Basic Fibroblast Growth Factor Is Expressed by CD19/CD11c-Positive Cells in Hairy Cell Leukemia

Increased High Molecular Weight FGF2 in Endocrine-Resistant Breast Cancer

Endocrine resistance may develop as a consequence of enhanced growth factor signaling. Fibroblast growth factor 2 (FGF2) consists of a low and several high molecular weight forms (HMW-FGF2). We previously demonstrated that antiprogestin-resistant mammary carcinomas display lower levels of progesterone receptor A isoforms (PRA) than B isoforms (PRB). Our aim was to evaluate the role of FGF2 isoforms in breast cancer progression. We evaluated FGF2 expression, cell proliferation, and pathway activation in models with different PRA/PRB ratios. We performed lentiviral infections of different FGF2 isoforms using the human hormone-responsive T47D-YA cells, engineered to only express PRA, and evaluated tumor growth, metastatic dissemination, and endocrine responsiveness. We assessed FGF2 expression and localization in 81 human breast cancer samples. Antiprogestin-resistant experimental mammary carcinomas with low PRA/PRB ratios and T47D-YB cells, which only express PRB, displayed higher levels of HMW-FGF2 than responsive variants. HMW-FGF2 overexpression in T47D-YA cells induced increased tumor growth, lung metastasis, and antiprogestin resistance compared to control tumors. In human breast carcinomas categorized by their PRA/PRB ratio, we found nuclear FGF2 expression in 55.6% of tumor cells. No differences were found between nuclear FGF2 expression and Ki67 proliferation index, tumor stage, or tumor grade. In low-grade tumor samples, moderate to high nuclear FGF2 levels were associated to carcinomas with low PRA/PRB ratio. In conclusion, we show that HMW-FGF2 isoforms are PRB targets which confer endocrine resistance and are localized in the nuclei of breast cancer samples. Hence, targeting intracellular FGF2 may contribute to overcome tumor progression.

Molecular and clinical significance of fibroblast growth factor 2 (FGF2 /bFGF) in malignancies of solid and hematological cancers for personalized therapies

Fibroblast growth factor (FGF) signaling is essential for normal and cancer biology. Mammalian FGF family members participate in multiple signaling pathways by binding to heparan sulfate and FGF receptors (FGFR) with varying affinities. FGF2 is the prototype member of the FGF family and interacts with its receptor to mediate receptor dimerization, phosphorylation, and activation of signaling pathways, such as Ras-MAPK and PI3K pathways. Excessive mitogenic signaling through the FGF/FGFR axis may induce carcinogenic effects by promoting cancer progression and increasing the angiogenic potential, which can lead to metastatic tumor phenotypes. Dysregulated FGF/FGFR signaling is associated with aggressive cancer phenotypes, enhanced chemotherapy resistance and poor clinical outcomes. In vitro experimental settings have indicated that extracellular FGF2 affects proliferation, drug sensitivity, and apoptosis of cancer cells. Therapeutically targeting FGF2 and FGFR has been extensively assessed in multiple preclinical studies and numerous drugs and treatment options have been tested in clinical trials. Diagnostic assays are used to quantify FGF2, FGFRs, and downstream signaling molecules to better select a target patient population for higher efficacy of cancer therapies. This review focuses on the prognostic significance of FGF2 in cancer with emphasis on therapeutic intervention strategies for solid and hematological malignancies.

Update on the biology and treatment options for hairy cell leukemia

Hairy cell leukemia (HCL) is an uncommon chronic leukemia of mature B cells. Leukemic B cells of HCL exhibit a characteristic morphology and immunophenotype and coexpress multiple clonally related immunoglobulin isotypes. Precise diagnosis and detailed workup is essential, because the clinical profile of HCL can closely mimic that of other chronic B-cell lymphoproliferative disorders that are treated differently. Variants of HCL, such as HCLv and VH4-34 molecular variant, vary in the immunophenotype and specific VH gene usage, and have been more resistant to available treatments. On the contrary, classic HCL is a highly curable disease. Most patients show an excellent long-term response to treatment with single-agent cladribine or pentostatin, with or without the addition of an anti-CD20 monoclonal antibody such as rituximab. However, approximately 30-40 % of patients with HCL relapse after therapy; this can be treated with the same purine analogue that was used for the initial treatment. Advanced molecular techniques have identified distinct molecular aberrations in the Raf/MEK-ERK pathway and BRAF (V600E) mutations that drive the proliferation and survival of HCL B cells. Currently, research in the field of HCL is focused on identifying novel therapeutic targets and potential agents that are safe and can universally cure the disease. Ongoing and planned clinical trials are assessing various treatment strategies, such as the combination of purine analogues and various anti-CD20 monoclonal antibodies, recombinant immunotoxins targeting CD22 (e.g., moxetumomab pasudotox), BRAF inhibitors, such as vemurafenib, and B-cell receptor signaling inhibitors, such as ibrutinib, which is a Bruton's tyrosine kinase inhibitor. This article provides an update of our current understanding of the pathophysiology of HCL and the treatment options available for patients with classic HCL. Discussion of variant forms of HCL is beyond the scope of this manuscript.

Hairy cell leukemia: current concepts

Hairy cell Leukemia (HCL) is a chronic lymphoproliferative disorder that was characterized in the late 1950s. HCL is defined, according to the WHO classification, as a mature (peripheral) B-cell neoplasm (1). HCL accounts for between 2-3% of all leukemia cases, with about 600 new cases diagnosed in the U.S. each year (1). HCL occurs more commonly in males, with an overall male to female ratio of approximately 4:1. The median age of onset is 52 years. This disease is seen more commonly in Caucasians and appears to be especially frequent in Ashkenazi Jewish males, with rare occurrence in persons of Asian and African descents (1). Hairy cells are distinct, clonal B cells arrested at a late stage of maturation. They are small B lymphoid cells that possess oval nuclei and abundant cytoplasm with characteristic micro-filamentous ("hairy") projections. They strongly express CD103, CD22, and CD11c (2). These cells typically infiltrate the bone marrow, the spleen, and to a lesser extent the liver, lymph nodes, and skin. Many patients present with splenomegaly and pancytopenia. Other clinical manifestations include recurrent opportunistic infections and vasculitis. Historically, HCL was considered uniformly fatal (2). However, recent treatment advances, using purine analogues such as Cladribine and Pentostatin, led to a significant improvement in prognosis with achievement of high response rates and durable remissions (2).

A simplified procedure for hematopoietic stem cell amplification using a serum-free, feeder cell-free culture system

Umbilical cord blood (UCB) is increasingly being used as a donor source of hematopoietic stem cells (HSCs) to treat blood malignancies. The main limitation to the widespread use of UCB is the low number of HSCs per unit. To compensate, a strategy of in vitro stem cell amplification has been attempted in different research laboratories. The major hurdle blocking success is the creation of culture conditions that support the growth of hematopoietic stem cells without their differentiation. We have designed a simple culture system for stem and progenitor cell expansion that resulted in an increased number of hematopoietic stem cells that maintain their ability to home to the bone marrow and to permanently engraft.

Evolving concepts in the pathogenesis of hairy-cell leukaemia

Hairy-cell leukaemia (HCL) has long been recognized as distinct from other chronic B-cell malignancies, but several questions remain unanswered. What is the HCL cell of origin? Why does HCL lack the hallmarks of most mature B-cell tumours (for example, chromosomal translocations and consistent lymph node involvement) and show unique features like 'hairy' morphology and bone-marrow fibrosis? Gene-expression profiling and other studies have recently provided new insights into HCL biology and have the potential to affect clinical practice.

Hairy cell leukemia (HCL) with extensive myelofibrosis responds to thalidomide

We present a 75-year-old man who was admitted to our hospital because of splenomegaly, transfusion-dependent anemia and thrombocytopenia. The diagnosis of idiopathic myelofibrosis was suggested by the bone marrow trephine biopsy, which was hypocellular with myelofibrosis. Thalidomide was started at a daily dose of 100 mg/d and increased to 400 mg/d. Within 12 weeks, thrombocytes increased to 100.000/microl, hemoglobin normalized, lasting for about 11 months. Then, thalidomide had to be discontinued because of mild polyneuropathy. A second bone marrow biopsy showed fibrosis as well as a diffuse infiltration of the bone marrow (80%) by lymphocytes with expression of CD11c, CD19, CD20, CD103. Tartrate resistant acid phosphatase test (TRAP) was also positive. Hairy cell leukemia was diagnosed and he was administered 2-chlorodeoxyadenosine (2-CDA) achieving a complete remission.

Coexpression and regulation of the FGF-2 and FGF antisense genes in leukemic cells

Fibroblast growth factor-2 (FGF-2) is a growth and survival factor whose expression is elevated in many hematopoietic malignancies. A natural antisense RNA (FGF-AS) has been implicated in the posttranscriptional regulation of FGF-2 mRNA expression. We demonstrate for the first time that FGF sense and antisense RNAs are coordinately expressed and translated in hematopoietic cells and tissues. Cytokine stimulation of growth-arrested K562 cells elicited a rapid transient increase in FGF-AS mRNA expression followed by a slower but sustained increase in FGF-2 mRNA. This was accompanied by a marked increase in the expression and nuclear translocation of FGF-2 and the FGF-AS encoded protein, GFG/NUDT6. These findings suggest a role for both FGF-2 and GFG proteins in the cell survival and proliferation of lymphoid and myeloid tumor cells.

Gene expression profiling of hairy cell leukemia reveals a phenotype related to memory B cells with altered expression of chemokine and adhesion receptors

Hairy cell leukemia (HCL) is a chronic B cell malignancy characterized by the diffuse infiltration of bone marrow and spleen by cells displaying a typical "hairy" morphology. However, the nature of the HCL phenotype and its relationship to normal B cells and to other lymphoma subtypes remains unclear. Using gene expression profiling, we show here that HCL displays a homogeneous pattern of gene expression, which is clearly distinct from that of other B cell non-Hodgkin lymphomas. Comparison with the gene expression profiles of purified normal B cell subpopulations, including germinal center (GC), pre-GC (naive), and post-GC (memory) B cells, shows that HCL cells are more related to memory cells, suggesting a derivation from this B cell population. Notably, when compared with memory cells, HCL cells displayed a remarkable conservation in proliferation, apoptosis, and DNA metabolism programs, whereas they appeared significantly altered in the expression of genes controlling cell adhesion and response to chemokines. Finally, these analyses have identified several genes that are specifically expressed in HCL and whose expression was confirmed at the protein level by immunocytochemical analysis of primary HCL cases. These results have biological implications relevant to the pathogenesis of this malignancy as well as clinical implications for its diagnosis and therapy.

bFGF rescues 423-cells from serum starvation-induced apoptosis downstream of activated caspase-3

Serum withdrawal rapidly induces apoptosis in rat 423-cells, while addition of bFGF results in cell survival. However, surviving cells initially display morphological changes characteristic for apoptotic cells and even process caspases. Active caspase-3 was detected at the single-cell level in those finally bFGF-rescued cells, while mitochondrial integrity was maintained. Generation of cleavage products of caspase targets was confirmed in surviving cells. Proteome analysis indicated multi-faceted survival activities of bFGF including upregulation of inhibitor-of-apoptosis and heat shock protein family members directly interfering with caspases. Our data suggest that the "point-of-no-return" in death-induced cells has to be moved downstream of activated caspase-3.

TIA-1 expression in hairy cell leukemia

We measured T-cell intracellular antigen-1 (TIA-1) expression in neoplastic cells from patients with hairy cell leukemia. Five of nine cases were positive for cytoplasmic TIA-1, with a small, dot-like, granular expression pattern. However, neoplastic cells were granzyme B- and perforin- negative in all cases. Other positive markers were CD20 in 9/9 cases, CD19 in 9/9 cases, DBA44 in 8/9 cases, LeuM5(CD11C) in 8/9 cases, IL-2R(CD25) in 7/9 cases, CD103 in 7/9 cases, FMC7 in 6/9 cases, and tartrate- resistant acid phosphatase in 5/7 cases. We also analyzed TIA-1 expression in 94 B cell lymphomas, including 19 diffuse, large cell lymphomas, 19 mantle cell lymphomas, six follicular lymphomas, two extranodal marginal zone B-cell lymphomas, 13 nodal marginal zone B-cell lymphomas, one mediastinal large-cell lymphoma, 19 diffuse small-cell lymphomas, 14 myelomas, and one splenic lymphoma with villous lymphocytes. All cases were negative for TIA-1 expression. Based on these findings, TIA-1 expression in neoplastic cells of low-grade B-cell lymphomas may be a good diagnostic marker for hairy cell leukemia. Moreover, TIA-1 reactivity in lymphomas does not necessarily indicate a T- or NK-cell derivation.

TGF-beta1 induces bone marrow reticulin fibrosis in hairy cell leukemia

The mechanisms that lead to reticulin fibrosis of bone marrow (BM) in hairy cell leukemia (HCL) are not fully understood. We therefore investigated the involvement of TGF-beta1, a potent fibrogenic cytokine, in this process. Immunoassays revealed that TGF-beta1 is present at higher concentrations in BM, serum, and plasma of HCL patients in comparison with healthy donors (P < 0.001). RT-PCR and immunofluorescence studies showed that TGF-beta1 is overexpressed at the mRNA and protein levels in peripheral blood, spleen, and BM mononuclear cells and that hairy cells (HCs) are the main source of TGF-beta1. Active TGF-beta1 correlated significantly with grades of BM fibrosis, infiltration with HCs, and serum procollagen type III aminoterminal propeptide (PIIINP). Ex vivo studies demonstrated that TGF-beta1 significantly enhances the production and deposition of reticulin and collagen fibers by BM fibroblasts. In addition, BM plasma of HCL patients increased the synthesis of type I and type III procollagens, the main components of reticulin fibers, at the mRNA and protein levels. This fibrogenic activity of BM plasma was abolished by neutralizing anti-TGF-beta1 antibodies. These results show, for the first time to our knowledge, that TGF-beta1 is highly expressed in HCs and is directly involved in the pathogenesis of BM reticulin fibrosis in HCL.

Comparative expressed sequence hybridization studies of hairy cell leukemia show uniform expression profile and imprint of spleen signature

Comparative expressed sequence hybridization (CESH) to chromosomes is a recently introduced technique that identifies chromosomal regions corresponding to a differential gene expression. This technique is analogous to comparative genomic hybridization (CGH) that detects genomic imbalances. We applied CESH for the study of hairy cell leukemia (HCL), a disorder with a largely unknown expression profile. Twelve HCL cases with spleen involvement were investigated by CESH and CGH. While the latter analysis identified only a few nonrecurrent genomic imbalances, CESH showed a consistent expression profile in all HCL cases. In addition, pairing normal spleen with normal lymph node, a "spleen signature" was established by CESH. This signature most likely reflects the expression profile of spleen-specific components, such as the sinusoidal lining cells from the red pulp and the marginal zone B cells from the white pulp. Imprint of the spleen signature was found in the HCL expression profile, suggesting that HCL may originate from a particular B-cell subset present in these splenic components. Besides pairing HCL with normal lymph node and spleen, we identified an "HCL signature" comprising several chromosome regions with altered expression. The most significantly underexpressed regions include 3p24, 3p21, 3q13.3-q22, 4p16, 11q23, 14q22-q24, 15q21-q22, 15q24-q25, and 17q22-q24; and 13q31 and Xq13.3-q21 were the most significantly overexpressed. These regions possibly harbor genes related to the biology and the pathogenesis of HCL. Their identification warrants further molecular investigations.

Rituximab in relapsed or refractory hairy cell leukemia

The purpose of this study was to investigate the efficacy and safety of the monoclonal antibody, rituximab, in relapsed or refractory hairy cell leukemia (HCL). Fifteen patients with relapsed or primary refractory HCL after nucleoside analogs received rituximab 375 mg/m2 weekly for a total of 8 planned doses. An additional 4 doses could be administered to responders who had not achieved complete response (CR). The overall response rate was 80%. Eight patients (53%) achieved CR, 2 (13%) attained CR by hematologic parameters with residual marrow disease (1% to 5% marrow hairy cells), and 2 (13%) had a partial response. Of the 12 responders followed for a median of 32 months (range, 8 to 45+ months), 5 patients (42%) had progression of disease 8, 12, 18, 23, and 39 months from the start of therapy. Three patients failed to respond (after 4, 6, or 8 doses). Reductions in serum interleukin-2 receptor (sIL-2R) levels correlated with response. Toxicity was minimal, and no infectious episodes were observed. Rituximab has significant activity and minimal toxicity in HCL and warrants further study. Rituximab should be explored further in HCL with regard to eradication of minimal residual disease and in combination with nucleoside analogs.

A morphometric study of bone marrow angiogenesis in hairy cell leukaemia with clinicopathological correlations

Bone marrow angiogenesis has recently been implicated in the pathophysiology and course of various haematological malignancies. Little is known, however, about the significance of this phenomenon in hairy cell leukaemia (HCL). We evaluated various morphometric characteristics of microvessels, highlighted by means of anti-CD34 immunohistochemistry, in the bone marrow of 44 patients with typical HCL, before and after treatment with interferon-alpha (IFN-alpha). Overall, bone marrow from 103 HCL patients and 20 controls was examined. Microvessel density (MVD) and several size- and shape-related parameters were quantified in the region of most intense vascularization using image analysis. MVD, size-related parameters and the percentage of branching microvessels were higher in HCL than in controls. Likewise, perimeter counts were higher in partial/non-responders than in complete responders. Achievement of complete response was accompanied by smaller calibre microvessels. IFN-alpha induced a decrease in MVD and branching values in cases with diffuse marrow involvement. In univariate analysis, progression-free survival was adversely affected by MVD, branching and major axis length. Multivariate analysis indicated that MVD/branching independently affected progression-free survival and the likelihood of complete response. Our data suggest that the generation of bone marrow microvessels indicated an increased risk of progression and IFN-alpha treatment failure in HCL. Furthermore, the prognostic significance of angiogenesis requires the concomitant assessment of MVD and the complexity of the microvascular network.

The role of autocrine FGF-2 in the distinctive bone marrow fibrosis of hairy-cell leukemia (HCL)

Bone marrow (BM) fibrosis is a central diagnostic and pathogenetic feature of hairy-cell leukemia (HCL). It is known that fibronectin (FN) produced and assembled by the malignant hairy cells (HCs) themselves is a major component of this fibrosis. It is also known that FN production is greatly enhanced by adhesion of HCs to hyaluronan (HA) via CD44. The aim of the present study was to establish the roles of fibrogenic autocrine cytokines (fibroblast growth factor-2 [FGF-2] and transforming growth factor beta [TGFbeta]) and of different isoforms of CD44 in this FN production. We show that HC adhesion to HA stimulates FGF-2, but not TGFbeta, production and that HCs possess FGF-2 receptor. In a range of experiments, FN production was greatly reduced by blocking FGF-2 but not TGFbeta. Moreover FN, but not FGF-2, secretion was blocked by down-regulation of the v3 isoform of CD44 and by addition of heparitinase. These results show that autocrine FGF-2 secreted by HCs is the principal cytokine responsible for FN production by these cells when cultured on HA. The central role of FGF-2 in the pathogenesis of the BM fibrosis of HCL was supported by our immunohistochemical demonstration of large amounts of this cytokine in fibrotic BM but not in HCL spleen where there is no fibrosis. As regards CD44 isoforms, the present work demonstrates that CD44v3 is essential for providing the heparan sulfate necessary for HC stimulation by FGF-2, whereas the signal for production of the cytokine was provided by HA binding to CD44H, the standard hematopoietic form of the molecule.

Regulation of hairy-cell survival through constitutive activation of mitogen-activated protein kinase pathways

The hairy cells (HCs) of hairy-cell leukemia are intrinsically activated mature clonal B cells. The aims of this study were to gain further insights into the nature of this activation and to assess its importance for the prolonged HC survival in this chronic disease. We show that HCs contain phosphorylated/activated p38 MAPK, JNK and ERK1/ERK2 (ERK1/2). PKC inhibitors increased the activation of p38 and JNK, but reduced the phosphorylation of ERK1/2. Moreover, PKC inhibition resulted in cell death; cell death was also observed when the activation of ERK1/2 in HCs was abrogated with an inhibitor of MEK1/2 activation. In addition to PKC, active Src kinase was also shown to be involved in the maintenance of Raf-independent ERK activation in HCs. During cell culture on a nonadherent surface, ERK phosphorylation was sustained, while phosphorylation of p38 and JNK decreased. This decrease was not observed in HCs cultured on vitronectin (VN), indicating that p38/JNK activation is probably a consequence of in vivo HC interaction with VN present in abundance in the red pulp of the spleen. Taken together, these results suggest that active p38/JNK make HCs susceptible to apoptosis, but the cells are effectively rescued by ERK activation involving constitutively active PKC and Src. These findings are relevant for the understanding of the prolonged cell survival of HCs and their selective sensitivity to some chemotherapeutic agents.

The biology of hairy cells

The evidence that hairy cells are activated clonal late B cells is presented. The largely non-specific (i.e. not confined to hairy-cell leukaemia) chromosome and genetic abnormalities are then described. Next, the features of malignant-cell activation are considered, including the distinctive morphology of hairy cells and their expression of activation-related antigens and activated adhesion receptors. Also, signalling and cytokine production are discussed in the context of malignant-cell activation. It is then demonstrated that many of the distinctive clinicopathological features of hairy-cell leukaemia can be explained in terms of the interaction of the activated malignant cells with other types of cell and tissue matrix. Finally, the biological basis of the hairy cell's unusually high sensitivity to IFN-alpha and nucleoside analogues is discussed.

Plasma vascular endothelial growth factor levels have prognostic significance in patients with acute myeloid leukemia but not in patients with myelodysplastic syndromes

BACKGROUND

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are positive regulators of angiogenesis. Increased levels in urine, serum, plasma, or malignant tissue have been associated with an adverse prognosis in patients with solid tumors.

METHODS

The authors used an enzyme-linked immunosorbent assay to measure VEGF and bFGF levels in plasma samples from 99 patients with previously untreated myelodysplastic syndromes (MDS) (n = 41 patients; 42%) or acute myeloid leukemia (AML) (n = 58 patients; 58%) and compared the results with the results from a group of normal control participants.

RESULTS

Increased expression levels of VEGF and bFGF were found in the plasma from patients with AML and MDS (P < 0.01) compared with the levels found in the control group. Plasma levels of VEGF in patients with AML or MDS were similar (median, 30.63 pg/mL and 34.41 pg/mL, respectively). There was no significant difference in bFGF levels between patients with AML and patients with MDS (median, 6.38 pg/mL and 6.98 pg/mL, respectively). Elevated levels of VEGF were associated with reduced survival (P = 0.02) in patients with AML as well as lower complete remission (CR) rates (P = 0.004). Elevated VEGF levels were not associated with reduced remission duration (CRD) in patients with AML. There was no correlation between VEGF levels and survival, CRD, or CR rates in patients with MDS. There was no correlation between bFGF levels and CR rates or survival in patients with either AML or MDS.

CONCLUSIONS

Plasma VEGF levels have prognostic significance in patients with AML. The lack of clinical relevance of VEGF levels in patients with MDS suggests some biologic difference between AML and MDS.

Expression of basic fibroblast growth factor is associated with poor outcome in non-Hodgkin's lymphoma

It is now clear that angiogenesis and angiogenesis factors are important in the pathogenesis of haematological malignancies. High pretreatment levels of serum basic fibroblast growth factor have been shown to be associated with poor prognosis in patients with non-Hodgkin's lymphoma. The aim of this study was to evaluate whether non-Hodgkin's lymphoma cells express basic fibroblast growth factor and/or its receptor (fibroblast growth factor receptor-1) and whether basic fibroblast growth factor expression correlates with basic fibroblast growth factor serum levels, intratumoral microvessel density, and patient outcome. We measured basic fibroblast growth factor by enzyme-linked immunosorbent assay in sera taken from 58 patients with non-Hodgkin's lymphoma before treatment and in 19 of them also after treatment. Pathological specimens at diagnosis were evaluated by immunohistochemistry staining using polyoclonal antibody against factor-VIII-related antigen, basic fibroblast growth factor and fibroblast growth factor receptor-1 to determine the expression of the microvessel count and basic fibroblast growth factor and fibroblast growth factor receptor-1. The lymphoma specimens demonstrated positive staining for basic fibroblast growth factor (in 23%) and fibroblast growth factor receptor-1 (in 58.5%). The patients who expressed basic fibroblast growth factor had a significantly worse progression-free and overall survival than those who did not (P=0.003 and P=0.03 respectively), while patients expressing fibroblast growth factor receptor-1 were less likely to achieve complete remission than those lacking the receptor (33% vs 65%, P=0.047). There was no correlation of basic fibroblast growth factor staining with either serum basic fibroblast growth factor levels or microvessel count. Basic fibroblast growth factor serum levels did not change significantly after treatment These results suggest that non-Hodgkin's lymphoma specimens express basic fibroblast growth factor and its receptor (fibroblast growth factor receptor-1) and this expression is associated with poor patient outcome.

Blood levels of angiogenin and vascular endothelial growth factor are elevated in myelodysplastic syndromes and in acute myeloid leukemia

Angiogenesis is of prognostic importance not only in solid tumors but also in malignant blood diseases. We measured levels of vascular endothelial growth factor (VEGF), angiogenin (ANG), and basic fibroblast growth factor (bFGF) in peripheral blood samples from 65 patients with myelodysplastic syndrome (MDS), from 25 patients with de novo acute myeloid leukemia (AML), and from 50 healthy donors. In matched samples, VEGF levels in serum were substantially higher than VEGF levels in plasma (380.7 +/- 56 pg/ml vs. 45.3 +/- 4.5 pg/ml, mean +/- SEM, p < 0.001), whereas serum and plasma levels of ANG were comparable and significantly correlated (r = 0.8; p < 0.01). Compared to normal controls (1.3 +/- 0.09 pg), serum levels of VEGF corrected for the peripheral blood platelet count (VEGF/10(6) platelets, VEGF(PLT)) were elevated in patients with refractory anemia (RA; 3.1 +/- 0.8 pg, p < 0.01), and reached maximal values in patients with advanced stage MDS (RAEB, RAEB-t) (3.5 +/- 0.6 pg, p < 0.001), de novo AML (3.6 +/- 1.1 pg, p < 0.05), and chronic myelomonocytic leukemia (CMML; 3.7 +/- 0.9 pg; p < 0.001). Levels of soluble ANG were elevated in RA (351 +/- 25.7 ng/ml, p < 0.001), in RAEB/RAEB-t (402 +/- 17.9 ng/ml; p < 0.001), in CMML (413.8 +/- 29.5 ng/ml; p < 0.001), and in patients with AML (305.1 +/- 17.1 ng/ml; p < 0.01, controls 255.4 +/- 8.1 ng/ml). Serum bFGF was neither elevated in MDS nor in AML patients. These results suggest that VEGF(PLT) is a marker of disease progression in MDS. Moreover, we show for the first time that elevated blood levels of ANG can be found in patients with myeloid malignancies, suggesting a role of ANG in the pathogenesis of these diseases.

Fibroblast growth factors and their receptors in hematopoiesis and hematological tumors

Fibroblast growth factors (FGFs) belong to a family of pleiotropic heparin-binding growth factors. They exert multiple functions on various cell types of mesodermal and neuroectodermal origin, affecting cell proliferation, motility, survival, and differentiation. FGF's exert their activity by interacting with tyrosine kinase receptors (FGFRs) and cell-surface heparan sulfate proteoglycans. This article reviews recent studies on the role of the FGF/FGFR system in embryonic hematopoietic development, hematopoiesis, and hematological tumors. FGFs exert both autocrine and paracrine functions in these biological processes by acting on blood cells and their precursors and accessory cells in the bone marrow, including stromal and endothelial cells.

Angiogenic and lymphangiogenic molecules in hematological malignancies

In this review, the role of angiogenic and lymphangiogenic growth factors in hematological malignancies is summarized, alongside with possible therapeutic applications. Recent data demonstrate the importance of angiogenesis in hematologic malignancies including leukemia, lymphoma, and multiple myeloma. Expression of angiogenic polypeptides vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) associate with clinical characteristics in human leukemia and lymphoma, and their serum concentrations serve as predictors of poor prognosis. VEGF and VEGF-C also act as survival factors on leukemia. Furthermore, certain hematological malignancies both produce angiogenic or lymphangiogenic growth factors including VEGF and VEGF-C, and also express their receptors, resulting in the generation of autocrine loops that may support cancer cell survival and proliferation. Inhibition of the action of key regulators of endothelial cell growth, alone or in combination with other antiangiogenic drugs and/or established chemo- or immunotherapy regimens, is a potential target for therapeutic intervention in hematological malignancies.

Basic fibroblast growth factor modulates the expression of glycophorin A and c-kit and inhibits erythroid differentiation in K562 cells

Basic fibroblast growth factor (bFGF) is produced by bone marrow stromal cells as well as by normal and leukemic hematopoietic cells. In this study, we examine the direct effects of bFGF on erythroid differentiation in K562 cells in order to determine whether bFGF can promote the expression of a primitive phenotype. Low levels of bFGF inhibited erythroid differentiation as evidenced by decreased expression of glycophorin A and increased expression of c-kit. bFGF also increased both the numbers and the sizes of colonies of K562 cells in soft agar assays. The addition of TGF-beta to these cells induced erythroid differentiation which resulted in an increase in glycophorin A and a decrease in c-kit. The simultaneous addition of bFGF and TGF-beta to K562 cells prevented both the TGF-beta-mediated increase in glycophorin A expression and the decrease in c-kit expression associated with erythroid differentiation. bFGF antagonised the TGF-beta-mediated promotion of erythroid differentiation in K562 cells in a dose dependent manner and these two cytokines counteracted each other on an approximately molar basis. These results indicate that bFGF alone increases expression of c-kit and promotes a primitive phenotype in K562 cells. In addition, bFGF counteracts the effects of differentiation-inducing cytokines, such as TGF-beta, on hematopoietic cells. It is therefore possible that enhanced production of bFGF by leukemic cells could contribute to their neoplastic phenotype by opposing the effects of negative regulators or cytokines that induce differentiation.

Significance of angiogenin plasma concentrations in patients with acute myeloid leukaemia and advanced myelodysplastic syndrome

Human angiogenin is a potent inducer of angiogenesis. The association between angiogenin and cancer progression and poor outcome in solid tumours has been documented, but its significance in leukaemias has not been evaluated. We evaluated plasma angiogenin levels in 101 previously untreated patients with acute myeloid leukaemia (AML) (59 patients) and advanced myelodysplastic syndrome (MDS) (42 patients). Angiogenin levels were significantly higher in AML and advanced MDS patients than in healthy individuals (P < 0.00001). Angiogenin levels were also significantly higher in advanced MDS than in AML (P = 0.001). Higher levels of angiogenin correlated with prolonged survival periods in both AML and advanced MDS patients (P = 0.02 and 0.01 respectively). We found no correlation between angiogenin plasma level and various patient characteristics, including age, performance status, antecedent haematological disorder, haemoglobin, white blood cell and platelet counts, and poor prognosis cytogenetics. There was no significant correlation between angiogenin level and complete remission rate and duration in AML or advanced MDS patients. In multivariate analysis, angiogenin concentration retained its significance as a prognostic factor in AML (P = 0.03), together with age (P = 0.00007) and haemoglobin (P = 0.03).

Plasma hepatocyte growth factor is a prognostic factor in patients with acute myeloid leukemia but not in patients with myelodysplastic syndrome

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The aim of our study was to evaluate plasma HGF levels and their prognostic significance in patients with newly diagnosed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The sandwich enzyme immunoassay technique was used to quantify HGF in stored samples obtained before treatment from patients with AML (59 patients) and MDS (42 patients) treated at The University of Texas MD Anderson Cancer Center. HGF levels were significantly higher in patients with AML or MDS than in healthy individuals (P < 0.0001). Higher HGF levels in both AML and MDS correlated significantly with white blood cell (P = 0.000001 for both groups) and monocyte counts (P = 0.0004 and 0.003, respectively), and with poor performance status (P = 0.03 and 0.001, respectively). Using Cox proportional hazard model and HGF levels as a continuous variable, plasma levels of HGF correlated with shorter survival of AML (P = 0.001), but not MDS (P = 0.34) patients. No significant correlation was observed between HGF levels and complete remission rate or duration. In the multivariate analysis HGF retained its significance as prognostic factor in AML (P = 0.02), along with age (P = 0.0005).

Bcl-2 expression correlates positively with serum basic fibroblast growth factor (bFGF) and negatively with cellular vascular endothelial growth factor (VEGF) in patients with chronic lymphocytic leukaemia

A large proportion of B-chronic lymphocytic leukaemia (B-CLL) cells express the anti-apoptotic protein Bcl-2. Basic fibroblast growth factor (bFGF) has been shown to upregulate the expression of Bcl-2 in B-CLL cell lines. Vascular endothelial growth factor (VEGF) has been shown to enhance the survival of endothelial cells by upregulating the expression of Bcl-2. In the present study, we measured serum and cellular levels of bFGF and VEGF in 85 patients with CLL using a commercial quantitative sandwich enzyme immunoassay technique. Levels of Bcl-2 were also assayed concomitantly using Western blot analysis. The mean serum level of bFGF was 53.4 pg/ml (range 0-589) and that of VEGF 459.2 pg/ml (range 33-1793). The mean cellular level of bFGF was 158.3 pg/2 x 105 cells (range 0.8-841) and VEGF, 42.4 pg/2 x 105 cells (range 0-244). A high correlation was found between serum and cellular bFGF levels (P < 0.001), but not between the corresponding VEGF levels. Twenty-nine of 69 patients (42%) evaluated for Bcl-2 level, expressed it. The Bcl-2 level was positively correlated with the serum bFGF level (P = 0.007). However, surprisingly there was a negative correlation between Bcl-2 expression and intracellular VEGF level (P = 0.003). A positive correlation was also found between serum bFGF and disease follow-up time and log white blood cell count. These findings indicate that in CLL there is a correlation between angiogenesis-related factors and apoptosis-related protein expression, and elevated bFGF levels may account for the elevated Bcl-2 levels.

Simultaneous elevation in the serum concentrations of the angiogenic growth factors VEGF and bFGF is an independent predictor of poor prognosis in non-Hodgkin lymphoma: a single-institution study of 200 patients

High serum concentrations of vascular endothelial growth factor (S-VEGF) and basic fibroblast growth factor (S-bFGF) are associated with unfavorable clinical characteristics in cancer. The combined effect of S-VEGF and S-bFGF on the survival of 200 patients with non-Hodgkin lymphoma (NHL) was studied. High S-VEGF and S-bFGF at diagnosis were associated with poor survival with the medians, the highest tertiles, or the highest quartiles as the cutoff values. The highest prognostic power was obtained when S-VEGF and S-bFGF were examined as a combination. Patients who had both S-VEGF and S-bFGF within the highest quartiles had only a 21% 5-year survival rate in contrast to a 64% 5-year survival rate among patients with both factors within the 3 lowest quartiles (P < .0001). Simultaneous elevation of S-VEGF and S-bFGF was associated with poor survival in different grades of lymphomas and in the largest histologic subgroup, the large-cell diffuse and immunoblastic lymphomas. S-VEGF (relative risk [RR], 1.83; P = .019) and S-bFGF (RR, 2.02; P = .0049) had independent influences on survival in multivariate models when tested together with the components of the International Prognostic Index (IPI). Patients with both S-VEGF and S-bFGF within the highest quartiles had nearly 3 times higher risk for death (RR, 2.90; 95% confidence interval [CI], 1.56-5.40;P = .0008) than the rest of the patients. This RR was higher than the relative risks associated with any of the components of the IPI in the same model. The authors conclude that the combination of S-VEGF and S-bFGF is a powerful prognostic variable in NHL.

Simultaneous elevation in the serum concentrations of the angiogenic growth factors VEGF and bFGF is an independent predictor of poor prognosis in non-Hodgkin lymphoma: a single-institution study of 200 patients

High serum concentrations of vascular endothelial growth factor (S-VEGF) and basic fibroblast growth factor (S-bFGF) are associated with unfavorable clinical characteristics in cancer. The combined effect of S-VEGF and S-bFGF on the survival of 200 patients with non-Hodgkin lymphoma (NHL) was studied. High S-VEGF and S-bFGF at diagnosis were associated with poor survival with the medians, the highest tertiles, or the highest quartiles as the cutoff values. The highest prognostic power was obtained when S-VEGF and S-bFGF were examined as a combination. Patients who had both S-VEGF and S-bFGF within the highest quartiles had only a 21% 5-year survival rate in contrast to a 64% 5-year survival rate among patients with both factors within the 3 lowest quartiles (P &lt; .0001). Simultaneous elevation of S-VEGF and S-bFGF was associated with poor survival in different grades of lymphomas and in the largest histologic subgroup, the large-cell diffuse and immunoblastic lymphomas. S-VEGF (relative risk [RR], 1.83; P = .019) and S-bFGF (RR, 2.02; P = .0049) had independent influences on survival in multivariate models when tested together with the components of the International Prognostic Index (IPI). Patients with both S-VEGF and S-bFGF within the highest quartiles had nearly 3 times higher risk for death (RR, 2.90; 95% confidence interval [CI], 1.56-5.40;P = .0008) than the rest of the patients. This RR was higher than the relative risks associated with any of the components of the IPI in the same model. The authors conclude that the combination of S-VEGF and S-bFGF is a powerful prognostic variable in NHL.