Microarray analysis of miRNA based on the regional lymph node metastasis status of esophageal squamous cell carcinoma

Background: Tendency toward extensive regional lymph node metastasis (LNM) is an important clinical characteristic of esophageal squamous cell carcinoma (ESCC) and differs greatly between patients. MicroRNAs (miRNAs) are involved in the invasion and metastasis of ESCC. We performed a microarray analysis of miRNAs based on LNM status to identify tumor-specific miRNAs for the prediction of LNM in ESCC. Methods: Four pairs of ESCC tumor tissues with or without LNM were selected for microarray analysis to identify differentially expressed miRNAs, then 50 tumor tissue samples were selected to verify the differences of the screened miRNAs with quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The relations between candidate miRNAs and clinicopathologic features were analyzed to confirm tumor specificity in the prediction of LNM in ESCC. Target gene prediction using miRWalk2.0 was used to analyze the potential mechanisms of the tumor-specific miRNAs. Results: The present microarray analysis identified significant differential expression in 62 miRNAs in the ESCC samples with LNM, compared to those without LNM. Of these, 19 miRNAs were selected for qRT-PCR verification, and three miRNAs were significantly upregulated in ESCC samples with !NM compared to those without LNM. The three miRNAs were not significantly associated with any other clinicopathologic features except for the TNM stage and could be regarded as tumor-specific miRNAs capable of predicting LNM in ESCC. Finally, 858 mRNAs were significantly associated with tumor-specific miRNAs and possibly involved in the regulation of LNM in ESCC. Conclusions: The present microarray analysis based on LNM status identified three tumor-specific miRNAs for predicting regional LNM in ESCC, which provides valuable clues for potential mechanism research and guarantees further investigation.