ABSTRACT
Objective: To investigate the expression of microRNA-1 (miRNA-1) in human esophageal squamous cell carcinoma (ESCC) tissues and its possible mechanism. Methods: The expression levels of miRNA-1 and LIM and SH3 domain protein 1 (LASP1) mRNA and LASP1 protein in 55 cases of ESCC and its adjacent para-cancerous tissues were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The potential target gene of miRNA-1 was predicted by online bioinformatics software. The target gene of miRNA-1 after Eca109 cells co-transfection with recombination dual luciferase reporter vector psiCHECK-2-LASP1 containing 3'-untranslated region (3'-UTR) with miRNA-1 binding site of LASP1 gene and miRNA-1 mimic was verified by dual-luciferase reporter assay system. The expressions of miRNA-1 and LASP1 protein in Eca109 cells after transfection with miRNA-1 mimic or miRNA-1 inhibitor were detected by real-time fluorescent quantitative-PCR and Western blotting, respectively. Results: The expression level of miRNA-1 in ESCC tissues was lower than that in adjacent para-cancerous tissues (P < 0.01), and the expression levels of LASP1 mRNA and protein were opposite (all P < 0.05). The expressions of miRNA-1 and LASP1 were associated with lymph metastasis, TNM staging and histological grade (all P < 0.05). The miRNA-1 expression in ESCC tissues was positively associated with LASP1 (r = +0.45, P < 0.05). LASP1 was target gene of miRNA-1. miRNA-1 could directly target the LASP1 3'-UTR. The expression level of miRNA-1 was up-regulated in Eca109 cells after transfection with miRNA-1 mimic (P < 0.01), and the expression level of LASP1 protein was down-regulated (P < 0.05). The expression level of miRNA-1 was down-regulated in Eca109 cells after transfection with miRNA-1 inhibitor (P < 0.05), and the expression level of LASP1 protein was up-regulated (P < 0.05). Conclusion: The expression level of miRNA-1 is low in ESCC tissues, and its mechanism may be associated with regulation of target gene LASP1.