| Background and objectives:Diffuse large B cell lymphoma is being to the heterogeneity of invasive tumors on clinic, histopathology, immunophenotypic and molecular genetics, It prefered to occuring in the elderly and is for30%～40%.of the entire NHL. Because the prognosis and treatment are quite different, DLBCL was divided into three immunological subtypes:the germinal center type (the germinal center B cell, GCB), non-germinal center type (non-germinal center B cell, NGCB) and CD5+type base on the different expression of CD10, Bcl-6, MUM1and CD5, Lymphoma in Dali where is Bai nationality lives is familiar., the immunological subtype and pathological features of clinical of the diffuse large B-cell lymphoma (the diffuse large B cell lymphoma, DLBCL) is worthy of exploration.Epigenetic modification is a hot spot of cancer research in recent years. DNA methylation and histone modifications is the important area in epigenetics. Histone modification attracted researchers attention due to the high diversity and the roles in the regulation of gene expression. Compared with DNA methylation, the mechanisms of histone modification is very complicated,. The post-translational modifications of the N terminus of histone acetylation was through phosphorylation, ubiquitin and others.. Those modifications affect the interaction between DNA and histones, and make chromatin loose and shrink, then regulate genes transcription. Currently the researchers pay more attention on histone methylation. The methylation of histones (histone methyltransferases, HMT) catalyzed by the histone methyltransferase enzyme. NSD2which is a lysine histone methyltransferase, containing the SET domain, belongs to the NSD (nuclear receptor binding SET domain containing) protein family members. It is homologous for the SET domain of this protein and SET2, a classic H3K36methylas. Indicated that NSD2may catalyze H3K36methylation. NSD protein is very interesting because of its contacting with the disease closely. In adults, the high expression of NSD2is closely related to many tumors, NSD2highly expressed in multiple myeloma in the chromosomal translocation t (4,14), But inhibit NSD2expression can inhibit tumor cell growth rate. EZH2is an evolutionarily highly conserved gene in PcG family methylation and the only catalytic enzymes for H3K27methylation. It related to histone modification and plays an important role on cell growth and development, Its roles on tumorigenes are early attention. Lots of research found that EZH2is highly expressed in many tumor cell lines. Genes which were regulated by EZH2in tumor cells is easy to inactive by DNA methylation in embryonic stem cells,. There are less report about the expression and biological genetics of NSD2and EZH2in diffuse large B-cell lymphoma. So this study will investigate the following issues:(1) the classification of the immunological subtype of DLBCL combined with immune markers, clinical and pathological analysis and the retrospective study of the diffuse large B cell lymphoma was carried out in Dali Bai area,;(2) Using immunohistochemical techniques and RT-PCR technique to detect the expression of NSD2and EZH2on protein and mRNA levels on diffuse large B-cell lymphoma, and discuss the expression and clinical meaning of NSD2and EZH2in diffuse large B cell lymphoma.Materials and methods:1, Collected100cases of the diffuse large B-cell lymphoma in paraffin-embedded specimens from2004to April8,2012, in the pathology department of the Affiliated Hospital of Dali University and Dali Bai Autonomous Prefecture People’s Hospital. With immunohistochemical with Envision two-step, the immunological subtype and clinical analysis on the diffuse large B-cell lymphoma in paraffin-embedded specimens was carried out.2, The expression of histone methyltransferase NSD2and EZH2expression in diffuse large B-cell lymphoma was checked though immunohistochemistry with Envision two-step the immunological subtype and RT-PCR, and analyze the related data.Results:Part one the clinical and pathological analysis of diffuse large B cell lymphoma in Dali Bai Autonomous Prefecture.(1) Clinical data:100cases of DLBCL Han61cases,39cases of Bai Autonomous; male53cases (53/100) and female47cases (47/100), the ratio of male to female is1.13:1; age range9-93years, median age51years,60cases is less than60years old (60/100);53cases is first appeared in the lymph nodes (53/100) and47cases (47/100) is starting outside of the lymph nodes;58cases (58/100) treatment in stage I+II and42cases (42/100) treatment in stage III+IV;(2) Immunological subtypes:1) GCB is35cases (35/100), including17males,18females; the age over60years is5casesand under60years is30case;21cases is first appeared in the lymph nodes and14starting outside of the lymph nodes;29cases in stage I+II visit,6cases in stageⅢ+IVvisit; This type patients is no related with gender and the starting site (P>0.05), and related with Nationality, age and clinical stage (P<0.05);2) NGCB type54cases, accounting for54%, including30males and24females; more than60years old27cases, less than60years old27case;30cases starting in the lymph nodes,24cases starting outside the lymph nodes;27cases of treatment when in stage I+II,27cases of treatment when in stage III+IV; This type of patients is no relation on gender and the starting site (P>0.05), relation on Nationality, age and clinical stage (P<0.05);3) CD5+type11cases, accounting for11%,6males,5females; more than60years of age8cases, less than60years old3cases;2cases starts in the lymph nodes,9cases starting in the lymph nodes;2cases for treatment at the time I+Ⅱ period,9cases for treatment at stage III+IV;This type of patients is not related with gender (P>0.05), and related with age, clinical stageand the starting site (P<0.05)Part two The expression and significance of Histone methyltransferase NSD2and EZH2in diffuse large B-cell lymphoma.(1) The results of immunohistochemistry:the experimental group,100cases of DLBCL paraffin-embedded tissue in NSD2positive expression rate of81%(81cases) and EZH2positive expression rate of93%(93cases); the control group25cases of benign reactive hyperplasia of lymph node tissue NSD2positive expression rate of4%(1cases), and EZH2positive expression rates of16%(4cases); statistical analysis showed that there is significant differences between the experimental group and control between NSD2and EZH2expression (P<0.05), NSD2is not related with gender, age and the starting site (P>0.05), and related with clinical stageand (P<0.05) EZH2is not related with gende, age, clinical stageand the starting site (P>0.05).(2) RT-PCR results:50cases in the experimental group, NSD2mRNA positive expression rate of80%(40cases), the EZH2mRNA positive rate was92%(46cases); control group,10cases of benign reactive hyperplasia of lymph nodes in NSD2mRNA positive expression rate of0,EZH2mRNA in positive expression rate of10%(1cases);there is significant differences between experimental and control groups on NSD2and of EZH2mRNA expression (P<0.05); there is significant differences between each Immunological subtypes of the expression in NSD2, it is not related with gender, age and the starting site (P>0.05), and related with clinical stageand (P<0.05); there is no significant differences between each Immunological subtypes of the expression in EZH2, it is not related with gender, age, the starting site and clinical stageand (P>0.05); Both the NSD2and EZH2on protein level and mRNA level in Diffuse large B-cell lymphoma histone methyltransferase is consistent.Conclusion:1,There is no relation on Nationality, age and clinical stage and related with the clinical stage and the starting site on the classification of diffuse large B-cell lymphoma subtypes GCB and NGCB;2, CD5type is related to age,, the starting location and clinical stage;3,the condition of NSD2and EZH2on protein level and mRNA level in Diffuse large B-cell lymphoma histone methyltransferase is consistent;4,the expression of NSD2and EZH2in DLBCL and benign lymph node is difference, it can be used for pathological diagnosis of the difficult diagnosis of malignant and benign lymph node lesions, provide guidance for the clinical diagnosis;5,Histone methyltransferase enzyme NSD2expression is related to the immunological subtype of DLBCL, however, the expression of EZH2does not concern on immunological subtype in diffuse large B-cell lymphoma. |
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