Functional Properties of PPFIA1, Located at the 11q13 Amplification Region, in Epithelial Cancer Cells

Material and Methods: Human iPSC were established from normal lung fibroblast, by transfecting Yamanaka factors and injected into severe combined immunodeficient (SCID) mice.Cells were isolated from each teratomas of different clones by enzyme digestion.Gene expression was examined by RT-PCR.Aging was confirmed by senescence-associated b-galactosidase (SA b-Gal) staining and division potential.Transformation was examined by colony formation in soft agar gel and tumor formation in SCID mouse.Results: Twelve clones of human iPSC from TIG-1 formed human teratomas.Histological analysis showed the existence of glandular epithelium, melanocyte, blood vessel, retinal tissue, cartilage-like tissue, striated muscle, hepatocyte like cells and connected tissue.The isolated cells from the teratoma were cultured in vitro exhibiting various types of cells with distinct morphology.Most of the cells ceased to divide sooner or later.Cell aging was confirmed by SA b-Gal staining.Colonies of clonal growth were isolated for further analysis of differentiated state showing expression of endothelin, CD34 and fibroblast specific protein etc.Interestingly, however, from one iPSC teratoma case, we could isolate big colonies forming in soft agar gel cultures.The isolated colony from the gel grew rapidly and long-term subcultivation was succeeded without senescent phenotypes.Some oncogenes but not iPSC marker genes were expressed in this cell line.Tumorigenic activity in SCID mouse is underway.Conclusions: A transformed cell line was established from human normal cell via its iPSC teratoma, though most of cells from teratoma exhibited cellular aging.