Abstract
To overcome TKIs resistance, we developed scFv and s-9R, two human single chain antibodies against EGFR(fig.1A). Here, we showed s-9R could deliver FAM-siRNA into EGFR positve NSCLC cells(fig.1B). A549, H1993 and H1975 were either transfected with KRAS, MET or EGFR siRNA or co-incubated with scFv/s-9R/ indicated siRNA mixtures, following treated with gefitinib. Compared with the control groups, the target genes' expression level were down-regulated in the s-9R/siRNA mixture groups detected by RT-qPCR and western blot(fig.1C and D). In vivo, s-9R/siRNA mixtures restored gefitinib sensitivity in TKIs resistance cells measured by MTT(fig.1E).
In vitro, the fusion proteins were gradually cleaned from normal tissues and enriched in the tumor till 48h assessed by Living image system(fig.2A). The co-administration of s-9R/siRNA and gefitinib treatment successfully suppressed the xenograft tumor progression (fig.2B) and prolonged the life span of nude mouse(fig.2C and D).
Therefore, the study provides not only a new scFv derivative to deliver siRNA into EGFR-positive NSCLC cells but also a flexible method to overcome TKIs resistance.
- © 2014 ERS
