Evidence for mRNA expression of vascular endothelial growth factor by X-ray irradiation in a lung squamous carcinoma cell line

Vascular endothelial growth factor (VEGF) is a multipotent cytokine which p lays an important role in various angiogenic conditions as well as in some tumor behaviors. Here we examined the induction of VEGF mRNA by X-ray irrad iation in a lung squamous cell carcinoma cell line (RERF-LC-AI), Irradiatin g the cells with 15 Gy X-rays significantly increased the mRNA expression u p to 2.5-fold of control at a post-irradiation time of 16-24 h. The inducti on of VEGF mRNA by X-ray irradiation was completely blocked by treating cel ls with either genistein (Src tyrosine kinase inhibitor) or H7 (protein kin ase C inhibitor). This suggests that the mechanism of induction might be co ncerned with the pathway which triggers Src tyrosine kinase of the cell sur face and the protein kinase C pathway. (C) 1998 Elsevier Science Ireland Lt d. All rights reserved.