All silenced cells generated tumors when injected in immunosuppressed mice, but silencing of Oct4, Sox2 and Klf4 generated mainly teratomas with mesoderm tissue.
Transient expression of the transcription factors OCT4, SOX2, KLF4, and C-MYC (OSKM) to induce partial reprogramming while avoiding the pluripotent state and teratoma formation has recently been discussed as a strategy for regenerating damaged tissues in vivo, whereby the impact of partial reprogramming on tissue repair remains to be elucidated.
Here, we show that mid-trimester AFSC cultured under MSC conditions contained a subset of cells endogenously expressing telomerase, CD24, OCT4, C-MYC, and SSEA4, but low/null levels of SOX2, NANOG, KLF4, SSEA3, TRA-1-60, and TRA-1-81, with cells unable to form embryoid bodies (EBs) or teratomas.