Overexpression of miR-1260b in Non-small Cell Lung Cancer is Associated with Lymph Node Metastasis

Lymph node (LN) metastasis is often an early event in the progression of malignant tumors and it contributes to the majority of cancer mortalities. MiRNAs play key roles in tumor metastasis. This study aimed to investigate the specific miRNAs as putative indicators of metastasis early diagnosis for non-small cell lung cancer (NSCLC). In this study, five NSCLC cases with LN metastasis and four cases without metastasis (NLN) were enrolled for Agilent Human miRNA array. The interested differentially expressed miRNA was validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in the LN metastasis (n = 46) and NLN (n = 39) groups. The microarray results revealed that three miRNAs (miR-1260b, miR-423-3p, miR-23a-5p) were differentially expressed in LN metastasis group compared with NLN group. The expression of miR-1260b was tested by qRT-PCR and the mean relative expression fold change (2(-Delta Delta Ct)) in LN metastasis was significantly higher than that in the NLN group (3.942, 1.743 respectively, P = 1.179E-04). The patients with tumor-node-metastasis (TNM) stage III were identified more frequently in LN metastasis group (P = 1.772E-11) and with a higher expression level of miR-1260b (5.126, P = 1.147E-06). In addition, the LN metastasis cases were associated with a poorly differentiated degree (P = 0.007). The overexpression of miR-1260b in NSCLC with LN metastasis can be regarded as a specific signature for early progression and prognosis of NSCLC.