Vascular endothelial growth factor A (
VEGF-A) is a key regulator of angiogenesis that binds to the receptors
VEGFR-1 and
VEGFR-2. It is well known that
VEGF-A levels are increased in
colorectal cancer (CRC) tissue compared to normal colorectal tissue, but little is known regarding the expression of the
VEGFR-1 and -2 receptors. The aim of the present study was to perform a quantitative analysis of
VEGFR-1 and -2 at the
mRNA and
protein level in tumour and normal colorectal tissue from CRC patients. Tissues were collected from 110 patients who underwent surgical resection for CRC. Receptor status was analysed at the gene expression level by real time RT-PCR using β-2-microglobulin and β-actin as reference genes.
Protein analysis was performed using the ELISA technique. Gene expression and
protein concentrations of
VEGFR-1 and -2 were significantly increased in CRC tissue compared to normal colorectal tissue (P<10-6 for both receptors). An association between the gene expression of
VEGFR-2 in CRC tissue and disease stage was detected (P=0.055). Significant correlations were also found between the gene expression of
VEGFR-1 and -2 in CRC tissue and normal colorectal tissue (P<10-4). The gene expression and
protein concentrations of
VEGFR-1 and -2 were increased in CRC tissue compared to normal colorectal tissue, indicating that both receptors are important in CRC. The clinical implications of these findings require further investigation.