Dissecting self-renewal in stem cells with RNA interference

Abstract

We present an integrated approach to identify genetic mechanisms that control self-renewal in mouse embryonic stem cells. We use short hairpin RNA (shRNA) loss-of-function techniques to downregulate a set of gene products whose expression patterns suggest self-renewal regulatory functions. We focus on transcriptional regulators and identify seven genes for which shRNA-mediated depletion negatively affects self-renewal, including four genes with previously unrecognized roles in self-renewal. Perturbations of these gene products are combined with dynamic, global analyses of gene expression. Our studies suggest specific biological roles for these molecules and reveal the complexity of cell fate regulation in embryonic stem cells.

Combined effects of the two reciprocal t(4;11) fusion proteins MLL·AF4 and AF4·MLL confer resistance to apoptosis, cell cycling capacity and growth transformation

“…Nanog -in combination with Oct4 and Sox2 -initiates a genetic program that allows embryonic stem cells to self-renew and to block differentiation processes (Ivanova et al, 2006). Recently, this 'core Nanog network' has been unraveled (Boyer et al, 2005).…”

Evidence‐Based Theory for Integrated Genome Regulation of Ontogeny—An Unprecedented Role of Nuclear FGFR1 Signaling

“…(B) The pluripotent gene network is based on Chen et al (2008) (Ivanova et al, 2006). nFGFR1 binding to gene promoters is marked by blue and black arrows.…”

TCL1 promotes blastomere proliferation through nuclear transfer, but not direct phosphorylation, of AKT/PKB in early mouse embryos

“…In ES, in fact, TCL1 is directly activated by Oct3/4 2 and is among the very few genes that are required for the mitotic self-renewal state, and the downregulation of which triggers ES differentiation. 3 The expression of TCL1 was also characterized during preimplantation embryo development, namely in the cells from which ES are derived, where it was found to shuttle between blastomere cortical regions and the nucleus by a cell cycle-dependent fashion and to be required for early blastomere proliferation, but not the acquisition of first embryonal differentiation traits. 4 TCL1 promotes cell proliferation by heterodimerization with AKT/ PKB, a serine/threonine kinase having a central role in the signaling pathways controlling cell proliferation and survival, and mediates both the transphosphorylation of AKT at the Ser472/473 residue 5 and the transfer of phosphorylated AKT to the nucleus.…”

“…1,2 It leads to the initiation of a stress response known as the unfolded protein response, whose initial goal is to resolve the ensuing stress; however, when unable to do so, it induces cell death. 3,4 ER stress-induced cell death has been shown to proceed primarily through apoptosis. It remained unclear whether ER stress is also associated with other forms of cell death.…”