Successful inhibition of EGFR in MCF-7 by cationic nanopolyplexes

Breast cancer appears to be the second most lethal type of cancer, which indeed necessitates implementation of novel therapeutics to target the involved oncogenes. The human epidermal growth factor receptor (EGFR) is an oncogene overexpressed in solid tumors (e.g., 82-90% overexpression in breast cancer), which results in tumor growth and development. Inhibition/suppression of EGFR at transcription level may control the signalling pathways resulting in tumor inhibition [1]. Genome-based therapeutics (e.g., classical gene therapy, antisense oligonucleotides, ribozymes, DNAzymes and RNA-interference) are now considered as promising therapeutic paradigms for treating genetic diseases in the post-genomic era. Success of such strategies depends exclusively upon efficient delivery, whereby pharmacological efficacy with minimum in vivo toxicity should be achieved. So far, viral and non-viral vectors have been exploited for gene therapy; however the use of viral vectors has been limited because of safety concerns. Non-viral gene delivery systems have advantages over viral delivery systems in several aspects including easy large scale propagation with high quality, safety, and low immunogenicity [2]. Potential advantages of non-viral transfection are biosafety and easy management [3]. However the draw back is their low transfection efficiency. In addition, physical properties such as size and zeta potential play a critical role in their effectiveness as a gene delivery carrier [4]. In this study, to pursue this hypothesis, we aimed to investigate the expression of EGFR in breast cancer MCF-7 cells upon treatment with anti-EGFR antisense oligdeoxyonucleotides (ODNs).