Fig. 8

circFIRRE promotes both primary OS progression and metastasis in vivo by sponging miRNAs. MG63 cells infected with empty virus (Group-A), sh-circFIRRE-1 (Group-B) or co-infected with sh-circFIRRE-1 and miR-486-3p+1225-5p sponges (Group-C) for in vivo assays. A-E Orthotopic xenograft tumor models (n=10 in each group). A IVIS imaging was applied to determine the OS lesions in situ. The representative images were acquired with the same exposure. B Micro-CT scans and 3-D reconstruction were performed to estimate bone destruction induced by tumorigenesis in situ. C-D Ki-67 and LUZP1 detection in bone lesions by IHC. E LUZP1 protein level in bone lesions was examined by western blot. F-N Tail vein metastasis models (n=10 in each group). F Representative IVIS imaging of metastatic tumor activity in the lung with the same exposure. G-I 3-D reconstructions of micro-CT. G The white arrowhead indicates the metastatic lesions in the lung. H-I Quantitation of tumor volumes and numbers. J-K Collected lungs and Hematoxylin and eosin (H&E) staining. K The black arrowhead indicates the metastatic lesions in the lung. L-N VEGF, CD31 and LUZP1 detection in lung lesions by IHC. O LUZP1 protein level in lung lesions was examined by western blot. P A proposed model of circFIRRE in modulating OS tumorigenesis, metastasis and angiogenesis via YY1-circFIRRE-miR-486-3p/miR-1225-5p-LUZP1 axis. Scale bars of IHC=100 μm and 50 μm