P-72: Specific Human Recombinant Antibodies Against Regeneration and Tolerance Factor (RTF


Bayat P *, Nejatollahi F ,

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Objective: Glioblastoma is one of the most dangerous and serious brain tumor which leads to patients' death within less than 1 to 3 years after diagnosis. Many approaches have been used to treat this lethal cancer but less than 5% of patients were cured by conventional treatment. We are going to investigate the effects of single chain (scFv) antibodies against RTF which is an over expressed molecule on the surface of glioblastoma cells. A previous study has shown that blocking RTF by means of anti-RTF monoclonal antibody induced apoptosis in A2780 ovarian carcinoma cell lines. Single chain antibodies have advantages over monoclonal antibodies including smaller size and better penetration into target tissue. Therefore, scFvs are proper candidates for plausible treatment. Materials and Methods: A repertoire of highly various scFvs was phage rescued and specific scFvs were selected against immunodominant epitope of RTF by panning process. PCR was done on clones obtained from panning and BstN1 fingerprinting was performed to distinguish the selected clones. Results: After four rounds of panning, the PCR results of 17 out of 20 randomly selected clones showed that they have the insert. BstN1 fingerprinting of the clones represented 9 different patterns. The clones with the common pattern with the frequency of %41 were selected as the source of the specific anti-RTF antibody for further studies. Conclusion: Immunotherapy with antibodies is a promising method for cancer treatment. Both in vitro and in vivo experiments have proved potential effects of monoclonal antibodies against RTF on A2780 ovarian carcinoma cell line. Applying single chain antibodies may assist us for better diagnosis and therapy of tumors. Further investigations are undergoing on binding ability of the selected scFvs to the glioblastoma cell line and also evaluation of apoptosis-induced by them in tumor cells needs to be assessed