and extracellular compartments supports MM cell proliferation, survival, migration and drug resistance through activation of various signaling (for example, PI3K/Akt, JAK/Stat-, Raf/MEK/MAPK-, NFkappaB- and Wnt-) pathways. Based on our enhanced understanding of the functional importance of the MM BM microenvironment and its inter-relation with the MM cell resulting in homing, seeding, proliferation and survival, new molecular targets have been identified and derived treatment regimens in MM have already changed fundamentally during recent years. These agents include thalidomide, its immunomodulatory derivative lenalidomide and the proteasome inhibitor bortezomib, which mediate tumor cytotoxicity in the BM milieu. Ongoing studies are further delineating MM pathogenesis in the BM to enhance cytotoxicity, avoid drug resistance and improve patient outcome.

Following up tumour angiogenesis: from the basic laboratory to the clinic

Preceded by three decades of intense basic research on tumour angiogenesis, we are assisting to the translation of anti-antiangiogenic therapies as medical oncologists are increasingly using pioneering anti-angiogenic drugs in combination with standard treatments. While basic knowledge in the field of angiogenesis is reaching maturity and our level of understanding of the complex process of vessel development and growth in health and disease has been enriched at the molecular and cellular levels, the translation of this knowledge to the clinic is still in its infancy. Identifying the most suitable drugs, and the optimal dosage and schedule, as well as monitoring patients' responses to anti-angiogenic therapy, remain challenging issues that currently limit the benefit of this new therapeutic approach in cancer. This review will focus on a comprehensive description of the experimental assays in which angiogenesis research has been founded and how the different assays complement and provide relevant information for the task of characterising the angiogenic properties of diverse tumours, giving us a variety of tools to follow up tumour angiogenesis in research models. Following up tumour angiogenesis in patients and their response to antiangiogenic therapy is a more challenging task that will benefit in the near future from the use of non-invasive imaging methods as well as molecular and cellular biomarkers of angiogenesis suitable for clinical oncology. As both the design of the anti-angiogenic therapies and monitoring of the response are improved in the coming years to properly tailor them to the angiogenic profile of every patient, we hope to achieve increasing response and benefit of including antiangiogenic drugs as standard in cancer therapy.

Genetic associations with thalidomide mediated venous thrombotic events in myeloma identified using targeted genotyping

A venous thromboembolism (VTE) with the subsequent risk of pulmonary embolism is a major concern in the treatment of patients with multiple myeloma with thalidomide. The susceptibility to developing a VTE in response to thalidomide therapy is likely to be influenced by both genetic and environmental factors. To test genetic variation associated with treatment related VTE in patient peripheral blood DNA, we used a custom-built molecular inversion probe (MIP)-based single nucleotide polymorphism (SNP) chip containing 3404 SNPs. SNPs on the chip were selected in "functional regions" within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and side effects associated with myeloma therapy. Patients and controls were taken from 3 large clinical trials: Medical Research Council (MRC) Myeloma IX, Hovon-50, and Eastern Cooperative Oncology Group (ECOG) EA100, which compared conventional treatments with thalidomide in patients with myeloma. Our analysis showed that the set of SNPs associated with thalidomide-related VTE were enriched in genes and pathways important in drug transport/metabolism, DNA repair, and cytokine balance. The effects of the SNPs associated with thalidomide-related VTE may be functional at the level of the tumor cell, the tumor-related microenvironment, and the endothelium. The clinical trials described in this paper have been registered as follows: MRC Myeloma IX: ISRCTN68454111; Hovon-50: NCT00028886; and ECOG EA100: NCT00033332.

Novel anti-myeloma agents and angiogenesis

During the last decade several novel agents have been used in the management of patients with multiple myeloma. Immunomodulatory drugs and proteasome inhibitors exert their efficacy both directly by inducing apoptosis of myeloma cells and indirectly through the interruption of the interactions between myeloma and stromal cells in the bone marrow (BM) microenvironment. These interactions are crucial for myeloma cell growth and survival. The adherence of myeloma cells to BM stromal cells leads to the overproduction of several cytokines with angiogenic properties that enhance the survival and growth of myeloma cells through paracrine and autocrine loops. The correlation of these molecules with clinical features and survival of myeloma patients supports the importance of angiogenesis in the pathogenesis of the disease and reveals these cytokines as suitable targets for the development of novel anti-myeloma therapies. This review summarises all available preclinical and clinical data for the effect of novel agents that are used in myeloma therapy, such as thalidomide, lenalidomide, bortezomib and VEGF inhibitors, on angiogenesis, which is at least partially responsible for their remarkable anti-myeloma efficacy.

Incorporation of the bone marker carboxy-terminal telopeptide of type-1 collagen improves prognostic information of the International Staging System in newly diagnosed symptomatic multiple myeloma

Several prognostic markers, including parameters of tumor burden and cytogenetics, were adopted to identify high-risk patients in multiple myeloma (MM). Recently, the International Staging System (ISS), including beta2-microglobulin (beta2M) and albumin, was introduced for patients with symptomatic MM. As bone disease is a hallmark of MM, we investigated the prognostic impact of the bone resorption marker carboxy-terminal telopeptide of type-1 collagen (ICTP) in combination with ISS, beta2M, albumin, deletion of chromosome 13 and high-dose therapy (HDT) in 100 patients with newly diagnosed symptomatic MM. beta2M alone, albumin alone, ISS, HDT, del(13q14) and ICTP were significant prognostic factors for overall survival (OS). In a multivariate analysis, ICTP was the most powerful prognostic factor (log-rank P<0.001, hazard ratio: ninefold increase). ICTP clearly separated two subgroups with a good and a worse prognosis within each of the three ISS stages (ISS I: P=0.027, ISS II: P=0.022, ISS III: P=0.013). Incorporation of ICTP in a combined ICTP-ISS score significantly (P<0.001) separated four risk groups with a 5-year OS rate of 95, 64, 46 and 22%, [corrected] respectively. These data demonstrate for the first time that the inclusion of the collagen-I degradation product ICTP, as a biomarker of bone resorption, adds to the prognostic value of ISS.

Targeting MET transcription as a therapeutic strategy in multiple myeloma

Multiple myeloma (MM) is an incurable indolent malignancy with an average lifespan of 3 years, underscoring the need for new therapies. Studies have shown that the receptor MET and its ligand hepatocyte growth factor play an important role in proliferation, migration, adhesion, and survival of MM cells. Hence, an effective way to decrease MET receptor may act as a viable therapeutic option. Since MET mRNA and protein have short half-lives, we hypothesized that transcription inhibitor will reduce MET transcript and protein levels and this will lead to cell death. Pharmacological (flavopiridol) and molecular (shRNA) transcription inhibitor were used to impede formation of MET transcripts. The diminution of global RNA synthesis with flavopiridol was related to phosphorylation status of Ser residues (r (2) = 0.90 and 0.92 for Ser2 and Ser5) on the C-terminal-domain of RNA polymerase II. This was accompanied with a time-dependent decrease in MET transcript, which reached to less than 30% (1 microM) and 10% (3 microM) by 24 h. This decline in transcript level was directly associated with a reduction in MET protein level (r (2) = 0.82) and resulted in cell death. Assessment of MET in MM survival was done by using shRNA targeted towards MET. When cells were infected with shRNA viral construct, there was increased cell death with a decline in MET transcript and protein. Taken together, our study demonstrates that MET plays a critical role in the survival and removal or lowering of MET by flavopiridol or shRNA results in the demise of MM cells.

Clinical correlations and prognostic relevance of HGF, VEGF AND FGF expression in Brazilian patients with non-Hodgkin lymphoma

The aims of this study were to correlate HGF, VEGF and FGF serum levels and microvessel density (MVD) with cell origin, biological behavior, tumor load and prognosis in NHL. Eighty-seven consecutive previously untreated NHL patients had serum samples collected; 37 (42%) of them also had serum follow-up samples; the control group was composed of 10 healthy blood donors. Cytokine serum levels were determined by ELISA, and MVD was measured by CD34 staining in paraffin blocks. HGF mean serum level was significantly higher in both early and advanced NHL stages when compared with the control group. HGF was also significantly higher in aggressive and indolent NHL when compared with the control group. Also, mean serum level of HGF in aggressive NHL was significantly higher than in indolent NHL. Regarding International Prognostic Index (IPI), HGF mean serum level at diagnosis was significantly higher for patients with IPI >2 when compared to IPI <or=2. Sequential analyses of HGF, VEGF and FGF serum levels in NHL showed that serum HGF and VEGF levels decreased significantly after 6 months of treatment completion. Our findings suggest that HGF serum level is associated with tumor load and aggressiveness, and response to treatment results in a decrease in HGF serum levels in NHL patients.