Fig. 4

SMYD3 facilitates OSCC cell stemness maintenance and proliferation in vitro and tumorigenesis in vivo. A Representative image of NC- or SMYD3 siRNA-transfected CAL-27 and UM-SCC-1 cells in a secondary tumorsphere formation assay. Scale bars: 50 μm. B Representative images of NC- or SMYD3 siRNA-transfected CAL-27 and UM-SCC-1 cells in a colony formation assay. C Representative images of NC- or SMYD3 siRNA-transfected CAL-27 and UM-SCC-1 cells in an EdU staining assay. Scale bars: 50 μm. D Western blotting analyses showing that SMYD3, c-MYC, BMI1, NANOG, SOX2 and H3K4me3 protein expression were decreased in CAL-27 and UM-SCC-1 cells. E Representative images of vector- or SMYD3 plasmid-transfected CAL-27 cells in a secondary tumorsphere formation assay. Scale bars: 50 μm. F Representative images of vector- or SMYD3 plasmid-transfected CAL-27 cells in a colony formation assay. G Representative images of vector- or SMYD3 plasmid-transfected CAL-27 cells in an EdU staining assay. Scale bars: 50 μm. H Western blotting analyses showing that SMYD3, c-MYC, BMI1, NANOG, SOX2 and H3K4me3 protein expression were elevated in SMYD3 plasmid-transfected CAL-27 cells. I Subcutaneous tumor formation in nude mice of shNC and shSMYD3 groups (n = 6/group). J, K Tumor weight and tumor growth curves in the nude mouse xenograft model. L IHC staining for Ki67 in xenografts (n = 6/group). Scale bars: 50 μm. M Western blotting analyses showing that SOX2 protein expression was reduced in shSMYD3 group than in shNC group in vivo. *P < 0.05, **P ≤ 0.01, and ***P ≤ 0.001