[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.