Effects of exogenous VEGF₁₆₅b on invasion and migration of human lung adenocarcinoma A549 cells

Abstract

Vascular endothelial growth factor 165 (VEGF₁₆₅)-mediated autocrine stimulation of tumor cells enhances the progression to a malignant phenotype. VEGF₁₆₅b competes with VEGF₁₆₅ and binds to vascular endothelial growth factor receptor (VEGFR), resulting in inhibition of downstream signal transduction pathways. This study was designed to investigate the role of VEGF₁₆₅b in the migration and invasion of human lung adenocarcinoma A549 cells. The full-length of VEGF₁₆₅b was constructed and cloned into an expression plasmid (pVEGF₁₆₅b), and then transfected into A549 cells. Dimethylthiazolyl- 1 -2, 5-diphenyltetrazolium bromide (MTT) assay was used to detect the effect of VEGF₁₆₅b on proliferation of transfected cells. Reverse transcription polymerase chain reaction (RT-PCR) was employed to examine the effect of VEGF₁₆₅b on the expression of VEGF₁₆₅ in transfected cells. Wound-healing assays were used to investigate the effect of VEGF₁₆₅b on migration of transfected cells. Matrix metalloproteinase (MMPs) activity assay and in vitro invasion assay were used to determine the role of VEGF₁₆₅b in invasion of transfected cells. There was no significant change in proliferation of A549 cells after transfection of pVEGF₁₆₅b, but the expression of VEGF₁₆₅, migration and invasion in A549 cells were inhibited. Furthermore, exogenous VEGF₁₆₅b inhibited the activity of MMP9 in the supernatant of A549 cells and the subsequent invasion capacity of those cells. We therefore conclude that exogenous VEGF₁₆₅b can inhibit the expression of VEGF₁₆₅, as well as the migration and invasion of A549 cells, but has no effect on the proliferation of A549 cells.

Keywords

VEGF₁₆₅b / non-small cell lung cancer / migration; invasion

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