Background: Increasing evidence shows that circular RNAs (circRNAs) play a key role in the development of colorectal cancer (CRC). An interesting candidate RNA in this context is hsa-circRNA-0067835 (circIFT80), but its network of actions is still unclear.
Methods: Big data mining technology was used to explore the downstream microRNAs (miRNA) and messenger RNAs (mRNA) of the circIFT80 network. A regulatory network, comprising circIFT80 and its corresponding miRNAs and mRNAs, was derived to preliminarily explore the potential mechanism of circIFT80 in CRC. Finally, the proposed regulatory network was experimentally verified at the cellular level.
Results: A total of 6 miRNAs were screened, of which hsa-miR-197-3p, hsa-miR-370-3p and hsa-miR-377-5p may be the most potential downstream miRNAs of hsa-circRNA-0067835 in CRC. A total of 74 up-regulated genes with opposite miRNA expression were selected for subsequent verification. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases revealed that the target genes occurred more frequently in cancer-related pathways. In addition, protein–protein interaction (PPI) analysis of the target genes revealed a set of involved genes from which the hubTop 10 genes were selected for further analysis. Moreover, circRNA-miRNA-hubTop 10 mRNA networks were constructed. According to this analysis, circIFT80 simultaneously regulates hsa-miR-197-3p, hsa-miR-370-3p, and hsa-miR-377-5p, among which hsa-miR-370-3p seems to be associated with further genes that may be relevant to CRC development. Therefore, the proposed circIFT80/hsa-miR-370-3p/WNT7B, SLC1A5, RCBTB1 and COL6A6 signal axes were subjected to experimental verification. It could be shown that circIFT80 was up-regulated in CRC tissues. The circIFT80 was able to inhibit apoptosis and promote proliferation, migration and invasion. Moreover, circIFT80 inhibited the expression of hsa-miR-370-3p and promoted the expression of COL6A6, RCBTB1, SLC1A5 and WNT7B in CRC cell lines. Dual luciferase reporter assays further validated that circIFT80 is able to bind to hsa-miR-370-3p which in turn targets WNT7B.
Conclusion: The circIFT80 may play a role in carcinogenesis through the new circIFT80/hsa-miR-370-3p/WNT7B signal axis. These findings may provide potential biomarkers and therapeutic targets for the treatment of CRC.



中文翻译：

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构建Hsa-circRNA-0067835-miRNA-mRNA调控网络初步研究结直肠癌发病机制

背景：越来越多的证据表明，环状 RNA (circRNA) 在结直肠癌 (CRC) 的发展中起关键作用。在这种情况下，一个有趣的候选 RNA 是 hsa-circRNA-0067835 (circIFT80)，但其作用网络仍不清楚。
方法：利用大数据挖掘技术探索circIFT80网络的下游microRNAs（miRNA）和信使RNAs（mRNA）。衍生出一个由circIFT80及其相应的miRNA和mRNA组成的调控网络，初步探索了circIFT80在CRC中的潜在作用机制。最后，在细胞水平上对所提出的监管网络进行了实验验证。
结果：共筛选出6个miRNA，其中hsa-miR-197-3p、hsa-miR-370-3p和hsa-miR-377-5p可能是hsa-circRNA-0067835在CRC中最具潜力的下游miRNA。共选择了 74 个具有相反 miRNA 表达的上调基因进行后续验证。基因本体论（GO）和京都基因和基因组百科全书（KEGG）数据库显示，靶基因在癌症相关通路中出现的频率更高。此外，靶基因的蛋白质-蛋白质相互作用 (PPI) 分析揭示了一组相关基因，从中选择 hubTop 10 基因进行进一步分析。此外，构建了circRNA-miRNA-hubTop 10 mRNA网络。根据该分析，circIFT80 同时调节 hsa-miR-197-3p、hsa-miR-370-3p 和 hsa-miR-377-5p，其中 hsa-miR-370-3p 似乎与可​​能与 CRC 发展相关的其他基因有关。因此，对所提出的circIFT80/hsa-miR-370-3p/WNT7B、SLC1A5、RCBTB1和COL6A6信号轴进行了实验验证。可以证明circIFT80在CRC组织中上调。circIFT80能够抑制细胞凋亡并促进增殖、迁移和侵袭。此外，circIFT80 抑制 hsa-miR-370-3p 的表达，并促进 CRC 细胞系中 COL6A6、RCBTB1、SLC1A5 和 WNT7B 的表达。双荧光素酶报告基因分析进一步验证了 circIFT80 能够与 hsa-miR-370-3p 结合，后者反过来靶向 WNT7B。RCBTB1和COL6A6信号轴进行了实验验证。可以证明circIFT80在CRC组织中上调。circIFT80能够抑制细胞凋亡并促进增殖、迁移和侵袭。此外，circIFT80 抑制 hsa-miR-370-3p 的表达，并促进 CRC 细胞系中 COL6A6、RCBTB1、SLC1A5 和 WNT7B 的表达。双荧光素酶报告基因分析进一步验证了 circIFT80 能够与 hsa-miR-370-3p 结合，后者反过来靶向 WNT7B。RCBTB1和COL6A6信号轴进行了实验验证。可以证明circIFT80在CRC组织中上调。circIFT80能够抑制细胞凋亡并促进增殖、迁移和侵袭。此外，circIFT80 抑制 hsa-miR-370-3p 的表达，并促进 CRC 细胞系中 COL6A6、RCBTB1、SLC1A5 和 WNT7B 的表达。双荧光素酶报告基因分析进一步验证了 circIFT80 能够与 hsa-miR-370-3p 结合，后者反过来靶向 WNT7B。
结论： circIFT80可能通过新的circIFT80/hsa-miR-370-3p/WNT7B信号轴在癌变中发挥作用。这些发现可能为CRC的治疗提供潜在的生物标志物和治疗靶点。