Induction of pluripotent stem cells from adult human fibroblasts by defined factors.
Level 5 - mechanism / opinion, no new human data
Bench in vitro cell culture and animal teratoma assay without clinical human subjects.
PubMed 18035408 · doi:10.1016/j.cell.2007.11.019
What was done
Adult human dermal fibroblasts were transduced with four defined transcription factors (Oct3/4, Sox2, Klf4, and c-Myc) to induce pluripotency. The resulting human induced pluripotent stem (iPS) cells were evaluated for stem cell properties, including morphology, proliferation, surface antigens, gene expression profiles, epigenetic status of pluripotent cell-specific genes, telomerase activity, and differentiation potential into cell types of all three germ layers in vitro and in teratomas.
What was found
The abstract reports no numerical data, reprogramming efficiency rates, or sample counts. Qualitatively, it reports that human iPS cells were similar to human embryonic stem cells in morphology, proliferation, surface antigens, gene expression, epigenetic status of pluripotent cell-specific genes, and telomerase activity, and that the cells successfully differentiated into cell types of the three germ layers in vitro and in teratomas.
Why it matters
This study demonstrates that adult human somatic cells can be reprogrammed into pluripotent stem cells using four defined transcription factors. This approach provides a foundation for generating patient- and disease-specific pluripotent stem cells without requiring human embryos.
Limits
The abstract does not provide sample size (n), quantitative reprogramming efficiencies, or failure rates. As a laboratory cell culture and teratoma model, the findings do not measure long-term genomic stability, clinical safety, or vector integration risks.
Cited by
- supports Shinya Yamanaka demonstrated that introducing specific transcription factors (Yamanaka factors) into somatic cells such as fibroblasts can revert them into induced pluripotent stem cells.