PAI-1 Expression Is Required for HDACi-Induced Proliferative Arrest in ras-Transformed Renal Epithelial Cells
Figure 1
Electrophoresis of the 35S-methionine-labeled saponin-resistant (SAP) protein fraction of v-ras-transformed renal cells and their NaB-treated counterparts indicated that PAI-1 (both the 50-kD and fully glycosylated 52-kD species) were expressed in NaB revertants but not in untreated cells (a). PAI-1 from normal kidney cells (NRK) served as a marker. The band above PAI-1 in v-ras cells (at 62-kD) is the heavily-glycosylated forms of osteopontin (a). Northern blotting confirmed the absence of PAI-1 mRNA in v-ras-transformants and the restoration of mRNA expression in response to NaB (b). 2-D electrophoretic mapping of the SAP fraction proteins derived from 35S-methionine-labeled cultures revealed, furthermore, that PAI-1 induction in response to NaB treatment was rather selective (c). Map positions of the glycosylated PAI-1 isoforms are indicated (solid red outlined rectangle). Proteins common between the cell types are highlighted in color (purple circles, red dashed line box, blue ovals indicating vimentin, and phosho-vimentin breakdown products and actin by black arrows) and did not change in abundance despite the significant PAI-1 induction evident in the v-ras/NaB protein profile (c).
