Activation of circ_0072088/miR‐1261/PIK3CA pathway accelerates lung adenocarcinoma progression

Abstract

Abstract Background Circular RNAs (circRNAs) are involved in the tumorigenesis and progression of lung adenocarcinoma (LUAD). This study aimed to determine the role of circ_0072088 in LUAD. Methods The existence and expression of circ_0072088 in human LUAD tissues and cell lines were determined through Sanger sequencing, quantitative reverse transcription‐polymerase chain reaction, and fluorescence in situ hybridization (FISH). Subsequently, the biological role of circ_0072088 was examined using loss‐of‐function assays in H1299 cells. Moreover, circ_0072088/miR‐1261/PIK3CA pathway‐mediated biological effects in H1299 were verified using bioinformatic prediction and experiments, including interaction analysis (FISH, luciferase reporter, and RNA‐pulldown assays), and tumor biological function test (CCK8 and colony formation, wound healing, and transwell assays). Finally, miR‐1261 and PIK3CA expression and LUAD patient survival were further analyzed using FISH, immunohistochemical staining, and the Kaplan–Meier plotter database, respectively. Results First, an increase in circ_0072088 was confirmed in human LUAD tissues. Thereafter, it was mainly localized in the cytoplasm and was found to enhance cell proliferation, migration, and invasion of H1299 cells. Mechanistically, circ_0072088 directly downregulated miR‐1261 expression, whereas increased PIK3CA gene expression was associated with poor overall survival of LUAD patients. The activation of the circ_0072088/miR‐1261/PIK3CA regulatory pathway may play a significant role in the tumorigenesis and progression of LUAD. Conclusions Circ_0072088‐dependent regulation of miR‐1261/PIK3CA is important for cell proliferation, migration, and invasion during the tumorigenesis and progression of LUAD, warranting the need to consider the circ_0072088/miR‐1261/PIK3CA regulatory pathway as a potential therapeutic target in patients with lung adenocarcinoma.

Keywords

• bioinformatics
• cell lines
• circRNAs
• lung adenocarcinoma
• tumorigenesis