Vascular endothelial growth factor levels in childhood acute lymphoblastic and myeloblastic leukemia

Molecular effects of genistein, as a potential anticancer agent, on CXCR-4 and VEGF pathway in acute lymphoblastic leukemia

BACKGROUND

Vascular endothelial growth factor (VEGF) is one of the angiogenic mediators that can be secreted by leukemic cells and plays an important role in tumor invasion and metastasis. Another important agent contributing to the relapse of ALL is C-X-C chemokine receptor type-4 (CXCR-4), expression of this receptor in cancer cells has been related to metastasis. It has been identified that genistein-a soy-derived isoflavonoid-has anti-angiogenesis functions. We aimed to show the effects of this compound on VEGF and CXCR-4 in Acute lymphoblastic leukemia (ALL) cell models.

METHODS AND RESULTS

The cytotoxicity of Genistein was measured using the MTS colorimetric assay. After being treated with Genistein, the expression of VEGF in mRNA and protein levels was measured in MOLT-4 and Jurkat cells. We also used flow cytometry assay to determine the expression of CXCR-4 in cell surfaces. We found that Genistein decreased cell viability in two cell models while was more effective on MOLT-4 cells. After Genistein-treatment, surface expression levels of CXCR-4 were decreased, while VEGF secretion and mRNA expression levels were increased in MOLT-4 and Jurkat cells.

CONCLUSIONS

The results suggest that Genistein may not be a reliable choice for the treatment of ALL; however, this different identified pattern can be useful for the recognition of VEGF and CXCR-4 modulators and thus for planning new treatments for leukemia and other VEGF related disorders.

The Neuropilin-1 Ligand, Sema3A, Acts as a Tumor Suppressor in the Pathogenesis of Acute Leukemia

Semaphorin-3A (Sema3A) and vascular endothelial growth factor (VEGF165) are ligands of neuropilin-1 (NRP-1 or CD304) and are related to immunoregulation and tumor angiogenesis, respectively. However, possible interactions between NRP-1 and Sema3A and VEGF165 in acute leukemia remain unclear, especially whether Sema3A plays a role in acute leukemia. In this study, both of the proportion of regulatory T cells (Tregs) and their expression of NRP-1 were found to increase in acute leukemia patients compared with healthy controls. In contrast, lower mRNA and plasma levels of Sema3A were detected in the acute leukemia patients. In vitro, the addition of exogenous Sema3A inhibited the expression of NRP-1 on Tregs and it promoted apoptosis of leukemia cells. However, in the presence of anti-Sema3A antibody, the effect of rhSema3A on NRP-1 expression was reversed. These results suggest that Sema3A promotes apoptosis in leukemia cells by inhibiting expression of NRP-1, and thus, represents a tumor suppressor protein with a role in the pathogenesis of acute leukemia. Consequently, NRP-1/Sema3A signaling may represent a novel target for the treatment of acute leukemia and should be further studied. Anat Rec, 302:1127-1135, 2019. © 2018 Wiley Periodicals, Inc.

Assessment of Angiogenesis in Children with Acute Lymphoblastic Leukemia Based on Serum Vascular Endothelial Growth Factor Assay

Introduction

Vascular endothelial growth factor A (VEGFA) is a key proangiogenic cytokine. The role of angiogenesis in acute lymphoblastic leukemia (ALL) is still unclear. The purpose of the study was to assess angiogenesis in children with ALL based on serum VEGFA level determined at diagnosis and at remission with further participant subdivision into different risk groups.

Materials and Methods

Forty children, aged 3-12 years (mean age: 8 years) with newly diagnosed ALL, were enrolled in the study. The control group (Group C) was twenty healthy children. According to the risk assessment, they were classified into a standard-risk group, an intermediate-risk group (IRG), or a high-risk group (HRG).

Results

The median serum VEGFA levels at diagnosis were significantly higher in IRG and HRG as compared to Group C. The VEGFA levels at remission were significantly higher in all study groups, as compared to Group C. The differences in median values of serum VEGFA levels between the study groups both at diagnosis and at remission were not statistically significant.

Conclusions

The angiogenesis in ALL seems to be intensified at diagnosis as a result of neoplasmatic bone marrow rebuilding and at remission as its intensive recovering.

Lipopolysaccharide Effect on Vascular Endothelial Factor and Matrix Metalloproteinases in Leukemic Cell Lines In vitro

Background:

Angiogenesis, the process of new vessels generation, plays a critical role in tumor invasion and metastasis. Vascular Endothelial Growth Factor (VEGF), as a cytokine, and Matrix Metalloproteinases (MMPs), has been the important factors that involved in angiogenesis. Lipopolysaccharide (LPS) has an essential effect on angiogenesis.

Objectives:

In this study the effect of LPS on VEGF production and MMP-2/MMP-9 activity in two leukemic cell lines has been assessed in vitro.

Materials and Methods:

Human leukemic U937 and THP1 cells were cultured in complete RPMI medium. Then the cells at the exponential growth phase were incubated with different concentrations of LPS (0 - 4 μg/mL) for 48 hours. Then the level of VEGF production and MMP-2/MMP-9 activity in cell culture supernatants were evaluated with the ELISA standard kits and gelatin zymography respectively.

Results:

U937 cells have produced a large amount of VEGF without any stimulus and LPS has not shown any substantial effect on VEGF production by these cells. However THP1 cells have produced a small amount of VEGF without stimulation and LPS significantly has increased VEGF production in these cells dose-dependently. Moreover LPS significantly has augmented the MMP-2/MMP-9 activity in the both leukemic cell lines in a dose-dependent manner.

Conclusions:

Our results have shown that LPS might be a potential inducer/enhancer of VEGF production and MMP-2/MMP-9 activity (angiogenic factors) in leukemia. Moreover the LPS effect on angiogenesis might be in part, due to its stimulatory effects on VEGF and MMPs. Overall LPS-stimulated leukemic cells might be good models for study and planning the useful therapeutic approaches for angiogenesis- dependent diseases.

Serum cytokine and adhesion molecule profile differs in newly diagnosed acute myeloid and lymphoblastic leukemia

AIMS

To compare serum levels of 17 cytokines and 5 adhesion molecules in patients with newly diagnosed acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) using biochip array technology.

METHODS

A total of 15 AML and 15 ALL patients were studied. Serum samples were taken prior to anticancer therapy and were analyzed by biochip based immunoassays on the Evidence Investigator analyzer. This approach allows simultaneous detection of multiple analytes from a single sample. T-tests were used for statistical analysis.

RESULTS

Comparing cytokine and adhesion molecules levels in newly diagnosed AML and ALL patients, we found significant increase in AML in serum IL-4 (P < 0.0001), IL-2 (P < 0.01), IL-3 (P < 0.05), and significant decrease (P < 0.05) in serum VEGF and VCAM-1.

DISCUSSION

Our results indicate that serum profile of cytokines and adhesion molecules differs in newly diagnosed AML and ALL patients. Further studies are needed to establish if these alterations could be used as a clinically relevant biomarker for acute leukemias.