Piwi互作RNA的筛选及其在儿童肾母细胞瘤组织中的表达

目的 探讨Piwi互作RNA（piRNA）在儿童肾母细胞瘤中的表达及临床意义。方法 对Piwi样蛋白2（Piwil2）基因重编程人成纤维细胞所形成的肿瘤样干细胞进行高通量测序，筛选出差异表达piRNA，并利用miRanda软件预测其靶基因，对靶基因进行基因本体（GO）功能分析。采用qRT-PCR检测差异表达piRNA及其靶基因在34例肾母细胞瘤患儿肿瘤组织及癌旁正常肾组织标本中的表达，并分析差异表达piRNA及其靶基因与肾母细胞瘤临床病理特征的关系。结果 通过高通量测序筛选出230个差异表达piRNA，利用miRanda软件预测出43个靶基因，经GO分析发现其参与的生物学过程主要为调节细胞钙离子浓度，分子功能主要为参与ATP酶的活动及多聚A尾RNA结合。选取5个未知的差异表达piRNA及其靶基因检测其在肾母细胞瘤肿瘤组织及癌旁正常组织中的表达情况，结果显示第13位未知上调piRNA（NU13）表达量在肿瘤组织中下调（P<0.01），其靶基因NOP56核糖核蛋白（NOP56）表达在肿瘤组织和癌旁正常组织中差异表达无统计学意义（P=0.58）；第9位未知上调piRNA（NU9）表达量在肿瘤组织中下调（P<0.01），其靶基因40S核糖体蛋白S8（RPS8）基因在肿瘤组织和癌旁正常组织中差异表达无统计学意义（P=0.29）；第5、7、9位未知下调piRNA（ND5、ND7、ND9）及其共同靶基因MT-RNR2样蛋白1（MTRNR2L1）基因的表达量在肿瘤组织中均下调（P均<0.01）。以上在儿童肾母细胞瘤组织中出现差异表达的piRNA及其靶基因与患儿年龄、性别、肿瘤临床分期、病理分型无明显相关性（P均>0.05）。结论 piRNA NU9、NU13、ND5、ND7、ND9及靶基因MTRNR2L1在儿童肾母细胞瘤组织中出现差异表达，有望成为鉴别肾母细胞瘤与正常肾组织的标志物。

Screening of Piwi-interacting RNAs and their expression in childhood nephroblastoma

Objective To investigate the expression and clinical significance of P-element-induced wimpy testis (Piwi)-interacting RNAs (piRNAs) in childhood nephroblastoma. Methods The differential piRNAs of Piwil2-iCSC (P-element-induced wimpy testis like 2Piwil2] reprogramming human fibroblast) were screened by high-throughput sequencing. Target genes were predicted by miRanda software and performed by gene ontology (GO) function analysis. Differential piRNAs and their target genes were detected by qRT-PCR in tumor tissues and normal kidney tissues of 34 children with nephroblastoma. The correlation of differential piRNAs and their target genes with clinicopathological characteristics of nephroblastoma was analyzed. Results A total of 230 differential piRNAs were screened out through high-throughput sequencing, and 43 target genes were predicted by miRanda. The GO analysis showed that the biological process of target genes was mainly involved in regulating the cytosolic calcium ion concentration and its molecular function was mainly involved in the activity of ATPase and poly (A) RNA binding. The expression of five unknown differentially expressed piRNAs and their target genes were detected in nephroblastoma and normal kidney tissues. The expression of NU13 (13th unknown upregulated piRNA) and NU9 (9th unknown upregulated piRNA) were significantly downregulated in tumor tissues (both P<0.01), while the expression of their target genes NOP56 ribonucleoprotein (NOP56, P=0.58) and 40S ribosomal protein S8 (RPS8, P=0.29) had no significant difference between tumor tissues and normal kidney tissues. The expression of ND5, ND7, ND9 (5th, 7th, 9th unknown downregulated piRNA) and their target gene MT-RNR2 like protein 1 (MTRNR2L1) were significantly downregulated in tumor tissues (all P<0.01). The above-mentioned piRNAs and their target genes had no significant correlation with age, gender, tumor stage, or pathological type of the children (all P>0.05). Conclusion piRNA NU9, NU13, ND5, ND7, ND9 and the target gene MTRNR2L1 are differentially expressed in children with nephroblastoma. They are expected to be markers to distinguish nephroblastoma from normal kidney tissues.