title: Comparative expressed sequence hybridization studies of t(11;18)(q21;q21)-positive and -negative gastric MALT lymphomas reveal both unique and overlapping gene programs.
abstract: 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. By comparing t(11;18)(q21;q21)-positive gastric MALT lymphomas to their t(11;18)(q21;q21)-negative counterparts, we found that the location of the MALT1 break point determines a difference in expression pattern within the t(11;18)(q21;q21)-positive group. Moreover, we could define a gastric MALT lymphoma signature, which most likely comprises the regions and genes with significance in the development of MALT lymphomas, by comparing both t(11;18)(q21;q21)-positive and -negative MALT lymphomas to normal lymphoid tissue. Finally, a significant imprint of the marginal zone signature, established by comparing microdissected, splenic B follicles with and without marginal zone, was evident in the expression profile of MALT lymphoma, further supporting a marginal zone origin for this type of B-cell non-Hodgkin's lymphoma.
authors.affiliation: Section of Morphology and Molecular Pathology, Department of Pathology, Katholieke Universiteit Leuven, Leuven, Belgium. xavier.sagaert@uz.kuleuven.ac.be
authors.forename: Xavier
authors.initials: X
authors.lastname: Sagaert
authors.forename: Thomas
authors.initials: T
authors.lastname: Tousseyn
authors.forename: Vera
authors.initials: V
authors.lastname: Vanhentenrijk
authors.forename: Peter
authors.initials: P
authors.lastname: Van Loo
authors.forename: Mathijs
authors.initials: M
authors.lastname: Baens
authors.forename: Peter
authors.initials: P
authors.lastname: Marynen
authors.forename: Gert
authors.initials: G
authors.lastname: De Hertogh
authors.forename: Karel
authors.initials: K
authors.lastname: Geboes
authors.forename: Christiane
authors.initials: C
authors.lastname: De Wolf-Peeters
mesh_terms: D000328:Adult; D000368:Aged; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D002887:Chromosomes, Human, Pair 18; D055028:Comparative Genomic Hybridization; D020224:Expressed Sequence Tags; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014178:Translocation, Genetic
chemical_list: C415943:API2-MALT1 fusion protein, human; D015514:Oncogene Proteins, Fusion