lncRNA及其基因多态性对托珠单抗治疗难治性RA的疗效预测研究

Tocilizumab has been recommended as the first-line biological drug for patients with refractory rheumatoid arthritis, whereas considerable proportion of refractory rheumatoid arthritis patients has showed inadequate response to tocilizumab. Based on the consideration of the high price of tocilizumab and other types of biologics being available, the identification of biomarker predicting the efficacy of tocilizumab will provide scientific evidence for the individualized treatment of tocilizumab. Recent studies have demonstrated that lncRNA could serve as a novel type of biomarker for predicting drug efficacy. In this project, we will expand our study sample size and perform the following studies. First, lncRNA array will be used to screen plasma lncRNA which could be used to predict the efficacy of tocilizumab, and the replication study will be conducted in an independent sample by qRT-PCR. Then, the associations of single-nucleotide polymorphisms (SNPs) within genes of confirmed lncRNA will be examined. Finally, the prediction and function annotation of target genes of confirmed lncRNA using bioinformatics methods will provide preliminary biological evidence for the association between lncRNA and the efficacy of tocilizumab. This project has the potential to identify serum lncRNA and SNPs within lncRNA genes used to predict the efficacy of tocilizumab, thus providing scientific evidence for the individualized treatment of tocilizumab.

托珠单抗是治疗难治性RA患者的一线生物制剂，然而有相当比例的难治性RA患者经托珠单抗治疗后疗效欠佳，鉴于托珠单抗价格高昂且有其他类型生物制剂可供选择，发现可预测托珠单抗疗效的生物标记物将有助于实现托珠单抗的个体化治疗。新近研究表明lncRNA有望作为预测药物疗效的一类新型生物标记物，本项目拟在已有研究样本基础上，扩大样本量，首先采用lncRNA芯片筛选可预测托珠单抗治疗难治性RA患者疗效的血浆lncRNA，并运用qRT-PCR技术进行独立验证；其次，检测分析lncRNA基因SNP位点与托珠单抗治疗难治性RA患者疗效之间的关系；最后，通过lncRNA靶基因预测及其功能注释，初步阐明基于lncRNA预测托珠单抗治疗难治性RA患者疗效的生物学依据。本项目完成将有望发现可预测托珠单抗治疗难治性RA患者疗效的血浆lncRNA及其基因SNP位点，为难治性RA患者的托珠单抗个体化治疗提供科学参考依据。

鉴于新近研究表明lncRNA有望作为预测药物疗效的一类新型生物标记物，本项目探索了lncRNA及其遗传变异作为预测托珠单抗治疗RA疗效生物标记物的潜在可能。项目组运用lncRNA芯片检测分析了5例经托珠单抗治疗后有效者与5例经托珠单抗治疗后无效者的血浆lncRNA和mRNA表达谱，结果发现983和430个lncRNA在有效者中表达上调、下调，356和537个mRNA在有效者中表达上调、下调。鉴于RA发病相关lncRNA亦有可可能作为RA药物疗效预测生物标记物，项目组运用lncRNA芯片检测分析了4例初诊且未用药RA患者与4例年龄、性别匹配健康对照的血浆lncRNA和mRNA表达谱，结果发现289个lncRNA在RA患者血浆中表达异常，其中169个lncRNA表达上调，120个lncRNA表达下调。此外，468个mRNA在RA患者血浆中表达异常，其中280个mRNA表达上调，188个mRNA表达下调。基于生物信息学分析，项目组对差异表达lncRNA靶基因进行了预测，对差异表达mRNA进行了基因本体论（gene ontology，GO）和信号通路富集分析。基于芯片检测结果与文献报道，项目组检测并分析了FAM211A-AS1、H19、HOTAIR、MALAT1、NEAT1基因38个多态性位点与托珠单抗治疗RA疗效之间的关系，初步分析结果表明上述基因多态性位点与托珠单抗治疗RA疗效无关。此外，项目组分析了基线体质指数（body mass index，BMI）、血常规指标（血红蛋白-Hb、血小板-Plt、中性粒细胞-淋巴细胞比-NLR、血小板-淋巴细胞比-PLR）与托珠单抗治疗RA疗效之间的关系，结果发现基线Plt、NLR与PLR高者比低者有更多的临床疾病活动指数改善。由于目前大多数lncRNA的生物学功能尚处于探索阶段，加上本项目目前所累积样本量有限，在后续研究中我们将结合lncRNA研究进展和不断积累样本量，继续探索lncRNA及其遗传变异与托珠单抗治疗RA疗效之间的关系，以期为我国RA患者托珠单抗个体化治疗提供参考依据。