Fig. 6.

Tail vein injection of shRNA specifically targeting circPTK2 significantly inhibited tumor metastasis in a patient-derived tumor xenograft (PDTX) model of CRC. PDTX model was established by using tumor tissues of 24 phase I and II patients. a Schematic of tail vein injection of circPTK2 or shRNA specifically targeting circPTK2 in the PDTX model. b circPTK2 levels of parental adjacent and tumor CRC tissue were assessed by qRT-PCR. c Six highest and lowest circPTK2-expressing tissues were selected for establishment of PDTX. circPTK2 levels of orthotopic xenografts isolated from mice of PDTX were assessed by qRT-PCR. d Vimentin expression in the tumor tissues of PDTX was analyzed via IHC (black arrows showed the vimentin⁺ areas and cells). e Cells were isolated from mice bearing lower circPTK2-expressing xenografts, which were injected with vector and circPTK2-overexpressing plasmid by tail vein. Migration and invasion of cells were detected. f Cells were isolated from mice bearing higher circPTK2-expressing xenografts, which were injected with control siRNA and circPTK2 siRNA by tail vein. Migration and invasion of cells were detected. g Cells were treated as Figure 6e and then injected into spleen of nude mice. Livers were isolated and stained with HE. Representative images of livers and their HE staining are shown. h Cells were treated as Figure 6f and then injected into spleen of nude mice. Representative images of livers and their HE staining are shown. The data are the mean ± SEM. *P<0.05, **P<0.01. P values were calculated by one-way ANOVA