title: Establishment of immortalized human amniotic mesenchymal stem cells.
abstract: Human amniotic mesenchymal cells (HAM cells) are known to contain somatic stem cells possessing the characteristics of pluripotency. However, little is known about the biology of these somatic cells because isolated HAM cells from amniotic membrane have a limited lifespan. To overcome  this problem, we attempted to prolong the lifespan of HAM cells by infecting retrovirus encoding human papillomavirus type16E6 and E7 (HPV16E6E7), bmi-1, and/or human telomerase reverse transcriptase (hTERT) genes and investigated their characteristics as stem cells. We confirmed the immortalization  of the four lines of cultured HAM cells for about 1 year. Immortalized human amnion mesenchymal cells (iHAM cells) have continued to proliferate over 200 population doublings (PDs). iHAM cells were positive for CD73, CD90, CD105, and CD44 and negative for CD34, CD14, CD45, and HLA-DR. They  expressed stem cell markers such as Oct3/4, Sox2, Nanog, Klf4, SSEA4, c-myc, vimentin, and nestin. They showed adipogenic, osteogenic, and chondrogenic differentiation abilities after induction. These results suggested that immortalized cell lines with characteristics of stem cells can be  established. iHAM cells with an extended lifespan can be used to produce good experimental models both in vitro and in vivo.
authors.affiliation: Department of Regenerative Medicine, University of Toyama, Graduate School of Medicine and Pharmaceutical Sciences, Toyama 930-0194, Japan.
authors.forename: Zan
authors.initials: Z
authors.lastname: Teng
authors.forename: Toshiko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Motonori
authors.initials: M
authors.lastname: Okabe
authors.forename: Ayaka
authors.initials: A
authors.lastname: Toda
authors.forename: Osamu
authors.initials: O
authors.lastname: Higuchi
authors.forename: Makiko
authors.initials: M
authors.lastname: Nogami
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoneda
authors.forename: Kaixuan
authors.initials: K
authors.lastname: Zhou
authors.forename: Satoru
authors.initials: S
authors.lastname: Kyo
authors.forename: Touru
authors.initials: T
authors.lastname: Kiyono
authors.forename: Toshio
authors.initials: T
authors.lastname: Nikaido
mesh_terms: D000650:Amnion / Q000166:cytology*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D002460:Cell Line; D003584:Cytological Techniques / Q000379:methods*; D006801:Humans; D000090062:Kruppel-Like Factor 4; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008819:Mice, Nude; D039904:Pluripotent Stem Cells / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology*