MLL-AF9 and MLL-AF4 oncofusion proteins bind a distinct enhancer repertoire and target the RUNX1 program in 11q23 acute myeloid leukemia.

In 11q23 leukemias, the N-terminal part of the mixed lineage leukemia (MLL) gene is fused to >60 different partner genes. In order to define a core set of MLL rearranged targets, we investigated the genome-wide binding of the MLL-AF9 and MLL-AF4 fusion proteins and associated epigenetic signatures in acute myeloid leukemia (AML) cell lines THP-1 and MV4-11. We uncovered both common as well as specific MLL-AF9 and MLL-AF4 target genes, which were all marked by H3K79me2, H3K27ac and H3K4me3. Apart from promoter binding, we also identified MLL-AF9 and MLL-AF4 binding at specific subsets of non-overlapping active distal regulatory elements. Despite this differential enhancer binding, MLL-AF9 and MLL-AF4 still direct a common gene program, which represents part of the RUNX1 gene program and constitutes of CD34+ and monocyte-specific genes. Comparing these data sets identified several zinc finger transcription factors (TFs) as potential MLL-AF9 co-regulators. Together, these results suggest that MLL fusions collaborate with specific subsets of TFs to deregulate the RUNX1 gene program in 11q23 AMLs.

The oncofusion protein FUS-ERG targets key hematopoietic regulators and modulates the all-trans retinoic acid signaling pathway in t(16;21) acute myeloid leukemia.

The ETS transcription factor ERG has been implicated as a major regulator of both normal and aberrant hematopoiesis. In acute myeloid leukemias harboring t(16;21), ERG function is deregulated due to a fusion with FUS/TLS resulting in the expression of a FUS-ERG oncofusion protein. How this oncofusion protein deregulates the normal ERG transcription program is unclear. Here, we show that FUS-ERG acts in the context of a heptad of proteins (ERG, FLI1, GATA2, LYL1, LMO2, RUNX1 and TAL1) central to proper expression of genes involved in maintaining a stem cell hematopoietic phenotype. Moreover, in t(16;21) FUS-ERG co-occupies genomic regions bound by the nuclear receptor heterodimer RXR:RARA inhibiting target gene expression and interfering with hematopoietic differentiation. All-trans retinoic acid treatment of t(16;21) cells as well as FUS-ERG knockdown alleviate the myeloid-differentiation block. Together, the results suggest that FUS-ERG acts as a transcriptional repressor of the retinoic acid signaling pathway.

Genome-wide binding of transcription factors in inv(16) acute myeloid leukemia.

The inv(16) translocation is associated with 5% of AML cases and gives rise to expression of the oncofusion protein CBFß-MYH11. Although different molecular mechanisms for the oncogenic activity of this fusion protein have been proposed these were mostly based on in vitro experiments or single loci analysis. Recently, we investigated the genome-wide action of this fusion protein in the context of other hematopoietic transcription factors (Mandoli et al., 2014). Here, we describe in detail the ChIP-seq and RNA-seq methods used to generate the data associated with this study. Our analysis of CBFß-MYH11 as well as multiple other hematopoietic transcription factors using ChIP-seq data revealed RUNX1 dependent binding of CBFß-MYH11 as well as interaction of the RUNX1/CBFß-MYH11 complex with other hematopoietic regulators. Further RNA-seq based analysis suggested that CBFß-MYH11 can act both as activator and repressor.

CBFB-MYH11/RUNX1 together with a compendium of hematopoietic regulators, chromatin modifiers and basal transcription factors occupies self-renewal genes in inv(16) acute myeloid leukemia.

Different mechanisms for CBFß-MYH11 function in acute myeloid leukemia with inv(16) have been proposed such as tethering of RUNX1 outside the nucleus, interference with transcription factor complex assembly and recruitment of histone deacetylases, all resulting in transcriptional repression of RUNX1 target genes. Here, through genome-wide CBFß-MYH11-binding site analysis and quantitative interaction proteomics, we found that CBFß-MYH11 localizes to RUNX1 occupied promoters, where it interacts with TAL1, FLI1 and TBP-associated factors (TAFs) in the context of the hematopoietic transcription factors ERG, GATA2 and PU.1/SPI1 and the coregulators EP300 and HDAC1. Transcriptional analysis revealed that upon fusion protein knockdown, a small subset of the CBFß-MYH11 target genes show increased expression, confirming a role in transcriptional repression. However, the majority of CBFß-MYH11 target genes, including genes implicated in hematopoietic stem cell self-renewal such as ID1, LMO1 and JAG1, are actively transcribed and repressed upon fusion protein knockdown. Together these results suggest an essential role for CBFß-MYH11 in regulating the expression of genes involved in maintaining a stem cell phenotype.

Cranio-cervical necrotizing fascitiis: case report and review of the literature.

Necrotising fascitiis is a rapidly progressive bacterial infection of the soft tissues and generally attacks the walls of the abdomen, the perineum, the limbs or, to a lesser degree, the cranio-cervical area. In the latter region, the infection involves the soft tissues of the neck, in a more or less extensive manner, and causes diffuse necrosis. Crepitation, areas with linear infiltration and others with fluctuation are detected on manual examination. Systemic symptoms such as fever, tachycardia, tachypnoea and signs of septic shock are always present, at least during the more advanced stages of the disease. Computed tomography may prove fundamental since it reveals an increase in the thickness and degree of impregnation of the cervical soft tissues, as well as the presence of liquid or gaseous infiltration in the thoracic areas, especially in cases of mediastinitis. Personal experience in a case is described which led to a review of the literature. The best approach in the management of this devastating condition is early diagnosis, adequate antibiotic treatment and radical surgical procedures, which may often need to be repeated several times.

Evaluation of Serratia peptidase in acute or chronic inflammation of otorhinolaryngology pathology: a multicentre, double-blind, randomized trial versus placebo.

The efficacy and tolerability of Serratia peptidase were evaluated in a multicentre, double-blind, placebo-controlled study of 193 subjects suffering from acute or chronic ear, nose or throat disorders. Treatment lasted 7-8 days, with the drug or placebo being administered at a rate of two tablets three times a day. After 3-4 days' treatment, significant symptom regression was observed in peptidase-treated patients. There was also a significant reduction in symptoms after 7-8 days for patients in both treatment groups but the response was more marked in those patients receiving the active drug. Statistical comparison between the two groups confirmed the greater efficacy and rapid action of the peptidase against all the symptoms examined at both stages. Tolerance was found to be very good and similar for both groups. It is concluded that Serratia peptidase has anti-inflammatory, anti-oedemic and fibrinolytic activity and acts rapidly on localized inflammation.