Clinical relevance of circulating angiogenic factors in patients with non-Hodgkin's lymphoma or Hodgkin's lymphoma

An Update on Protein Kinases as Therapeutic Targets-Part I: Protein Kinase C Activation and Its Role in Cancer and Cardiovascular Diseases

Protein kinases are one of the most significant drug targets in the human proteome, historically harnessed for the treatment of cancer, cardiovascular disease, and a growing number of other conditions, including autoimmune and inflammatory processes. Since the approval of the first kinase inhibitors in the late 1990s and early 2000s, the field has grown exponentially, comprising 98 approved therapeutics to date, 37 of which were approved between 2016 and 2021. While many of these small-molecule protein kinase inhibitors that interact orthosterically with the protein kinase ATP binding pocket have been massively successful for oncological indications, their poor selectively for protein kinase isozymes have limited them due to toxicities in their application to other disease spaces. Thus, recent attention has turned to the use of alternative allosteric binding mechanisms and improved drug platforms such as modified peptides to design protein kinase modulators with enhanced selectivity and other pharmacological properties. Herein we review the role of different protein kinase C (PKC) isoforms in cancer and cardiovascular disease, with particular attention to PKC-family inhibitors. We discuss translational examples and carefully consider the advantages and limitations of each compound (Part I). We also discuss the recent advances in the field of protein kinase modulators, leverage molecular docking to model inhibitor-kinase interactions, and propose mechanisms of action that will aid in the design of next-generation protein kinase modulators (Part II).

Vascular Growth in Lymphomas: Angiogenesis and Alternative Ways

The formation of new blood vessels is a critical process for tumor growth and may be achieved through different mechanisms. Angiogenesis represents the first described and most studied mode of vessel formation, but tumors may also use alternative ways to secure blood supply and eventually acquire resistance to anti-angiogenic treatments. These non-angiogenic mechanisms have been described more recently, including intussusceptive microvascular growth (IMG), vascular co-option, and vasculogenic mimicry. Like solid tumors, angiogenic and non-angiogenic pathways in lymphomas play a fundamental role in tumor growth and progression. In view of the relevant prognostic and therapeutic implications, a comprehensive understanding of these mechanisms is of paramount importance for improving the efficacy of treatment in patients with lymphoma. In this review, we summarize the current knowledge on angiogenic and non-angiogenic mechanisms involved in the formation of new blood vessels in Hodgkin's and non-Hodgkin's lymphomas.

Inflammatory microenvironment in classical Hodgkin’s lymphoma with special stress on mast cells

Classical Hodgkin’s lymphoma (CHL) accounts for 10% of all lymphomas. Nodular sclerosis and mixed cellularity accounts for nearly 80% of all CHL cases. The number of mast cells in CHL correlates with poor prognosis, is significantly higher in nodular sclerosis than in other CHL subtypes, and an association between the degree of angiogenesis and the number of intratumoral mast cells has been demonstrated in CHL. Even with the best available treatment, a significant percentage of CHL patients progress or relapse after first-line therapy. 50% of patients with disease relapse achieve subsequent long-term disease control with salvage therapies. In this context, new potential therapeutic opportunities are required, and mast cells may be regarded as a new target for adjuvant treatment of CHL through the inhibition of angiogenesis and tissue remodeling and allowing the secretion of cytotoxic cytokines.

Soluble PD-L1 is a promising disease biomarker but does not reflect tissue expression in classic Hodgkin lymphoma

Individually, tissue and soluble markers involved in the programmed cell death protein 1/programmed death-ligand (PD-1/PD-L) axis have been described as biomarkers with clinical value in classical Hodgkin lymphoma (cHL). In the context of the success of immune checkpoint blockade therapy in cHL, it is interesting to discover whether plasma levels of proteins in the PD-1/PD-L axis are a reflection of expression by the corresponding tissue. Paired tissue and plasma samples of cHL patients were collected and analysed for PD-1, PD-L1 and PD-L2 levels. In addition, vascular endothelial growth factor (VEGF) and CD83, molecules regarded to influence the expression of PD-1, PD-L1 and/or PD-L2, were included. PD-L1 was upregulated in the plasma of cHL patients compared to healthy controls and correlated well with several clinical parameters. Strong PD-L1 expression in the tumour microenvironment contributed to high soluble (s)PD-L1 levels, although there was no direct correlation between plasma PD-L1 levels and total expression of PD-L1 in corresponding cHL tissue. Interestingly, we observed a positive correlation between VEGF and PD-1 levels in both tissue and plasma. In conclusion, although PD-L1 is a promising soluble biomarker in cHL, its levels do not reflect the total tissue expression. Future studies focusing on PD-L1 as a predictor for immune checkpoint treatment response, should include both biopsy and plasma samples.

Hepatocyte Growth Factor: A Microenvironmental Resource for Leukemic Cell Growth

Chronic lymphocytic leukemia (CLL) is characterized by the progressive expansion of B lymphocytes CD5+/CD23+ in peripheral blood, lymph-nodes, and bone marrow. The pivotal role played by the microenvironment in disease pathogenesis has become increasingly clear. We demonstrated that bone marrow stromal cells and trabecular bone cells sustain survival of leukemic B cells through the production of hepatocyte growth factor (HGF). Indeed the trans-membrane kinase receptor for HGF, c-MET, is expressed on CLL cells and STAT3 TYR⁷⁰⁵ or AKT phosphorylation is induced after HGF/c-MET interaction. We have further observed that c-MET is also highly expressed in a peculiar type of cells of the CLL-microenvironment showing nurturing features for the leukemic clone (nurse-like cells: NLCs). Since HGF treatment drives monocytes toward the M2 phenotype and NLCs exhibit features of tumor associated macrophages of type 2 we suggested that HGF, released either by cells of the microenvironment or leukemic cells, exerts a double effect: (i) enhances CLL cells survival and (ii) drives differentiation of monocytes-macrophages to an oriented immune suppressive phenotype. We here discuss how paracrine, but also autocrine production of HGF by malignant cells, may favor leukemic clone expansion and resistance to conventional drug treatments in CLL, as well as in other hematological malignancies. Novel therapeutic approaches aimed to block HGF/c-MET interactions are further proposed.

Biology of Tumor Associated Macrophages in Diffuse Large B Cell Lymphoma

The tumor associated microenvironment is known to play a vital role during the development and progression of different malignant tumors. As a part of tumor microenvironment, tumor associated macrophages (TAMs) are crucial for the genesis, proliferation, metastasis, and survival of tumor cells. Recently, more and more studies showed that TAMs were related with poor clinical status and survival in patients with diffuse large B cell lymphoma (DLBCL). Considering the complex roles which TAMs play in the tumor microenvironment of DLBCL, the aim of this study was to review the biological mechanisms between TAMs and DLBCL cells, including extracellular matrix remodeling and angiogenesis promotion, tumor promotion, immune suppression, and phagocytosis inhibition. This review will help us to further understand the comprehensive impact of TAMs on DLBCL and explore possible prognostic markers and therapeutic targets.

Angiogenic Molecules in Hodgkin's Disease: Results from Sequential Serum Analysis

Increased angiogenic activity has been demonstrated in lymphoproliferative diseases including Hodgkin's disease. In the current study, the levels of circulating angiogenic molecules in 60 Hodgkin's patients were determined prior to and after treatment and correlated to disease stage and prognostic score. Hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were increased in Hodgkin's patients in comparison to healthy controls (p<0.001). Angiogenin and angiopoietin-2 levels did not differ from controls. HGF, VEGF, TNF-α and angiogenin decreased significantly in Hodgkin's patients after standard treatment (p<0.001 for HGF, p<0.05 for VEGF, TNF-α and angiogenin). Furthermore, HGF and TNF-α increased with advancing stage of disease (p<0.05). HGF and VEGF correlated significantly with IL-6 (r=0.56, p<0.0005 and r=0.57, p<0.001 respectively). In conclusion, Hodgkin's disease displays an angiogenic activity as depicted by the increased serum levels of a number of angiogenic cytokines. HGF seems to be the prominent molecule in Hodgkin's disease, which may be used to monitor the disease status and the response to treatment.

Current Status and Future Prospects of Biomarkers in the Diagnosis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has one of the highest death rates of any cancer in the world, and its incidence is increasing worldwide. Early-stage diagnosis of HCC is thus crucial for medical treatment. Detection of tumor biomarkers is one of the main methods for the early diagnosis of HCC. At present, α-fetoprotein (AFP) is the most practical serum biomarker for HCC diagnosis. However, the diagnostic accuracy of HCC with serum AFP exhibits both sensitivity and specificity far below satisfaction, especially with small sizes of HCC. As a result, the discovery of new biomarkers and/or their combination to enhance both the sensitivity and specificity for laboratory diagnosis of HCC is a crucial goal. With the development of new technology and advances in research, a number of new and specific biomarkers of HCC have been discovered. These biomarkers and their applications for the diagnosis, treatment monitoring and prognosis prediction of HCC, are reviewed in this article.

Atypical variants of nodular lymphocyte-predominant Hodgkin lymphoma show low microvessel density and vessels of distention type

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) presents different histopathologic growth patterns, including atypical forms showing overlapping histopathologic and clinical features with T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL). Because growth patterns are associated with vessel distribution, the aim of the present study was to compare angiogenesis in different NLPHL patterns with THRLBCL as well as other lymphomas. Atypical variants of NLPHL and THRLBCL (n=10 per group) both showed a low microvessel density (MVD; 1.16-1.31/μm²) with a diffuse vessel distribution. In contrast, in typical NLPHL (n=10), follicular areas with low MVD were retained, whereas an increase in vessels in the interfollicular areas was observed (MVD 1.35/μm²). THRLBCL and typical NLPHL could additionally be distinguished by differences in their molecular angiogenesis signature. Furthermore, the number of intravascular T cells was significantly reduced in THRLBCL (0.0028 T cells/mm² vessel area) when compared with typical NLPHL (0.0059 T cells/mm² vessel area), potentially reflecting the different composition of the microenvironment in these 2 lymphoma entities. The results of our study reveal a similar vascular pattern and angiogenesis behavior in atypical NLPHL variants and THRLBCL in contrast to the retained follicular pattern in typical NLPHL.

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.

Lymphoma: immune evasion strategies

While the cellular origin of lymphoma is often characterized by chromosomal translocations and other genetic aberrations, its growth and development into a malignant neoplasm is highly dependent upon its ability to escape natural host defenses. Neoplastic cells interact with a variety of non-malignant cells in the tumor milieu to create an immunosuppressive microenvironment. The resulting functional impairment and dysregulation of tumor-associated immune cells not only allows for passive growth of the malignancy but may even provide active growth signals upon which the tumor subsequently becomes dependent. In the past decade, the success of immune checkpoint blockade and adoptive cell transfer for relapsed or refractory lymphomas has validated immunotherapy as a possible treatment cornerstone. Here, we review the mechanisms by which lymphomas have been found to evade and even reprogram the immune system, including alterations in surface molecules, recruitment of immunosuppressive subpopulations, and secretion of anti-inflammatory factors. A fundamental understanding of the immune evasion strategies utilized by lymphomas may lead to better prognostic markers and guide the development of targeted interventions that are both safer and more effective than current standards of care.

Clinical significance of serum hepatocyte growth factor (HGF) levels in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. This study was conducted to investigate the serum levels of hepatocyte growth factor (HGF)in HCC patients and the relationship with tumor progression and known prognostic parameters. Fifty-four patients with HCC were investigated. Pretreatment HGF levels were employed the quantitative sandwich enzyme immunoassay technique (ELISA). Age and sex matched 20 healthy controls were included in the analysis. The median age of the patients was 60 years (range 36-77 years); where males consistituted of majority of the group (88.8%). All of patients had cirrhotic history. Fourty-six percent (n = 25) of patients had Child-Pugh Score A, 30% (n = 16) had Score B or C. All of the patients were treated with local therapies but none of them received sorafenib. The baseline serum HGF levels were significantly higher in patients with HCC than in the control group (p < 0.001). Male patients had higher serum HGF levels compared with female patients (p = 0.01). Serum HGF levels were significantly higher in the patients with elevated serum ALT levels than others with normal serum ALT levels (p = 0.05). Poor performance status (p < 0.001), viral etiology of cirrhosis (p = 0.03), larger tumor size (p = 0.01), lower serum hemogloblin levels (p = 0.03), and not be treated for HCC (p = 0.001) related to worse survival. However, serum HGF did not have significantly adverse effect on survival (p = 0.58). Despite serum HGF levels were found diagnostic value, serum HGF levels had no prognostic value in patients with HCC.

A phase II study of thalidomide and vinblastine for palliative patients with Hodgkin's lymphoma

INTRODUCTION

Patients with Hodgkin's Lymphoma (HL) who relapse or progress after primary therapy and subsequent high dose chemotherapy with autologous stem cell transplantation (ASCT) cannot be cured with conventional treatment. We combined thalidomide (THAL), an agent with anti-angiogenic and immunomodulatory properties, with vinblastine, which is active after ASCT, to determine the objective response rate, improvement in B symptoms and toxicity in patients with refractory HD.

METHODS

Patients were eligible if they HD that progressed after chemotherapy and ASCT or had declined or were ineligible for curative therapy. Treatment consisted of THAL 200 mg orally given daily. After 2 weeks, VBL 6 mg IV was given weekly x 6 doses on an eight-week cycle. Response and toxicity assessment occurred following each cycle.

RESULTS

Eleven patients were enrolled, 1 progressed within 6 days of study enrollment and was subsequently treated with alternative palliative therapy and thus 11 patients are response evaluable and 10 are evaluable for toxicity.

PATIENT CHARACTERISTICS

relapsed after ASCT: 7; median number of prior chemotherapy regimens: 3 (range 1-5); median time to progression post-ASCT: 7 months (range 2-29). Four patients had a partial response to treatment (response rate 36%); two patients had stable disease. B symptoms were present at enrollment in four patients and resolved completely on treatment in two patients. Five had disease progression within 3 months of starting treatment. The median duration of response was 9 months (range 0-22 months). Toxicity was mild and limited to grade 2 neuropathy in 6 patients and grade 2 or 3 neutropenia in 4 patients.

CONCLUSIONS

In this small study in chemotherapy- refractory HL, THAL and VBL demonstrated encouraging activity with some durable responses and acceptable toxicity. These results suggest that chronic low dose chemotherapy combined with less toxic immunomodulatory or anti-angiogenic drugs warrants further study.

VEGF and bFGF gene polymorphisms in patients with non-Hodgkin's lymphoma

Angiogenesis and lymphangiogenesis are important in the proliferation and survival of the malignant hematopoietic neoplasms, including non-Hodgkin's lymphomas (NHLs). Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) play an important role in the initiation of angiogenesis. Both VEGF and bFGF have been reported to have prognostic significance in NHL. The present study aimed to determine an association between the VEGF and bFGF gene polymorphisms and disease susceptibility and progression. VEGF (rs3025039; 936 C>T) and bFGF (rs308395, -921 G>C) variants were determined in 78 NHL patients and 122 healthy individuals by PCR-RFLP technique. The presence of the VEGF 936T allele was found to significantly associate with worse prognosis of the disease (expressed by the highest International Prognostic Index (IPI)) (0.41 versus 0.20, P = 0.044 for IPI 4 among patients having and lacking the T allele). The VEGF 936T variant was also more frequent among patients with IPI 4 than in controls (OR = 3.37, P = 0.029). The bFGF -921G variant was more frequently detected among patients with aggressive as compared to those with indolent histological subtype (0.37 versus 0.18, P = 0.095) and healthy individuals (0.37 versus 0.19, OR = 2.51, P = 0.038). These results imply that VEGF and bFGF gene polymorphisms have prognostic significance in patients with NHL.

Phase II open label study of the oral vascular endothelial growth factor-receptor inhibitor PTK787/ZK222584 (vatalanib) in adult patients with refractory or relapsed diffuse large B-cell lymphoma

PTK787/ZK222584 (vatalanib), an orally active inhibitor of vascular endothelial growth factor receptors (VEGFRs), was evaluated in this phase II study of 20 patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Patients received once-daily PTK787/ZK222584 at a target dose of 1250 mg. Eighteen patients were evaluable for response: one patient had a complete response (CR), six patients had stable disease but subsequently progressed, 10 patients had progressive disease by three cycles and one subject withdrew before response evaluation. The patient who attained a CR underwent autologous stem cell transplant and remains disease-free 76 months after study completion. There were no grade 4 toxicities. Grade 3 thrombocytopenia occurred in 20% and grade 3 hypertension occurred in 10%. There were no episodes of grade 3 proteinuria. In conclusion, PTK787/ZK222584 was well tolerated in a heavily pretreated population of patients with DLBCL, although its therapeutic potential as a single agent in DLBCL appears limited.

High MET gene copy number predicted poor prognosis in primary intestinal diffuse large B-cell lymphoma

BACKGROUND

MET is a proto-oncogene with its copy number (CN) alterations been reported in some cancers, but not in primary intestinal diffuse large B-cell lymphoma (PI-DLBL) yet.

METHODS

In this retrospective study, we performed histology and chart reviews, immunohistochemistry and quantitative polymerase chain reaction for MET CN alterations on 28 surgically resected PI-DLBLs.

RESULTS

There were 12 men and 16 women with a median age of 70 and a mean follow-up of 32 months. The median MET CN was 2.20 (range, 1.04 to 3.35). CN gain was observed in 11 cases, including 5 with CN greater than 3. Nine patients (32%) had diploid CN and eight (29%) with CN loss. Patients with gain or diploid CN showed significantly worse prognosis (P = 0.046) than those with CN loss. Furthermore, MET CN greater than 3 was associated with an adverse outcome (P = 0.003). Intestinal perforation at presentation was the sole clinicopathological factor associated with a poor prognosis (P = 0.004) and perforation was correlated with CN greater than 3 (P = 0.002).

CONCLUSIONS

Our finding of MET CN gain as a poor prognostic factor in PI-DLBL patients might serve as the rationale for targeting MET signaling pathway in the treatment of these patients.

Serum vascular endothelial growth factor-a levels during induction therapy in children with acute lymphoblastic leukemia

OBJECTIVE

To evaluate serum vascular endothelial growth factor (VEGF) levels in children with acute lymphoblastic leukemia (ALL) during the induction phase of chemotherapy.

DESIGN

Prospective sudy.

SETTING

Setting: Hospital-based study over 18 months.

PATIENTS

30 children with ALL and 17 healthy age- and sex-matched controls.

INTERVENTION

Serum concentration of VEGF-A-165 isoform (s-VEGF) was measured by enzyme-linked immunoabsorbant assay at diagnosis and at the end of induction chemotherapy.

MAIN OUTCOME MEASURES

s-VEGF was compared with markers of tumor burden. Kinetics of s-VEGF was assessed in response to induction chemotherapy.

RESULTS

Median VEGF was significantly lower in untreated patients than in controls (17.0 vs. 42.6 pg/mL, P=0.004). s-VEGF levels were fairly correlated with WBC count (r=-0.56, P=0.004) and LDH (r=-0.52, P=0.02) at diagnosis. All patients but one were in morphologic remission at the end of induction. Median s-VEGF concentration on day 29/33 was significantly higher than on day 1 (44.2 pg/mL, P=0.009).

CONCLUSIONS

Untreated children with ALL have significantly lower s-VEGF concentration than controls. At the end of the induction therapy, s-VEGF increased to levels similar to controls. The role of ligand-receptor interaction between VEGF and VEGF receptors on leukemia cells needs to be further delineated.To identify the risk factors for scholastic backwardness in children.

Expression of COX-2 on Reed-Sternberg cells is an independent unfavorable prognostic factor in Hodgkin lymphoma treated with ABVD

Cyclooxygenase 2 (COX-2) is an inflammatory enzyme involved in the pathogenesis and prognosis of several malignancies. In the present study, we investigated the prognostic value of COX-2 expression in a large (N = 242), uniformly treated Hodgkin lymphoma (HL) population from the Spanish Network of HL using tissue microarrays. Univariate and multivariate analysis was done, including comparing the most recognized clinical variables: the early- and advanced-stage subgroups. COX-2 was expressed on Reed-Sternberg cells in 37% of patients. There were no differences in the distribution of clinical variables according to COX-2 expression. With a median follow-up time of 58 months, PFS at 5 years was 60% and 79% for COX-2+ and COX-2− patients, respectively (P = .003). The overall survival was 73% and 91%, respectively (P < .001). The major impact on prognosis was observed in the early AA stage (I-II) group. In fact, in these low-risk groups the expression of COX-2 defined a group with significantly worse progression-free and overall survival. In conclusion, COX-2 was expressed on Reed-Sternberg cells in one-third of HL patients and was a major independent, unfavorable prognostic factor in early-stage HL. We conclude that COX-2 may be a major prognostic variable in HL and a potential therapeutic target.

Molecular Pathogenesis of Hodgkin's Lymphoma: Increasing Evidence of the Importance of the Microenvironment

Hodgkin's lymphoma (HL) represents the most common subtype of malignant lymphoma in young people in the Western world. Most patients can be cured with modern treatment strategies, although approximately 20% will die after relapse or progressive disease. The histologic hallmark of the disease is the presence of the characteristic Hodgkin Reed-Sternberg (HRS) cells in classical HL and so-called lymphocyte-predominant (LP) cells in nodular lymphocyte-predominant HL. HL is unique among all cancers because malignant cells are greatly outnumbered by reactive cells in the tumor microenvironment and make up only approximately 1% of the tumor. Expression of a variety of cytokines and chemokines by the HRS and LP cells is believed to be the driving force for an abnormal immune response, perpetuated by additional factors secreted by reactive cells in the microenvironment that help maintain the inflammatory milieu. The malignant HRS and LP cells manipulate the microenvironment, permitting them to develop their malignant phenotype fully and evade host immune attack. Gene expression signatures derived from non-neoplastic cells correlate well with response to initial and subsequent therapies, reflecting their functional relevance. Recent biomarker studies have added texture to clinical outcome predictors, and their incorporation into prognostic models may improve our understanding of the biologic correlates of treatment failure. Moreover, recent preclinical and clinical studies have demonstrated that the tumor microenvironment represents a promising therapeutic target, raising hope that novel treatment strategies focused on the interface between malignant and reactive cells will soon emerge.

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.

Clinical significance of serum vascular endothelial growth factor, endostatin, and leptin levels in children with lymphoma

BACKGROUND

A number of clinical studies conducted in adults have demonstrated the prognostic significance of angiogenic factors in malignancies, however, only a limited number of studies have been conducted in children. The aim of this study was to determine serum vascular endothelial growth factor (VEGF), endostatin, and leptin levels in children with lymphoma and to investigate whether these factors provide prognostic information.

PROCEDURE

Serum samples from 36 children with lymphoma (non-Hodgkin lymphoma (NHL) N = 21, Hodgkin lymphoma (HL) N = 15) were collected at diagnosis and during remission. Serum samples were also collected from 18 healthy children as the control group. Serum VEGF and endostatin levels were quantified by using enzyme-linked immunosorbent assay (ELISA) and serum leptin by immunoradiometric assay.

RESULTS

The serum VEGF levels were found elevated in patients compared to controls (P = 0.033), while endostatin and leptin levels were lower in patients than in controls (endostatin, 43.9 ± 5.8 ng/ml vs. 123.6 ± 13.5 ng/ml, P < 0.001; leptin, 5 ± 1.5 ng/ml vs. 6.7 ± 1.2 ng/ml, P = 0.013). VEGF levels declined (pre, 151.6 ± 55.9 pg/ml vs. post, 16.2 ± 7.9 pg/ml, P = 0.041), while endostatin and leptin levels increased in patients who achieved remission (33 of 36 patients) when compared to pre-treatment levels (endostatin pre, 43.1 ± 5.9 ng/ml vs. post, 65.9 ± 6.8 ng/ml, P = 0.047; leptin, pre, 5.3 ± 1.6 ng/ml vs. post, 9.8 ± 2.7 ng/ml, P = 0.012). Serum VEGF, endostatin, and leptin levels were not predictive of survival.

CONCLUSION

Serial measurement of serum VEGF, endostatin, and leptin levels could potentially be used to predict response to treatment or progressive disease in children with lymphoma.

Does serum soluble vascular endothelial growth factor levels have different importance in pediatric acute leukemia and malignant lymphoma patients?

Vascular endothelial growth factor (VEGF) seems to play a central role in angiogenesis-lymphangiogenesis in hematological malignancies. There are limited data related to childhood hematologic malignancies. The aim of the study was to evaluate soluble VEGF (sVEGF) levels in children with acute leukemia and malignant lymphoma (ML) at diagnosis and in remission. The levels of serum sVEGF were measured by enzyme-linked immunosorbent assay (ELISA) in 20 children with acute leukemia, 33 children with different histopathological subtypes of ML, and 20 healthy controls. The levels of sVEGF at diagnosis (range 2 -1040 pg/mL; median 52 pg/mL) was significantly lower than in remission (range 136 -1960 pg/mL; median 630 pg/mL) in acute myeloid leukemia (AML) group (P = .018). The sVEGF levels at diagnosis (range: 2 -640 pg/mL; median 89 pg/mL) was significantly lower compared to remission values (range: 116 -1960 pg/mL; median 136 pg/mL) in patients with acute lymphoblastic leukemia (ALL) (P = .002). In ML group, including Burkitt's lymphoma (BL), T-cell non-Hodgkin's lymphoma (NHL), and Hodgkin's lymphoma (HL), sVEGF levels at diagnosis were higher than remission levels, but there was no statistically significant difference (P >.05). On the other hand, there were significant difference between levels in active disease and control group, ie, BL versus control, T-cell NHL versus control, and HL versus control (P = .008, P = .043, P = .007, respectively). The authors noticed that sVEGF levels showed distinct behavioral pattern in different childhood malignancies at diagnosis and in remission. In acute leukemia and ML patients, VEGF acts through different pathophysiological mechanisms, in both bone marrow (BM) angiogenesis and lymphoid tissue lymphangiogenesis.

Inhibition of c-MET is a potential therapeutic strategy for treatment of diffuse large B-cell lymphoma

Hepatocyte growth factor/c-MET has emerged as a potential therapeutic target for several cancers; however, its role in diffuse large B-cell lymphoma (DLBCL) has not been fully elucidated. In this study, we first investigated the role of c-Met in a large series of DLBCL tissues in a tissue microarray format. We then followed this with in vitro studies on DLBCL cell lines using either pharmacological inhibitors of c-Met or siRNA knockdown strategy. c-Met was found to be overexpressed in 73.2% of patients (186/254) and was significantly associated with overexpression of p-AKT (P=0.0274), p-GSK3 (P=0.0047) and Ki-67 (P=0.0012). Interestingly, c-Met overexpression was significantly more common in the germinal center subtype of DLBCL, as compared with activated B cell subtype (P=0.0002). Overexpression of c-Met in DLBCL was significantly associated with better survival (P=0.0028) and remained significant in multivariate analysis with international prognostic index, thereby confirming c-Met as independent prognostic marker for better outcome in DLBCL. In vitro pharmacological c-Met inhibition and siRNA targeted against c-Met triggered caspase-dependent apoptosis. These findings provide evidence that c-Met is an independent prognostic marker for better outcome in Middle Eastern DLBCL. This data also enlightens the fact that c-Met through AKT kinase has a critical role in carcinogenesis of DLBCL, and strongly suggest that targeting c-Met may have therapeutic value in treatment of DLBCL.

Prognostic Factors in Follicular Lymphoma

Follicular lymphoma (FL) is one of the most common types of non-Hodgkin's lymphoma. It is usually diagnosed at an advanced stage, for which many treatment options exist, however, no curative standard therapy has been identified. The outcome is highly variable with a median survival of approximately 10 years. The life expectancy of patients with FL has been extended with the use of rituximab, a monoclonal antibody targeting the CD20 antigen on FL cells, but there remains a group of patients who fail to respond to chemoimmunotherapy and die early of their disease. Transformation of FL to an aggressive histology is an important event with high morbidity and mortality. The Follicular Lymphoma International Prognostic Index has become the clinically useful prognostic tool, but gives only a rough estimate of expected outcome. There is a need for useful biomarkers for prediction of the disease course of single patients to individualize therapy, especially in the new era of chemoimmunotherapy.

The prognostic significance of VEGF-C and VEGF-A in non-Hodgkin lymphomas

Angiogenesis and lymphangiogensis are important in the proliferation and survival of the malignant hemeopoietic neoplasms. The aim of this study is to determine the prognostic role of angiogenesis and lymphangiogenesis in the development of lymphoma. For this aim, VEGF-A and VEGF-C were explored by immunohistochemistry in 177 cases. VEGF-C and VEGF-A were found to be positive in 34 and 61% of the samples. There was a good correlation between VEGF-C and VEGF-A expression (p = 0.0001). The clinical prognostic indicators were not significantly different between VEGF-C (+) and (-) and/or VEGF-A (+) and (-) cases. Overall survival (OS) rate was shorter in cases with VEGF-A (+) and VEGF-C (+) cases than with negative cases (p = 0.03 and p = 0.0005, respectively). The OS was significantly shorter in aggressive lymphomas expressing VEGF-A and VEGF-C but not in indolent lymphomas. The results of Cox regression analyses showed that VEGF-A and VEGF-C expressions are independent prognostic parameters (OR: 2.6, 95% CI: 1.3-5.0 for both (+) cases). In conclusion, VEGF-C and VEGF-A were positive in 34 and 61%, respectively, of the cases with NHL. The significant correlation between VEGF-C and VEGF-A suggests that lymphangiogenesis is important in the pathogenesis of lymphomas as shown in angiogenesis. The significantly shorter survival rates of VEGF-C and/or VEGF-A expressions indicate that angiogenesis and lymphangiogenesis are important in clinical outcome. Autocrine VEGF-A and VEGF-C crosstalks in lymphoma cells are important in lymphoma biology and inhibition of these signals with anti-angiogenic/anti-lymphangiogenic drugs and combination with chemo-immunotherapy regimens will be more useful in these cases.

Angiogenesis in non-Hodgkin's lymphoma: Clinico-pathological correlations and prognostic significance in specific subtypes

The aim of the study was to evaluate angiogenesis in different subtypes of non-Hodgkin's lymphoma (NHL) and to correlate angiogenic scores to clinical endpoints. Pre-therapeutic lymph node biopsies from 308 patients with NHL [107 follicular B-cell lymphoma (FL), 94 diffuse large B-cell lymphoma (DLBCL), 107 peripheral T-cell lymphoma (PTCL)] were studied. Microvessels were scored according to the Chalkley and microvessel density method (MVD) methods. Vascular endothelial growth factor (VEGF) protein expression was evaluated by immunohistochemistry. Both Chalkley and MVD methods showed, that the lymphoma subtypes differed significantly in angiogenic scores (P < 0.001). Angiogenic scores in tumor area were highest in PTCL, and lowest in FL. However, a remarkable high microvessel density was found in interfollicular areas of FL. In FL, high interfollicular MVD scores predicted progressive disease and poorer overall and event-free survival (P = 0.024 and 0.013). High interfollicular Chalkley scores correlated with transformation to DLBCL (P = 0.01). VEGF expression was detected in all NHL subtype, and the strongest expression was found in PTCL. In FL, patients with diffuse VEGF expression in lymphoma cells had poorer overall survival than those with focal expression.

Diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, particularly in parts of the developing world, and is increasing in incidence. This article reviews the current modalities employed for the diagnosis of HCC, including serum markers, radiological techniques and histological evaluation, and summarises international guidelines for the diagnostic approach to HCC.

Elevated pretreatment interleukin-10 serum level is an International Prognostic Score (IPS)-independent risk factor for early treatment failure in advanced stage Hodgkin lymphoma

Early treatment failure is still a clinical challenge despite high cure rates in Hodgkin lymphoma (HL) patients. To identify the biological risk factors predicting early treatment failure, we performed a retrospective case-control study. Forty-seven pretherapeutic serum samples were available from 47 advanced stage HL patients with early treatment failure and from 47 matched controls in complete remission. All patients were treated within German Hodgkin Study Group phase 3 trials. Matching was done according to treatment, stage, age, gender, International Prognostic Score (IPS) and histological subtype. Pretreatment serum levels of 30 cytokines, chemokines and soluble receptors were determined using immunoassays and flow cytometer based cytometric bead arrays. Only interleukin-10 serum levels were significantly associated with early treatment failure after statistical correction for multitesting (paired-sign test, p = 0.0008). In summary, pretherapeutic interleukin-10 levels are associated with early treatment failure within 12 months after the end of treatment in advanced stage HL independently from known clinical factors such as age or IPS.

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

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

Angiogenesis-related growth factors and cytokines in the serum of patients with B non-Hodgkin lymphoma; relation to clinical features and response to treatment

Increased angiogenesis has been shown to be a feature of non-Hodgkin lymphomas (NHL). In the current study, the pretreatment levels of circulating molecules related to angiogenesis were determined in 49 B-cell NHL patients and correlated with histological grade, disease stage and prognostic score. In 25 patients, the same molecules were defined after standard treatment. Vascular endothelial growth factor (VEGF), angiogenin, interleukin-2 (IL-2), IL-6, IL-8 and IL-16 were measured. Increased levels of VEGF, IL-6 and IL-8 were found in the whole group of untreated patients in comparison with normal controls (P < 0.05), whereas, IL-2 was higher in the subgroup of indolent NHL. Overall, there was no significant decrease in the levels of these molecules after treatment. However, by stratification into group of responders vs. non-responders pretreatment IL-8 was significantly increased whereas IL-16 was decreased in the subgroup of complete responders. According to the REAL classification IL-2 was higher in the low risk compared with intermediate plus high-risk group. There was no association with disease stage or the International Prognostic Score. Both indolent and aggressive B cell lymphomas have increased production of angiogenic mediators and cytokines with IL-8 and IL-16 potentially reflecting the response to treatment.

Prognostic significance of EBV-LMP1 and VEGF-A expressions in non-Hodgkin's lymphomas

BACKGROUND AND AIM

EBV is an important virus in the pathogenesis of NHL. VEGF-A is the essential factor in tumor angiogenesis. There is evidence of cross talk between angiogenesis and viral carcinogenesis. The viral latent protein LMP1, may play a role by inducing expression of angiogenic factors In this study EBV-LMP1 and VEGF-A expressions have been studied in cases with NHL and prognostic significance of these has been evaluated.

PATIENTS AND METHODS

One hundred seventy-seven cases (60 had low grade lymphoma (LGL), 117 had aggressive lymphoma (AL)) with NHL have been included in this analysis. Immunohistochemistry has been used for the detection of EBV and VEGF-A.

RESULTS

EBV was found in 25 cases (14%); 5 of 60 cases with LGL while 20 of 117 cases with AL had EBV positivity; (OR: 2.3, 95% CI: 0.8-6.3, p=0.113). VEGF-A expression was found in 108 cases (61%); 30 of 60 cases with LGL and 78 of 117 cases with AL showed VEGF-A expression. There was an association between VEGF-A and aggressive histology (OR: 2.0, 95% CI: 1.1-3.8, p=0.031). EBV positivity was associated with VEGF-A expression in diffuse large B cell lymphoma (DLBCL) (0.045). Mean Survival rates were shorter in EBV (+) and/or VEGF-A (+) cases.

COMMENT

Highly significant association between VEGF-A and EBV expression and survival rate, suggests an association between angiogenesis and viral lymphomagenesis. Targeting both the angiogenesis and EBV may be important in the therapy of cases with NHL expressing EBV and/or VEGF-A.

A phase II study of enzastaurin, a protein kinase C beta inhibitor, in patients with relapsed or refractory mantle cell lymphoma

BACKGROUND

Protein kinase C beta (PKCbeta), a pivotal enzyme in B-cell signaling and survival, is overexpressed in most cases of mantle cell lymphoma (MCL). Activation of PI3K/AKT pathway is involved in pathogenesis of MCL. Enzastaurin, an oral serine/threonine kinase inhibitor, suppresses signaling through PKCbeta/PI3K/AKT pathways, induces apoptosis, reduces proliferation, and suppresses tumor-induced angiogenesis.

PATIENTS AND METHODS

Patients with relapsed/refractory MCL, and no more than four regimens of prior therapy, received 500 mg enzastaurin, orally, once daily.

RESULTS

Sixty patients, median age 66 years (range 45-85), Eastern Cooperative Oncology Group performance status of zero to two (48% had baseline International Prognostic Index of 3-5), were enrolled. Most patients had prior CHOP-like chemotherapy and/or rituximab (median = 2 regimens). No drug-related deaths occurred. There was one case each of grade 3 anemia, diarrhea, dyspnea, vomiting, hypotension, and syncope. Fatigue was the most common toxicity. Although no objective tumor responses occurred, 22 patients (37%, 95% CI 25% to 49%) were free from progression (FFP) for > or =3 cycles (one cycle = 28 days); 6 of 22 were FFP for >6 months. Two patients remain on treatment and FFP at >23 months.

CONCLUSION

Freedom from progression for >6 months in six patients and a favorable toxicity profile with minimal hematological toxicity indicate that enzastaurin warrants evaluation as maintenance therapy and combination chemotherapy in MCL.

Serum angiogenin levels predict treatment response in patients with stage IV melanoma

This work was conducted to find out new potential serum markers and study their role as predictive factors in patients with metastatic melanoma. Serum samples from 68 patients with stage IV malignant melanoma were collected just before current treatment and screened for 79 different cytokines by using a multi-cytokine array. Angiogenin, which is a protein capable of promoting angiogenesis, was found to be markedly elevated among a sub-group of patients with progressive disease (PD) and thus was subjected to further analysis. The mean serum angiogenin level was 270 ng/ml and the median 236 ng/ml (STD 163 ng/ml). Concentrations were significantly higher among men than in women (P = 0.031), whereas patient's age, site of the primary tumour, Clark's or Breslow's classifications were not associated with angiogenin levels. Patients with only lymph node metastases had markedly lower angiogenin levels than those with metastases at other sites (P = 0.05). High angiogenin levels were significantly (P = 0.015; Kruskal-Wallis) associated with poor treatment response with chemoimmunotherapy. Treatment-related survival (TRS) was shorter (10 months) in patients with above-median values than in those with below-median levels (19 months, P = NS). Cox multivariate regression model was used to control for the confounding by the classical prognostic factors of melanoma (age, sex, disease burden, performance score, site of metastases). Disease burden was the only variable that remained in the model as a significant independent predictor of TRS (P = 0.044). These data suggest that serum angiogenin levels might be of predictive value in the evaluation of treatment response for patients with stage IV melanoma.

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.

Serum VEGF as a significant marker of treatment response in hodgkin lymphoma

This pilot study aimed at determining serum VEGF levels (S-VEGF) at diagnosis and at restaging in children with Hodgkin lymphoma, and investigating whether this parameter provides prognostic information for remission after 2 courses of chemotherapy. PET-CT fusion was performed to assess response to treatment. Changes in S-VEGF levels were found to correlate with response to treatment for most of the children. This provides a rationale for exploring clinical interest in S-VEGF measurements in a larger group of children with Hodgkin lymphoma, and using the test for clinical trials of anti-angiogenic therapies.

A concise review of serum markers for hepatocellular cancer

BACKGROUND

The rising incidence of hepatocellular cancer in the US and worldwide has sparked a renewed interest in HCC serum markers. HCC typically develops in patients with chronic liver disease and cirrhosis. It is in these target populations that serum markers are most urgently needed. Unfortunately, the currently available markers lack sensitivity and specificity. A number of novel candidate markers have recently been introduced.

METHODS

We performed a review of the literature (2001-2006) of traditional and novel serum markers for hepatocellular cancer.

RESULTS

Several promising new HCC markers have been identified over the past 5 years. They include single proteins, complex proteomics features, and tumor-specific autoantibodies. The excitement about the new markers is tempered by the realization that none of them have yet met the most stringent criteria defined by the Early Detection Research Network (EDRN).

CONCLUSION

A new generation of HCC serum markers awaits validation in properly controlled clinical studies.

Angiogenin: a review of the pathophysiology and potential clinical applications

Angiogenin is a member of the ribonuclease (RNase) superfamily: enzymes of innate substrate specificity, but divergent functional capacities. Angiogenin is a normal constituent of the circulation and contained in a vasculature that rarely undergoes proliferation, but in some physiological and pathological conditions its levels increase in blood, promoting neovascularization. Hence, angiogenesis is a common pathophysiological attribute of angiogenin. In malignant disease, the most studied pathological state in regard to angionenin, abnormally high levels are seen, which may be of prognostic significance. Angiogenin has also been studied in other non-malignant pathological states. The aim of this review article is to provide an overview of the biochemistry and physiology of angiogenin, specifically in relation to the human pathological states where angiogenin has been implicated and finally, its potential clinical applications.

The expression of fibroblast growth factors and their receptors in Hodgkin's lymphoma

The expression of fibroblast growth factors (FGF1 and FGF2) and their receptors has been reported in a variety of human neoplasms, including haematological neoplasia. Fibroblast growth factors can promote tumour growth directly, or indirectly through promoting the growth of vessels. In the present study, we evaluated the expression of FGF1 and FGF2 as well as FGF receptors 1-4 (FGFR1-FGFR4) in 39 cases of Hodgkin's lymphoma, including all subtypes, as well as Hodgkin's lymphoma cell lines. FGF1 and FGF2 and their receptors FGFR2-FGFR4, but not FGFR1, were found to be expressed by the malignant cells in the majority of cases. Interestingly, only FGFR3, but none of the FGFs or the other FGFRs, was expressed by the Hodgkin's lymphoma cell lines. This indicates that only FGFR3 is constitutively expressed by Hodgkin's lymphoma cells, whereas FGFs and the other FGFRs are induced in vivo. Culture of the Hodgkin's cell lines under conditions of hypoxic stress could induce vascular endothelial growth factor (VEGF) but not FGF expression. FGFs, in contrast to VEGF, might be expressed in response to paracrine stimuli. In situ hybridization did not reveal FGFR3 gene amplification or translocation as the cause of constitutive FGFR3 expression, as has been shown in a subset of multiple myeloma. FGFR3 might be expressed as part of the Hodgkin's cell phenotype. The demonstration of widespread expression of FGFs and some of their receptors in Hodgkin's lymphoma suggests that FGFs are important for sustaining growth of the lymphoma and suggests that anti-FGF antibodies could be used as an adjuvant treatment.

Functional analysis of HGF/MET signaling and aberrant HGF-activator expression in diffuse large B-cell lymphoma

Inappropriate activation of MET, the receptor tyrosine kinase for hepatocyte growth factor (HGF), has been implicated in tumorigenesis. Although we have previously shown that HGF/MET signaling controls survival and proliferation of multiple myeloma (MM), its role in the pathogenesis of other B-cell malignancies has remained largely unexplored. Here, we have examined a panel of 110 B-cell malignancies for MET expression, which, apart from MM (48%), was found to be largely confined to diffuse large B-cell lymphomas (DLBCLs) (30%). No amplification of the MET gene was found; however, mutational analysis revealed 2 germ-line missense mutations: R1166Q in the tyrosine kinase domain in 1 patient, and R988C in the juxtamembrane domain in 4 patients. The R988C mutation has recently been shown to enhance tumorigenesis. In MET-positive DLBCL cells, HGF induces MEK-dependent activation of ERK and PI3K-dependent phosphorylation of PKB, GSK3, and FOXO3a. Furthermore, HGF induces PI3K-dependent α4β1 integrin-mediated adhesion to VCAM-1 and fibronectin. Within the tumor microenvironment of DLBCL, HGF is provided by macrophages, whereas DLBCL cells themselves produce the serine protease HGF activator (HGFA), which autocatalyzes HGF activation. Taken together, these data indicate that HGF/MET signaling, and secretion of HGFA by DLBCL cells, contributes to lymphomagenesis in DLBCL. (Blood. 2006;107:760-768)

Angiogenic factors may have a different prognostic role in adult acute lymphoblastic leukemia

Angiogenesis plays an important role in solid tumors and hematologic malignancies. The prognostic significance of angiogenic factors in adult acute lymphoblastic leukemia (ALL) remains ambiguous. We therefore analyzed the impact of angiogenic factor levels on overall survival of newly diagnosed adult ALL patients. Plasma levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), interleukin-1 receptor alpha (IL-1Ralpha), IL-6, IL-8, VEGF receptors VEGFR1 and VEGFR2, and thrombopoietin (TPO) were measured in plasma samples of 95 patients by enzyme-linked immunosorbent assay (ELISA). In a univariate Cox proportional hazards model, higher levels of IL-1Ralpha, IL-8, VEGFR1, and VEGFR2 were predictive of poor survival. In contrast, higher levels of VEGF were predictive of longer survival, and higher levels of bFGF suggested a similar trend (P = .09). The multivariate model simultaneously included VEGF (relative risk [RR] for death, 8.01; P = .001 for levels less than or equal to 19.5 pg/mL), IL-1Ralpha (RR, 5.12; P = .007 for levels greater than 373 pg/mL), and VEGFR2 (RR, 4.01; P = .04 for levels greater than 8222 pg/mL) as independent factors for survival. Of interest is the association of high levels of VEGF with good prognosis and higher levels of VEGF receptors with poor outcome. These data reflect the complexity by which angiogenic factors may affect the clinical behavior of patients with ALL, and this complexity should be considered in any therapeutic strategy incorporating antiangiogenic agents.