X-rays Affect the Expression of Genes Involved in Angiogenesis

• Published in: Anticancer research 2004-09, Vol.24 (5A), p.2941-2945
• Main Authors: POLYTARCHOU, C, GLIGORIS, T, KARDAMAKIS, D, KOTSAKI, E, PAPADIMITRIOU, E
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Carrier Proteins - biosynthesis; Carrier Proteins - genetics; Chick Embryo; Chorioallantoic Membrane - blood supply; Chorioallantoic Membrane - radiation effects; Cytokines - biosynthesis; Cytokines - genetics; Gene Expression - radiation effects; Medical sciences; Neovascularization, Physiologic - genetics; Neovascularization, Physiologic - radiation effects; Nitric Oxide Synthase - biosynthesis; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase Type II; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; RNA, Messenger - radiation effects; Tumors; Vascular Endothelial Growth Factor A - biosynthesis; Vascular Endothelial Growth Factor A - genetics; X-Rays
• ISSN: 0250-7005; 1791-7530

Background: We have previously shown, using the chicken embryo chorioallantoic membrane (CAM) model of in vivo angiogenesis, that X-rays act on the extracellular matrix and enhance normal and tumor-induced angiogenesis. In the present work, we studied the effect of X-rays on the gene expression of three proteins that are important regulators of angiogenesis: vascular endothelial growth factor (VEGF), heparin affin regulatory peptide (HARP) and inducible nitric oxide synthase (iNOS). Materials and Methods: An area of 1 cm 2 of the CAM, restricted by a plastic ring, was irradiated at room temperature. The expression of the genes was studied using RT-PCR and the amounts of the mRNAs were quantified using image analysis of the corresponding agarose gels of the RT-PCR products. Results: VEGF mRNA was decreased 6 h after irradiation. However, at later time points, VEGF expression was significantly increased compared with the nonirradiated tissue. Similarly, X-rays down-regulated both HARP and iNOS expression 6 h after irradiation and the effect was reversed at later time points, similarly to the effect of X-rays on VEGF. Conclusion: These data support the notion that X-rays increase the expression of genes that favor angiogenesis.