Fig. 1

Co-injection of miPSCs with cancer cells maintained the stemness of miPSCs. A A schematic design of the experiment. The miPSCs were mixed with human-derived cancer cells, transplanted into mice, and iPSC-derived cells were isolated from the primary culture of the tumors. B Representative photographs of tumors in mice and excised from mice. The miPS-Panc1, tumor from mixtures of miPSCs and PANC1 cells; miPS-Bxpc3, tumors from mixtures of miPSCs and BxPC3 cells; miPS-Pk8, tumors from mixtures of miPSCs and PK8 cells. miPSCs denotes the teratoma derived from the injection of only miPSCs. n = 3 for each condition. C Representative photographs of primary cultures of tumors, miPS-Panc1 cells (a), miPS-Bxpc3 cells (b), miPS-Pk8 cells (c), and miPSCs (d), showing colonies of GFP positive cells while the cells from miPSC derived tumors were negative for GFP. D Representative photographs of cells survived after the treatment with 1.5 μg/ml of puromycin for 1 week. miPa cells from miPS-Panc1 cells (a), miBx from miPS-Bxpc3 cells (b), miPk from miPS-Pk8 cells (c). The miPSCs were sensitive to this condition and did not survive. E The histological stains of tumor sections with hematoxylin and eosin (H&E). The endoderm-derived glands (red arrow), the ectoderm-derived squamous epithelium (asterisk), and the mesoderm-derived cartilage tissues (black arrow) were found in miPSC tumors. No teratoma phenotype but malignant phenotypes with mitotic figures and nuclear atypia (red arrows) were found in miPS-Panc1, miPS-Bxpc3, and miPS-Pk8 tumors. Scale bars = 307 μm (top) and 32 μm (bottom). F Immunostaining of the tumor sections with anti-GFP Ab. G) A histogram of the area immunoreactive to anti-GFP analyzed by ImageJ software. All data were obtained from three independent tumors (n = 3), statistically analyzed, and presented as mean ± SD. Scale bar = 307 μm. H ~ L Relative expression levels of stemness and CSC genes assessed by RT-qPCR. All data were obtained from three different experiments and statistically analyzed. *, p < 0.05; **, p < 0.001; ***, p < 0.0001