FIG. 3.
Restoration of cleaved DLK1 levels in the medium of Dlk1Total knocked down 3T3-L1 cells. 3T3-L1 cells were transfected at 0 h with either Dlk1Total or scramble siRNA and grown in either 3T3-L1–conditioned medium (Cond. med.) (A) or a medium containing known concentrations of purified human DLK1 (hDLK1) (B). mRNA levels of cell cycle–related genes were determined by qRT-PCR 48 h after transfection. Significance was tested by a two-way ANOVA (**P < 0.01; ***P < 0.0001), and qRT-PCR raw data were normalized against multiple stably expressed endogenous controls (data not shown).