Circular RNA circ_0000515 adsorbs miR-542-3p to accelerate bladder cancer progression via up-regulating ILK expression.

Guohui Peng,Jing Guan,Manchao Cao,Pengfei Leng,Yuanfa Feng,Lijun Peng

doi:10.18632/aging.203818

Abstract

Background: Bladder cancer (BC) is a common cause of cancer-relevant deaths globally. This study is designed to delve into expressions, biological functions and molecular mechanisms of circ_0000515 in BC.Methods: Quantitative real-time polymerase chain reaction was accomplished to examine circ_0000515, miR-542-3p and integrin-linked kinase (ILK) mRNA expressions in BC tissues and cell lines. In RT-4 and RT-112 cells with circ_0000515 depletion and UMUC3 and BIU-87 cells with this circ RNA overexpression, a cell counting kit-8 assay was adopted to monitor the viability. Besides, transwell assay was conducted to detect cell migration and aggressiveness, and luciferase reporter gene assay was applied to probe the interplay among circ_0000515, miR-542-3p and ILK mRNA. Additionally, Besides, the regulatory function of circ_0000515 on miR-542-3p expression was under the assay of quantitative real-time polymerase chain reaction, and western blot was fulfilled to determine the regulative function of circ_0000515/miR-542-3p axis on ILK protein expressions. A xenograft animal was modeled to examine lung metastasis in vivo.Results: Circ_0000515 and ILK expressions were significantly elevated in BC tissues and cell lines, while that of miR-542-3p was dramatically suppressed. Knocking down circ_0000515 could significantly repress the growth, migration and aggressiveness of BC cells while overexpression of circ_0000515 showed opposite effects. Moreover, circ_0000515 knockdown inhibited pulmonary metastasis in vivo. Circ_0000515 was validated to adsorb miR-542-3p, and ILK was testified as the downriver target of miR-542-3p. Circ_0000515 could ascend ILK expression through repressing that of miR-542-3p.Conclusions: Circ_0000515, as a tumor promoter, strengthens the viability, migration and aggressiveness of BC cells via modulating miR-542-3p/ILK axis.

Highlights

Bladder cancer (BC) is a prevalent driver of cancerpertinent deaths globally
MiR542-3p expression in BC cell line with circ_0000515 depletion was increased significantly (Figure 4F). These findings indicated that miR-542-3p was the downriver target of circ_0000515
MiR-542-3p inhibitor was transfected into BC cells, and quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays manifested that integrin-linked kinase (ILK) mRNA and protein expression were ascended significantly; circ_0000515 knockdown repressed the expression level of ILK in both RT-4 and RT-112 cells while miR-542-3p inhibitors could partially reverse the inhibitory effects of knocking down circ_0000515 on ILK expressions (Figure 5H–5J and Supplementary Figure 1). These findings suggested that ILK was the downstream target of miR-542-3p in bladder cancer, and circ_0000515 regulated ILK expression through decoying miR-542-3p

Summary

Introduction

Bladder cancer (BC) is a prevalent driver of cancerpertinent deaths globally. BC incidence rises with age, reaching a peak at 50-70 years old [1]. Circ_0071196 facilitates BC cell proliferative and migrative abilities via tuning miR-19b-3p/CIT axis [3]; circRNA FOXO3 inhibits BC progression via regulating miR-95p/TGFBR2 axis [4]; circ_0061140 boosts BC metastasis via targeting miR-1236 [5]. Methods: Quantitative real-time polymerase chain reaction was accomplished to examine circ_0000515, miR542-3p and integrin-linked kinase (ILK) mRNA expressions in BC tissues and cell lines. The regulatory function of circ_0000515 on miR-542-3p expression was under the assay of quantitative real-time polymerase chain reaction, and western blot was fulfilled to determine the regulative function of circ_0000515/miR-542-3p axis on ILK protein expressions. Results: Circ_0000515 and ILK expressions were significantly elevated in BC tissues and cell lines, while that of miR-542-3p was dramatically suppressed. Conclusions: Circ_0000515, as a tumor promoter, strengthens the viability, migration and aggressiveness of BC cells via modulating miR-542-3p/ILK axis

Methods

Results

Conclusion