Figure 3.
Tumorigenicity Assays. (A) Soft agar colony formation assay: in an anchorage-independent growth assay only tumor CR cells formed visible spheres after two weeks in soft agar culture. Scale bars: 500 µm. (B) Xenografts: tumorigenic properties of tumor CR cells were defined by an in vivo assay. Six-week-old athymic mice were inoculated with 1 × 106 normal or tumor conditional cell reprogramming (CR) cells (left). The resulting tumors were resected after 3–3.5 months of injection and stained with Hematoxylin and eosin (H&E) (middle) staining (right). (C) Tumor growth: tumor CR cells formed palpable tumors three weeks after injection in both flank and mammary sites displaying similar growth rates and patterns.