Figure 2

GRG5 over-expression enhances ESC self-renewal and leads to the generation of malignant teratomas. (a) Western Blot analysis of pluripotency factors in CONTROL and OE GRG5 ESCs. (b) Protein levels of total (pRB) and inactive (ppRB) RB protein in CONTROL and OE GRG5 ESCs. (c) Growth curves of CONTROL and OE GRG5 ESCs. Mean ± SD of n = 4 independent experiments. *P < 0.05 (d) Teratomas formed upon intramuscular injection of CONTROL and OE GRG5 ESCs in immunocompromised mice. (Scale bar, 0.5 cm) Box plot illustrating the average size of CONTROL and OE GRG5 teratomas. Mean ± SD of n = 8 independent teratomas. *P < 0.05 (e) Pictures and quantification of immunohistological staining for the proliferation marker Ki67 in CONTROL and OE GRG5 teratoma cryosections. DAB was used as chromogen and Hematoxylin as counterstain (x100). Mean + SD of n = 2 independent experiments. (f) H&E stained cryosections of CONTROL and OE GRG5 teratomas showing hemorrhagic areas (white arrowhead) (Scale bar, 50 μm) Quantification of the volume of the hemmorhagic region in CONTROL and OE GRG5 teratomas. Mean + SD of n = 3 independent experiments. *P < 0.05 (g) H&E staining pictures showing CONTROL (black line) and OE GRG5 (black dots) teratoma borders. White arrow: Host muscle cells. (Scale bar, 100 μm) (h) Histological analysis with H&E and PAS-D staining of CONTROL and OE GRG5 teratoma cryosections presenting derivatives of the three primary germ layers. Black cross: Cartilage, Black star: Neuroepihelium, Black arrowhead: Columnal epithelium with goblet cells. (x100, x400) (i) Comparison of teratoma tissue composition based on analysis of H&E stained cryosections. Mean ± SD of n = 3 teratomas. *P < 0.05.