Abstract
Epidermal growth factor receptor (EGFR) network appears to be a rich target for prostate cancer. Thus, in this current investigation, to pursue our newly developed anti-EGFR monoclonal antibody (mAb) in prostate cancer, its inhibitory effect was investigated in PC3 cells. The binding specificity of antibody was examined by flow cytometry and immunofluorescence staining. The cultivated cells were treated with various doses of the anti-EGFR mAb at different time points and the cellular and/or molecular impacts were assessed. MTT assay was utilized to examine the cytotoxic effects. Semi-quantitative RT-PCR was used to evaluate the expression of EGFR and some important apoptosis signaling molecules (e.g., MAPK-1, STAT-5, Akt-1 kinase). Flow cytometric and immunofluorescence staining analyses showed that the anti-EGFR mAb can bind to EGFR with high specificity. The results revealed that the anti-EGFR mAb can inhibit cell growth in a dose and time dependent manner. RT-PCR analysis revealed that the binding of anti-EGFR mAb to its receptors can eventually result in downregulation of Akt-1 kinase gene, but not MAPK-1, STAT-5 and EGFR genes. Based on our findings, it can be concluded that Akt-1 is the most important downstream signaling molecules affected by anti-EGFR mAbs.