title: BCL6 expression correlates with the t(1;19) translocation in B-lymphoblastic leukemia.
abstract: OBJECTIVE
  Study to date suggests that BCL6 protein expression in B-cell neoplasia predominates in germinal center-derived tumors, but less is known regarding its expression in B-lymphoblastic leukemia. Therefore, we designed a comprehensive study of BCL6 expression in B-lymphoblastic leukemia.
  
  
  METHODS
  BCL6, LMO, and HGAL protein expression in B-lymphoblastic leukemia was investigated using immunohistochemical staining of paraffin-embedded bone marrow specimens. Cryptic TCF3(E2A)-PBX1 rearrangements were investigated using interphase fluorescence in situ hybridization.
  
  
  RESULTS
  Six (12%) of 52 B-lymphoblastic leukemias demonstrated BCL6 protein expression, with B-cell lymphoblastic leukemias containing a t(1;19) translocation demonstrating the strongest staining (three of three). Additional t(1;19) cases beyond the screening study showed similar results. Public microarray expression database mining showed that BCL6 messenger RNA expression levels in B-lymphoblastic leukemia correlated with the protein expression findings. Finally, other markers of B-cell development correlated with BCL6 expression in t(1;19) B-lymphoblastic leukemia cases, with LMO2 and HGAL proteins expressed in six (67%) of nine and eight (89%) of nine cases, respectively.
  
  
  CONCLUSIONS
  BCL6 expression is present in a subset of B-lymphoblastic leukemias, especially in cases containing the 1;19 translocation. Investigation for TCF3(E2A)-PBX1 rearrangements may be useful in BCL6-positive B-lymphoblastic leukemia.
authors.affiliation: From the University of California, San Francisco, and anne.deucher@ucsfmedctr.org.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Deucher
authors.affiliation: From the University of California, San Francisco, and.
authors.forename: Zhongxia
authors.initials: Z
authors.lastname: Qi
authors.affiliation: From the University of California, San Francisco, and.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Yu
authors.affiliation: University of New Mexico, Albuquerque.
authors.forename: Tracy I
authors.initials: TI
authors.lastname: George
authors.affiliation: From the University of California, San Francisco, and.
authors.forename: Joan E
authors.initials: JE
authors.lastname: Etzell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051560:Proto-Oncogene Proteins c-bcl-6; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: C084103:BCL6 protein, human; D004268:DNA-Binding Proteins; D015514:Oncogene Proteins, Fusion; D051560:Proto-Oncogene Proteins c-bcl-6; C543638:TCF3-PBX1 fusion protein, human
keywords: B-ALL; B-lymphoblastic leukemia; BCL6; TCF3(E2A)-PBX1; t(1;19)