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Cytogenetic Alterations (cytogenetic + alteration)
Selected AbstractsmicroRNAs in acute myeloid leukemia: Expression patterns, correlations with genetic and clinical parameters, and prognostic significanceGENES, CHROMOSOMES AND CANCER, Issue 3 2010Rotraud Wieser Acute myeloid leukemia (AML) is a malignant disease of hematopoietic cells whose emergence, course, and prognosis is affected by specific recurrent genetic alterations like chromosome aberrations and point mutations, as well as by changes in the expression of certain genes. In the past 2 years, microRNAs (miRNAs),a novel class of small RNA molecules involved in posttranscriptional gene regulation,have also been shown to be aberrantly expressed in AML. Furthermore, specific miRNA expression patterns were found to be associated with certain genetic and cytogenetic alterations in this disease, and two studies identified miRNAs whose expression levels were predictive of survival. Interestingly, the results of these analyses showed only very limited congruence. This review summarizes published reports on the expression patterns of miRNAs in AML, and discusses possible reasons for the differences in their results. © 2009 Wiley-Liss, Inc. [source] Hereditary gastrointestinal stromal tumors sharing the KIT Exon 17 germline mutation p.Asp820Tyr develop through different cytogenetic progression pathwaysGENES, CHROMOSOMES AND CANCER, Issue 2 2010Isabel Veiga Hereditary gastrointestinal stromal tumor (GIST) syndrome is a rare autosomal dominant genetic disorder originated by germline mutations in the KIT or PDGFRA genes. We report the third family with hereditary predisposition to GIST due to the KIT Exon 17 germline mutation p.Asp820Tyr and characterize the cytogenetic progression pathways followed by different GIST sharing the same primary genetic event, using a combination of chromosome banding, comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH) analyses. The missense mutation p.Asp820Tyr was detected in the proband's rectal and gastric GIST, as well as in his aunt's GIST epiplon metastasis. The mutation p.Asp820Tyr was subsequently also found in the proband's peripheral blood DNA, as well as in that of 4 of 10 relatives thus far analyzed. CGH analysis revealed loss of 14q and 15q in the proband's gastric lesion, whereas FISH analysis of the proband's rectal GIST did not detect loss of 14q and 15q, but instead loss of 4q and 22q and gain of 20q, indicating that the two tumors were independent GIST. Chromosome banding and CGH analyses of the aunt's GIST epiplon metastasis revealed multiple cytogenetic alterations, including 1p loss, but none in common with the two proband's GIST. We conclude that, although the patients share the same KIT Exon 17 germline mutation, the multiple GIST analyzed followed different pathogenetic progression pathways, each of which did not significantly differ from what has been described in sporadic GIST. © 2009 Wiley-Liss, Inc. [source] Prognostic significance of secondary cytogenetic alterations in follicular lymphomasGENES, CHROMOSOMES AND CANCER, Issue 12 2008Nathalie A. Johnson Follicular lymphoma (FL) is an indolent lymphoma with a long median survival. Transformation to a more aggressive histology (TLy) is a major cause of mortality. The critical events leading to TLy are unknown. We assessed the prognostic significance of secondary cytogenetic alterations on overall survival (OS) and transformation from 210 diagnostic FL biopsies. We analyzed serial and transformed karyotypes for recurrent alterations that predict transformation. Over 10 years, 31% of cases developed TLy. The only alteration in diagnostic karyotypes that correlated with an inferior OS was an additional X chromosome in males only (P = 0.005) suggesting that other mechanisms including epigenetic factors and over-expression of genes on the X chromosome may play a role in FL pathogenesis. In transformed karyotypes, 8q24 (MYC) translocations were common (14/37) and resulted in a median survival of 3 months posttransformation (P = 0.01). In serially obtained biopsies (28 pts), 43% of the later biopsies lacked the cytogenetic alterations found in the original FL karyotype, suggesting that karyotypic progression of FL is not strictly linear in all cases. Consequently, studying clonal evolution in FL using serial biopsies may not represent the full complexity of genetic alterations leading to transformation. © 2008 Wiley-Liss, Inc. [source] High sensitivity of chemiluminescent methodology for detection of clonal CDR3 sequences in patients with acute lymphoblastic leukemiaHEMATOLOGICAL ONCOLOGY, Issue 2 2004E. Leal Abstract Detection of minimal residual disease (MRD) in patients with B-cell acute lymphoblastic leukemia (B-ALL) has been achieved using several radioactive labelling methodologies; however, limited information exists about the use of chemiluminescent labelling. Although many malignant disorders are related to cytogenetic alterations, there is not a consistent chromosomal translocation that could serve as a tumour marker for the monitoring of MRD. ALL are derived from B-lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementary Determining Regions (CDR). Among these, CDR3 is considered unique for each lymphocyte and used as a tumour-specific marker in B-ALL patients. In this study, the CDR3 was labelled with digoxigenin and used as a patient-specific probe to test its sensitivity for further detection of MRD. Fourteen pretreatment samples of bone marrow (BM) or peripheral blood (PB) from B-ALL patients were included. Tumour-specific probes were designed from each clonal product by elimination of the consensus sequences. Ten digoxigenin-labelled probes were hybridized with a mixture of their respective clonal DNA and the polyclonal product from a normal healthy donor, in serial dilutions from 1:1 up to 1:107. A sensitivity range of 1:103,1:106 was obtained, with an average of 1:105. Crossed tests performed in four patients, showed right probe specificity in all cases. We propose that the design of allele-specific probes with chemiluminescent labelling, represents a reliable, sure and sensitive alternative methodology for MRD detection in patients with B-cell lymphoproliferative disorders. Copyright © 2004 John Wiley & Sons, Ltd. [source] Mucosa-associated lymphoid tissue lymphoma: Molecular pathogenesis and clinicopathological significancePATHOLOGY INTERNATIONAL, Issue 8 2007Hiroshi Inagaki Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade tumor closely associated with chronic inflammation such as that of Helicobacter pylori gastritis, Sjogren's syndrome, and Hashimoto's thyroiditis. Tumor regression by H. pylori eradication alone is well known in gastric MALT lymphoma, but some tumors occur in the absence of pre-existing chronic inflammation. The understanding of MALT lymphoma biology has significantly improved, and recurrent cytogenetic alterations have been detected. These include the trisomies 3 and 18, and the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). At least some of these alterations result in the constitutive activation of the nuclear factor (NF)-,B pathway, and may exert anti-apoptotic action. Apoptosis inhibitor 2,MALT lymphoma-associated translocation 1 (API12 - MALT1) fusion, resulting from t(11;18)(q21;q21), is specific to, and is the most common in, MALT lymphomas, and its clinicopathological significance has been studied extensively. The focus of the present review is on the recent progress made in elucidating MALT lymphomagenesis and its clinicopathological impact, especially in terms of the effect of API2-MALT1 fusion on this unique tumor. [source] | ||||||||||