Figure 3.

Sphere-forming cells exhibited high tumorigenicity in vivo. (A) The representative examples of xenograft tumors formed after subcutaneous injection with the PLC/PRF/5 parental cells and sphere-forming cells. (B) The top row shows the nodules formed by injecting 2 × 10⁵, 5 × 10⁵ and 1 × 10⁶ PLC/PRF/5 parental cells, separately. The bottom row shows the nodules formed by injecting 5 × 10², 1 × 10³, 2.5 × 10³, 5 × 10³, 1 × 10⁴ and 5 × 10⁴ PLC/PRF/5 sphere-forming cells, separately. (C) H&E staining revealed that the histological features of xenograft tumors induced by the PLC/PRF/5 sphere-forming cells were similar to those induced by the parental cells.