环状 RNA PTK2 通过海绵吸附 miR-134-5p 并激活 CELF2/PTEN 信号通路抑制胃癌的发生和转移。

CircPTK2 inhibits the tumorigenesis and metastasis of gastric cancer by sponging miR-134-5p and activating CELF2/PTEN signaling.

机构信息

Department of Gastroenterology, Shanghai Jiao Tong University Affiliated Sixth people's Hospital, Shanghai 200233, PR China.

出版信息

Pathol Res Pract. 2021 Nov;227:153615. doi: 10.1016/j.prp.2021.153615. Epub 2021 Sep 14.

DOI:10.1016/j.prp.2021.153615

PMID:34562827

Abstract

BACKGROUND

CircRNAs are a new subset of noncoding RNAs formed by covalent closed loops and play crucial roles in the regulation of cancer gene expression. However, the roles and underlying mechanisms of circRNAs in gastric cancer (GC) remain indistinct. This study aimed to explore the role and mechanism of hsa_circ_0006421 (circPTK2) in GC.

METHODS

The differential expression of circRNAs between GC tissues and adjacent normal tissues were identified by a circRNA expression profiling. Associations of circPTK2 or miR-134-5p expression with clinicopathological characteristics and prognosis of GC patients were analyzed by chi-square of Fisher's exact tests and Kaplan-Meier analysis. CCK8, colony formation, EdU assays and animal models were performed to assess the effects of circPTK2 on proliferation and invasion of GC cells. CircPTK2-specific probes were used to purify the RNA pulled down from the circPTK2, and enrichment of circPTK2 and miR-134-5p was detected by qRT-PCR. The effects of circPTK2 on miR-134-5p expression and CELF2/PTEN signaling were examined by qRT-PCR and Western blotting analysis.

RESULTS

Low expression of circPTK2 and high expression of miR-134-5p were related to the poor survival, and high expression of miR-134-5p was related to the tumor recurrence in GC patients. Overexpressing circPTK2 suppressed the proliferation, colony formation, DNA synthesis and cell invasion as well as xenograft tumor growth and lung metastasis in vitro and in vivo, whereas silencing circPTK2 had the opposite effects. Moreover, circPTK2 was negatively correlated and co-localized with miR-134-5p in the cytoplasm of GC tissue cells. circPTK2 bound to and sponged miR-134-5p in GC cells, and miR-134-5p facilitated cell growth and invasion but attenuated circPTK2 induced tumor suppressive effects and CELF2/PTEN signaling activation in GC cells.

CONCLUSIONS

circPTK2 functions as a tumor suppressor in GC by sponging miR-134-5p and activating the CELF2/PTEN axis.

摘要

背景

CircRNAs 是一类新的非编码 RNA，由共价闭合环组成，在调控癌症基因表达中发挥着关键作用。然而，circRNAs 在胃癌（GC）中的作用和潜在机制仍不清楚。本研究旨在探讨 hsa_circ_0006421（circPTK2）在 GC 中的作用和机制。

方法

通过 circRNA 表达谱分析鉴定 GC 组织与相邻正常组织之间 circRNAs 的差异表达。通过卡方检验和 Kaplan-Meier 分析分析 circPTK2 或 miR-134-5p 表达与 GC 患者临床病理特征和预后的关系。通过 CCK8、集落形成、EdU 检测和动物模型评估 circPTK2 对 GC 细胞增殖和侵袭的影响。使用 circPTK2 特异性探针从 circPTK2 下拉纯化 RNA，并通过 qRT-PCR 检测 circPTK2 和 miR-134-5p 的富集。通过 qRT-PCR 和 Western blot 分析检测 circPTK2 对 miR-134-5p 表达和 CELF2/PTEN 信号的影响。

结果

circPTK2 低表达和 miR-134-5p 高表达与 GC 患者的不良生存相关，而 miR-134-5p 高表达与肿瘤复发相关。过表达 circPTK2 抑制了体外和体内的增殖、集落形成、DNA 合成和细胞侵袭以及异种移植肿瘤生长和肺转移，而沉默 circPTK2 则有相反的效果。此外，circPTK2 在 GC 组织细胞的细胞质中与 miR-134-5p 呈负相关和共定位。circPTK2 在 GC 细胞中与 miR-134-5p 结合并海绵吸附 miR-134-5p，miR-134-5p 促进细胞生长和侵袭，但减弱了 circPTK2 在 GC 细胞中诱导的肿瘤抑制作用和 CELF2/PTEN 信号激活。