Cir-ITCH inhibits gastric cancer migration, invasion and proliferation by regulating the Wnt/\u03b2-catenin pathway

Yang Peng,Hong Hong Wang

doi:10.1038/s41598-020-74452-8

Yang Peng, Hong Hong Wang

Open Access

https://doi.org/10.1038/s41598-020-74452-8

Copy DOI

Abstract

Circular RNAs (circRNAs) are differentially expressed in various tumours, but the expression and regulatory mechanisms of circular RNA ITCH (cir-ITCH) in gastric cancer remain unclear. For this reason, in the present study, we assessed the expression of cir-ITCH and the associated regulatory mechanism of cir-ITCH in gastric cancer. Through RTq-PCR assays, we observed that cir-ITCH expression was attenuated in gastric cancer cell lines and tissues, with cir-ITCH expression in gastric cancer tissues with lymph node metastasis being considerably lower than that observed in gastric cancer tissues without lymph node metastasis. In addition, we demonstrated that cir-ITCH or linear ITCH may be a useful marker for gastric cancer prognosis by Kaplan–Meier survival analysis. We also showed that cir-ITCH overexpression could increase linear ITCH expression through miR-17 via RNA immunoprecipitation (RIP) and luciferase reporter assays. Moreover, in vivo and in vitro experimental results showed that cir-ITCH can act as a tumour suppressor to prevent gastric cancer tumourgenesis by sponging miR-17. The Wnt/β-catenin pathway plays a crucial role during the carcinogenesis of cancers, and we observed that cir-ITCH could negatively regulate Wnt/β-catenin signalling, which could be restored by miR-17. In summary, cir-ITCH was shown to prevent gastric cancer tumourgenesis through the Wnt/β-catenin signalling pathway by sequestering miR-17.

Highlights

Circular RNAs are differentially expressed in various tumours, but the expression and regulatory mechanisms of circular RNA ITCH in gastric cancer remain unclear
We observed that linear ITCH expression did not differ between the total RNA and poly(A)-enriched RNA samples in both AGS and MKN45 cells, whereas cir-ITCH expression was attenuated in the poly(A)-enriched RNA compared with that observed in total RNA in these two gastric cancer cell lines (Fig. 1B)
As cir-ITCH shares some miRNA binding sites with the 3′UTR of ITCH and can regulate linear ITCH expression in different c ancers[16,17,18], we inferred that cir-ITCH may be a crucial gene in the development of gastric cancer

Summary

Introduction

Circular RNAs (circRNAs) are differentially expressed in various tumours, but the expression and regulatory mechanisms of circular RNA ITCH (cir-ITCH) in gastric cancer remain unclear. In vivo and in vitro experimental results showed that cir-ITCH can act as a tumour suppressor to prevent gastric cancer tumourgenesis by sponging miR-17. Cir-ITCH was shown to prevent gastric cancer tumourgenesis through the Wnt/β-catenin signalling pathway by sequestering miR-17. MiRNAs can regulate the expression of tumour suppressor genes and oncogenes by binding to the 3′UTRs of mRNA, and recent studies having shown that circular RNAs (circRNAs) possess miRNA binding sites and function as sponges to sequester m iRNAs4,5. Wnt/β-catenin pathway can be regulated by cir-ITCH in colorectal cancer by sponging miR-7 and miR-20a18. In addition to regulating the Wnt/β-catenin pathway, cir-ITCH can affect the expression of other genes. No studies have investigated the functional roles of circRNAs in gastric cancer

Methods

Results

Conclusion