FIG. 1.

Mitochondrial changes in Ras-expressing cells. (A) MitoSox fluorescence images of Ras-expressing cells and cells with a control vector obtained from cells 2 and 8 days after selection. (B) DCFDA fluorescence images of cells as described for panel A. Nuclei were counterstained with Hoechst 33342. PC means phase-contrast images, and the arrows point to vacuoles that characterize the cytoplasm of Ras-senescent cells. (C) Magnified immunofluorescence image to visualize the vacuoles in the cytoplasm of Ras-senescent cells stained with DFCDA. (D to F) Fluorescence intensity of cells analyzed by flow cytometry and stained with DHE, DCFDA, or Mitofluor Green as indicated. (G) Real-time PCR measuring the relative levels of mtDNA versus nuDNA in cells with control vector or its derivative expressing oncogenic ras.