Human Hepatocyte-Derived Induced Pluripotent Stem Cells: MYC Expression, Similarities to Human Germ Cell Tumors, and Safety Issues

Figure 8

iPSC generated from mouse hematopoietic stem cells. Tumors produced were mainly solid mixed germ cell tumors (a, H&E 20x). The teratoma component showed derivatives from all three germ layers (b, H&E 100x), with the ectodermal (neuroglial, star) and endodermal (squamous epithelium, arrow, and exocrine pancreas, vertical arrowheads) derivatives being shown; small foci of embryonal carcinoma (horizontal arrowheads) were intermingled. At higher magnification (c, H&E 200x), the embryonal carcinoma cells formed small dispersed nests (star) within the teratoma component (immature neuroglial tissue, arrow). MYC immunohistochemical reactivity was very faint and focal in the embryonal carcinoma foci (d, 200x).

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