Pten null mutant ESCs generate larger tumors than wild type with a similar rate of in vivo ECC generation.

(A) Karyotype of wild type and Pten−/− ESCs (B) Proliferation of Pten+/+, −/− and shp knockdown murine ESCs under self renewing conditions. (C) Annexin V staining by flow cytometry on day 4 in self-renewing culture. (D) SSEA1 and Oct4 staining by flow cytometry on day 4 of self-renewing culture. (E) Re-plating assay showing numbers of wells with alkaline phosphatase (AP) positive colonies 6 days after sorting 10 cells/well into a 96 well plates. (F) Total tumor weight after 6 weeks. Pten−/− tumors were significantly larger by non-parametric analysis. (G) Testicular tumor derived from wild type or Pten−/− ESCs (Scale bar = 0.5 cm). Histology of tumors showing derivatives of ectoderm (ecto), mesoderm (meso) and endoderm (endo) (Magnification 200×). Immunofluorescence for SSEA1 and Oct4 in tumor sections and percentage SSEA1+ by flow cytometry (mean ± SD) (Magnification 400×). **  =  p<0.005, N/S  =  not significant.