Fig. 4
OPN produced by MEFs promotes the tumor growth and metastasis of ATL cells inoculated into NOG mice. Six-week-old female NOG mice were subcutaneously inoculated with TL-OmI cells alone (n = 5) or together with either WT MEFs (n = 5) or OPN KO MEFs (n = 5) (1 × 107 cells per cell type). WT-MEFs (n = 3) or OPN KO MEFs (n = 3) only were also inoculated as negative controls. a Survival rate was monitored by death of the mice. b The tumor size was measured every 3–4 days. c Blood was collected from the tail vein for measurement of the mouse OPN level in the plasma and for d detection of metastatic cells as quantified by the number of tax genes assessed using qPCR. e Metastasis to the liver was evaluated by immunohistochemical staining of human CD4 on day 40. For all of b–e, bars indicate mean values ± SEM. Statistically significant differences are shown with P value (*P < 0.05, **P < 0.01). For a–d, filled square, TL-OmI + WT MEFs; open square, TL-OmI + OPN KO MEFs; filled circle, TL-OmI only; open circle, WT MEFs; filled triangle, OPN KO MEFs