Objective      To determine the effect of nanoparticles for antisense oligodeoxynucleotide (ASODN) of human telomerase reverse transcriptase (hTERT) mRNA on the proliferation and hTERT expression in A549 cells.       Methods      MTT assay was used to detect the proliferation in A549 cells

and the cells treated by ASODN

PEI/SODN and PEI/ASODN (40  μg/ml). Intracellular fluorescence intensity was detected by laser confocal microscopy in the cells after being transfected with 5′-FITC-labelled ASODN (FASODN). Inverse microscopy was used to observe the modality of A549 cells transfected by PEI/ASODN. The expression of hTERT mRNA were determined by RT-PCR. The expression of hTERT protein was detected by immunohistochemictry assay kit. Cell apoptosis were determined by flow cytometry (FCM). To observe the tumor targeting effect of NGR (Asn-Gly-Arg)

a total of 36 A549 cells transplanted nude rats were injected with ASON

PEI/ASON

PEI/ASON-PEG and PEI/ASON-PEG-CNGR solutions respectively via tail vein. The distribution of PEI/ASON-PEG-CNGR in the heart

brain

kidneys

lungs and liver was observed in 1

3 and 6 h after injection.       Results      PEI/ASODN exerted inhibitory effects on the proliferation in A549 cells in a time-dependent manner. The intracellular fluorescence in PEI/FASODN treated cells was obviously stronger than that in FASODN group (PEI free) after transfection. After transfecting PEI/ASODN for 72 h

the hTERT mRNA expression was decreased obviously compared with control group (P0.05). The hTERT protein expression of PEI/ASODN group was reduced. FCM showed that the early and later apoptosis rates in PEI/ASODN group was 36.53% and 54.28% respectively. Animal in vivo experiment showed that PEI/ASON-PEG-CNGR had good tumor targeting effect.       Conclusion      PEI/FASODN of hTERT can inhibit the proliferation in A549 cells effectively

suppress mRNA and protein expression of hTERT and cause cell apoptosis.