Musashi2 is required for the self-renewal and pluripotency of embryonic stem cells

Recent studies have shown that the RNA binding protein Musashi 2 (Msi2) plays prominent roles during development and leukemia. Additionally, in embryonic stem cells (ESC) undergoing the early stages of differentiation, Msi2 has been shown to associate with Sox2, which is required for the self-renewal of ESC. These findings led us to examine the effects of Msi2 on the behavior of ESC. Using an shRNA sequence that targets Msi2 and a scrambled shRNA sequence, we determined that knockdown of Msi2 disrupts the self-renewal of ESC and promotes their differentiation. Collectively, our findings argue that Msi2 is required to support the self-renewal and pluripotency of ESC. We used microarrays to better understand global changes in ESC gene expression following the knockdown of the RNA-binding protein Msi2 as compared to control ESC expressing a scrambled shRNA. Mouse embryonic stem cells (D3) were treated with lentivirus engineered for the expression of a Msi2 targeting shRNA sequence or scrambled (control) shRNA sequence. Following selection for infected cells with puromycin, cells were subcultured at low density and allowed to grow for 4 days (see treatment protocol) before RNA was extracted. RNA was collected and analyzed one time for each of the two samples.