Fig. 4. Regulatory element E9 is active in MLL-ENL leukemic cells.

A). MLL-ENL-ER cells were cultured with 4-HT (MLL-ENL induced), or without 4-HT for 72 hours (no MLL-ENL). The expression of MEIS1 was detected by real-time PCR.
(B–D). Enriched histone marks at E9 correlated with active Meis1 expression in acute myeloid leukemic cells. Crosslinked chromatin was immunoprecipitated with antibodies against H3K4me1 (B), H3K27ac (C) and H3K4me3 (D) in the MLL-ENL fusion cell line before and after adding 4HT. The precipitated DNA was amplified using primers spanning the Meis1 promoter (mP1, mP2) and the enhancer E9 region (mE9-1, mE9-2, mE9-3, mE9-4) using qPCR. Data are shown as fold change of precipitated DNA versus input DNA. Each experiment was repeated at least three times.