MiroRNA-31-3p Promotes the Invasion and Metastasis of Non-Small-Cell Lung Cancer Cells by Targeting Forkhead Box 1 (FOXO1)

Abstract

Objective. To explore the possibility of microRNA miR-31-3p as a biomarker for bone metastasis of non-small-cell lung cancer (NSCLC) and its molecular mechanism to the invasion and metastasis of NSCLC cells. Methods. Real-time quantitative PCR (RT-qPCR) was used to detect the expression levels of miR-31-3p and forkhead box 1 (FOXO1) in NSCLC tissues, serum, and cells to analyze the correlation between the expression levels of miR-31-3p and the clinicopathology of NSCLC. After interference with or overexpressing miR-31-3p, NSCLC cell proliferation, apoptosis, invasion ability, and migration ability were detected by MTT, flow cytometry, Transwell, and scratch experiment, respectively. The interaction between miR-31-3p and FOXO1 was further verified by the dual-luciferase reporter experiment. Western blot was performed to detect the protein expression of FOXO1 in tissues and FOXO1, RhoA, p-RhoA, ROCK-2, and p-ROCK-2 in cells. Results. In tissues, serum, and NSCLC cell line A549 of the NSCLC patients, the expression of FOXO1 was notably lower, and the miR-31-3p expression was significantly higher. Overexpression of miR-31-3p could distinctly improve the proliferation, invasion, and migration of A549 cells, meanwhile inhibit cell apoptosis, and activate the RhoA/ROCK-2 signaling pathway, while interfering with the expression of miR-31-3p has the opposite function. Besides, bioinformatics analysis and luciferase reporter assay confirmed that FOXO1 was a target gene of miR-31-3p. Overexpressing FOXO1 could inhibit the proliferation and metastasis of A549 cells, but overexpressing miR-31-3p reverses the results. Conclusion. This study confirmed that miR-31-3p promotes the proliferation, invasion, and migration of NSCLC cells and inhibits apoptosis through targeted regulating FOXO1 and be a potential therapeutic targets for the treatment of NSCLC.

The Roles and Regulatory Mechanisms of Tight Junction Protein Cingulin and Transcription Factor Forkhead Box Protein O1 in Human Lung Adenocarcinoma A549 Cells and Normal Lung Epithelial Cells

“…FOXO1 is a forkhead transcription factor of the FOXO subfamily and a shared component among pathways regulating diverse cellular functions such as differentiation, metabolism, proliferation, and survival [18]. Furthermore, the upregulation of FOXO1 affects the malignancy of various cancers, including non-small-cell lung cancer (NSCLC) [49,50]. In NSCLC, overexpressing FOXO1 could inhibit the proliferation and metastasis of A549 cells [49].…”

Extracellular circulating miRNAs as potential non-invasive biomarkers in non-small cell lung cancer patients

“…Expression of this miRNA was negatively associated with large tumour size, distant metastasis, advanced TNM stage and poor prognosis (89). The research of Zeng et al (91) showed that the expression miR-31-3p level was significantly higher in serum and NSCLC tissue. Further analysis showed that high expression of miR-31-3p with the TNM classification, and lymphatic metastasis could be used as risk factors and independent predictors of bone metastasis, while tumour size could be used as a risk factor for bone metastasis.…”

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

“…Tumors are often considered incurable once bone metastasis has occurred and current diagnostic methods expose patients to radiation, thus biomarkers for early detection and prediction of patients at risk are highly sought after ( 176 , 195 ). Multiple miRNA biomarkers have been identified for detection of bone metastasis in prostate cancer ( 168 – 175 ), breast cancer ( 176 , 177 ), hepatocellular carcinoma ( 178 ) and lung cancer ( 180 – 182 ). Additionally, in lung cancer bone metastasis, Valencia et al.…”