Open AccessMicroRNA 92b Controls the G1/S Checkpoint Gene p57 in Human Embryonic Stem Cells
Author(s) -
Sengupta Srikumar,
Nie Jeff,
Wagner Ryan J.,
Yang Chuhu,
Stewart Ron,
Thomson James A.
Publication year - 2009
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1002/stem.84
Subject(s) - biology , embryonic stem cell , microrna , stem cell , cell cycle , microbiology and biotechnology , reporter gene , gene , transfection , somatic cell , gene expression , genetics
Human embryonic stem (ES) cells exhibit a shorter G 1 cell cycle phase than most somatic cells. Here, we examine the role of an abundant, human ES cell‐enriched microRNA, miR‐92b, in cell cycle distribution. Inhibition of miR‐92b in human ES cells results in a greater number of cells in the G 1 phase and a lower number in the S phase. Conversely, overexpression of miR‐92b in differentiated cells results in a decreased number of cells in G1 phase and an increased number in S‐phase. p57 , a gene whose product inhibits G 1 to S‐phase progression, is one of the predicted targets of miR‐92b. Inhibition of miR‐92b in human ES cells increases p57 protein levels, and miR‐92b overexpression in differentiated cells decreases p57 protein levels. Furthermore, miR‐92b inhibits a luciferase reporter construct that includes part of the 3′ untranslated region of the p57 gene containing the predicted target of the miR‐92b seed sequence. Thus, we show that the miRNA miR‐92b directly downregulates protein levels of the G 1 /S checkpoint gene p57 . STEM CELLS 2009;27:1524–1528