lncRNA LOC339524 inhibits the proliferation of bladder cancer cells by targeting the miR‑875‑5p/COPS7A signaling axis

Abstract

It has been reported that long non-coding RNAs (lncRNAs) play a crucial role in the progression of various types of cancer. The role of numerous lncRNAs in a variety of cancer types has been investigated. However, the underlying mechanisms of the majority of lncRNAs in bladder cancer (BCa) remain to be elucidated. In the present study, abnormally expressed lncRNAs in BCa and para-carcinoma tissues were identified through screening the Cancer RNA-Seq Nexus database and were validated using reverse transcription-quantitative PCR. It was found that LOC339524 expression levels were markedly downregulated in BCa tissues and cells (J82, T24, UM-UC-3 and 5637). LOC339524 overexpression was revealed to suppress the proliferation of BCa cells. LOC339524 was also discovered to act as a sponge for microRNA (miR)-875-5p, as identified using dual luciferase reporter assays and biotin pull-down analysis. LOC339524 downregulated the expression of miR-875-5p and knockdown of miR-875-5p expression inhibited the proliferation of bladder cancer cells. In addition, COP9 signalosome subunit 7A (COPS7A) was identified to be the target gene of miR-875-5p and COPS7A expression level was upregulated following LOC339524 overexpression. lncRNA LOC339524 was proposed to function as a competitive endogenous RNA to facilitate the expression of COPS7A by binding to miR-875-5p. In conclusion, the findings of the present study suggested that LOC339524 may inhibit cell proliferation in BCa by targeting the miR-875-5p/COPS7A signaling axis.

MicroRNA-875-5p inhibits the growth and metastasis of cervical cancer cells by promoting autophagy and apoptosis and inhibiting the epithelial-mesenchymal transition

“…These results support that miR-875-5p plays a crucial role in the growth and metastasis of CC. In agreement with our data, previous reports showed that miR-875-5p is involved in a number of types of cancer, such as gastrointestinal tract, lung and some other cancers (22,24,32). For example, miR-875-5p may inhibit tumor growth and metastasis in HCC by downregulating the expression of the initiation factor 3 subunit a (eIF3a) (22).…”

“…To our knowledge, no studies have evaluated the relationship between miR-875-5p and CC. Previous studies on miR-875-5p have confirmed that miR-875-5p affects cancer growth and metastasis in hepatocellular (22,49), lung (50) and bladder (24) cancers, suggesting the potential of this miRNA as a biomarker in the diagnosis and therapeutics of cancer. The low expression of miR-875-5p has been shown to be significantly associated with an unfavorable prognosis and clinical features of HCC, including large tumor size, venous invasion and advanced TNM stage, suggesting the potential clinical importance of this miRNA (22).…”

“…For example, miR-875-5p may inhibit tumor growth and metastasis in HCC by downregulating the expression of the initiation factor 3 subunit a (eIF3a) (22). Furthermore, miR-875-5p may inhibit cell proliferation in bladder cancer (24). However, the role of miR-875-5p in CC and the specific mechanism of its role remain unclear.…”

“…MicroRNA-875-5p, originally identified as a novel therapeutic target for prostate cancer, was shown to counteract the epithelial-tomesenchymal transition and enhance the radiotherapy response (21). Currently, numerous studies have also shown that miR-875-5p acts as a tumor suppressor in different types of human cancer, including HCC (22), gastric carcinoma (23), prostate cancer (21), and bladder cancer (24). A recent study reported that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro and inhibited tumorigenesis in vivo (25).…”