A novel protein encoded by a circular RNA circPPP1R12A promotes tumor pathogenesis and metastasis of colon cancer via Hippo-YAP signaling
A novel protein encoded by a circular RNA circPPP1R12A promotes tumor pathogenesis and metastasis of colon cancer via Hippo-YAP signaling
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环状RNA circPPP1R12A编码的新型蛋白质通过Hippo-YAP信号促进结肠癌的肿瘤发病机制和转移
DOI：
10.1186/s12943-019-1010-6
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发表时间：
2019-03-29
期刊：
影响因子：
37.3
通讯作者：
Jiang, Jingting
中科院分区：
文献类型：
--
作者：
Zheng, Xiao;Chen, Lujun;Jiang, Jingting
背景：环状rna （circRNAs）在肿瘤进展过程中发挥着重要的调节作用。最近的研究表明，尽管circRNAs通常通过miRNA海绵调节基因表达，但它们可能在肿瘤发病过程中编码小肽。然而，circrna是否参与结肠癌（CC）的肿瘤发生在很大程度上仍未被探索。方法采用circRNA芯片检测CC组织中circRNA的表达谱。采用实时荧光定量PCR、RNase R酶切法和组织芯片技术证实circPPP1R12A的存在及其表达模式。采用核质量分离法和荧光原位杂交（FISH）分析了circPPP1R12A的亚细胞分布。采用SDS-PAGE和LC/MS对circPPP1R12A的蛋白编码能力进行了评价。采用慢病毒法稳定转染CC细胞，评估细胞在裸鼠体内的增殖、迁移、侵袭、肿瘤发生和转移，明确circPPP1R12A及其编码蛋白circPPP1R12A-73aa的功能作用。通过rna测序和Western blotting分析进一步鉴定circPPP1R12A-73aa调控的关键信号通路。结果我们首先筛选了CC组织中人类circRNAs的表达谱，发现hsa_circ_0000423（称为circPPP1R12A）在CC组织中的表达显著增加。我们还发现circPPP1R12A主要定位于CC细胞的细胞质中。Kaplan-Meier分析显示circPPP1R12A水平较高的患者总生存期明显较短。通过功能获得和功能丧失的方法，结果表明circPPP1R12A在CC细胞的增殖、迁移和侵袭中发挥了关键作用。此外，我们发现circPPP1R12A携带一个开放阅读框（ORF），该框编码一个功能蛋白（称为circPPP1R12A-73aa）。接下来，我们发现PPP1R12A-C在体外和体内促进CC的增殖、迁移和侵袭能力，而不是circPPP1R12A。最后，我们发现circPPP1R12A-73aa通过激活Hippo-YAP信号通路促进CC的生长和转移。此外，YAP特异性抑制剂Peptide 17显著减轻了circPPP1R12A-73aa对CC细胞的促进作用。在本研究中，我们发现circPPP1R12A在CC的发展过程中具有编码潜力，并且circPPP1R12A-73aa通过激活Hippo-YAP信号通路促进CC的肿瘤发病和转移。我们的发现可能为开发新的CC潜在治疗靶点提供有价值的见解。
BackgroundIt has been well established that circular RNAs (circRNAs) play an important regulatory role during tumor progression. Recent studies have indicated that even though circRNAs generally regulate gene expression through miRNA sponges, they may encode small peptides in tumor pathogenesis. However, it remains largely unexplored whether circRNAs are involved in the tumorigenesis of colon cancer (CC).MethodsThe expression profiles of circRNAs in CC tissues were assessed by circRNA microarray. Quantitative real-time PCR, RNase R digestion assay and tissue microarray were used to confirm the existence and expression pattern of circPPP1R12A. The subcellular distribution of circPPP1R12A was analyzed by nuclear mass separation assay and fluorescence in situ hybridization (FISH). SDS-PAGE and LC/MS were employed to evaluate the protein-coding ability of circPPP1R12A. CC cells were stably transfected with lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPPP1R12A and its encoded protein circPPP1R12A-73aa. RNA-sequencing and Western blotting analysis were furthered employed to identify the critical signaling pathway regulated by circPPP1R12A-73aa.ResultsWe firstly screened the expression profiles of human circRNAs in CC tissues and found that the expression of hsa_circ_0000423 (termed as circPPP1R12A) was significantly increased in CC tissues. We also found that circPPP1R12A was mostly localized in the cytoplasm of CC cells. Kaplan-Meier analysis showed that patients with higher levels of circPPP1R12A had a significantly shorter overall survival. By gain- and loss-of-function approaches, the results suggested that circPPP1R12A played a critical role in proliferation, migration and invasion of CC cells. Furthermore, we showed that circPPP1R12A carried an open reading frame (ORF), which encoded a functional protein (termed as circPPP1R12A-73aa). Next, we found that PPP1R12A-C, not circPPP1R12A, promoted the proliferation, migration and invasion abilities of CC in vitro and in vivo. Finally, we identified that circPPP1R12A-73aa promoted the growth and metastasis of CC via activating Hippo-YAP signaling pathway. In addition, the YAP specific inhibitor Peptide 17 dramatically alleviated the promotive effect of circPPP1R12A-73aa on CC cells.ConclusionsIn the present study, we illustrated the coding-potential of circRNA circPPP1R12A in the progression of CC. Moreover, we identified that circPPP1R12A-73aa promoted the tumor pathogenesis and metastasis of CC via activating Hippo-YAP signaling pathway. Our findings might provide valuable insights into the development of novel potential therapeutic targets for CC.