Upregulated expression of miR-421 is associated with poor prognosis in non-small-cell lung cancer

Abstract

BackgroundNon-small-cell lung cancer (NSCLC) represents the most frequent subtype of lung cancer. MicroRNAs (miRNAs) have attracted a lot of attention with regard to their clinical significance and crucial biological functions in various human cancers. This study aimed to investigate the prognostic significance of microRNA-421 (miR-421) and its correlation with tumor progression in NSCLC.Materials and methodsExpression levels of miR-421 in both serum and tissue samples were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The prognostic value of miR-421 was evaluated using Kaplan–Meier survival analysis and Cox regression assay. To explore the functional role of miR-421 during NSCLC progression, cell experiments were carried out.ResultsExpression of serum and tissue miR-421 was upregulated in the NSCLC patients compared with the normal controls (all P<0.001), and the expression showed a significant correlation between the serum samples and tissues (R=0.475, P<0.001). The increased miR-421 expression was associated with positive lymph-node metastasis and advanced TNM stage (all P<0.05). Moreover, patients with high miR-421 expression had poor overall survival compared with those with low expression (log-rank P=0.007). The overexpression of miR-421 proved to be an independent prognostic factor for NSCLC (HR=1.991, 95% CI=1.046–3.791, P=0.036). According to the cell experiments, the proliferation, migration and invasion of NSCLC cells were suppressed by knockdown of miR-421.ConclusionOverexpression of miR-421 serves as a prognostic biomarker and may be involved in the promotion of tumor progression in NSCLC.

ORP8 induces apoptosis by releasing cytochrome�c from mitochondria in non‑small cell lung cancer

“…Four different analytical programs were used to reveal that miR-421 could target ORP8. Previous research has revealed that miR-421 expression is upregulated and associated with poor prognosis in non-small-cell lung cancer (29). The present experiments revealed the role of miR-421 by determining that it targets ORP8, indicating that the upregulated miR-421 expression led to the reduction of ORP8 expression in NSCLC cells.…”

“…ORP8 is a target of miR-421. Studies have revealed that upregulated miR-421 expression is associated with poor prognosis in NSCLC (29). Therefore, it was assessed whether the downregulation of ORP8 in NSCLC was due to miR-421 dysregulation.…”

MicroRNA-1298 is downregulated in non-small cell lung cancer and suppresses tumor progression in tumor cells

“…Overexpression of miR-193b in glioma patients serves as a candidate diagnostic and prognostic biomarker [28]. In NSCLC patients, there are also some miRNAs members that have been determined as potential prognostic indicators, such as miR-126 [29], miR-451 [30] and miR-421 [31]. According to the survival analysis, this study obtained evidence for miR-1298 as an independent prognostic biomarker in the patients with NSCLC, which indicated by the survival curves and Cox regression analysis data.…”

Downregulation of miR-1826 Indicates a Poor Prognosis for Osteosarcoma Patients and Regulates Tumor Cell Proliferation, Migration, and Invasion

“…The miRNAs with deregulated expression values play important roles in tumorigenesis. For example, increased expression of miR-421 was observed in non-small-cell lung cancer patients and demonstrated to serve as a prognostic biomarker and tumor progression regulator [18]. Downregulated expression of miR-383-5p was detected in gastric cancer patients, which was related with a shorter survival time, tumor size, and differentiation grades and determined as a tumor suppressor [19].…”