Fateme Tabrizi - Department of Biology, Faculty of Science, Yazd University, Yazd,Iran
Mohammad Mehdi Heidari, - Department of Biology, Faculty of Science, Yazd University, Yazd,Iran
Mehri Khatami - Department of Biology, Faculty of Science, Yazd University, Yazd,Iran

Background: Studies in designing nanobodies have gainedmore and more interest in recent years due to their appreciableadvantages compared to therapeutic monoclonal antibodies(mAbs). while nanobodies have high tissue penetration, lowimmunogenicity, and, safety, mAb delivery to tumor cells insidethe body is restricted due to its size. Epitopes can be recognizedby nanobodies simply, but they are often inaccessible toconventional antibodies. Therapeutic nanobodies can be clonedin a prokaryotic host to check their efficacy. Ramucirumab isan approved mAb indicated for gastric cancer as well as breastcancer patients. While more target-therapy procedures for cancerwill continue to arise, nanobodies provide a novel insightinto gastric cancer and breast cancer therapeutic strategies. Inthis research, an approach is presented for designing anti-VEGFreceptor ۲ nanobody using bioinformatics.Materials and Methods: The structure of Ramucirumabepitopewas analyzed and the site-directed mutagenesis wasdone in CDR۳ domain to intensify the epitope-CDR۳ interactionaffinity. To obtain the nanobody DNA sequence, with theapplication of codon optimization, the reverse translation wasperformed for the acquired protein sequence of nanobody fromstructure analyses. The process was validated utilizing in silicocloning of acquired nanobody gene sequence.Results: The gene sequence for nanobody was obtained and canbe used in further experiments such as cloning in the prokaryotichost and evaluating the antigen-nanobody attachment using western blot and ELISA.Conclusion: These findings indicate designing nanobodies fortargeted therapy of gastric cancer and breast cancer patientshas shown notable anti-tumor beneficence by the means of enhancedaffinity for the VEGF receptor ۲ binding domain, andalso for recognizing conserved epitopes which are mainly unreachableto monoclonal antibodies. Designing nanobodies isan emerging novel technique that provides targeted therapy forcancer.

gastric cancer, breast cancer, VEGFR۲, therapeuticnanobodies, computational biology