RNA sequencing expression analysis of murine MLL-AF9;NRAS acute myeloid leukemia cells silenced for E2-2.

We investigated the role of the transcriptional regulators Id2 and E2-2 (encoded by Tcf4) in the context of MLL-rearranged acute myeloid leukemia (AML). Using an AML mouse model driven by a Tet-off inducible MLL-AF9 allele co-expressed with oncogenic NRASG12D, we demonstrated that MLL-AF9 regulates the E protein pathway by suppressing Id2, while activating the expression of its target E2-2. Moreover, we found that Id2 over-expression in MLL-AF9 AML cells results inhibition of leukemia growth, loss of leukemia stem cell-associated gene expression pattern and induction of differentiation. E2-2 silencing phenocopies Id2 overexpression in MLL-AF9-AML cells. To study the gene expression changes associated with E2-2 depletion in the context of MLL-rearranged AML, RNA sequencing analysis was performed on MLL-AF9;NRAS AML cells transduced with vectors expressing hairpins against E2-2 (shTcf4#654 and shTcf4#3646) or a control hairpin against Renilla luciferase (shRen). Overall design: Primary AMLs driven by MLL/AF9 expression linked to cherry reporter, in association with oncogenic NRASG12D (MLL/AF9;NRAS) were generated by reconstituting lethally irradiated congenic mice with fetal liver cells co-transduced with the MSCV-MLL/AF9-IRES-cherry retroviral vector and a second vector co-expressing NRASG12D together with luciferase (MSCV-luciferase-IRES-NRASG12D). RNA sequencing analysis sequencing analysis was performed on MLL-AF9;NRAS AML cells transduced in vitro with vectors expressing hairpins against E2-2 (shTcf4#654 and shTcf4#3646) or a control hairpin against Renilla luciferase (shRen) linked to the reporter GFP. Viable GFP-positive cells were FACS-sorted 2 days after transduction and used for RNA sequencing analysis. Two independent biological replicates of the experiment were used for the RNA sequencing (9-5-14 and 14-4-14).

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Ghisi M, Kats L, Masson F, Li J, Kratina T, Vidacs E, Gilan O, Doyle MA, Newbold A, Bolden JE, Fairfax KA, de Graaf CA, Firth M, Zuber J, Dickins RA, Corcoran LM, Dawson MA, Belz GT, Johnstone RW