LncRNA-NAALADL2-AS2作为ceRNA调控miRNA网络介导弥漫大B细胞淋巴瘤 MYC/BCL-2过表达的作用及机制研究

Diffuse large B-cell lymphoma (DLBCL) is a highly heterogeneous disease. The co-expression of MYC and BCL-2 in DLBCL was called dual expressors (DE-DLBCL), and has been associated with poor response to therapy and shorter survival. Our previous research found upregulation of LncRNA-NAALADL2-AS2 in DLBCL, which could act as ceRNA to regulate miRNA networks mediating MYC/BCL-2 overexpression. Besides, given that NAALADL2-AS2 was also activated by NF-κB, it was assumed that there might be a feedback loop from NAALADL2-AS2 high expression inhibiting miR-24/34a via and thus activating NF-κB. Aiming at this hypothesis, we are to investigate: ① the mechanism and significance of NAALADL2-AS2 as ceRNA inhibiting miRNA networks and mediating MYC/BCL-2 overexpression; ② the mechanism of the feedback loop from NAALADL2-AS2 high expression inhibiting miR-24/34a via and thus activating NF-κB; and .③ how the above mentioned pathway induces DLBCL to proliferate and develop resistance to therapy at the cellular and animal level, and thus providing novel evidences for the diagnosis and treatment paradigm of DLBCL.

弥漫大B细胞淋巴瘤（DLBCL）是高度异质性的淋巴肿瘤，伴“MYC/BCL-2”双表达者治疗反应差，生存期显著缩短。课题组前期发现DLBCL中存在LncRNA-NAALADL2-AS2高表达，其可能作为ceRNA调控miRNA网络介导MYC/BCL-2过表达；且NAALADL2-AS2受NF-κB调控，NAALADL2-AS2高表达通过抑制miR-24/34a上调NF-κB信号形成反馈通路。本研究拟针对此假说开展以下研究：①阐明DLBCL中NAALADL2-AS2作为ceRNA抑制miRNA网络，介导MYC/BCL-2过表达的机制及意义；②NAALADL2-AS2通过抑制该miRNA网络中的miR-24/34a上调NF-κB信号形成反馈通路，致NF-κB信号持续活化的内在机制。③在细胞水平和模式生物水平阐明上述通路促进DLBCL增殖、耐药的效能，为DLBCL的治疗提供有价值的基础研究信息。

弥漫大B细胞淋巴瘤（DLBCL）是高度异质性的淋巴肿瘤，伴“MYC/BCL-2”双表达者治疗反应差，生存期显著缩短。课题组通过高通量 LncRNA 芯片 Human LncRNA Microarray及生物信息学分析，发现DLBCL中存LncRNA-NAALADL2-AS2高表达，其可能作为ceRNA调控miRNAs网络介导MYC/BCL-2过表达，进而介导DLBCL细胞的存活和化疗抵抗。本课题运用 siRNA干扰、miRNA转染、转录因子调控、蛋白检测等实验手段，从临床样本、体外及体内实验三个层面阐明上述反馈通路在DLBCL增殖、耐药中的促进作用，为DLBCL的临床治疗提供有价值的基础研究信息。.主要研究结果：1、NAALADL2-AS2在DLBCL 细胞表达，并与患者预后相关，其作为 ceRNA 显著抑制 miR-34a、miR-125a表达，进而上调BCL-2表达，与DLBCL细胞凋亡抑制相关。2、体外细胞及模式动物水平研究 NAALADL2-AS2 通过上述通路促进 DLBCL细胞耐药的效能，发现抑制NAALADL2-AS2可通过上调miR-34a、miR125a，进一步下调BCL-2蛋白，逆转DLBCL细胞对氟达拉滨及美罗华耐药。.本研究阐明了 DLBCL 中 NAALADL2-AS2 作为 ceRNA 抑制 miRNA网络，介导 BCL-2 过表达导致耐药的具体机制，为基于此通路基础上促进DLBCL细胞凋亡及耐药逆转的分子靶向治疗提供理论依据。