Self-seeding circulating tumor cells promote the proliferation and metastasis of human osteosarcoma by upregulating interleukin-8

The migration, invasion, and proliferation capacities of C-F5M2 cells were higher than those of F5M2 cells, and the growth rate of C-F5M2 cell-derived tumors was higher than that of F5M2 cell-derived tumors in nude mouse models. a GFP-labeled F5M2 cells were subcutaneously implanted in the left dorsal region of nude mice to establish the “donor tumors”, and SOSP-9607 cells were implanted in the right hind limbs to establish the “recipient tumors”. b H&E staining was used to identify the donor tumor tissues. c H&E staining was used to identify the recipient tumor tissues. d The seeded recipient tumors were excised, dissociated and placed in culture medium, and then the self-seeding CTCs (GFP-labeled and named C-F5M2 cells) were selected and enriched by adding puromycin in the culture medium. e The transwell assay to test cell migration ability. Representative images of F5M2 cells subjected to the transwell migration assay. Cells were stained with crystal violet and observed under optical microscope. f Representative images of C-F5M2 cells subjected to the transwell migration assay. g The migration rate of C-F5M2 cells was higher than that of F5M2 cells (P？<？0.001). h Representative images of F5M2 cells subjected to the transwell invasion assay. i Representative images of the C-F5M2 cells subjected to the transwell invasion assay. j The invasive capacity of C-F5M2 cells was higher than that of F5M2 cells (P？<？0.01). k The MTT assay in F5M2 and C-F5M2 cells. The proliferation rate of C-F5M2 cells was significantly higher than that of F5M2 cells (P？<？0.001). l The tumor volumes in the C-F5M2 group were larger than those in the F5M2 group (P？<？0.05). m Representative images of primary F5M2 and C-F5M2 tumors in nude mic