I-bevacizumab as a target molecule for vascular endothelial growth factor in tumors

Vascular endothelial growth factor A is essential for vessel forming in tumor tissue. Bevacizumab as a monoclonal antibody is a specific binding for this factor, it inhibits tumor growth. In this study, monoclonal antibody labeled with Iodine-131 (¹³¹I) and performed in vitro quality control and tumor cell growth inhibition tests. Radiochemical purity and stability in were determined using thin-layer chromatography and radio- gel electrophoresis, respectively. In vitro studies were performed for specific binding and cellular toxicity on SKOV-3 ovarian cancer cell line. The biodistribution of ¹³¹I-bevacizumab was investigated using male mice. The radiochemical purity of the complex was more than 99%. Its stability in phosphate-buffered saline and human blood serum at 48 hours postpreparation was 78% ± 1.2% and 93% ± 0.6%, respectively. (131)I-bevacizumab was significantly bound to cells. Significant cell death was achieved with (131)I-bevacizumab at a concentration of 500 nM. Animal biodistribution was not showed any instability regards to low accumulation of ¹³¹I-bevacizumab in the stomach and salivary glands after 24 hours and 48 hours. These findings indicate that the new radiolabeled antibody should be further evaluated in tumor bearing animals and, possibly, in humans as a new radiopharmaceutical agent for use in.