title: MALT1 and BCL10 aberrations in MALT lymphomas and their effect on the expression of BCL10 in the tumour cells.
abstract: Among the genetic abnormalities reported to occur in mucosa-associated lymphoid tissue (MALT) lymphomas, the three translocations t(11;18)(q21;q21), t(1;14)(p22;q32) and t(14;18)(q32;q21) are of particular interest because they appear to be specific for, or at least closely related to this type of B-cell non-Hodgkin's lymphoma. These translocations affect the MALT1 (18q21) and BCL10 (1p22) genes. We retrieved 77 consecutive biopsies of MALT lymphomas (documented with frozen material) over a 10-year period and investigated these cases for the presence of these three translocations with fluorescence in situ hybridisation, along with the immunohistochemical analysis of the intracellular localisation of the BCL10 protein. The above-listed translocations occurred mutually exclusive and were detected in 10, 1 and 3% of the cases, respectively (the latter incidence being much lower than in the previously reported studies by one single group). These genetic rearrangements corresponded well with the aberrant subcellular localisation of the BCL10 protein as found by immunohistochemistry: t(11;18)(q21;q21) and (1;14)(p22;q32) were marked by a, respectively, moderate to strong nuclear BCL10 staining pattern while t(14;18)(q32;q21)-positive MALT lymphomas were characterised by a perinuclear BCL10 staining pattern. This study further supports the close interaction between the MALT1 and BCL10 proteins in the pathogenesis of MALT lymphomas and may indicate that BCL10 immunohistochemistry is a simple technique to identify those MALT lymphoma cases with an underlying genetic aberration.
authors.affiliation: Division of Morphology and Molecular Pathology, Katholieke Universiteit Leuven, Leuven, Belgium. xavier.sagaert@uz.kuleuven.ac.be
authors.forename: Xavier
authors.initials: X
authors.lastname: Sagaert
authors.forename: Michael
authors.initials: M
authors.lastname: Laurent
authors.forename: Mathys
authors.initials: M
authors.lastname: Baens
authors.forename: Iwona
authors.initials: I
authors.lastname: Wlodarska
authors.forename: Christiane
authors.initials: C
authors.lastname: De Wolf-Peeters
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000032:analysis / Q000235:genetics*; D000074018:B-Cell CLL-Lymphoma 10 Protein; D020169:Caspases; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics*; D014178:Translocation, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000074018:B-Cell CLL-Lymphoma 10 Protein; C118591:BCL10 protein, human; D009363:Neoplasm Proteins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein