Tumor formation constitutes a major obstacle to the clinical application of embryonic stem cell-derived (ESC-derived) cells. In an attempt to find major extracellular signaling and intrinsic factors controlling tumorigenicity and therapeutic functionality of transplanted ESC-derived retinal progenitor cells (ESC-RPCs), we evaluated multiple kinds of ESC-RPCs in a mouse retinal degeneration mode...

Teratocarcinomas are tumors that develop spontaneously in the gonads and usually contain a rapidly dividing, undifferentiated stem cell population. Immature ovarian teratocarcinomas are highly malignant with only 30-60% of patients surviving for 2 years after diagnosis. We have used microcell fusion to introduce individually tagged normal human chromosomes into the PA-1 human teratocarcinoma ce...

Long-term cultures of telomerase-transduced adult human mesenchymal stem cells (hMSC) may evolve spontaneous genetic changes leading to tumorigenicity in immunodeficient mice (e.g., hMSC-TERT20). We wished to clarify whether this unusual phenotype reflected a rare but dominant subpopulation or if the stem cell origin allowed most cells to behave as cancer stem cells. Cultures of the hMSC-TERT20...

Seventy-five clonal populations of morphologically transformed 10T1/2 cells were established from independent Type II and Type III foci that were of spontaneous origin or were induced by the carcinogenic agents jV-methyl-JV'-nitro-jV-nitrosoguanidine, benzo(a)pyrene diol epoxide-I, and 3-methylcholanlhrene. Clonal populations were characterized for ex pression of selected transformation phenoty...

Evaluation of human iPS cells by neural differentiation and tumorigenicity Yohei Okada, M.D., Ph.D.and Hideyuki Okano, M.D., Ph.D. Kanrinmaru Project, School of Medicine, Keio University Department of Physiology, School of Medicine, Keio University (Clin Neurol 2011;51:1079-1080)

The biological functions of the BC047440 gene highly expressed by hepatocellular carcinoma (HCC) are unknown. The objective of this study was to reconstruct antisense eukaryotic expression vectors of the gene for inhibiting HepG2 cell proliferation and suppressing their xenograft tumorigenicity. The full-length BC047440 cDNA was cloned from human primary HCC by RT-PCR. BC047440 gene fragments w...

Rab25 is a newly discovered member of the Rab11 subfamily of the Rab protein family. The purpose of this study was to investigate the proliferation of derivatives of the human breast cancer cell line MCF-7 with different levels of expression of the Rab25 gene and their tumorigenicity in nude mice. The effect of different expression levels of the Rab25 gene on various biological activities of th...

Clonal subpopulations of a chemically induced tumorigenic rat liver epithelial cell line were analyzed for their cellular, biochemi cal, and in vitro growth properties and their tumorigenicity after injection into day-old newborn isogeneic rats. The phenotypic properties studied included DMA content; growth rate in culture; activities of 7-glutamyl transpeptidase, NADH diaphorase, pyruvate kina...