Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deletions of the long arm of chromosome 6 (6q) are among the most frequent chromosome aberrations in malignant lymphomas and often occur as secondary changes in addition to typical translocations, such as t(14;18). Using fluorescence in situ hybridization (FISH) with two YAC probes hybridizing to 6q23-24 and with the centromeric probe D6Z1 as internal control, we studied 31 cases of low-grade and eight cases of high-grade B-cell lymphoma. Deletions of 6q23-24 were detected in 21 patients (56.8%) by FISH, compared to 13 patients (33.3%) by chromosome analysis. Deletions of 6q23-24 were found by FISH in 5 of 13 cases of small lymphocytic lymphoma, in 2 of 3 cases of mantle cell lymphoma, in 10 of 14 cases of t(14;18) positive low-grade follicular lymphoma, and in 4 of 8 cases of high-grade follicular lymphoma. This study shows that deletions of 6q23-24 are more frequent in B-cell lymphomas than previously suggested and that they can be detected more sensitively by FISH than by chromosome analysis. Contrary to previous reports indicating that the region 6q23-24 is preferentially deleted in low-grade lymphomas without t(14;18), our results indicate that deletions of 6q23-24 appear to be common in other pathological subsets of B-cell lymphoma as well, especially in follicular lymphomas with t(14;18).
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PMID:Frequent deletions of 6q23-24 in B-cell non-Hodgkin's lymphomas detected by fluorescence in situ hybridization. 908 72

Gastric MALT lymphoma is a distinct entity related to Helicobacter pylori gastritis. Some studies suggest a role for trisomy 3 in the genesis of these lymphomas, but they mainly focused on low-grade MALT lymphoma. Gastric MALT lymphoma, however, comprises a spectrum from low- to high-grade cases. Furthermore, its exact relation to primary diffuse large B cell lymphoma (DLBCL) of the stomach is not clear. We applied in situ hybridisation (ISH) with centromeric probes on 43 samples of 39 patients with primary gastric lymphoma (13 samples with low-grade MALT lymphoma, 25 with high-grade MALT lymphoma and five with DLBCL) to detect numerical aberrations of 10 chromosomes. ISH was performed immunohistochemically on nuclei isolated from paraffin-embedded resection tissue and on whole paraffin sections using immunofluorescence. In six of 13 low-grade MALT lymphomas trisomy was detected (46%) and mostly involved chromosome 3 (33%). In high-grade MALT lymphomas, trisomies were found in 16 of 25 cases (64%), mainly involving chromosomes 12 and 18. Trisomy 3 was present in only 13% of these cases. Of five DLBCL, only one showed trisomy. Nine of the 16 aberrant high-grade MALT lymphomas (56%) showed trisomy of more than one chromosome per case vs two of six for low-grade cases. In lymphomas with separate low- and high-grade tumour components some trisomies were detected in both components, whereas others occurred only in the high-grade tumour cells. This supports the hypothesis that high-grade MALT lymphomas can develop from a low-grade type and that this progression is accompanied by the acquisition of more genetic aberrations. However, trisomy 3 probably does not play a major role in this progression.
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PMID:Gastric low-grade MALT lymphoma, high-grade MALT lymphoma and diffuse large B cell lymphoma show different frequencies of trisomy. 1037 86

The translocation of chromosome 11, long arm, region 2, band 1, to chromosome 18, long arm, region 2, band 1 (t(11;18)(q21;q21)) represents a recurrent chromosomal abnormality in extranodal marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (MALT) type and leads to a fusion of the apoptosis inhibitor-2 (API2) gene on chromosome 11 and the MALT lymphoma-associated translocation (MLT) gene on chromosome 18. A 2-color fluorescence in situ hybridization (FISH) assay, which can be used for the detection of t(11;18) in interphase nuclei and metaphase chromosomes on fresh and archival tumor tissue, was developed. The P1 artificial chromosome (PAC) clone located immediately telomeric to the MLT gene and the PAC clone spanning the API2 gene were differentially labeled and used to visualize the derivative chromosome 11 resulting from t(11;18), as evident by the overlapping or juxtaposed red and green fluorescent signals. The assay was applied to interphase nuclei of 20 cases with nonmalignant conditions and 122 B-cell non-Hodgkin's lymphomas (NHLs). The latter group comprised 20 cases of nodal follicle center cell lymphoma and diffuse large B-cell NHL, 10 cases of gastric diffuse large B-cell lymphoma, 10 cases of hairy cell leukemia, and 82 cases of MZBCL (41 extranodal from various locations, 19 nodal, and 22 splenic MZBCL) including 35 cases with an abnormal karyotype, 2 of which revealed t(11;18). By interphase FISH, t(11;18) was detected in 8 gastrointestinal low-grade MALT-type lymphomas including the 2 cytogenetically t(11;18)(+) cases. In the 8 t(11;18)(+) cases, the FISH results were confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) using API2 and MLT specific primers. Our results indicate that t(11;18)(q21;q21) specifically characterizes a subgroup of low-grade MZBCL of the MALT-type and that the FISH assay described here is a highly specific and rapid test for the detection of this translocation.
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PMID:Detection of t(11;18)(q21;q21) by interphase fluorescence in situ hybridization using API2 and MLT specific probes. 1097 68

The characterization of genetic aberrations in paraffin-embedded tumor material is impaired by contaminating normal cells. In the present study on the genetic causes of loss of HLA expression in diffuse large B-cell lymphoma (DLBCL), we compared the efficacy of microdissection with flow cytometric sorting of tumor cells. Single-cell suspensions from paraffin-embedded material of 5 DLBCL cases were stained for CD79a and DNA content (propidium iodide). Fluorescent in situ hybridization (FISH) using HLA class II and chromosome 6 centromeric probes and loss of heterozygosity (LOH) analysis with 5 HLA-specific microsatellite markers were performed on microdissected and flow cytometry-sorted fractions. FISH confirmed considerable enrichment of the samples after flow cytometric sorting and disclosed tumor heterogeneity in 4 cases. Moreover, lymphomas with a so-called zebra LOH pattern in the microdissected material showed unambiguous LOH after flow cytometric sorting, revealing in 1 case a biologically relevant hemizygous deletion in the HLA region.
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PMID:Flow cytometric sorting of paraffin-embedded tumor tissues considerably improves molecular genetic analysis. 1450 96

We present the study of 16 cases of splenic marginal zone B-cell lymphoma (SMZBL) combining conventional cytogenetics and fluorescence in situ hybridization technique (FISH). We used a locus specific probe (11q22.3) that hybridizes with Ataxia Telangiectasia Mutated gene (ATM) and a centromeric probe of chromosome 11 as a control. Deletions in ATM gene region have been found in B-cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma (MCL) and have been considered as an independent prognosis factor in these pathologies. The aim of our study was to determine the ATM status in SMZBL because no specific studies concerning ATM status in SMZBL have been reported and other B-cell malignances have shown ATM deletions. No deletions were detected in any of the 16 cases. ATM deletions could be considered a rare event in SMZBCL.
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PMID:Absence of ATM deletions in 16 cases of splenic marginal-zone B-cell lymphoma (SMZBCL). 1460 69

t(11;18)(q21;q21) Translocation and trisomy 3 are the most common chromosomal aberrations reported in low-grade mucosa-associated lymphoid tissue (MALT) lymphoma. The current study aims to investigate the frequency of these chromosomal aberrations in a series of 52 extranodal B-cell lymphomas. The tumours were categorised into three histological grades: grade 1 (low-grade lymphoma of MALT type), grade 2 [diffuse large B-cell lymphoma (DLBCL) with MALT component] and grade 3 (DLBCL without MALT component). Fluorescence in situ hybridisation analyses on paraffin tissue sections were performed using a locus-specific probe for the 18q21 region and a centromeric probe for chromosome 3. The 18q21 rearrangement was detected in 9 of 40 (23%) cases, including 7 of 23 (30%) grade-1 and 2 of 11 (18%) grade-3 tumours. Amplification of the 18q21 region was detected in 10 of 40 (25%) cases, and trisomy 3 was detected in 9 of 34 (26%) cases. Amplification of the 18q21 region may be an important alternative pathogenetic pathway in MALT lymphoma and was found almost exclusively in tumours without 18q21 rearrangement. Our study showed that tumours with 18q21 rearrangement and 18q21 amplification develop along two distinct pathways, and the latter was more likely to transform into high-grade tumours upon acquisition of additional genetic alterations, such as trisomy 3. Trisomy 3 was more frequently found in coexistence with 18q21 abnormalities, suggesting that it was more likely to be a secondary aberration.
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PMID:18q21 Rearrangement and trisomy 3 in extranodal B-cell lymphomas: a study using a fluorescent in situ hybridisation technique. 1536 30

Decreased major histocompatibility class II (MHCII) expression is associated with poor survival in diffuse large B-cell lymphoma (DLBCL). Immune-privileged site DLBCL (IP-DLBCL) patients reportedly have frequent large deletions at the MHCII locus whereas the mechanism of decreased expression in non-IP-DLBCL is unknown. Gene expression profiling data were used for correlation analyses between expression levels of MHCII genes with each other and their transcriptional regulator, CIITA. Comparative genomic hybridization (CGH) assessed chromosomal alterations at MHCII-related loci. Finally, a map was created of expression of genes that are telomeric, within, or centromeric to the MHCII locus. Correlation coefficients among MHCII genes ranged from 0.73 to 0.92, whereas those between adjacent and intervening genes were lower (-0.12 to 0.49). Correlations between MHCII and CIITA expression were higher (0.53 to 0.60) than between CIITA and neighboring genes (-0.05 to 0.22). In 23 MHCII(-) cases, CGH detected 2 losses and 2 gains at MHCII loci. Expression of genes telomeric, within, and centromeric to MHCII loci were near normal in most MHCII(-) cases. Large deletions of the MHCII locus are uncommon in non-IP-DLBCL, implicating altered transcription as the operative mechanism for decreased expression.
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PMID:Loss of major histocompatibility class II expression in non-immune-privileged site diffuse large B-cell lymphoma is highly coordinated and not due to chromosomal deletions. 1623 29

The prognosis for patients with mucosa-associated lymphoid tissue (MALT) lymphomas is good; these tumours have usually an indolent course with overall survival rates that are greater than 80% at 5-year, but some rare cases with histological transformation in aggressive diffuse large cell lymphoma have also been diagnosed. Here, we present cytogenetic results on endoscopic bioptic material of 42 cases of primary gastric extranodal marginal zone B-cell lymphoma (EMZL) using fluorescence in situ hybridization (FISH) approach with API2, MALT1 and centromeric probes for chromosome 3 and 18, and their impact on the clinical outcome.
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PMID:Chromosome instability and translocation t(11;18) in primary gastric marginal zone B-cell lymphoma of MALT-type. 1760 63

In a subset of B-cell malignancies, the genes encoding members of the cyclin D familiy are juxtaposed to immunoglobulin loci through recurrent chromosomal translocations. Here, we identified the gene encoding cyclin E1 as novel translocation partner of the immunoglobulin heavy chain (IGH) locus involved in a t(14;19)(q32;q12) in a case of t(8;14)(q24;q32) IGH-MYC-positive leukemic diffuse large B-cell lymphoma. The translocation breakpoints were cloned and mapped to the switch region Salpha1 of IGH in 14q32 and approximately 60kb centromeric to CCNE1 in 19q12. Immunohistochemical analysis revealed overexpression of the cyclin E1 protein in this case, which to a comparable extent was observed in 3/41 independent DLBCL. These data indicate that cyclin E1 may act as a novel oncogene in B-cell lymphomagenesis.
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PMID:Identification of the gene encoding cyclin E1 (CCNE1) as a novel IGH translocation partner in t(14;19)(q32;q12) in diffuse large B-cell lymphoma. 1945 96

Mantle cell lymphomas (MCL), characterized by the t(11;14)(q13;q32), frequently carry secondary genetic alterations such as deletions in chromosome 17p involving the TP53 locus. Given that the association between TP53-deletions and concurrent mutations of the remaining allele is weak and based on our recent report that the Hypermethylated in Cancer 1 (HIC1) gene, that is located telomeric to the TP53 gene, may be targeted by deletions in 17p in diffuse large B-cell lymphoma (DLBCL), we investigated whether HIC1 inactivations might also occur in MCL. Monoallelic deletions of the TP53 locus were detected in 18 out of 59 MCL (31%), while overexpression of p53 protein occurred in only 8 out of 18 of these MCL (44%). In TP53-deleted MCL, the HIC1 gene locus was co-deleted in 11 out of 18 cases (61%). However, neither TP53 nor HIC1 deletions did affect survival of MCL patients. In most analyzed cases, no hypermethylation of the HIC1 exon 1A promoter was observed (17 out of 20, 85%). However, in MCL cell lines without HIC1-hypermethylation, the mRNA expression levels of HIC1 were nevertheless significantly reduced, when compared to reactive lymph node specimens, pointing to the occurrence of mechanisms other than epigenetic or genetic events for the inactivation of HIC1 in this entity.
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PMID:Genomic deletion and promoter methylation status of Hypermethylated in Cancer 1 (HIC1) in mantle cell lymphoma. 1966 7


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