Stable Oct 4 expression in adult foreskin cells without additional cytokines in vitro

[jim3405]

Stable Oct 4 expression in adult foreskin cells without additional cytokines in vitro
The transcription factor Oct 4 is required for the maintenance of stem cells pluripotency and self-renewal, and activity of Oct 4 is essential for the identity of the pluripotential founder cell population in the mammalian. Recently we found that the cells from adult foreskin subcutaneous tissue stably expressed Oct 4 under the condition of no additional cytokines in the medium and feeder cells. Isolated foreskin cells were stably passaged and expressed stem cell marker Oct 4, Nanog, Rex 1, Nestin and Sox 2 by RT-PCR analysis. Meanwhile Oct 4 expression in foreskin cells was validated by immunofluorescence and western blotting assay. When passage12, Oct 4-positive foreskin cells were 94 % by flow cytometer analysis. After green fluorescent protein regulated by the Oct 4 promoters was introduced into foreskin cells, adult foreskin cells activated Oct 4 promoter to express green fluorescent protein. Under the condition of the culture medium containing 15 % fetal bovine serum, 10-5 M RA did not downregulate Oct 4 expression directly. But 10-5 M RA in the serum-free medium downregulated Oct 4 expression and upregulated ectodermal marker Neuro D expression under the same circumstance. Activin A in serum-free medium also downregulated Oct 4 expression and induce foreskin cells into endodermal differentiation, as detected by the expression of endoderm marker Sox 17. Foreskin cells stably express Oct 4 and other stem cell markers and have the characteristics of stem cell, so foreskin cells as a Oct 4 expression model are studied on relationship of Oct 4 and other stem cell markers, also as a novel stem cell source are used to human regenerative medicine in the future.