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

Serum Levels of Vascular Endothelial Growth Factor and Its Receptor in Newly Diagnosed Paediatric Acute Lymphoblastic Leukemia

Autocrine and paracrine loop involving vascular endothelial growth factor (VEGF) and its receptor have been described in haematological malignancies. However, scarce literature is present on angiogenesis in paediatric acute lymphoblastic leukemia (ALL) with studies showing controversial results. The aim was to study serum levels of VEGF and its receptors in paediatric ALL at the time of diagnosis and at the end of induction phase and to compare these levels with clinico-haematological parameters in these patients. Serum VEGF, VEGFR-1 and VEGFR-2 levels were measured by enzyme-linked immunoabsorbant assay at diagnosis (day 0) and at the end of induction phase (day 35) in 30 newly diagnosed paediatric ALL patients and in 10 healthy controls. Median s-VEGF was significantly lower at day 0 as compared to day 35 (196.15 vs. 606.75 pg/ml: p < 0.001). s-VEGFR-1 levels were detectable only in 7 patients at day 0 and were below detection level at day 35 in all patients. Median s-VEGFR-2 at day 0 was significantly lower as compared to day 35 (17,577.5 vs. 20,507.5 pg/ml; p = 0.005). Median VEGF-R1 showed an inverse relationship with VEGF-R2 but was statistically insignificant. All patients were in remission at the end of induction. Thus, leukemic infiltration of bone marrow affects angiogenesis and reduces pro-angiogenic markers VEGF and VEGFR-2 in serum possibly due to increased local consumption by blasts. A successful induction leads to clearing of blasts causing restoration of normal hematopoiesis with normalization of VEGF and VEGFR-2 levels.

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.

Endothelial Function in Children with Acute Lymphoblastic Leukemia (ALL) May Reflect the Clinical Outcome

Endothelial dysfunction is a common feature of early complications of hemato-oncologic therapy. The aim of our study was to assess the profile of endothelial function at diagnosis time, then during initial treatment phase of acute lymphoblastic leukemia (ALL), and to verify the presence of its correlation with early clinical outcome (ECO). 28 ALL children and 18 healthy age-matched control ones were recruited. Study group was examined at baseline and at 33rd and 78th day of treatment. At each protocol step the endothelial function was assessed by measurement of sP-selectin (CD62-P), PAI-1(serpinE1), sE-selectin (CD62E), sICAM-1(sCD54), sVCAM-1(sCD106), and VEGF concentrations. Higher baseline sICAM-1 and sVCAM-1 levels and lower sP-selectin and VEGF were observed in children with ALL. sICAM-1, sVCAM-1, and sE-selectin levels were decreasing following the treatment with protocol I. Higher sE-selectin and lower baseline sICAM-1 levels were observed in children treated unsuccessfully. Lower PAI-1 levels were observed in children who survived. Higher baseline sE-selectin levels and lower sICAM-1 and VEGF were observed in children treated unsuccessfully. A decrease in sE-selectin and lower PAI-1 at the 78th day of therapy were associated with better ECO. High baseline VEGF and sE-selectin levels, significant increase in PAI-1, and low initial sICAM-1 levels are prognostics for poorer prognosis in the ALL children.

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.