Abstract
Abstract
Thyroid cancer is known as the most common endocrine malignancy, with an increasing incidence rate over the past decades. Although thyroid tumor represents a favorable prognosis, a minority of patients experience tumor metastasis and recurrence. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is normally overexpressed in different types of cancers. In thyroid tumors, EGFR expression is shown to be correlated with advanced metastatic features and therapeutic resistance. Affibody molecules are the small-sized proteins that are genetically designed and engineered to have an affinity for specific target molecules. In this study, four recombinant proteins (probes) were designed for targeting EGFR receptor in thyroid cancer cells. Affibody probes were recombinantly expressed using a prokaryotic host and purified with an affinity purification column. The cytotoxic effect of EGFR-specific affibodies was determined in thyroid cell lines (BCPAP and 8305C) using MTT and apoptosis assay. To measure the properties of the designed probes, they were conjugated with FITC and binding affinity was calculated using binding assays and flow cytometry. The results demonstrate that EGFR specific affibodies exert an antiproliferative and apoptotic effect on thyroid cancer cell lines. Moreover, the engineered affibodies demonstrate high-affinity binding in thyroid cell lines that have baseline EGFR expression, but not in EGFR-negative cells. Overall, EGFR-specific affibodies might have the potential application for both detection and targeting of TC.