FGF1 induces resistance to chemotherapy in ovarian granulosa tumor cells through regulation of p53 mitochondrial localization

a Upper panel: Average flow cytometry quantification of apoptotic cells characterized by their low DIOC staining and cell condensation (DIOC-, Size-)？±？SEM for 3 experiments done in triplicate. Non-transfected COV434 (NT), two COV434-Mock clonal cell lines and three COV434-FGF1 clonal cell lines were treated with etoposide (25？μg/mL) for 16？h, or not treated (Ctl), The t-tests compare to NT Eto. Lower panel: FGF1 levels in non-transfected, mock and FGF1 overexpressing clones using western blot analysis. Total proteins are visualized with the Biorad stain free system. b Immunofluorescence study for cytochrome c release. COV434-Mock C1 and -FGF1 C1 cells were treated with 25？μg/mL etoposide for 4？h. Cells were stained with an anti-cytochrome c antibody (green) and TO-PRO-3 (blue) to visualize nuclei (left panels). Scale bar represents 40？μm. The histogram presents the average percentages？±？SEM for 3 independent experiments of cells exhibiting cytochrome c release (right panel). The t-test compares to Mock cells similarly treated. c Upper panel: Western blot analysis of total proteins for procaspase-9, cleaved caspase-9 and ？3 and PARP levels. COV434-Mock and -FGF1 cells were treated or not (0？h) with 25？μg/mL etoposide for 2, 4, 6, or 16？h. Lower panel: histograms present the average fold-change decrease of cleaved caspase-9, cleaved caspase-3 and cleaved PARP in COV434-FGF1 cells？±？SEM from pooled results of three FGF1 overexpressing clones (n？=？8). Two-tailed unpaired t-tests results are shown as * for P？≤？0.05, ** for P？≤？0.01 and *** for P？≤？0.00