Construction of bacteriophage derived vector with specific affinity for EGFR expressing cells with the aim of targeted drug delivery and cellular imaging

Abstract

Introduction: The relation of epidermal growth factor receptor (EGFR) dysregulation with development of epithelial derived cancers have been proved. Therefore, it is usually established as a desired target for gene therapy. The development of novel vectors such as bacteriophage for gene delivery can be applicable in cancer treatment. Here, we purpose an approach for targeting phage particles to mammalian cells, which may be used in gene delivery. Aims: The aims are (i) Construction of a modified phage capable of displaying EGF as tumor targeting molecule and GFP as the tracing element, and (ii) Detection and targeting of EGFR over expressing cells. Methods: sfGFP-EGF coding sequence was inserted at the N-terminus of pIII gene in the phagemid pIT2. The phage displaying sfGFP-EGF was amplified using bacterial system and incubated with EGFR overexpressing cells. The EGF/EGFR interactions was monitored by fluorescence microscopy and FACS analysis. The phage particles were then used for A-431 cell based ELISA. Results: The FACS analysis showed a significant shift in the mean fluorescence intensity (MFI) of the cells treated with sfGFP-EGF phage displaying in contrast to phage displaying sfGFP. The binding of phage displaying sfGFP-EGF to A431 cells were monitored and the results indicated that phage displaying sfGFP-EGF could detect and bind to EGFR on the cell surface and the ELISA results showed that the phages displaying EGF and sfGFP-EGF have the ability to specifically bind the EGFR expressing cells. Conclusions: The recognition and specificity of the constructed vector towards EGFR were elucidated using different biological assays such as flow cytometry, ELISA and fluorescence based imaging experiments. We believe that the vector constructed in the current study has the potential to be engineered for gene delivery purposes as well as tumor detection.