Identification of miR‑124a as a novel diagnostic and prognostic biomarker in non‑small cell lung cancer for chemotherapy

Abstract

Previous studies have suggested that dysregulation of microRNA (miR) -124a is associated with various types of human cancer. However, there are few studies reporting the level of miR‑124a expression in non‑small cell lung cancer (NSCLC). The present study investigated the association between miR‑124a and NSCLC by analyzing the differential expression of miR‑124a in NSCLC using the GEO database, as well as subsequently performing reverse transcription‑quantitative polymerase chain reaction analysis on 160 NSCLC biopsies, 32 of which were paired with adjacent normal tissues. The results indicated that mir‑124a expression levels were decreased in NSCLC tumor biopsies compared with adjacent normal tissues. The overall survival (OS) in patients with a high expression of miR‑124a was prolonged relative to patients with low expression of miR‑124a. The expression levels of miR‑124a were associated with clinical characteristics, including lymph‑node metastasis, tumor differentiation, tumor node metastasis (TNM) stage and diameter. Frequently, lymph‑node metastasis, TNM stage, diameter and lack of chemotherapy have been associated with a worse prognosis in patients. In addition, the present study identified that high expression of miR‑124awith chemotherapy may increase OS. In conclusion, the current study demonstrated that miR‑124a was downregulated in NSCLC, and miR‑124a was a potential prognostic tumor biomarker response to chemotherapy.

Figure 1.

Analysis of miR-124a expression in NSCLC patients using the GEO database. (A) Expression levels of miR-124a in 16 different cell lines derived from the GEO database. (B) Expression levels of miR-124ain normal vs. other cancers derived from the GEO database. (C) Expression levels of miR-124ain 30 paired lung cancer tissues derived from the GEO database. The fold-change for miR-124a expression levels was calculated using thelog2 ratio of paired tumor/normal expression. (D) Expression levels of miR-124ain normal vs. 17 paired lung cancer tissues derived from the GEO database. *P<0.05, **P<0.01 vs. normal tissues. miR, microRNA; NSCLC, non-small cell lung cancer; GEO, Gene Expression Omnibus; FC, fold change.

Figure 2.

Analysis of miR-124a expression in 32 paired NSCLC tissues using the reverse transcription-quantitative polymerase chain reaction. (A) Expression levels of miR-125a-3p in 32 paired NSCLC tissues. (B) Expression levels of miR-125a-3p in 32 normal vs. 160 lung cancer tissues. NSCLC, non-small cell lung cancer; miR, microRNA; FC, fold change.

Figure 3.

Univariate survival analysis of different clinical parameters in non-small cell lung cancer. Univariate survival analysis of (A) overall survivaland (B) disease-free survival stratified by lymph node metastasis, (C) overall survival and (D) disease-free survival stratified by tumor node metastasis stage, and (E) overall survival and (F) disease-free survival stratified by tumor diameter, as determined by Kaplan-Meier plots estimates.

Figure 4.

Survival analysis of chemotherapy and miR-124a expression in non-small cell lung cancer. Univariate survival analysis of (A) overall survival and (B) disease-free survival stratified by chemotherapy, (C) overall survival and (D) disease-free survival stratified by miR124-a expression, and (E) overall survival and (F) disease-free survival stratified by chemotherapy and miR-124a expression, as determined by Kaplan-Meier plots estimates. miR, microRNA; P&H, chemotherapy and high miR-124a expression; N&L, no chemotherapy and low miR-124a expression.