摘要目的 分析弥漫性大B细胞淋巴瘤(DLBCL)中bcl-6基因5'非编码区突变频率及与其生发中心B细胞(GCB)型的相关性.方法 对60例DLBCL行套式PCR检测t(14;l8)易位,并经免疫组织化学EnVision两步法进行GCB和非GCB分子分型.PCR扩增bcl-6主要突变区,测序检测突变位点.结果 60例中7例(11.7%)发生t(14;18)易位,为主要断裂点发生转位;联合免疫组织化学分析和t(14;18)易位检测,筛选出GCB型18例和非GCB型42例;5'非编码区总突变率为20.0%(12/60),GCB型突变率为7/18,非GCB型突变率为11.9%(5/42);+363和+469位点频繁发生突变.结论 DLBCL的bcl-65'非编码区发生突变频率较国外低,突变多发生于GCB型中.t(14;18)易位检测有助于DLBCL的分子分型.

abstractsObjective 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 GCBsubgroups (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 GCBsubtype and detection of t(14 ;18) seems helpful in the classification of DLBCL.