Refinement of 1p36 Alterations Not Involving PRDM16 in Myeloid and Lymphoid Malignancies

Fluorescence in situ hybridization was performed to characterize 81 cases of myeloid and lymphoid malignancies with cytogenetic 1p36 alterations not affecting the PRDM16 locus. In total, three subgroups were identified: balanced translocations (N = 27) and telomeric rearrangements (N = 15), both mainly observed in myeloid disorders; and unbalanced non-telomeric rearrangements (N = 39), mainly observed in lymphoid proliferations and frequently associated with a highly complex karyotype. The 1p36 rearrangement was isolated in 12 cases, mainly myeloid disorders. The breakpoints on 1p36 were more widely distributed than previously reported, but with identifiable rare breakpoint cluster regions, such as the TP73 locus. We also found novel partner loci on 1p36 for the known multi-partner genes HMGA2 and RUNX1. We precised the common terminal 1p36 deletion, which has been suggested to have an adverse prognosis, in B-cell lymphomas [follicular lymphomas and diffuse large B-cell lymphomas with t(14;18)(q32;q21) as well as follicular lymphomas without t(14;18)]. Intrachromosomal telomeric repetitive sequences were detected in at least half the cases of telomeric rearrangements. It is unclear how the latter rearrangements occurred and whether they represent oncogenic events or result from chromosomal instability during oncogenesis

A Comprehensive Microarray-Based DNA Methylation Study of 367 Hematological Neoplasms

Background: Alterations in the DNA methylation pattern are a hallmark of leukemias and lymphomas. However, most epigenetic studies in hematologic neoplasms (HNs) have focused either on the analysis of few candidate genes or many genes and few HN entities, and comprehensive studies are required. Methodology/Principal Findings: Here, we report for the first time a microarray-based DNA methylation study of 767 genes in 367 HNs diagnosed with 16 of the most representative B-cell (n = 203), T-cell (n = 30), and myeloid (n = 134) neoplasias, as well as 37 samples from different cell types of the hematopoietic system. Using appropriate controls of B-, T-, or myeloid cellular origin, we identified a total of 220 genes hypermethylated in at least one HN entity. In general, promoter hypermethylation was more frequent in lymphoid malignancies than in myeloid malignancies, being germinal center mature B-cell lymphomas as well as B and T precursor lymphoid neoplasias those entities with highest frequency of gene-associated DNA hypermethylation. We also observed a significant correlation between the number of hypermethylated and hypomethylated genes in several mature B-cell neoplasias, but not in precursor B- and T-cell leukemias. Most of the genes becoming hypermethylated contained promoters with high CpG content, and a significant fraction of them are targets of the polycomb repressor complex. Interestingly, T-cell prolymphocytic leukemias show low levels of DNA hypermethylation and a comparatively large number of hypomethylated genes, many of them showing an increased gene expression. Conclusions/Significance: We have characterized the DNA methylation profile of a wide range of different HNs entities. As well as identifying genes showing aberrant DNA methylation in certain HN subtypes, we also detected six genes DBC1, DIO3, FZD9, HS3ST2, MOS, and MYOD1 that were significantly hypermethylated in B-cell, T-cell, and myeloid malignancies. These might therefore play an important role in the development of different HNs

Chronic neutrophilic leukemia: a clinical perspective

Juliane Menezes, Juan Cruz Cigudosa Molecular Cytogenetics Group, Human Cancer Genetics Program, Spanish National Cancer Research Centre – CNIO, Madrid, SpainAbstract: Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm (MPN) that includes only 150 patients described to date meeting the latest World Health Organization (WHO) criteria and the recently reported CSF3R mutations. The diagnosis is based on morphological criteria of granulocytic cells and the exclusion of genetic drivers that are known to occur in others MPNs, such as BCR-ABL1, PDGFRA/B, or FGFR1 rearrangements. However, this scenario changed with the identification of oncogenic mutations in the CSF3R gene in approximately 83% of WHO-defined and no monoclonal gammopathy-associated CNL patients. CSF3R T618I is a highly specific molecular marker for CNL that is sensitive to inhibition in vitro and in vivo by currently approved protein kinase inhibitors. In addition to CSF3R mutations, other genetic alterations have been found, notably mutations in SETBP1, which may be used as prognostic markers to guide therapeutic decisions. These findings will help to understand the pathogenesis of CNL and greatly impact the clinical management of this disease. In this review, we discuss the new genetic alterations recently found in CNL and the clinical perspectives in its diagnosis and treatment. Fortunately, since the diagnosis of CNL is not based on exclusion anymore, the molecular characterization of the CSF3R gene must be included in the WHO criteria for CNL diagnosis. Keywords: CSF3R, SETBP1, CNL, neutrophilic, WHO, PTK inhibitor

Experimente zur Keramikherstellung: Formung, Bemalung und Brand gleicher Schälchen (Film 3, Teil 3)

Adam Winter drückt Ton in eine Formschüssel und dreht auf einer Töpferscheibe die überstehende Tonmasse mittels einer starren Schablone ab. Danach wird die lederharte Schüssel aus der Formschüssel entnommen und der Schüsselfuß nachgedreht. Mit einem Polierstahl glättet Adam Winter die Oberfläche, bevor er verschiedenfarbige Überzüge aufträgt. In einem handelsüblichen Töpferofen brennt er viele dieser Schälchen in Schutzkapseln, damit die Temperatur gleichmäßig um die Keramik verteilt wird. Während des Brandes reduziert er außerdem den Sauerstoffgehalt. Am Schluss werden die Schälchen entnommen und anhand einer zerbrochenen Schale gezeigt, wie tief die Hitze in den Scherben eindringen konnte. (aufgenommen in Rauenthal zwischen 1965 und 1973

Sequential gene targeting to make chimeric tumor models with de novo chromosomal abnormalities.

The discovery of chromosomal translocations in leukemia/lymphoma and sarcomas presaged a widespread discovery in epithelial tumors. With the advent of new-generation whole-genome sequencing, many consistent chromosomal abnormalities have been described together with putative driver and passenger mutations. The multiple genetic changes required in mouse models to assess the interrelationship of abnormalities and other mutations are severe limitations. Here, we show that sequential gene targeting of embryonic stem cells can be used to yield progenitor cells to generate chimeric offspring carrying all the genetic changes needed for cell-specific cancer. Illustrating the technology, we show that MLL-ENL fusion is sufficient for lethal leukocytosis and proof of genome integrity comes from germline transmission of the sequentially targeted alleles. This accelerated technology leads to a reduction in mouse numbers (contributing significantly to the 3Rs), allows fluorescence tagging of cancer-initiating cells, and provides a flexible platform for interrogating the interaction of chromosomal abnormalities with mutations

Analysis of myelodysplastic syndromes with complex karyotypes by high-resolution comparative genomic hybridization and subtelomeric CGH array

Molecular cytogenetic techniques enabled us to clarify numerical and structural alterations previously detected by conventional cytogenetic techniques in 37 patients who had myelodysplastic syndromes with complex karyotypes. Using high-resolution comparative genomic hybridization (HR-CGH), we found the most recurrent alterations to be deletion of 5q (70%), 18q (35%), 7q (32%), 11q (30%), and 20q (24%), gain of 11q (35%) and 8q (24%), and trisomy of chromosome 8 (19%). Furthermore, in 35% of the patients, 20 amplifications were identified. These amplifications were shown by FISH to involve some genes previously described as amplified in hematological malignancies, such as ERBB2, MLL and RUNX1. In addition, two other genes, BCL6 and BCL2, which are classically related to apoptosis and non-Hodgkin lymphoma, were shown for the first time to be involved in amplification. Genomic alterations involving different subtelomeric regions with losses in 4p16, 5p15.3, 6q27, 18p11.3, and 18q23 and gains in 1p36.3 and 19p13.3 were detected by HR-CGH. Array CGH analysis of the subtelomeric regions in some samples was able to confirm a number of these alterations and found some additional alterations not detected by conventional CGH. (C) 2004 Wiley-Liss, Inc