Figure 4.

Both PKCα and PKCδ regulate PAI-1 expression in glioblastoma cells. A) A172 cells were stimulated with EGF for indicated times, and phosphorylation of PKC isoforms was analyzed by Western blotting using specific antibodies. B) A172 cells were treated with EGF for indicated times, and localization of PKCα and PKCδ was examined by confocal immunofluorescence microscopy. The numbers represent fluorescent intensity analyzed as described in Materials and Methods. C) A172 cells were transfected with control siRNA (con.) or siRNAs targeted to PKCα or PKCδ for 48 h as indicated, and then stimulated with EGF for 7 h. RNA was isolated after 7 h and subjected to Northern blot analysis using PAI-1 cDNA as a probe. D) Cells were transfected with PKCα siRNA or PKCδ siRNA for 48 h as indicated and stimulated with EGF for 30 min, and indicated proteins were analyzed by Western blotting. Blots were stripped and reprobed with anti-tubulin antibody as a loading control.