CD99调控miR-9诱导经典霍奇金淋巴瘤H/RS细胞再分化的机制研究

H/RS cells of Classical Hodgkin lymphoma derives from the mutant and disabled B lymphocytes in germinal center. Our recent research indicated that over-expression of CD99 in L428 of H/RS cell line results in the restoration of B-cell characteristics by increasing expression of plasma cell differentiation switch gene PRDM1, and specially inhibiting the high level of miR-9 expression. Particularly inhibiting miR-9 also triggered PRDM1 expressing. Therefor, we put forward a new content about inducing differentiation,that CD99 regulates miR-9 inducing H/RS cell to terminal B cell redifferentiation.In this study, we would increase H/RS cell lines to further the research. Gene and miRNA transfection, interfering, in vitro and in vivo experiments , proteomics and bioinformatic analysis will be applied for the following purposes:（1）to confirm that CD99 and miR-9 can induce H/RS cells redifferentiation toward terminal B cells ；（2）to verify that CD99 exerts the inducing differentiation function through the pathway of modulating miR-9/PRDM1；（3）to analyse and determine the intermediate proteins or pathways between CD99 and miR-9. Our study is to reveal a new mechanism of inducing H/RS cell differentiation, provide precise targets and theory evidence for cHL therapy by inducing H/RS cell differentiation, and further clarify the pathogenesis and development of H/RS cells.

经典霍奇金淋巴瘤（cHL）H/RS细胞起源于生发中心残疾B淋巴细胞，与细胞分化阻滞相关。前期我们发现H/RS细胞株L428稳定过表达CD99后重现B细胞特性，出现浆细胞分化基因PRDM1表达，miR-9表达受抑；单独抑制miR-9也可出现PRDM1表达，由此提出一个新的诱导分化内容：即CD99调控miR-9诱导H/RS细胞向终末B细胞再分化。本项目拟增加H/RS细胞株，采用基因和miRNA转染及干扰、体内外实验，并结合蛋白组学和生物信息学进行（1）确认CD99和miR-9诱导H/RS细胞向终末B细胞再分化；（2）证实CD99通过调控miR-9/PRDM1途径发挥诱导分化作用；（3）分析检测CD99和miR-9之间的调节蛋白或通路。旨在揭示一个新的诱导H/RS细胞分化机制，为cHL的诱导分化治疗提供理论依据和精确靶标，进一步阐明H/RS细胞发生发展的机理。

霍奇金淋巴瘤是一种常见的淋巴造血系统恶性肿瘤，近年来，随着生存环境的不断恶化、生活工作压力的不断上升以及器官移植免疫抑制剂的应用等，该病的发病率呈逐年升高趋势。目前诱导分化治疗将成为未来肿瘤治疗的一个新的发展方向，经典霍奇金淋巴瘤肿瘤细胞H/RS细胞起源于生发中心残疾的B淋巴细胞，与细胞分化阻滞相关。本课题检测了CD99和PRDM1基因在经典霍奇金淋巴瘤组织和细胞中低表达甚至缺失表达，经典霍奇金淋巴瘤细胞株L428细胞CD99基因上调后或下调miR-9，PRDM1蛋白的表达水平上调，恢复了部分B细胞表型和生发中心标记，并且出现浆细胞分化标记；过表达CD99基因下调了miR-9的表达，下调miR-9并不影响CD99的表达水平；miR-9能与TGF-βR1基因3′UTR结合，miR-9通过TGF-β1/Smad2/Smad3/Smad4信号途径调控L428细胞再分化，并且TGF-β1/Smad2/Smad3/Smad4信号通路每一个成员均能调控浆细胞分化开关蛋白PRDM1的表达。另外在研究过程中发现IMP3选择性的在HRS细胞中表达，IMP3可能成为霍奇金淋巴瘤的一个辅助诊断标记，和CD30一起共同帮助诊断霍奇金淋巴瘤。.本项目基本顺利完成，不仅揭示CD99调控miR-9诱导H/RS细胞向终末B细胞再分化的机制，为cHL的临床诱导分化治疗提供理论根据和和治疗靶标，同时也进一步阐明H/RS细胞的发生发展机制。