Adenovirus enhances adeno-associated virus expression in drug-sensitive and drug-resistant tumor cells and the related mechanism / 中国肿瘤生物治疗杂志

ABSTRACT

Objective:To investigate the enhancing effect of low dose adenovirus on rAAV2 expression in drug-sensi- tive and drug-resistant tumor cells and to explore the related mechanism.Methods:Human small cell lung cancer NCI- H446 cells,human lung adenocarcinoma A549 cells,human gastric cancer SGC7901 cells,human oral epithelial cancer KB cells,and VCR-resistant KB cells(KB/VCR)were transfected with rAAV2-GFP alone or combined with AdS-RFP or with AdS-TERT-RFP.GFP expression in the infected tumor cells was observed and analyzed by fluorescence microscope and fluorescence activated cell sorting(FACS).GFP protein and phosphorylation level of ERK and AKT in the infected tumor cells were detected by Western blotting.Quantitative analysis of DNA copies of GFP and mRNA expression of GFP, HSPG,?_v integrin,FGFR-1 in the infected tumor cells were performed by Real-time PCR.Results:The results of FACS demonstrated that the mean intensity of GFP fluorescence and the GFP positive rate after infection with rAAV2-GFP com- bined with Ad5-RFP or Ad5-TERT-RFP increased by 0.3-3 and 4-8 folds,respectively.GFP expression in the tumor cells with combined infection showed 4-6 folds increase and the phosphorylation level of ERK and AKT also increased.GFP mRNA expression in the combined infection tumor cells increased by 3.83-7.33 folds;there was no differences in the GFP DNA copies between rAAV2-GFP group and rAAV2-GFP plus Ad5-RFP group.Cellular receptors HSPG,?_v integrin and FGFR-1 mRNA expression was slightly increased in rAAV2-GFP plus Ad5-RFP.Conclusion:Lower dose of recombinant adenovirus can obviously enhance the expression of rAAV2 in drug-sensitive and drug-resistant tumor cells,which might be related to the activation of signal transduction pathway and increase of intracellular transcription.