Stable expression of the cytoplasmically restricted GFP-NES1-SAR protein is sufficient to transform MCF-12A Cells. (A) Fluorescence imaging of stably expressed GFP-only, GFP-SAR, GFP-NLS-SAR and GFP-NES1-SAR in living MCF-12A cells. Green - GFP fluorescence. White dashed lines represent cell outlines. (B) Quantification of anchorage-independent colony formation of pooled MCF-12A cell populations stably expressing the GFP-only, GFP-SAR, GFP-NLS-SAR or GFP-NES1-SAR proteins. Two independent, stably transfected MCF-12A populations for each construct were seeded in triplicate soft agarose cultures and colonies visible by 6X bright field microscopy were counted 21 days later. Bars show average numbers of colonies per plate +/- s.e.m.