Generation of Remosomes by the SWI/SNF Chromatin Remodeler Family.

Chromatin remodelers are complexes able to both alter histone-DNA interactions and to mobilize nucleosomes. The mechanism of their action and the conformation of remodeled nucleosomes remain a matter of debates. In this work we compared the type and structure of the products of nucleosome remodeling by SWI/SNF and ACF complexes using high-resolution microscopy combined with novel biochemical approaches.

FACT Assists Base Excision Repair by Boosting the Remodeling Activity of RSC.

FACT, in addition to its role in transcription, is likely implicated in both transcription-coupled nucleotide excision repair and DNA double strand break repair. Here, we present evidence that FACT could be directly involved in Base Excision Repair and elucidate the chromatin remodeling mechanisms of FACT during BER. We found that, upon oxidative stress, FACT is released from transcription related protein complexes to get associated with repair proteins and chromatin remodelers from the SWI/SNF family.

Global analysis of DNA methylation and transcription of human repetitive sequences.

Half of the human genome consists of repetitive DNA sequences. Recent studies in various organisms highlight the role of chromatin regulation of repetitive DNA in gene regulation as well as in maintainance of chromosomes and genome integrity. Hence, repetitive DNA sequences might be potential "sensors" for chromatin changes associated with pathogenesis.

Changes in the expression of telomere maintenance genes suggest global telomere dysfunction in B-chronic lymphocytic leukemia.

In this study, we explored the telomeric changes that occur in B-chronic lymphocytic leukemia (B-CLL), in which telomere length has recently been demonstrated to be a powerful prognostic marker. We carried out a transcriptomic analysis of telomerase components (hTERT and DYSKERIN), shelterin proteins (TRF1, TRF2, hRAP1, TIN2, POT1, and TPP1), and a set of multifunctional proteins involved in telomere maintenance (hEST1A, MRE11, RAD50, Ku80, and RPA1) in peripheral B cells from 42 B-CLL patients and 20 healthy donors. We found that, in B-CLL cells, the expressions of hTERT, DYSKERIN, TRF1, hRAP1, POT1, hEST1A, MRE11, RAD50, and KU80 were more than 2-fold reduced (P < .

Analysis of VH genes in marginal zone lymphoma reveals marked heterogeneity between splenic and nodal tumors and suggests the existence of clonal selection.

Background And Objectives: To clarify the relationship between splenic (SMZL) and nodal marginal zone (NMZL) lymphomas, we analyzed immunoglobulin variable heavy chain (VH) gene usage and mutation patterns in these tumors.

Design And Methods: VH genes were cloned and sequenced from 49 lymphoma samples (35 SMZL and 14 NMZL).

Results: A biased usage of VH gene was found with overrepresentation of VH1 in SMZL cases (13/35) and VH4 in NMZL cases (7/14).

Human corticotropin-releasing factor type 1 receptor analysis with white blood cells mRNAs and DNA.

The human corticotropin-releasing factor receptor type 1 (hCRF-R1) functional transcript is mainly expressed in the anterior pituitary corticotrophs, a tissue usually not available for clinical investigation. Splice variants translated into defective isoforms of the receptor have been described in few peripheral tissues. The aim of this work was to determine whether peripheral white blood cells from healthy individuals, an accessible tissue for clinical investigation, were suitable for the analysis of the hCRF-R1 transcript and gene.