Increased serum levels of vascular endothelial growth factor predict risk of progression in early B-cell chronic lymphocytic leukaemia

An overview of prognostic markers in patients with CLL

Chronic lymphocytic leukemia (CLL) is a low-grade B-cell lymphoproliferative disorder. It is the most prevalent type of leukemia in the western countries, with a median age at diagnosis of 70 years. In 2023, it is estimated that there will be 18,740 new cases of CLL, and an estimated 4,490 people will die of this disease. It represents 1.0% of all new cancer cases in the U.S. The rate of new cases was 4.6 per 100,000 men and women per year based on 2016-2020 cases, age-adjusted. Death rates from CLL are higher among older adults, or those 75 and older. The death rate was 1.1 per 100,000 men and women per year based on 2016-2020 deaths, age-adjusted. A common question that patients with CLL ask during their first clinic visit is: "How long will it be before I would need treatment?" Although this might seem like a simple question, the answer is not straight forward. CLL is a heterogenous disease, with a variable clinical course. Some patients may present with an aggressive disease requiring early initiation of treatment, while others have an indolent course and some, having so called smoldering CLL, may never need treatment. The variability in disease course can make predicting disease prognosis a complicated process. This brings forth the importance of establishing prognostic models that can predict disease course, time to treatment, and survival outcomes in such a heterogenous disease. The Rai and Binet staging systems were developed in the late 1970s to early 1980s. They separated patients into different stages based on clinical characteristics and laboratory findings. These simple staging systems are still in use; however, several prognostic markers need to be added for an individualized assessment and, with the recent development of genomic techniques leading to better understanding of CLL at the molecular level, newer prognostic markers have emerged.

Mesenchymal stromal cell senescence in haematological malignancies

Acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL), and multiple myeloma (MM) are age-related haematological malignancies with defined precursor states termed myelodysplastic syndrome (MDS), monoclonal B-cell lymphocytosis (MBL), and monoclonal gammopathy of undetermined significance (MGUS), respectively. While the progression from asymptomatic precursor states to malignancy is widely considered to be mediated by the accumulation of genetic mutations in neoplastic haematopoietic cell clones, recent studies suggest that intrinsic genetic changes, alone, may be insufficient to drive the progression to overt malignancy. Notably, studies suggest that extrinsic, microenvironmental changes in the bone marrow (BM) may also promote the transition from these precursor states to active disease. There is now enhanced focus on extrinsic, age-related changes in the BM microenvironment that accompany the development of AML, CLL, and MM. One of the most prominent changes associated with ageing is the accumulation of senescent mesenchymal stromal cells within tissues and organs. In comparison with proliferating cells, senescent cells display an altered profile of secreted factors (secretome), termed the senescence-associated-secretory phenotype (SASP), comprising proteases, inflammatory cytokines, and growth factors that may render the local microenvironment favourable for cancer growth. It is well established that BM mesenchymal stromal cells (BM-MSCs) are key regulators of haematopoietic stem cell maintenance and fate determination. Moreover, there is emerging evidence that BM-MSC senescence may contribute to age-related haematopoietic decline and cancer development. This review explores the association between BM-MSC senescence and the development of haematological malignancies, and the functional role of senescent BM-MSCs in the development of these cancers.

Relation of Neutrophil Gelatinase-Associated Lipocalin Overexpression to the Resistance to Apoptosis of Tumor B Cells in Chronic Lymphocytic Leukemia

The resistance to apoptosis of chronic lymphocytic leukemia (CLL) cells partly results from the deregulated production of survival signals from leukemic cells. Despite the development of new therapies in CLL, drug resistance and disease relapse still occur. Recently, neutrophil gelatinase-associated lipocalin (NGAL), a secreted glycoprotein, has been suggested to have a critical role in the biology of tumors. Thus, we investigated the relevance of NGAL in CLL pathogenesis, analyzed the expression of its cellular receptor (NGAL-R) on malignant B cells and tested whether CLL cells are resistant to apoptosis through an autocrine process involving NGAL and NGAL-R. We observed that NGAL concentrations were elevated in the serum of CLL patients at diagnosis. After treatment (and regardless of the therapeutic regimen), serum NGAL levels normalized in CLL patients in remission but not in relapsed patients. In parallel, NGAL and NGAL-R were upregulated in leukemic cells from untreated CLL patients when compared to normal peripheral blood mononuclear cells (PBMCs), and returned to basal levels in PBMCs from patients in remission. Cultured CLL cells released endogenous NGAL. Anti-NGAL-R antibodies enhanced NGAL-R⁺ leukemia cell death. Conversely, recombinant NGAL protected NGAL-R⁺ CLL cells against apoptosis by activating a STAT3/Mcl-1 signaling pathway. Our results suggest that NGAL and NGAL-R, overexpressed in untreated CLL, participate in the deregulation of the apoptotic machinery in CLL cells, and may be potential therapeutic clues for CLL treatment.

Comparison of three oral selenium compounds in cancer patients: Evaluation of differential pharmacodynamic effects in normal and malignant cells

BACKGROUND

Selenium (Se) compounds have demonstrated therapeutic synergism in combination with anticancer treatments whilst reducing normal tissue toxicities in a range of experimental models. While reduction in some toxicities of chemotherapy and radiation has been confirmed in randomised clinical trials, they have not been powered to evaluate improved anticancer efficacy. A lack of data on the clinical potencies of the main nutritionally-relevant forms of Se and the relationship between their pharmacokinetic (PK) profiles and pharmacodynamic (PD) effects in cancer patients has hampered progress to date. The primary objective of this study was to determine the dose and form of Se that can be most safely and effectively used in clinical trials in combination with anti-cancer therapies.

STUDY METHODS

In a phase I randomised double-blinded study, the PD profile of sodium selenite (SS), Se-methylselenocysteine (MSC) and seleno-l-methionine (SLM) were compared in two cohorts of 12 patients, one cohort with chronic lymphocytic leukaemia (CLL) and the other with solid malignancies. All 24 patients were randomised to receive 400 μg of elemental Se as either SS, MSC or SLM, taken orally daily for 8 weeks. PD parameters were assessed before, during and 4 weeks after Se compound exposure in plasma and peripheral blood mononuclear cells (PBMCs).

RESULTS

No significant sustained changes were observed in plasma concentrations of vascular endothelial growth factor-α (VEGF-α), expression of proteins associated with endoplasmic reticulum stress (the unfolded protein response) or in intracellular total glutathione in PBMCs, in either disease cohort or when grouped by Se compound.

CONCLUSIONS

At the 400 μg dose level no substantial changes in PD parameters were noted. Extrapolating from pre-clinical data, the dose examined in this cohort was too low to achieve the Se plasma concentration (≥ 5 μM) expected to elicit significant PD effects. Recruitment of a subsequent cohort at higher doses to exceed this PK threshold is planned.

Circulating Angiogenesis Regulators in Cancer Patients

Background/Aims

To date, numerous studies have demonstrated that several angiogenesis regulators circulate in the blood and may function as endocrine factors in cancer patients. This review aims to give a comprehensive insight into the possible clinical value of circulating angiogenesis regulators, mainly basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF), angiogenin, pleiotrophin, thrombospondin (TSP) and endostatin (ES) in cancer patients.

Methods

A computerized (MEDLINE) and a manual search based on the reference lists of the publications were performed to identify articles published on this topic.

Results

In a detailed literature search, approximately 100 publications were found up to the end of 1999. Circulating angiogenic factors such as bFGF, VEGF, HGF and angiogenin have been evaluated not only as diagnostic and/or prognostic factors but also as predictive factors in cancer patients. On the other hand, little is known about the clinical significance of negative regulators. Neither the source nor the mechanism of protein externalization has been clarified in detail.

Conclusions

Although there are no known factors with established clinical utility, circulating angiogenesis regulators may be useful in several situations. They could be used to determine the risk of developing cancer, to screen for early detection, to distinguish benign from malignant disease, and to distinguish between different types of malignancies. In patients with established malignancies such factors might be used to determine prognosis, to predict the response to therapy, and to monitor the clinical course. Further investigations are warranted to assess the specific utility of each factor.

HIF-1-mediated expression of Foxo1 serves an important role in the proliferation and apoptosis of osteoblasts derived from children's iliac cancellous bone

Activation of the transcription factor hypoxia inducible factor‑1α (HIF-1α) is considered critical for the stimulation of osteogenic markers including runt‑related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin, which are closely associated with forkhead boxclass O1 (Foxo1) levels in osteoblasts. The present study explored the associations between HIF‑1α and Foxo1 in the regulation of cell viability, proliferation and apoptosis of osteoblasts. Osteoblasts obtained from children's iliac cancellous bone were used in the present study, which were confirmed by immunofluorescence staining for the osteoblast marker osteocalcin. The results revealed that the levels of reactive oxygen species and apoptosis were markedly increased in cells with knockdown of HIF‑1α. By contrast, these were reduced in response to overexpressed HIF‑1α. In addition, HIF‑1α overexpression significantly stimulated cell viability, which was suppressed by silencing HIF‑1α. HIF‑1α overexpression also significantly increased the transcriptional and translational levels of Foxo1. Conversely, silencing HIF‑1α markedly suppressed the expression levels of Foxo1. Furthermore, silencing HIF‑1α reduced the expression of osteogenic markers, including Runx2, ALP and osteocalcin. Runx2 and ALP expression induced by HIF1α were markedly reversed by Foxo1 small interfering (si)RNA, whereas osteocalcin was not significantly affected by Foxo1 siRNA. Therefore, the cooperation of and interactions between HIF‑1α and Foxo1 may be involved in the regulation of osteoblast markers, and serve a pivotal role in the proliferation and apoptosis of osteoblast. The HIF1α‑induced expression of Runx2 and ALP may be completely dependent on the expression levels of Foxo1, and in turn, osteocalcin may be partially dependent on Foxo1 expression.

Microvessel Density as a Surrogate Prognostic Marker in Patients with Multiple Myeloma: A Meta-Analysis

BACKGROUND/AIMS

Bone marrow (BM) angiogenesis is considered a hallmark of multiple myeloma (MM) development and progression, and can be quantified with the use of microvessel density (MVD). The purpose of this study is to provide a review and a meta-analysis of the current literature regarding the prognostic value of MVD in the overall survival (OS) of MM patients.

METHODS

MEDLINE was screened for studies evaluating the OS of MM patients with regard to their MVD count in BM trephine. The pooled hazard ratio (HR) and its associated 95% confidence interval (CI) among MM patients with a high and low MVD count was the primary end point. Secondary outcomes included odds ratios (OR) for 12-, 36-, and 60-month survival.

RESULTS

Ten eligible trials were identified for the analysis of the primary end point and 9 for the secondary end points. Pooled HR for OS was 1.85 (95% CI: 1.25-2.73, p = 0.002). The pooled OR of survival were 1.59 (95% CI: 1.02-2.46, p = 0.04) at 12 months, 2.90 (95% CI: 1.68-5.03, p = 0.0001) at 36 months, and 3.42 (95% CI: 2.41-4.85, p < 0.00001) at 60 months, in favor of the low MVD group.

CONCLUSION

This meta-analysis provides persuasive evidence that MVD has significant impact on the clinical outcome of MM patients.

C-C motif ligand 11 reduction in CLL patients serum after vitamin D supplementation

BACKGROUND

Vitamin D (VD) deficiency results in a worse prognosis in patients with chronic lymphocytic leukemia (CLL) and may affect the production of cytokines. Nonetheless, there is the lack of studies dealing with VD supplementation and its impact on chemokines in CLL patients.

AIM

The primary endpoint of our interventional study was to evaluate the effect of cholecalciferol supplementation on serum chemokines levels in CLL patients.

MATERIALS AND METHODS

Eighteen subjects with CLL were enrolled for the study. Six-month-long cholecalciferol supplementation was performed in CLL patients with serum 25-OH-D3 levels below 30 ng/ml. Cytokines levels were assessed at the beginning of the study and after 6 months. Baseline measurements of cytokines were compared to those in apparently healthy controls.

RESULTS

Increased levels of CCL2, CCL3, CCL4, CXCL8, CXCL10, TNFα, bFGF, G-CSF, and VEGF were found in CLL patients in comparison with the healthy controls. In the course of the VD supplementation a decrease in serum levels of chemokines CCL11, CCL3, and cytokine PDGF-BB was observed. The decrease of CCL11 was found in CLL patients on VD supplementation solely, whereas the decrease of CCL3 and PDGF-BB was observed in CLL subjects on both chemotherapy and VD supplementation.

CONCLUSION

The VD supplementation may exert beneficial effect on chemokines levels in CLL patients with VD deficiency.

Microenvironment interactions and B-cell receptor signaling in Chronic Lymphocytic Leukemia: Implications for disease pathogenesis and treatment

Chronic Lymphocytic Leukemia (CLL) is a malignancy of mature B lymphocytes which are highly dependent on interactions with the tissue microenvironment for their survival and proliferation. Critical components of the microenvironment are monocyte-derived nurselike cells (NLCs), mesenchymal stromal cells, T cells and NK cells, which communicate with CLL cells through a complex network of adhesion molecules, chemokine receptors, tumor necrosis factor (TNF) family members, and soluble factors. (Auto-) antigens and/or autonomous mechanisms activate the B-cell receptor (BCR) and its downstream signaling cascade in secondary lymphatic tissues, playing a central pathogenetic role in CLL. Novel small molecule inhibitors, including the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib and the phosphoinositide-3-kinase delta (PI3Kδ) inhibitor idelalisib, target BCR signaling and have become the most successful new therapeutics in this disease. We here review the cellular and molecular characteristics of CLL cells, and discuss the cellular components and key pathways involved in the cross-talk with their microenvironment. We also highlight the relevant novel treatment strategies, focusing on immunomodulatory agents and BCR signaling inhibitors and how these treatments disrupt CLL-microenvironment interactions. This article is part of a Special Issue entitled: Tumor Microenvironment Regulation of Cancer Cell Survival, Metastasis, Inflammation, and Immune Surveillance edited by Peter Ruvolo and Gregg L. Semenza.

HIF-1α regulates the interaction of chronic lymphocytic leukemia cells with the tumor microenvironment

Hypoxia-inducible transcription factors (HIFs) regulate a wide array of adaptive responses to hypoxia and are often activated in solid tumors and hematologic malignancies due to intratumoral hypoxia and emerging new layers of regulation. We found that in chronic lymphocytic leukemia (CLL), HIF-1α is a novel regulator of the interaction of CLL cells with protective leukemia microenvironments and, in turn, is regulated by this interaction in a positive feedback loop that promotes leukemia survival and propagation. Through unbiased microarray analysis, we found that in CLL cells, HIF-1α regulates the expression of important chemokine receptors and cell adhesion molecules that control the interaction of leukemic cells with bone marrow and spleen microenvironments. Inactivation of HIF-1α impairs chemotaxis and cell adhesion to stroma, reduces bone marrow and spleen colonization in xenograft and allograft CLL mouse models, and prolongs survival in mice. Of interest, we found that in CLL cells, HIF-1α is transcriptionally regulated after coculture with stromal cells. Furthermore, HIF-1α messenger RNA levels vary significantly within CLL patients and correlate with the expression of HIF-1α target genes, including CXCR4, thus further emphasizing the relevance of HIF-1α expression to CLL pathogenesis.

Signaling and molecular basis of bone marrow niche angiogenesis in leukemia

Angiogenesis, the process of blood vessel formation, is necessary for tissue survival in normal and pathologic conditions. Increased angiogenesis in BM niche is correlated with leukemia progression and resistance to treatment. Angiogenesis can interfere with disease progression and several angiogenic (such as vascular growth factors) as well as anti-angiogenic factors (i.e. angiostatin) can affect angiogenesis. Furthermore, miRs can affect the angiogenic process by inhibiting angiogenesis or increasing the expression of growth factors. Given the importance of angiogenesis in BM for maintenance of leukemic clones, recognition of angiogenic and anti-angiogenic factors and miRs as well as drug resistance mechanisms of leukemic blasts can improve the therapeutic strategies. We highlight the changes in angiogenic balance within the BM niche in different leukemia types. Moreover, we explored the pathways leading to drug resistance in relation to angiogenesis and attempted to assign interesting candidates for future research.

Thymoquinone overcomes chemoresistance and enhances the anticancer effects of bortezomib through abrogation of NF-κB regulated gene products in multiple myeloma xenograft mouse model

Multiple myeloma (MM) is a B cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow. With the advent of novel targeted agents, the median survival rate has increased to 5−7 years. However, majority of patients with myeloma suffer relapse or develop chemoresistance to existing therapeutic agents. Thus, there is a need to develop novel alternative therapies for the treatment of MM. Thus in the present study, we investigated whether thymoquinone (TQ), a bioactive constituent of black seed oil, could suppress the proliferation and induce chemosensitization in human myeloma cells and xenograft mouse model. Our results show that TQ inhibited the proliferation of MM cells irrespective of their sensitivity to doxorubicin, melphalan or bortezomib. Interestingly, TQ treatment also resulted in a significant inhibition in the proliferation of CD138+ cells isolated from MM patient samples in a concentration dependent manner. TQ also potentiated the apoptotic effects of bortezomib in various MM cell lines through the activation of caspase-3, resulting in the cleavage of PARP. TQ treatment also inhibited chemotaxis and invasion induced by CXCL12 in MM cells. Furthermore, in a xenograft mouse model, TQ potentiated the antitumor effects of bortezomib (p < 0.05, vehicle versus bortezomib + TQ; p < 0.05, bortezomib versus bortezomib + TQ), and this correlated with modulation of various markers for survival and angiogenesis, such as Ki-67, vascular endothelial growth factor (VEGF), Bcl-2 and p65 expression. Overall, our results demonstrate that TQ can enhance the anticancer activity of bortezomib in vitro and in vivo and may have a substantial potential in the treatment of MM.

Angiogenic factors in chronic lymphocytic leukaemia (CLL): Where do we stand?

The role of angiogenesis in haematological malignancies such as chronic lymphocytic leukaemia (CLL) is difficult to envision, because leukaemia cells are not dependent on a network of blood vessels to support basic physiological requirements. Regardless, CLL cells secrete high levels of major angiogenic factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF). Nonetheless, it remains unclear how most angiogenic factors regulate accumulation and delayed apoptosis of CLL cells. Angiogenic factors such as leptin, granulocyte colony-stimulating factor (G-CSF), follistatin, angiopoietin-1 (Ang1), angiogenin (ANG), midkine (MK), pleiotrophin (PTN), progranulin (PGRN), proliferin (PLF), placental growth factor (PIGF), and endothelial locus-1 (Del-1), represent novel therapeutic targets of future CLL research but have remained widely overlooked. This review aims to outline our current understanding of angiogenic growth factors and their relationship with CLL, a still uncured haematopoietic malignancy.

Vascular endothelial growth factor A (VEGFA) gene polymorphisms have an impact on survival in a subgroup of indolent patients with chronic lymphocytic leukemia

Vascular endothelial growth factor (VEGF)-mediated angiogenesis contributes to the pathogenesis of B-cell chronic lymphocytic leukaemia (CLL). We investigated the impact of VEGFA gene diversity on the clinical outcome of patients with this disease. A VEGFA haplotype conformed by positions rs699947 (–1540C>A), rs833061 (–460T>C) and rs2010963 (405C>G) and two additional single-nucleotide polymorphisms (SNPs), rs3025039 (936C>T) and rs25648 (1032C>T), were analysed in 239 patients at the time of their CLL diagnosis. Here, we showed that homozygosity for rs699947/rs833061/rs2010963 ACG haplotype (ACG^+/+ genotype) correlated with a reduced survival in CLL patients (ACG^+/+ vs other genotypes: HR = 2.3, p = 0.002; recessive model). In multivariate analysis, the ACG^+/+ genotype was identified as a novel independent prognostic factor (HR = 2.1, p = 0.005). Moreover, ACG homozygosity subdivided patients with CLL with otherwise indolent parameters into prognostic subgroups with different outcomes. Specifically, patients carrying the ACG^+/+ genotype with mutated IgV_H, very low and low-risk cytogenetics, initial clinical stage, CD38 negative status or early age at diagnosis showed a shorter survival (ACG^+/+ vs other genotypes: HR = 3.5, p = 0.035; HR = 3.4, p = 0.001; HR = 2.2, p = 0.035; HR = 3.4, p = 0.0001 and HR = 3.1, p = 0.009, respectively). In conclusion, VEGFA ACG^+/+ genotype confers an adverse effect in overall survival in CLL patients with an indolent course of the disease. These observations support the biological and prognostic implications of VEGFA genetics in CLL.

Immunohistochemical analysis of IL-6, IL-8/CXCR2 axis, Tyr p-STAT-3, and SOCS-3 in lymph nodes from patients with chronic lymphocytic leukemia: correlation between microvascular characteristics and prognostic significance

A number of studies have looked into the pathophysiological role of angiogenesis in CLL, but the results have often been inconsistent. We aimed to gain direct insight into the angiogenic process in lymph nodes involved by CLL, focusing on proangiogenic cytokines and microvessel morphometry. The tissue levels of VEGF, Th-2 cytokines IL-6 and IL-8, IL-8 receptor CXCR2, and tyrosine p-STAT-3/SOCS-3 axis modulating cytokine expression were evaluated immunohistochemically in 62 CLL/SLL cases. Microvascular characteristics were evaluated by image analysis. Results were analyzed with regard to clinicopathological characteristics. Proliferation centers (PCs) were less well vascularised compared to non-PC areas. IL-8 and CXCR2 expression was distinctly uncommon as opposed to IL-6, VEGF and SOCS-3, which were detected in the vast majority of cases. The latter two molecule expressions were more pronounced in the PCs in ∼40% of the cases. p-STAT-3 immunoreactivity was recorded in 66.67% of the cases with a predilection for PCs. Microvessel morphometry was unrelated to proangiogenic cytokines, p-STAT-3, SOCS-3, or survival. Microvascular caliber and VEGF expression were higher in Binet stage A, whereasIL-6 expression was higher in stage C. VEGF and p-STAT-3 exerted a favorable effect on progression, which remained significant in multivariate analysis, thereby constituting potential outcome predictors in CLL patients.

Critical signal transduction pathways in CLL

Receptor tyrosine kinases (RTKs) are cell-surface transmembrane receptors that contain regulated kinase activity within their cytoplasmic domain and play a critical role in signal transduction in both normal and malignant cells. Besides B cell receptor (BCR) signaling in chronic lymphocytic leukemia (CLL), multiple RTKs have been reported to be constitutively active in CLL B cells, resulting in enhanced survival and resistance to apoptosis of the leukemic cells induced by chemotherapeutic agents. In addition to increased plasma levels of various types of cytokines/growth factors in CLL, we and others have detected that CLL B cells spontaneously produce multiple cytokines in vitro which may constitute an autocrine loop of RTK activation on the leukemic B cells. Moreover, aberrant expression and activation of non-RTKs, for example, Src/Syk kinases, induce resistance of the leukemic B cells to therapy. Based on current available knowledge, we detailed the impact of aberrant activities of various RTKs/non-RTKs on CLL B cell survival and the potential of using these signaling components as future therapeutic targets in CLL therapy.

Angiogenesis and hematological malignancies

Since the initial hypotheses on the importance of angiogenesis in the pathogenesis of cancer approximately 30 years ago, there have been major advances in the understanding of the cellular and molecular mechanisms involved in the regulation of this complex process of new vessel formation. Among the multitude of factors, vascular endothelial growth factor (VEGF) has emerged as one of the most potent angiogenic factors, being implicated in the initiation of signal transduction responsible for cell proliferation, survival, migration and adhesion. Inhibition of VEGF and its signaling pathway offers a potential new molecular target in cancer therapy. This article reviews the role of angiogenesis and its mediators, particularly vascular endothelial growth factors, in hematological malignancies, as well as the potential use of anti-angiogenic therapies in the management of these conditions.

Angiogenesis as a treatment target in leukemia

SUMMARY The importance of angiogenesis in the growth and survival of leukemia has been well established and confirmed by several studies. In the last 20 years, several antiangiogenic agents have been used in preclinical and clinical studies of the treatment of leukemia. This review article summarizes the literature focusing on the relationship between angiogenesis and disease progression, and the advantages and limits of the antiangiogenic treatment of leukemia.

VEGF and bFGF gene polymorphisms in Polish patients with B-CLL

Among a variety of angiogenic factors involved in the B cell chronic lymphocytic leukemia (B-CLL), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were identified. Their levels have been regarded as prognostic markers of the progression of disease. The objective of the present study was to assess whether polymorphisms located within the genes coding for these key angiogenic activators contribute to disease susceptibility and/or progression in patients with B-CLL. For this purpose, 180 individuals were investigated, including 68 B-CLL patients and 112 healthy controls. All individuals were typed for the VEGF (936 C > T) and bFGF (−921 C > G) alleles using PCR–RFLP technique. Only a slight prevalence of the VEGF T variant was observed among patients as compared to healthy individuals (p = 0.095) with a significant difference when high risk (stage III/IV) patients were considered (OR = 3.81, p = 0.045). No other significant association was observed between the VEGF polymorphism and progression of the disease. The VEGF alleles and genotypes segregated similarly in patients with different stage of the disease according to Rai classification. No significant relationships were also observed for the bFGF polymorphism with either susceptibility to B-CLL (when compared to control group) or progression of the disease. These results suggest the possible association of the VEGF polymorphism with high risk B-CLL.

Role of VEGF/VEGFR in the pathogenesis of leukemias and as treatment targets (Review)

Angiogenesis plays an important role in solid tumor growth, progression and metastasis. Evidence suggests that the progression of hematolymphoid malignancies also depends on the induction of new blood vessel formation under the influence of acute leukemia, myelodysplastic syndromes, myeloproliferative neoplasms, multiple myeloma and lymphomas. The vascular endothelial growth factor (VEGF) is the most important proangiogenic agent that activates receptors on vascular endothelial cells and promotes blood vessel regeneration. It has been demonstrated that VEGF/VEGF receptor (VEGFR) expression is upregulated in several types of hematolymphoid tumor cells accompanied with angiogenesis. The levels of VEGF/VEGFR are correlated with the treatment, relapse and prognosis of hematolymphoid tumors. In order for VEGF family and their receptors as antiangiogenic targets to treat solid tumors, several antiangiogenic agents targeting VEGF-related pathways have been used for the treatment of hematolymphoid malignancies in clinical trials. The results demonstrate a promising therapeutic intervention in multiple types of hematolymphoid tumors. This review aims to summarize recent advances in understanding the role of VEGF and angiogenesis in leukemias, mainly focusing on their upstream transcriptors, downstream targets and the correlation of VEGF/VEGFR with the treatment, relapse or prognosis of leukemia. The progress of VEGF and its receptors as attractive targets for therapies are also discussed in clinical application.

Cross-talk between chronic lymphocytic leukemia cells and bone marrow endothelial cells: role of signal transducer and activator of transcription 3

Chronic lymphocytic leukemia bone marrow is characterized by increased angiogenesis. However, the molecular mediators of neovascularization and the biologic significance of increased endothelial cell proliferation in chronic lymphocytic leukemia require further investigation. Because signal transducer and activator of transcription 3 is constitutively activated in chronic lymphocytic leukemia, we studied the role of signal transducer and activator of transcription 3 in modulating vascular endothelial growth factor expression and the effect of vascular endothelial cells on chronic lymphocytic leukemia cells. Using chromatin immunoprecipitation, we found that anti-signal transducer and activator of transcription 3 antibodies immunoprecipitated DNA of signal transducer and activator of transcription 3, vascular endothelial growth factor, and other signal transducer and activator of transcription 3-regulated genes. In addition, signal transducer and activator of transcription 3-short interfering RNA significantly reduced messenger RNA levels of vascular endothelial growth factor in chronic lymphocytic leukemia cells, suggesting that signal transducer and activator of transcription 3 induces vascular endothelial growth factor expression in chronic lymphocytic leukemia. Remarkably, bone marrow chronic lymphocytic leukemia cells expressed high levels of vascular endothelial growth factor, and high vascular endothelial growth factor levels were detected in the plasma of patients with untreated chronic lymphocytic leukemia and correlated with white blood cell count. Chronic lymphocytic leukemia bone marrow biopsies revealed increased microvascular density and attachment of chronic lymphocytic leukemia cells to endothelial cells. Coculture of chronic lymphocytic leukemia cells and human umbilical vein endothelial cells showed a similar attachment. Furthermore, coculture studies with human umbilical vein endothelial cells showed that human umbilical vein endothelial cells protected chronic lymphocytic leukemia cells from spontaneous apoptosis by direct cell-to-cell contact as assessed by flow cytometry using annexin V. Our data suggest that constitutively activated signal transducer and activator of transcription 3 induces vascular endothelial growth factor production by chronic lymphocytic leukemia cells and that chronic lymphocytic leukemia cells derive a survival advantage from endothelial cells via cell-to-cell contact.

Bone marrow stromal cell-derived vascular endothelial growth factor (VEGF) rather than chronic lymphocytic leukemia (CLL) cell-derived VEGF is essential for the apoptotic resistance of cultured CLL cells

Chronic lymphocytic leukemia (CLL) cells feature a pronounced apoptotic resistance. The vascular endothelial growth factor (VEGF) possesses a role in this apoptotic block, although underlying functional mechanisms and the involvement of the microenvironment are unclear. In this study, the VEGF status in CLL was assessed by enzyme-linked immunosorbent assay and immunofluorescence. VEGF receptor 2 (VEGFR2) phosphorylation was determined flow cytometrically and by immunofluorescence. For co-culture, CLL cells were cultivated on a monolayer of the bone marrow-derived stromal cell (BMSC) line HS5. Secreted VEGF was neutralized using the monoclonal antibody mAb293 (R&D Systems, Minneapolis, MN, USA). To block protein secretion, we used Brefeldin A. VEGF was downregulated in BMSCs by small interfering RNA (siRNA), and we assessed survival by annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. CLL cells express and secrete VEGF and possess phosphorylated VEGFR2. This positive VEGF status is not sufficient to prevent spontaneous apoptosis in vitro. Coculture with BMSCs, which secrete vast amounts of VEGF, maintains in vitro CLL cell survival. Blockage of secreted VEGF using the monoclonal antibody mAb293 significantly reduced the survival support for cocultured CLL cells. Both general blockage of protein secretion by Brefeldin A in BMSCs, but not in CLL cells, and siRNA-mediated downregulation of VEGF in BMSCs, significantly reduced the coculture-mediated survival support for CLL cells. It can be concluded that BMSC-derived proteins and VEGF, in particular, but not CLL cell-derived VEGF, is essentially involved in the coculture-mediated survival support for CLL cells. Hence, therapeutic targeting of VEGF signaling might be a promising approach to overcome the apoptotic resistance CLL cells feature within their natural microenvironment.

High serum angiogenin at diagnosis predicts for failure on long-term treatment response and for poor overall survival in non-Hodgkin lymphoma

BACKGROUND

Angiogenin is a potent inducer of angiogenesis. We prospectively evaluated the prognostic significance of serum angiogenin from 204 consecutive non-Hodgkin lymphoma (NHL) patients diagnosed and treated in a single institution.

METHODS

Serum angiogenin, VEGF, and bFGF concentrations at diagnosis were determined using a quantitative sandwich enzyme immunoassay technique. Kaplan-Meier survival curves were compared by the log-rank test. Multivariate survival analyses were performed using the parametric model of Weibull and the non-parametric proportional hazards model of Cox.

RESULTS

Patients with a high serum angiogenin at diagnosis (>median; 401 ng/ml) had significantly lower 5-year survival rate than those with a low (≤ median) angiogenin (42% versus 63%, respectively; P = 0.0073). Serum angiogenin provided additional information to the International Prognostic Index (IPI) identifying a subgroup (serum angiogenin >median and IPI>1) with very poor prognosis (5-year survival 19%, P < 0.0001). In receiver operating characteristic (ROC) analyses the accuracy of the IPI to correctly classify patients with favourable or poor survival was improved from fair to good by complementing the IPI with serum angiogenin concentration. With patients who initially achieved complete response (CR) after chemotherapy, a high angiogenin at diagnosis (>median; relative risk (RR) 2.38; P = 0.0077) and an advanced tumour stage (III-IV; RR 2.41; P = 0.0087) were the only independent predictors for patients with unfavourable outcome although first responding well to therapy.

CONCLUSIONS

We conclude that elevated serum angiogenin surfaced as an independent predictor for failure in long-term treatment response and for poor overall survival in a series of 204 NHL patients, and might thus also complement the IPI in identifying the patients with particularly aggressive and/or treatment resistant disease.

Phase II trials of single-agent anti-VEGF therapy for patients with chronic lymphocytic leukemia

Between 2005 and 2008, we conducted separate phase II clinical testing of three distinct anti-VEGF therapies for patients with relapsed/refractory CLL. Collectively, 46 patients were accrued to trials of single-agent anti-VEGF antibody (bevacizumab, n = 13) or one of two receptor tyrosine kinase inhibitors (AZD2171, n = 15; sunitinib malate, n = 18). All patients have completed treatment. Patients received a median of two cycles of bevacizumab, AZD2171, or sunitinib malate. All three trials were closed early due to lack of efficacy. No complete or partial remissions were observed. Individually and collectively, these studies indicate that single-agent anti-VEGF therapy has minimal clinical activity for patients with relapsed/refractory CLL.

Angiopoietin-2 plasma dosage predicts time to first treatment and overall survival in chronic lymphocytic leukemia

The clinical relevance of angiopoietin-2 (Ang2) in chronic lymphocytic leukemia (CLL) was previously suggested by the association between high Ang2, and shorter progression-free survival reported in small series of patients. Here, we evaluated Ang2 glycoprotein levels in plasma samples collected from a multicentric cohort of CLL patients (n = 316) using an enzyme-linked immunosorbent assay method, and we investigated its prognostic role in relation to time to first treatment (TTFT) and overall survival. Based on a cutoff equal to 2459 pg/mL, we divided our cohort in 2 subsets (high and low Ang2) composing 100 (31.6%) and 216 (68.4%) patients, respectively. High Ang2 was predictive of reduced TTFT (P < .001) and overall survival (P = .002). Multivariate analysis confirmed that high Ang2 was an independent prognosticator for TTFT (hazard ratio = 1.739; 95% confidence interval, 1.059-2.857; P = .029). Significant associations were found between high Ang2 and advanced Binet stages (P < .001), high beta(2)-microglobulin (P < .001), unmutated variable region of immunoglobulin heavy chain gene status (P < .001), high CD38 and zeta-chain-associated protein kinase 70 expression (P < .001 and P = .003), and intermediate/high cytogenetic risk (P = .005). Moreover, Ang2 added prognostic power to other conventional prognosticators and helped to refine prognosis among CLL subsets with both high and low vascular endothelial growth factor plasma levels. Ang2 plasma level may be a useful independent prognosticator for CLL.

Lysophosphatidic acid receptor expression in chronic lymphocytic leukemia leads to cell survival mediated though vascular endothelial growth factor expression

Lysophosphatidic acid (LPA) protects chronic lymphocytic leukemia (CLL) cells from apoptosis. Vascular endothelial growth factor (VEGF) also protects CLL cells against apoptosis. The mechanism for LPA protection against apoptosis in CLL cells is unknown. Herein, we show CLL cells express LPA receptors LPA(1-5) but in normal B cells, LPA(1) was rarely expressed and LPA(3,) LPA(4,) and LPA(6) were undetectable whereas the other LPA receptors were expressed. LPA plasma levels are similar in patients with CLL compared to healthy controls. In contrast, plasma levels of VEGF are elevated in patients with CLL compared to healthy controls and LPA treatment induced VEGF secretion in CLL cells. CLL cells also express VEGF receptors and LPA protection against Flu induced apoptosis is blocked by inhibition of VEGF receptor activation. These results indicate that LPA protects CLL cells from apoptosis through higher expression of LPA receptors and autocrine production of VEGF.

Does adiponectin act as an antiangiogenic factor in B-cell chronic lymphocytic leukemia?

Angiogenesis is involved in the pathogenesis of B-cell chronic lymphocytic leukemia (CLL), and high microvascular density has been found in CLL to be associated with a poor prognosis. In this study, we assessed serum levels of adiponectin in 69 patients with Binet stage A B-CLL, and these values were retrospectively correlated with bone marrow (BM) microvessel area and serum levels of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), angiogenin, PECAM-1 (CD31), matrix metalloproteinase-9 (MMP-9), interleukin-8 (IL-8), syndecan-1, and the percentage of CD38⁺ or ZAP-70⁺ CLL cells. The positive correlation between serum levels of adiponectin and VEGF (P = .03) does not translate into an increase of the extent of BM angiogenesis (P = .404), FGF-2 (P = .348), angiogenin (P = .402), and CD31 (P = .248) serum concentrations. Accordingly, IL-8 (P = .175), syndecan-1 (P = .06), and MMP-9 (P = .144) circulating levels were not likely to reflect adiponectin concentration. Furthermore, patients with higher levels of adiponectin had a more favorable biological profile as defined by a lower number of both CD38⁻ (r = −0.294; P = .02) and ZAP-70⁺ (r = −0.285; P = .04). Finally, we evaluated the presence of adiponectin in B-CLL cells at gene expression level. RMA intensity values for adiponectin gene transcript denote a homogeneous low expression in B-CLL cells, whereas VEGF transcript was highly expressed with a degree of interpatient variability. Overall, these data seem to indicate that adiponectin could be involved as an antiangiogenic factor in B-CLL.

Aberrant regulation of pVHL levels by microRNA promotes the HIF/VEGF axis in CLL B cells

The molecular mechanism of autocrine regulation of vascular endothelial growth factor (VEGF) in chronic lymphocytic leukemia (CLL) B cells is unknown. Here, we report that CLL B cells express constitutive levels of HIF-1alpha under normoxia. We have examined the status of the von Hippel-Lindau gene product (pVHL) that is responsible for HIF-1alpha degradation and found it to be at a notably low level in CLL B cells compared with normal B cells. We demonstrate that the microRNA, miR-92-1, overexpressed in CLL B cells, can target the VHL transcript to repress its expression. We found that the stabilized HIF-1alpha can form an active complex with the transcriptional coactivator p300 and phosphorylated-STAT3 at the VEGF promoter and recruit RNA polymerase II. This is initial evidence that pVHL, without any genetic alteration, can be regulated by microRNA and explains the aberrant autocrine VEGF secretion in CLL.

Post-collection, pre-measurement variables affecting VEGF levels in urine biospecimens

Angiogenesis, the development and recruitment of new blood vessels, plays an important role in tumour growth and metastasis.Vascular endothelial growth factor (VEGF) is an important stimulator of angiogenesis.Circulating and urinary VEGF levels have been suggested as clinically useful predictors of tumour behaviour, and investigations into these associations are ongoing.Despite recent interest in measuring VEGF levels in patients, little is known about the factors that influence VEGF levels in biospecimens. To begin to address this question, urine samples were collected from patients with solid tumours undergoing radiotherapy and healthy volunteers.Four factors were examined for their effects on VEGF concentrations as measured by chemiluminescent immunoassay: time from sample collection to freezing, number of specimen freeze–thaw cycles, specimen storage tube type and the inclusion or exclusion of urinary sediment. The results of this study indicate that time to freeze up to 4 hrs, number of freeze–thaw cycles between one and five, and different types of polypropylene tubes did not have statistically significant effects on measured urinary VEGF levels. Urinary sediment had higher VEGF levels than supernatant in five of six samples from healthy patients.It is not clear whether there is an active agent in the sediment causing this increase or if the sediment particles themselves are affecting the accuracy of the assay.Therefore, we recommend centrifuging urine, isolating the supernatant, and freezing the sample in polypropylene microcentrifuge tubes or cryogenic vials within 4 hrs of collection.In addition, we recommend the use of samples within five freeze–thaw cycles.

Dysregulated angiogenesis in B-chronic lymphocytic leukemia: morphologic, immunohistochemical, and flow cytometric evidence

BACKGROUND

The extent of enhanced bone marrow angiogenesis in chronic lymphocytic leukemia (CLL) and relationship to proangiogenic factors and prognostic indicators is largely unexplored.

METHODS

To further investigate the role of angiogenesis in CLL by evaluating the topography and extent of angiogenesis in a group of CLL bone marrow biopsies, to study the expression of pro and antiangiogenic vascular factors in CLL cells to more precisely document the cell types producing these factors, and to evaluate the role, if any, of localized hypoxia in upregulation of angiogenesis in CLL We used immunohistochemistry (IHC) (n = 21 pts) with antibodies to CD3 and CD20, proangiogenic (VEGF, HIF-1a) and antiangiogenic (TSP-1) factors, and VEGF receptors -1 and -2 to examine pattern/extent of CLL marrow involvement, microvessel density (MVD), and angiogenic characteristics; flow cytometry (FC) was performed on 21 additional cases for VEGF and TSP-1.

RESULTS

CLL patients had higher MVD (23.8 vs 14.6, p~0.0002) compared to controls (n = 10). MVD was highest at the periphery of focal infiltrates, was not enhanced in proliferation centers, and was increased irrespective of the presence or absence of cytogenetic/immunophenotypic markers of aggressivity. By IHC, CLL cells were VEGF(+), HIF-1a (+), TSP-1(-), VEGFR-1(+), and VEGFR-2(+). By FC, CLL cells were 1.4-2.0-fold brighter for VEGF than T cells and were TSP-1(-).

CONCLUSION

CLL demonstrates enhanced angiogenesis, with increased MVD, upregulated VEGF and downregulated TSP-1. Upregulation of HIF-1a in all CLL cases suggests localized tissue hypoxia as an important stimulant of microvessel proliferation. The presence of VEGF receptors on CLL cells implies an autocrine effect for VEGF. Differences in MVD did not correlate with traditional genetic/immunophenotypic markers of aggressiveness.

Lysophosphatidic acid (LPA) induces the expression of VEGF leading to protection against apoptosis in B-cell derived malignancies

Vascular endothelial growth factor (VEGF) is a survival and angiogenesis factor that is a target for therapy in a variety of cancers. In many hematological malignancies, VEGF production is increased leading to cell survival responses. Herein, we demonstrate that lysophosphatidic acid (LPA) induces mRNA expression of VEGF in the multiple myeloma cell line, U266, the Burkitt's lymphoma cell line, BJAB, and the chronic lymphocytic leukemia (CLL)-like cell line, I-83. This increase in mRNA levels of VEGF corresponded with increased luciferase activity of the VEGF promoter in BJAB and I-83 cells and increased protein levels in I-83 cells. Secretion of VEGF was also increased in these cells following LPA treatment. LPA treatment also caused the activation of both VEGFR1 and VEGFR2. The increase in VEGF expression by LPA is mediated by the activation of c-Jun N-terminal Kinase (JNK) and transcription factor NFkappaB since blocking JNK or NFkappaB activation inhibited LPA induced VEGF expression. Furthermore, we have demonstrated that LPA protects cells from apoptosis and blocking activation of both VEGFR1 and VEGFR2 using a VEGF receptor kinase inhibitor prevented LPA survival responses. Knocking down expression of VEGFR1 and inhibiting activation of NFkappaB and JNK also blocked LPA induced protection against apoptosis. Taken together, this indicates that LPA contributes to VEGF production in B cell malignancies leading to cell survival.

Markers of increased angiogenesis and their correlation with biological parameters identifying high-risk patients in early B-cell chronic lymphocytic leukemia

We wondered whether there was any association between the extent of increased angiogenesis and IgV(H) gene mutational status, expression of CD38 and ZAP-70 in early B-cell chronic lymphocytic leukemia (CLL) patients. Circulating levels of vascular endothelial growth factor (VEGF) correlated positively with ZAP-70-expression (P=0.03), CD38- expression (P=0.03) and mutational status of IgV(H) (P=0.005). The same did not apply when correlations were sought with either bone marrow angiogenesis or serum levels of basic fibroblatic growth factor (FGF-2). Studies to determine how to integrate variables reflecting increased angiogenesis with other prognostic markers such as CD38, ZAP-70, IgV(H) status and cytogenetic abnormalities are needed to optimize risk stratification for individual patients.

Elevated Vascular Endothelial Growth Factor Pretreatment Levels Are Correlated with the Tumor Burden in Hodgkin Lymphoma and Continue to Be Elevated in Prolonged Complete Remission

BACKGROUND

Vascular endothelial growth factor (VEGF) has been described as an essential cytokine in the regulation of angiogenesis. Its elevation in peripheral blood or bone marrow has been associated with an unfavorable outcome in different hematologic neoplasms. Hodgkin lymphoma represents approximately one fifth of all lymphomas, and the roles of angiogenesis and VEGF in Hodgkin lymphoma have not been well defined at present.

PATIENTS AND METHODS

Vascular endothelial growth factor serum levels were determined by enzyme-linked immunosorbent assay in 54 newly diagnosed patients, 26 patients in prolonged complete remission (CR), and 54 healthy controls. Vascular endothelial growth factor levels were compared among the different populations and correlated with prognostic factors and disease evolution.

RESULTS

Newly diagnosed patients showed an increase in VEGF level compared with the CR subgroup (549 pg/mL vs. 327.5 pg/mL; P = 0.023) and with healthy controls (549 pg/mL vs. 140 pg/mL; P < 0.001). Patients in CR also showed an elevated VEGF with respect to healthy controls (327.5 pg/mL vs. 140 pg/mL; P = 0.01). Elevated VEGF was also statistically correlated with newly diagnosed patients with a greater tumor burden (594.5 pg/mL vs. 391 pg/mL; P = 0.009), with > or = 4 involved areas (608 pg/mL vs. 507 pg/mL; P = 0.036), and with an Eastern Cooperative Oncology Group performance status of > or = 1 (812 pg/mL vs. 447pg/mL; P = 0.005). Vascular endothelial growth factor was also elevated in advanced-stage disease, in patients with B symptoms, and poor-risk groups, but none of them became statistically significant.

CONCLUSION

Pathologic angiogenesis is an activated pathway in Hodgkin lymphoma and participates in Hodgkin lymphoma progression. This has been shown by an elevated VEGF level in patients: before first treatment, with greater tumor burden, and with a higher number of involved areas. Furthermore, VEGF continues to be elevated in patients with Hodgkin lymphoma after prolonged CR.

Bone biopsy derived marrow stromal elements rescue chronic lymphocytic leukemia B-cells from spontaneous and drug induced cell death and facilitates an "angiogenic switch"

A novel bone biopsy technique was used to generate a robust stromal cell system to study how stroma modulates CLL B-cell apoptosis and how the leukemic cell-stromal interaction influences secretion of vascular factors. Marrow stromal elements (MSE) rescued CLL B-cells from both spontaneous and drug induced apoptosis, partly due to soluble factors. When CLL B-cells were added to the MSE cultures, a dramatic increase in the secretion of basic fibroblast growth factor and decrease in the secretion of thrombospondin was observed. These results indicate the interaction between CLL B-cells and marrow stromal elements regulates angiogenic switching and may be linked to disease progression.

B-cell chronic lymphocytic leukemia: correlation of clinical stages with angiogenic cytokine expression

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of non-cycling B cells in lymphatic and extralymphatic tissues. Earlier studies had validated that angiogenesis was increased in B-CLL. Increased serum concentrations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) connote a poor prognosis in early-stage B-CLL. Early progression is also related to transforming growth factor-beta (TGF-beta), which inhibits B-cell proliferation and immunoglobulin production. The authors investigated the expression of CD34, VEGF, bFGF, and TGF-beta and their receptors in different stages of B-CLL by analyzing bone marrow samples from 23 patients (11 with Rai stages 0-II; 12 with stages III or IV). TGF-beta2 was expressed more strongly in stages 0 to II than in stages III or IV (P=0.03). There was no significant difference in the intensity of CD34, TGF-beta1, VEGF, and bFGF and their receptors between stages 0 to II and stages III or IV. Staining showed bFGF expression to be stronger than VEGF expression (P=0.001). Results did not confirm an association between the intensity of angiogenesis and B-CLL stage. The expression of TGF-beta2 was stronger in early-stage disease and may help slow disease progression.

Emerging drugs for chronic lymphocytic leukaemia

Although the philosophy of management of patients with chronic lymphocytic leukaemia (CLL) has been altered with the advent of fludarabine-based therapies, impact on long-term survival is unclear and a significant proportion of patients will develop resistance to fludarabine. Similar to other haematological malignancies, a potential for 'cure' is likely to be achieved only if 'high-quality' complete remissions (CRs) are achieved. Treatment options for patients who develop resistance to fludarabine continue to be limited, with only a proportion obtaining a response (usually not CRs) with salvage therapies. This review summarises novel therapies that are being evaluated in patients with CLL, specifically those targeting the antiapoptotic Bcl-2 family of proteins and receptors (e.g., CD40, CD80, HLA-DR) involved in mediating survival signals from the microenvironment.

Circulating sCD138 and some angiogenesis-involved cytokines help to anticipate the disease progression of early-stage B-cell chronic lymphocytic leukemia

Syndecan-1 (CD138) is a transmembrane heparin sulfate proteoglycan expressed on distinct stages of differentiation of B-lymphoid cells. Its prognostic value in B-cell chronic lymphocytic leukemia (B-CLL) has not been evaluated so far. The serum concentration of sCD138 and some angiogenesis-involved cytokines: vascular endothelial growth factor (VEGF), basis fibroblast growth factor (bFGF), and endostatin were studied in 52 previously untreated patients with B-CLL. We found that bFGF and sCD138 levels were significantly higher in B-CLL patients than in controls. In patients with sCD138 level or endostatin level below the median value the lymphocyte count was higher than in patients with serum level of those cytokines above the median value. In patients with progressive disease bFGF level was significantly higher and sCD138 level significantly lower than in patients with stable one. Moreover, high sCD138 level was associated with longer lymphocyte doubling-free survival, and, on the limit of statistical significance, a high endostatin level was associated with shorter progression-free survival. We conclude that serum sCD138 level is increased in early stage B-CLL patients and may have a positive prognostic value as to the dynamics of the disease.