Coculture in vitro with endothelial cells induces cytarabine resistance of acute myeloid leukemia cells in a VEGF-A/VEGFR-2 signaling-independent manner

Biochem Biophys Res Commun. 2022 Jan 8:587:78-84. doi: 10.1016/j.bbrc.2021.11.090. Epub 2021 Nov 27.

Abstract

An interaction between acute myeloid leukemia (AML) cells and endothelial cells in the bone marrow seems to play a critical role in chemosensitivity on leukemia treatment. The endothelial niche reportedly enhances the paracrine action of the soluble secretory proteins responsible for chemoresistance in a vascular endothelial growth factor A (VEGF-A)/VEGF receptor 2 (VEGFR-2) signaling pathway-dependent manner. To further investigate the contribution of VEGF-A/VEGFR-2 signaling to the chemoresistance of AML cells, a biochemical assay system in which the AML cells were cocultured with human endothelial EA.hy926 cells in a monolayer was developed. By coculture with EA.hy926 cells, this study revealed that the AML cells resisted apoptosis induced by the anticancer drug cytarabine. SU4312, a VEGFR-2 inhibitor, attenuated VEGFR-2 phosphorylation and VEGF-A/VEGFR-2 signaling-dependent endothelial cell migration; thus, this inhibitor was observed to block VEGF-A/VEGFR-2 signaling. Interestingly, this inhibitor did not reverse the chemoresistance. When VEGFR-2 was knocked out in EA.hy926 cells using the CRISPR-Cas9 system, the cytarabine-induced apoptosis of AML cells did not significantly change compared with that of wild-type cells. Thus, coculture-induced chemoresistance appears to be independent of VEGF-A/VEGFR-2 signaling. When the transwell, a coculturing device, separated the AML cells from the EA.hy926 cells in a monolayer, the coculture-induced chemoresistance was inhibited. Given that the migration of VEGF-A/VEGFR-2 signaling-dependent endothelial cells is necessary for the endothelial niche formation in the bone marrow, VEGF-A/VEGFR-2 signaling contributes to chemoresistance by mediating the niche formation process, but not to the chemoresistance of AML cells in the niche.

Keywords: Chemoresistance; Cytarabine; Endothelial cells; Leukemia cells; Vascular endothelial growth factor receptor 2 (VEGFR-2).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / pharmacology
  • Antimetabolites, Antineoplastic / pharmacology*
  • Cell Cycle / drug effects
  • Cell Cycle / genetics
  • Cell Line
  • Cell Movement / drug effects
  • Coculture Techniques
  • Cytarabine / pharmacology*
  • Drug Resistance, Neoplasm / genetics*
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism
  • Endothelial Cells / pathology
  • Gene Expression Regulation, Leukemic
  • Gene Knockout Techniques
  • HL-60 Cells
  • Humans
  • Indoles / pharmacology
  • Jurkat Cells
  • K562 Cells
  • Leukemia, Myeloid, Acute / drug therapy
  • Leukemia, Myeloid, Acute / genetics
  • Leukemia, Myeloid, Acute / metabolism
  • Leukemia, Myeloid, Acute / pathology
  • Models, Biological
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / metabolism
  • Neovascularization, Pathologic / pathology
  • Neovascularization, Pathologic / prevention & control
  • Phosphorylation
  • Signal Transduction
  • U937 Cells
  • Vascular Endothelial Growth Factor A / genetics*
  • Vascular Endothelial Growth Factor A / metabolism
  • Vascular Endothelial Growth Factor Receptor-2 / antagonists & inhibitors
  • Vascular Endothelial Growth Factor Receptor-2 / deficiency
  • Vascular Endothelial Growth Factor Receptor-2 / genetics*

Substances

  • 3-(4-dimethylaminobenzylidene)-1,3-dihydroindol-2-one
  • Angiogenesis Inhibitors
  • Antimetabolites, Antineoplastic
  • Indoles
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Cytarabine
  • KDR protein, human
  • Vascular Endothelial Growth Factor Receptor-2