The inhibitory effects of nanosize delivery system for antisense oligonucleotide of hTERT on EC9706 cells.

A nanosize delivery system (NDS) for oligonucleotides (ODNs) was established, and the effects mediated by NDS containing the antisense oligonucleotides (ASODNs) for hTERT mRNA on EC9706 cells were investigated by methyl thiazolyl tetrazolium (MTT) assay, RT-PCR, immunohistochemistry and flow cytometry. The inhibitory effects of ASODNs-NDS on EC9706 cells proliferation had a concentration-dependent and time-dependent manner. There was a significant difference in inhibitory rate between cell control group and ASODNs (I --> VIII)-NDS groups (p < 0.05). However, no significant difference was found between cell control group and NDS group, SODN (sense oligonucleotide) group or ASODNs group (p > 0.05). After transfection of ASODNs-NDS for 72 h, the level of hTERT mRNA decreased observably compared with cell control group (p < 0.05), and cells apoptosis appeared in the ASODNs-NDS groups. The ASODNs complementary to the sites to which Sp1 and c-myc bind had stronger effects on EC9706 cell proliferation and apoptosis.