Figure 2. Tumor-derived cell lines provide insight into consequences of MST loss-of-function.

(A) Immunoblot of tumor-derived cell line lysates. Okadaic acid (OA, 150nM) was used as a pharmacologic activator of MST to reveal changes in downstream signaling. (B) Upper: BrdU incorporation is higher in MST^Null versus MST^WT tumor-derived cells. Data shown represents pooled values from three experiments including two cell lines each of MST^WT and MST^Null cell lines. Lower: MST^WT (680^+/+) cells show increased β-Gal staining as compared to MST^Null (911^F/F), indicating an increased number of senescent cells. Data shown represents four technical replicates. (C) Upper panels: representative images of the invasion potential of (a,c) MST^WT and (b,d) MST^Null cells. Note that MST^Null cells were able to invade even in the absence of a nutritional gradient, as shown by violet staining in (d). Lower panels: as evidenced by MF20 staining, (e) MST^WT cells were able to differentiate down the myogenic lineage, while (f) MST^Null cells were not. Data shown represents four technical replicates. (D) Quantitation of invasion (upper panel) and differentiation (lower panel) assays shown in (C).