T(11;18)(q21;q21)-positive gastrointestinal MALT lymphomas are heterogeneous with respect to the V(H) gene mutation status.

Aim: To investigate how t(11;18)(q21;q21)-positive gastrointestinal MALT lymphomas relate to other marginal zone lymphomas with respect to the somatic mutation pattern of the V(H) genes and the expression of the marker CD27.

Methods: The V(H) gene of 7 t(11;18)(q21;q21)-positive gastrointestinal MALT lymphomas was amplified by PCR using family specific V(H) primers and a consensus J(H) primer. PCR products were sequenced and mutation analysis of the CDR and the FR regions was performed.

Comparative expressed sequence hybridization studies of t(11;18)(q21;q21)-positive and -negative gastric MALT lymphomas reveal both unique and overlapping gene programs.

Among the genetic abnormalities reported to occur in MALT lymphomas, the translocation t(11;18)(q21;q21) is of particular interest because it is exclusively documented in MALT lymphomas, mainly with gastrointestinal location. It results in the creation of a fusion protein API2-MALT1 that activates the transcription factor NF-kappaB through enhanced IKK gamma polyubiquitination. Here, we apply the recently developed molecular technique termed comparative expressed sequence hybridization to identify differentially expressed chromosomal regions related to the pathogenesis of gastric MALT lymphomas.

T-cell/histiocyte-rich large B-cell lymphoma shows transcriptional features suggestive of a tolerogenic host immune response.

Background: Gene expression profiling has successfully identified the prognostic significance of the host response in lymphomas. The aggressive T-cell/histiocyte-rich large B-cell lymphoma and the indolent nodular lymphocyte-predominant Hodgkin's lymphoma are both characterized by a paucity of tumor cells embedded in an overwhelming background. The tumor cells of both lymphomas share several characteristics, while the cellular composition of their microenvironment is clearly different.

Translocations targeting CCND2, CCND3, and MYCN do occur in t(11;14)-negative mantle cell lymphomas.

The genetics of t(11;14)(q13;q32)/cyclin D1-negative mantle cell lymphoma (MCL) is poorly understood. We report here 8 MCL cases lacking t(11;14) or variant CCND1 rearrangement that showed expression of cyclin D1 (2 cases), D2 (2 cases), and D3 (3 cases). One case was cyclin D negative.

Is there a difference in childhood T-cell acute lymphoblastic leukaemia and T-cell lymphoblastic lymphoma?

To distinguish the similarities or differences between T-cell acute lymphoblastic leukaemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL), we retrospectively analyzed the clinical, immunophenotypic, cytogenetic, and molecular characteristics in 37 children diagnosed between December 1990 and December 2003. Comparative Expressed Sequence Hybridisation (CESH) was used to determine gene expressing profile in both diseases. Twenty two patients suffered from T-ALL and 15 patients were diagnosed as T-LBL.

Telomeric IGH losses detectable by fluorescence in situ hybridization in chronic lymphocytic leukemia reflect somatic VH recombination events.

Routine interphase fluorescence in situ hybridization (FISH) analysis of chronic lymphocytic leukemia (CLL) with LSI IGH/CCND1 assay, applied to differentiate CLL from leukemic mantle cell lymphoma, identified a subset of cases (42/174) with translocation-like IGH signal pattern. To unravel the underlying 14q32/IGH aberrations, 14 of these cases were subjected to cytogenetic, detailed FISH, and V(H) mutation analyses. FISH identified cryptic losses of various portions of the IGHV region in all 14 cases.

Forkhead box protein P1 expression in mucosa-associated lymphoid tissue lymphomas predicts poor prognosis and transformation to diffuse large B-cell lymphoma.

Purpose: Gene expression profiling studies have reported upregulated mRNA expression of forkhead box protein P1 (FOXP1) in response to normal B-cell activation and high expression in a poor prognosis subtype of diffuse large B-cell lymphoma (DLBCL). Recently, it was also found that FOXP1 rearrangements and expression of its protein occur in mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we investigated FOXP1 expression in its relationship to morphology, genetic features, and prognosis in a series of 70 MALT lymphomas.

Comparative expressed sequence hybridization reveals differential gene expression in morphological breast cancer subtypes.

In this study, comparative expressed sequence hybridization (CESH) has been used to compare gene expression patterns in three morphologically different breast cancer subtypes: classic-type invasive lobular carcinoma (ILC), poorly differentiated ERBB2-negative invasive ductal carcinoma-not otherwise specified (IDC-NOS), and poorly differentiated ERBB2-positive IDC-NOS. CESH allows global detection of chromosomal regions with differential gene expression in a way similar to that of comparative genomic hybridization (CGH). Eight cases of each breast cancer subtype were included in the study.

Large cleaved and immunoblastic lymphoma may represent two distinct clinicopathologic entities within the group of diffuse large B-cell lymphomas.

Purpose: The reliability of immunohistochemistry for subdividing diffuse large B-cell lymphomas (DLBCL) into germinal center B-cell-like (GCB) and non-GCB prognostic subgroups is debated. In this study we evaluated the prognostic significance of such subgrouping on a series of 153 DLBCL patients. Furthermore, we investigated whether both subgroups could comprise clinicopathologic entities recognized by their morphology and characterized by a distinct phenotype, specific genetic abnormalities, and clinical characteristics.

Comparative expressed sequence hybridization studies of hairy cell leukemia show uniform expression profile and imprint of spleen signature.

Comparative expressed sequence hybridization (CESH) to chromosomes is a recently introduced technique that identifies chromosomal regions corresponding to a differential gene expression. This technique is analogous to comparative genomic hybridization (CGH) that detects genomic imbalances. We applied CESH for the study of hairy cell leukemia (HCL), a disorder with a largely unknown expression profile.