title: Brief report: evaluating the potential of putative pluripotent cells derived from human testis.
abstract: Human adult germline stem cells (haGSCs) were established from human testicular biopsies and were claimed to be pluripotent. Recently, the gene expression profile of haGSCs demonstrated that these cells presented with a fibroblast rather than a pluripotent identity. Nevertheless, haGSCs were reported to generate teratomas. In this report, we address this discrepancy. Instead of using haGSCs, which are no longer available for the stem cell community, we used a human testicular fibroblastic cell (hTFC) line that presents with a gene expression profile highly similar to that of haGSCs. Indeed, as shown by microarray analysis, the similarity between hTFCs and haGSCs is comparable to human embryonic stem cell (hESC) lines derived by different laboratories. We argue that the almost identical gene expression profile of hTFCs and haGSCs should result in a very similar if not identical differentiation potential. Strikingly, hTFCs were not able to generate teratomas after injection into nude mice. Instead, they formed a mesenchymal lesion that morphologically resembled the putative haGSC-derived teratomas reported previously. We conclude that haGSCs, which exhibit a profile similar to that of fibroblasts and could not generate teratomas, are not pluripotent. Future work will have to show if pluripotent cells can be derived from human testicular biopsies. Mouse work and certain testicular germ cell tumors indicate that this will be possible.
authors.affiliation: Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.
authors.forename: Kinarm
authors.initials: K
authors.lastname: Ko
authors.forename: Peter
authors.initials: P
authors.lastname: Reinhardt
authors.forename: Natalia
authors.initials: N
authors.lastname: Tapia
authors.forename: Rebekka K
authors.initials: RK
authors.lastname: Schneider
authors.forename: Marcos J
authors.initials: MJ
authors.lastname: Araúzo-Bravo
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Han
authors.forename: Boris
authors.initials: B
authors.lastname: Greber
authors.forename: Julee
authors.initials: J
authors.lastname: Kim
authors.forename: Sabine
authors.initials: S
authors.lastname: Kliesch
authors.forename: Martin
authors.initials: M
authors.lastname: Zenke
authors.forename: Hans R
authors.initials: HR
authors.lastname: Schöler
mesh_terms: D003114:Colony-Forming Units Assay; D005347:Fibroblasts / Q000166:cytology* / Q000502:physiology; D020869:Gene Expression Profiling; D016259:Genes, myc; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics; D008297:Male; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D055748:SOXB1 Transcription Factors / Q000235:genetics; D013724:Teratoma / Q000473:pathology; D013737:Testis / Q000166:cytology*; D019076:Transgenes
chemical_list: D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors