Combined EGFR and c-Src Antisense Oligodeoxynucleotides Encapsulated with PAMAM Denderimers Inhibit HT-29 Colon Cancer Cell Proliferation

Colon cancer continues to be one of the most common cancers, and the importance and necessity of newtherapies needs to be stressed. The most important proto-oncogen factors for colon cancer appear to beepidermal growth factor receptor, EGFR, and c-Src with high expression and activity leading to tumor growthand ultimately to colon cancer progression. Application of c-Src and EGFR antisense agents simultaneouslyshould theoretically therefore have major benefit. In the present study, anti-EGFR and c-Src specific antisenseoligodeoxynucleotides were combined in a formulation using PAMAM dendrimers as a carrier. Nano drug entryinto cells was confirmed by flow cytometry and fluorescence microscopy imaging and real time PCR showed geneexpression of c-Src and EGFR, as well as downstream STAT5 and MAPK-1 with the tumor suppressor geneP53 to all be downregulated. EGFR and c-Src protein expression was also reduced when assessed by westernblotting techniques. The effect of the antisense oligonucleotide on HT29 cell proliferation was determined byMTT assay, reduction beijng observed after 48 hours. In summary, nano-drug, anti-EGFR and c-Src specificantisense oligodeoxynucleotides were effectively transferred into HT-29 cells and inhibited gene expression intarget cells. Based on the results of this study it appears that the use of antisense EGFR and c-Src simultaneouslymight have a significant effect on colon cancer growth by down regulation of EGFR and its downstream genes.