Inhibitory action of antisense oligodeoxynucleotide on radiotherapy-induced expression of vascular endothelial growth factor (VEGF) in a liver cancer cell line

Objective: To study the mechanism of serum VEGF increase in tumor patients during radiotherapy and the inhibitory action of its antisense oligodeoxynucleotide (AS-ODN) on expression of VEGF protein induced by radiotherapy in a liver cancer cell line. Methods: To detect the change of the serum VEGF in tumor patients during radiotherapy dynamically and the inhibitory action of the (AS-ODN) on expression of VEGF induced by radiotherapy in a liver cancer cell line. Results: The changes of the serum VEGF in four patients receiving radiotherapy rised continuously. Their levels of serum VEGF began to increase during radiotherapy with the peak value appeared in the first two weeks, and then declined to the pre-radiotherapy range. Irradiating the liver cancer cells with X-rays significantly increased the VEGF expression and secretion. The level of VEGF protein in the patient group treated with AS-ODN and X irradiation was significantly reduced than that of the group treated with X irradiation only. Conclusion: The induction of VEGF protein expression by X irradiation in tumor cells may result in increase of the serum VEGF in the tumor patients during radiotherapy and the induction can be blocked by VEGF AS-ODN