title: [Acquired somatic mutations in non-coding region of bcl-6 gene in germinal center-type diffuse large B-cell lymphoma].
abstract: OBJECTIVE
  To investigate the mutation of 5' non-coding region of bcl-6 gene in germinal center B-cell (GCB) subtype of diffuse large B-cell lymphoma (DLBCL).
  
  
  METHODS
  t(14;18) detection and immunohistochemical staining (EnVision method) were performed in 60 cases of DLBCL, which were divided into GCB and non-GCB subtypes. Polymerase chain reaction (PCR), single-strand conformation polymorphism and direct DNA sequencing were used to identify mutations in the 5' non-coding region of the bcl-6 gene.
  
  
  RESULTS
  Seven of 60 cases showed t(14;18) translocation in the major breakpoint region. Using minimally acceptable criteria, 18 of 60 cases were probably to be germinal centre derived. Bcl-6 mutations were detected in 12 of 60 cases (20.0%) of DLBCL, with a significantly higher frequency in the GCB subgroups (7/18) than in the non-GCB subgroups (11.9%, 5/42). Bcl-6 mutations occurred most frequently in +363 and +469 sites. An association of bcl-6 mutation and GCB subgroup was obtained.
  
  
  CONCLUSIONS
  The 5' regulatory region of the bcl-6 gene underwent less frequent somatic hypermutation during lymphomagenesis than the results of previous reports. Bcl-6 mutation occurred mostly in the GCB subtype and detection of t(14;18) seems helpful in the classification of DLBCL.
authors.affiliation: Institute of Pathology and Forensic Medicine, Department of Pathology and Patho-physiology, Zhejiang University, Hangzhou, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Ying-ying
authors.initials: YY
authors.lastname: Cai
authors.forename: Jie
authors.initials: J
authors.lastname: Mao
authors.forename: Kai-yan
authors.initials: KY
authors.lastname: Yang
authors.forename: Guo-rong
authors.initials: GR
authors.lastname: Chen
authors.forename: Ren
authors.initials: R
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000473:pathology; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018858:Germinal Center / Q000473:pathology*; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017354:Point Mutation; D051560:Proto-Oncogene Proteins c-bcl-6; D014178:Translocation, Genetic; D055815:Young Adult
chemical_list: C084103:BCL6 protein, human; D004268:DNA-Binding Proteins; D051560:Proto-Oncogene Proteins c-bcl-6