Fig. 5

CDCP1 knockout inhibits cell proliferation and colony-forming capabilities in HpSCs. a qPCR analysis of the CDCP1 mRNA expression level in siRNA-treated HpSCs. Con, untransfected HpSCs; siNC, HpSCs transfected with negative control siRNA; siCDCP1-1, siCDCP1-2, and siCDCP1-3, HpSCs transfected with siCDCP1. Total RNA was isolated 48 h after siRNA transfection. Results shown as mean fold change ± SD (n = 3 independent experiments). b FACS analysis of the CDCP1 expression level at the cell surface 72 h after siRNA transfection. Filled area, unstained HpSCs; blue line, untransfected HpSCs; red line, HpSCs transfected with negative control siRNA; black line, HpSCs transfected with siCDCP1. c, d Representative images of the proliferation of siRNA-treated HpSCs (c) and cell number counts (d) 96 h after cell plating onto 24-well plates at a density of 2000 cells/well. Scale bars: 100 μm. Results shown as mean cell number count ± SD (n = 3 independent experiments). Mann–Whitney test, ***P < 0.0001, NS no significant difference. e, f Viability of siRNA-treated HpSCs determined by colony-formation assay. Representative images of colonies are shown in (c). Lower lane shows a magnified image of the upper lane. Colony number counts and cell number counts in each colony are shown in (f). HpSCs transfected with negative control siRNA and siCDCP1 were seeded onto 24-well plates at a density of 400 cells/well, photographs taken, and colony number counts and cell number counts were performed 96 h after cell plating. Con, untransfected HpSCs; siNC, HpSCs transfected with negative control siRNA; siCDCP1, HpSCs transfected with siCDCP1. Scale bars: 100 μm. Results shown as mean ± SD (n = 3 independent experiments). Mann–Whitney test, *P < 0.05, **P < 0.001, ***P < 0.0001, NS no significant difference. See also Additional file 4: Figure S4. CDCP1 CUB domain-containing protein 1