Figure 4

MiR-21 determines TGF-β1-induced fibroblast activation.

(A). TGF-β1 promotes miR-21 maturation and increases mature miR-21. The left panel and graphic show the Northern blot data and realtime PCR results for mature miR-21 48 hours after TGF treatment; the right graphic shows the realtime PCR results for pri-, pre- and mature miR-21 at different time points after TGF-β1 stimulation. (B). miR-21 over-expression triggers FSP1 expression. The left panel shows the Western blot data for FSP1 and α-SMA (another CAF marker), the middle graphic shows the realtime PCR result and the right panel shows the miR-21 overexpression efficiency. (C). miR-21 knockdown blocks TGF-β1-induced FSP1 expression. The Western blot data shows the expression of FSP1 and α-SMA, the middle graphic shows the realtime PCR result and the right panel shows the miR-21 knockdown efficiency. (D). Fibroblasts overexpressing miR-21 promote tumor growth in the xenografted mouse model. (E). Fibroblasts with knocked down miR-21 inhibit tumor growth in the xenografted mouse model. For both experiments, the schematic drawing shows the positions where the cells were injected and the graphic shows the tumor growth curve. The tumor size (median ± error) in the A375 plus miR-21 knocked down or overexpressed fibroblasts group and in the A375 plus untreated fibroblasts group at the end point is significantly different (**: P < 0.001; #: P < 0.001). The picture shows the isolated tumors, where tumors in the same position in each group are from the same mouse. The pictures in the bottom are representative fluorescence microscopy images, the greens are fibroblasts.