Zhang X Y, Ma Z P, Cui W L, Pang X L, Chen R, Wang L, Zhang W, Li X X
Department of Pathology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China.
Zhonghua Bing Li Xue Za Zhi. 2018 Jan 8;47(1):25-31. doi: 10.3760/cma.j.issn.0529-5807.2018.01.006.
To investigate the role of PRDM1 gene inactivaion in the regulation of C-MYC in diffuse large B-cell lymphoma (DLBCL), and to explore the correlation of its immunophenotype and prognosis. 100 cases paraffin-embedded DLBCL tissues were collected from January 2009 to December 2015 at the First Affiliated Hospital of Xinjiang Medical University along with 20 cases of reactive proliferative lymph nodes as control. Immunohistochemical methods were used to detect the expression of CD20, CD10, MUM1, Ki-67, bcl-6, PRDM1/Blimp1, C-MYC and PAX5 protein. The tumors were classified into two subtypes according to Hans classification.The expression of PRDM1 and C-MYC gene in tumor group and control group was detected by reverse transcription PCR (RT-PCR) and the relationship between PRDM1 and C-MYC gene was analyzed.OCI-LY1 (GCB subtype) and OCI-LY3 (non-GCB subtype) cell lines were transfected with small interfering RNA by cationic liposome reagent transfection, and the expression of C-MYC in the transfected cell lines was detected by RT-PCR and Western blot. The Kaplan-Meier method was used to analyze the prognostic significance of PRDM1/Blimp1 and C-MYC at protein and mRNA levels. There were 27 cases of GCB subtype and 73 cases of non-GCB subtype according to Hans classification. The positive expression of Blimp1 in DLBCL group and proliferative lymph nodes in control group was seen in 26(26.0%) and 20 cases(100%), respectively. There were 58 cases with high expression of PRDM1 at mRNA level, including 22 cases of GCB subtype and 36 cases non-GCB subtype, and the difference was statistically significant (=0.004). There were differences in PRDM1 gene expression between the two immunological subtypes, serum lactate dehydrogenase (serum LDH) level, presence of B symptoms, tumor primary sites and other clinical pathological parameters, while C-MYC expression was different in gender, IPI score, and serum LDH levels. Upon PRDM1/Blimp1 gene silencing in the two cell lines, C-MYC protein and gene expression were up-regulated in the transfection group, compared with the blank control group and negative control group by reverse transcription PCR and Western blot analyses. Moreover, PRDM1 expression was significantly associated with C-MYC(χ(2)=7.648, =0.006) at mRNA level. The up-regulation of C-MYC gene expression induced by PRDM1 inactivation in DLBCL may play an important role for the development of DLBCL.PRDM1 protein and mRNA are associated with immunophenotyping and PRDM1 mRNA is a marker of poor prognosis.
探讨PRDM1基因失活在弥漫性大B细胞淋巴瘤（DLBCL）中对C-MYC的调控作用，并探讨其免疫表型与预后的相关性。收集2009年1月至2015年12月新疆医科大学第一附属医院100例石蜡包埋的DLBCL组织，并选取20例反应性增生性淋巴结作为对照。采用免疫组织化学方法检测CD20、CD10、MUM1、Ki-67、bcl-6、PRDM1/Blimp1、C-MYC和PAX5蛋白的表达。根据Hans分类将肿瘤分为两个亚型。通过逆转录PCR（RT-PCR）检测肿瘤组和对照组中PRDM1和C-MYC基因的表达，并分析PRDM1与C-MYC基因之间的关系。用阳离子脂质体试剂转染法将小干扰RNA转染OCI-LY1（GCB亚型）和OCI-LY3（非GCB亚型）细胞系，通过RT-PCR和Western blot检测转染细胞系中C-MYC的表达。采用Kaplan-Meier法分析PRDM1/Blimp1和C-MYC在蛋白和mRNA水平的预后意义。根据Hans分类，GCB亚型27例，非GCB亚型73例。DLBCL组和对照组增生性淋巴结中Blimp1的阳性表达分别为26例（26.0%）和20例（100%）。PRDM1 mRNA水平高表达58例，其中GCB亚型22例，非GCB亚型36例，差异有统计学意义（=0.004）。两种免疫亚型之间PRDM1基因表达、血清乳酸脱氢酶（血清LDH）水平、B症状的存在、肿瘤原发部位及其他临床病理参数存在差异，而C-MYC表达在性别、国际预后指数（IPI）评分和血清LDH水平方面存在差异。在两种细胞系中PRDM1/Blimp1基因沉默后，通过逆转录PCR和Western blot分析，转染组C-MYC蛋白和基因表达较空白对照组和阴性对照组上调。此外，在mRNA水平上PRDM1表达与C-MYC显著相关（χ(2)=7.648，=0.006）。DLBCL中PRDM1失活诱导的C-MYC基因表达上调可能在DLBCL的发生发展中起重要作用。PRDM1蛋白和mRNA与免疫表型相关，PRDM1 mRNA是预后不良的标志物。
