O-16: Evaluation of Anti-Her2 Single Chain Antibodies in Her2-Positive Breast Cancer Cell Lines (Pages: 25-26)

Asgharpour M *, Nejatollahi F , Jaberipour M , Hosseini A ,


Around 25% of patients with breast cancer have HER2-positive disease which makes HER2 an ideal target receptor for cancer immunotherapy. In this study, we produced a source of specific single chain antibodies (scFv) against HER2 and investigated their anti-proliferative effects on HER2-positive breast cancer cell lines. Also, we evaluated their inhibitive effects on HER2 expression at both the gene and protein levels. Moreover, the effects of produced scFv antibodies on VEGF and SDF-1 gene expressions were assessed. Materials and Methods: Four rounds of panning were performed to select specific and high affinity scFv antibodies against three immune-dominant epitopes of HER2 from a phage-display library of scFv. PCR and fingerprinting were done on the clones after the panning process. The selected clones were screened for the ability to bind the HER2-positive breast cancer cell lines (BT-474 and SKBR-3) by flowcytometry. The proliferation assay was performed using MTT assay on HER2-positive cell lines, BT-474 and SKBR-3, and on HeLa cells as the HER2-negative cell line. HER2- positive cell lines were treated with 3 specific scFvs and the expression of HER2, VEGF, and SDF-1 mRNA were measured by real time PCR. In addition, the expression level of HER2 protein was also evaluated by western blotting analysis after treatment with anti- HER2 scFv antibodies in HER2-positive cell lines