title: Teratoma formation by human embryonic stem cells is site dependent and enhanced by the presence of Matrigel.
abstract: When implanted into immunodeficient mice, human embryonic stem cells (hESCs) give rise to teratoma, tumor-like formations containing tissues belonging to all three germ layers. The ability to form teratoma is a sine qua non characteristic of pluripotent stem cells. However, limited data are available regarding the effects of implantation site and the methods employed for implantation on the success rate of teratoma formation. In this study, the rate of teratoma formation in immunodeficient mice was site dependent: subcutaneous (25-100%), intratesticular (60%), intramuscular (12.5%), and under the kidney capsule (100%). Co-injecting the hESCs with Matrigel increased subcutaneous teratoma formation efficiency from 25-40% to 80-100%. We did not observe site-specific differences in the teratoma composition at the histological level. However, subcutaneous teratomas were quite distinct, easy to remove, and caused minimal discomfort to the mice. Also, subcutaneous teratomas displayed larger proportion of solid tissues as opposed to cyst formation that dominated the teratomas formed at the other sites. Interestingly, a chromosomally abnormal hESCs with trisomy 20 formed teratomas where the ratio of differentiated to undifferentiated tissues was significantly decreased suggesting defective pluripotency of the cells. In conclusion, subcutaneous implantation of hESCs in presence of Matrigel appears to be the most efficient, reproducible, and the easiest approach for teratoma formation by hESCs. Also, teratoma formation can be employed to study the development defects exhibited by the chromosomally abnormal hESC lines.
authors.affiliation: Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology and Metabolism, University Hospital of Odense and Medical Biotechnology Center, University of Southern Denmark, Winsløwparken, Odense, Denmark. tprokhorova@health.sdu.dk
authors.forename: Tatyana A
authors.initials: TA
authors.lastname: Prokhorova
authors.forename: Linda M
authors.initials: LM
authors.lastname: Harkness
authors.forename: Ulrik
authors.initials: U
authors.lastname: Frandsen
authors.forename: Nicholas
authors.initials: N
authors.lastname: Ditzel
authors.forename: Henrik D
authors.initials: HD
authors.lastname: Schrøder
authors.forename: Jorge S
authors.initials: JS
authors.lastname: Burns
authors.forename: Moustapha
authors.initials: M
authors.lastname: Kassem
mesh_terms: D000818:Animals; D017690:Cell Transplantation; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D004338:Drug Combinations; D053595:Embryonic Stem Cells / Q000473:pathology / Q000502:physiology; D006801:Humans; D007797:Laminin / Q000378:metabolism*; D051379:Mice; D016688:Mice, Inbred NOD; D039904:Pluripotent Stem Cells / Q000473:pathology / Q000502:physiology; D011509:Proteoglycans / Q000378:metabolism*; D013724:Teratoma / Q000209:etiology / Q000473:pathology
chemical_list: D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen