Poly (amido amine) dendrimer silences the expression of epidermal growth factor receptor and p53 gene in vitro

Abstract

To understand more about the lower generations of poly(amido amine) dendrimer (PAMAM) as a non-viral vector for antisense (ANS) therapy, a 21-mer epidermal growth factor receptor (EGFR) ANS was delivered by generation five of PAMAM in T47D breast carcinoma cells in culture. The semi-quantitative polymerase chain reaction (PCR) and western blot analysis were used to quantify the expression of EGFR mRNA and protein, respectively. The results showed that PAMAM G5/ANS nanoparticles were able to decrease the level of EGFR mRNA more than 40% even at the lower dendrimer primary amine to the antisense phosphate groups (N/P) ratio of 0.5. But, only the data of western blot analysis at the higher N/P ratios of 10 and 20 showed a decrease of the protein expression level similar to the mRNA expression level. Moreover, PAMAM dendrimer had a positive effect on the EGFR ANS action to inhibit the EGFR mRNA and protein expression. Further studies revealed that PAMAM G5 dendrimer as such inhibits the expression of EGFR in a concentration-dependent manner. Since PAMAM as such was able to inhibit the mRNA expression of p53 gene, we speculated that the effect of PAMAM G5 on the EGFR is a kind of its non-selective effect on the transcription and/or translation machinery of the cell. Key words: Poly(amido amine) dendrimer (PAMAM) dendrimer, epidermal growth factor receptor (EGFR) antisense, epidermal growth factor, RNAi, polyamidoamine dendrimer, toxicogenomics, gene delivery.