应用细胞芯片荧光原位杂交技术检测弥漫性大B细胞淋巴瘤3q27重排

目的 研究3q27染色体断裂及bcl-6基因扩增与弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma, DLBCL)与其分子分类及治疗效果、临床分期的关系.方法 用细胞芯片荧光原位杂交(fluorescence in situ hybridization,FISH)技术对60例DLBCL的标本进行3q27染色体断裂及bcl-6扩增检测;采用免疫组化S-P法在组织微阵列上同步观测CD20、CD10、bcl-6、MUM1的表达,进行生发中心样(germinat center Bcell-like,GCB)和非生发中心样(non-germinal center B-cell-like, non-GCB)分子分类;通过对临床病例的分析得出与治疗效果及临床分期的信息;统计分析以上各因素之间的关系.结果 在60例DLBCL中,GCB占48.3%(29/60),non-GCB占51.7%(31/60).FISH结果显示,3q27断裂阳性15例,bcl-6基因扩增阳性22例.存在3q27染色体断裂的15例中BCL-6蛋白表达阳性3例(20.0%),阴性12例(80.0%),与无3q27染色体断裂者相比其BCL-6蛋白表达率降低(P=0.017).在60例DLBCL中,bcl-6扩增22例,其中GCB 5例(22.7%),non-GCB 17例(77.3%),与无bcl-6扩增者相比差异有统计学意义(P=0.003).在36例经正规CHOP治疗的DLBCL中,bcl-6扩增15例,其治疗效果显效、部分有效、无效分别为4(26.7%)、4(26.7%)、7(46.7%),与无bcl-6扩增的病例比差异有统计学意义(P=0.016).bel-6扩增与BCL-6蛋白表达及I临床分期的关系差异无统计学.BCL-6蛋白表达阳性组、阴性组与治疗效果及临床分期关系差异无统计学意义.结论 存在bel-6基因断裂的病例,其BCL-6蛋白表达率低.存在bcl-6基因扩增的DLBCL多数为non-GCB,并且治疗效果差,临床分期较晚,可能与DLBCL晚期染色体呈多倍体增加的趋势有关.

Detection of 3q27 chromosomal abnormality in diffuse large B cell lymphoma using FISH on cell microarray

OBJECTIVE: To investigate the association of 3q27 chromosome rearrangement with bcl-6 gene amplification and the molecular classification, therapeutic efficacies, and clinical stages in diffuse large B cell lymphoma (DLBC). METHODS: The newly invented cell microarray was used to detect 3q27 chromosome rearrangement and bcl-6 gene amplification in 60 cases of DLBCL by fluorescence in situ hybridization (FISH). The molecular classification of germinal center B-cell-like (GCB) and non-germinal center B-cell-like (non-GCB) was investigated by analyzing the expression of CD20, CD10, bcl-6 and MUM1 simultaneously by immunohistochemical S-P method and tissue microarray. The information of therapeutic efficacies and clinical stages was obtained by analyzing clinical cases. The relationships among the factors were analyzed by statistics. RESULTS: In 60 cases of DLBCL, 48.3%(29/60) were GCB and 51.7%(31/60) were non-GCB. The 3q27 chromosome rearrangement and bcl-6 gene amplification were present in 15 and 22 cases respectively. In 15 cases with 3q27 rearrangement, bcl-6 protein expression was positive in 3(20.0%), which was significantly different from that in cases without 3q27 rearrangement (P=0.017). In 60 cases of DLBCL, bcl-6 gene amplification was present in 22 cases, in which 5(22.7%) were GCB and 17(77.3%) were non-GCB, which was significantly different from that in cases without bcl-6 gene amplification (P=0.003). In 36 cases undergoing the normal CHOP program treatment, bcl-6 gene amplification was present in 15 cases and the rates of the complete remission, partial remission and no change were 4(26.7%), 4(26.7%) and 7(46.7%) respectively, and again it was significantly different from that in cases without bcl-6 gene amplification (P=0.016). There were no statistical significances among bcl-6 gene, BCL-6 protein expression, and clinical stages. Cases with BCL-6 protein positive and negative expression were not correlated with therapeutic efficacies and clinical stages. CONCLUSION: There is lower expression of BCL-6 protein in cases with bcl-6 gene fragmentation. Cases with bcl-6 gene amplification are non-GCB with worse therapeutic results and later clinical stages. There may be other genes near chromosome 3q27 associated with DLBCL prognosis.