AF4 and AF4-MLL mediate transcriptional elongation of 5-lipoxygenase mRNA by 1, 25-dihydroxyvitamin D3.

The human 5-lipoxygenase (5-LO), encoded by the ALOX5 gene, is the key enzyme in the formation of pro-inflammatory leukotrienes. ALOX5 gene transcription is strongly stimulated by calcitriol (1α, 25-dihydroxyvitamin D3) and TGFβ (transforming growth factor-β). Here, we investigated the influence of MLL (activator of transcript initiation), AF4 (activator of transcriptional elongation) as well as of the leukemogenic fusion proteins MLL-AF4 (ectopic activator of transcript initiation) and AF4-MLL (ectopic activator of transcriptional elongation) on calcitriol/TGFβ-dependent 5-LO transcript elongation.

AF4 and AF4N protein complexes: recruitment of P-TEFb kinase, their interactome and potential functions.

AF4/AFF1 and AF5/AFF4 are the molecular backbone to assemble "super-elongation complexes" (SECs) that have two main functions: (1) control of transcriptional elongation by recruiting the positive transcription elongation factor b (P-TEFb = CyclinT1/CDK9) that is usually stored in inhibitory 7SK RNPs; (2) binding of different histone methyltransferases, like DOT1L, NSD1 and CARM1. This way, transcribed genes obtain specific histone signatures (e.g.

From a multipotent stilbene to soluble epoxide hydrolase inhibitors with antiproliferative properties.

Inspired by nature: Natural product isopropylstilbene was identified as an inhibitor of soluble epoxide hydrolase exhibiting antiproliferative properties. Following the natural product inspired design approach, a library of (E)-styryl-1H-benzo[d]imidazoles was synthesized and evaluated with recombinant enzyme and on several cancer cell lines.

Functional analysis of the two reciprocal fusion genes MLL-NEBL and NEBL-MLL reveal their oncogenic potential.

MLL gene aberrations are frequently diagnosed in infant acute myeloid leukemia (AML). We previously described the MLL-NEBL and NEBL-MLL genomic fusions in an infant AML patient with a chromosomal translocation t(10;11)(p12;q23). NEBL was the second Nebulin family member (LASP1, NEBL) which was found to be involved in MLL rearrangements.

Epigenetics and blood disorders.

The last three decades of cancer research were guided by the hypothesis that cancer cells evolve due to the accumulation of many genetic aberrations over time. While this is still true for most solid cancers, it might be different in haemato-malignant diseases, which are mostly characterized by chromosomal translocations that exhibit only few additional mutations. Some of the resulting fusion gene products functionally interfer with epigenetic mechanisms.