title: microRNAs regulate human embryonic stem cell division.
abstract: microRNAs (miRNAs) regulate numerous physiological processes such as cell division and differentiation in many tissue types including stem cells. To probe the role that miRNAs play in regulating processes relevant to embryonic stem cell biology, we used RNA interference to silence DICER and DROSHA, the two main miRNA processing enzymes. Consistent with a role for miRNAs in maintaining normal stem cell division and renewal, we found that perturbation of miRNA pathway function in human embryonic stem cells (hESCs) attenuates cell proliferation. Normal cell growth can be partially restored by introduction of the mature miRNAs miR-195 and miR-372. These miRNAs regulate two tumor suppressor genes, respectively: WEE1, which encodes a negative G2/M kinase modulator of the CycB/CDK complex and CDKN1A, which encodes p21, a CycE/CDK cyclin dependent kinase inhibitor that regulates the G1/S transition. We show that in wild-type hESCs, WEE 1 levels control the rate of hESC division, whereas p21 levels must be maintained at a low level for hESC division to proceed. These data support a model for hESC cell cycle control in which miRNAs regulate negative cell cycle modulators at two phases of the cell cycle to ensure proper replenishment of the stem cell population.
authors.affiliation: Department of Biochemistry and Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.
authors.forename: Junlin
authors.initials: J
authors.lastname: Qi
authors.forename: Jenn-Yah
authors.initials: JY
authors.lastname: Yu
authors.forename: Halyna R
authors.initials: HR
authors.lastname: Shcherbata
authors.forename: Julie
authors.initials: J
authors.lastname: Mathieu
authors.forename: Amy Jia
authors.initials: AJ
authors.lastname: Wang
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Seal
authors.forename: Wenyu
authors.initials: W
authors.lastname: Zhou
authors.forename: Bradford M
authors.initials: BM
authors.lastname: Stadler
authors.forename: David
authors.initials: D
authors.lastname: Bourgin
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.forename: Angel
authors.initials: A
authors.lastname: Nelson
authors.forename: Carol
authors.initials: C
authors.lastname: Ware
authors.forename: Christopher
authors.initials: C
authors.lastname: Raymond
authors.forename: Lee P
authors.initials: LP
authors.lastname: Lim
authors.forename: Jill
authors.initials: J
authors.lastname: Magnus
authors.forename: Irena
authors.initials: I
authors.lastname: Ivanovska
authors.forename: Robert
authors.initials: R
authors.lastname: Diaz
authors.forename: Alexey
authors.initials: A
authors.lastname: Ball
authors.forename: Michele A
authors.initials: MA
authors.lastname: Cleary
authors.forename: Hannele
authors.initials: H
authors.lastname: Ruohola-Baker
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D046228:Microarray Analysis; D008954:Models, Biological; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009841:Oligonucleotides / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D034622:RNA Interference; D043244:Ribonuclease III / Q000235:genetics
chemical_list: C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D035683:MicroRNAs; D009687:Nuclear Proteins; D009841:Oligonucleotides; D011505:Protein-Tyrosine Kinases; C499349:WEE1 protein, human; C517918:DROSHA protein, human; D043244:Ribonuclease III