Fig 5. ASPP2 dominates over Gal-1 thus robustly inducing senescence and abrogating mammosphere formation.

(A) SA-β-gal assay of MCF-7 cells transfected with plasmids encoding H-rasG12V, ASPP2, Gal-1 or the combination of the latter two, as indicated. Cells were stained 7 days after transfection. On the left, percentages of SA-β-gal positive cells are shown in the graph (mean ± SEM, n = 3). On the right, representative images from the assay. (B) Mammosphere formation assay with MCF-7, MDA-MB-231 or HS-578T breast cancer cell lines. Mammospheres were transfected with Gal-1, ASPP2, or both (1:1 ratio) and cells were then grown under non-adherent conditions for 9 days. On the right, representative images of mammospheres are shown as indicated. (A, B) Statistical significance of differences between controls and treated samples was examined using one-way ANOVA (mean ± SEM n≥3; ns, not significant; ****, p<0.0001).