Figure 1
Tumorigenesis of mMSC cell lines established under culture at 20% O 2 . (A) Very weak telomere signals and chromosome fusions in MSC1226 at P49 revealed by FISH with the telomere-specific (CCCTAA)3 probe. White arrows, telomere free signals. Red arrows, end-to-end chromosome fusions. (B-C) Mineralized tumor formed by i.p. injection of 2 × 106 MSC1226 cells at P49. Black arrow heads, areas of mineralization. (D-G) Teratoma-like tumor formed by MSC0509 cells at P24. The tumor contains large areas of necrosis (D) and endoderm (E), mesoderm (F) and ectoderm (G). Tissue sections in (C) to (G) were stained with hematoxylin-eosin. Original magnification in A ×1000, in C-G ×200.