title: Translocations involving MUM1 are rare in diffuse large B-cell lymphoma.
abstract: Diffuse large B-cell lymphoma (DLBCL) comprises a diverse group of neoplasms that have recently been subdivided by gene expression profiling and immunohistochemical studies into at least 2 subgroups [germinal center (GC) type and non-GC type]. The non-GC subtype has a post-GC activated phenotype and typically expresses MUM1 by immunohistochemistry. We hypothesized that MUM1 may be dysregulated/up-regulated in these tumors by a chromosomal translocation, as is seen in many cases of plasma cell myeloma [where MUM1 is juxtaposed with the immunoglobulin heavy chain gene (IgH)]. Therefore, using a novel MUM1 break-apart probe constructed in our laboratory, we performed fluorescence in situ hybridization on 33 cases of DLBCL (17 GC type and 16 non-GC type) for a MUM1 translocation. We identified 1 case of a MUM1 translocation out of 31 cases with successful fluorescence in situ hybridization. This case was a non-GC DLBCL (1/15). We conclude that genetic abnormalities involving MUM1 are rare in DLBCL and that a mechanism of deregulation of the MUM1 protein other than by a translocation event is involved in the majority of non-GC cases.
authors.affiliation: Department of Pathology, University of New Mexico, Albuquerque, NM 87102, USA.
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Hunt
authors.forename: Bryan
authors.initials: B
authors.lastname: Hall
authors.forename: Kaaren K
authors.initials: KK
authors.lastname: Reichard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D018858:Germinal Center / Q000473:pathology; D006801:Humans; D017403:In Situ Hybridization; D050835:Interferon Regulatory Factors / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D014178:Translocation, Genetic / Q000235:genetics / Q000276:immunology*; D000099218:Interferon Regulatory Factor-4
chemical_list: D000951:Antigens, Neoplasm; D050835:Interferon Regulatory Factors; D000099218:Interferon Regulatory Factor-4