574411

MIR451A

microRNA 451a;MIR451A;microRNA 451a

microRNA 451

17q11.2

ncRNA

BACKGROUND: MicroRNAs play important roles in coordinating a variety of cellular processes. Abnormal expression of miRNAs has been linked to several cancers. However, the functional role of miR-451 in esophageal squamous cell carcinoma remains unclear. AIMS: The present study explored the effects of miR-451 on the biological behavior of the esophageal carcinoma cell line EC9706. METHODS: Synthetic miR-451 mimics were transfected into EC9706 cells using Lipofectamine 2000. The expression of miR-451 was analyzed by RT-PCR and the expressions of Bcl-2, AKT and phosphorylated AKT were analyzed by Western blotting. The MTT assay, soft agar colony formation assay, transwell assay and FACS were used to assess the effect of miR-451 on EC9706 cell proliferation, invasion, metastasis and apoptosis. tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice. RESULTS: In comparison to the controls, a significant increase in the expression of miR-451 was associated with significantly decreased expressions of Bcl-2, AKT and p-AKT, and a significant increase in the apoptosis rate. The number of cell clones was significantly decreased by miR-451 expression, which also caused the inhibition of cell proliferation. The average number of cells penetrating the matrigel was significantly lower than the controls. Injection of miR-451 inhibited tumor growth in a xenograft model. CONCLUSIONS: Upregulated expression of miR-451 induced apoptosis and suppressed cell proliferation, invasion and metastasis in the esophageal carcinoma cell line EC9706. In addition, injection of miR-451 inhibited tumor growth in a xenograft model of esophageal cancer.

MicroRNA (miRNA) expression is deregulated in many types of human cancers, including thyroid cancer. The purpose of this study was to investigate miRNA deregulation in papillary thyroid carcinoma (PTC), particularly with lymph node (LN) metastasis. To identify the miRNA signature in PTC with LN metastasis, miRNAs isolated from PTC patients with LN metastasis (n = 3) and without LN (NLN) metastasis (n = 3) were used for microarray analysis. Four differentially expressed miRNAs including miR-2861, miR-451, miR-193b, and miR-1202 were selected for further validation between the LN group (n = 51) and the NLN group (n = 36) using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The miRNA microarray results showed that compared to the NLN group, upregulation of four miRNAs including miR-2861, miR-451, miR-193b, and miR-1202 was associated with LN metastasis, whereas four other miRNAs including miR-let-7i, miR-542-5p, miR-664*, and miR-564 were downregulated in the LN group. In the validation cohort, the expression of either miR-2861 or miR-451 in the LN group was significantly greater than that in the NLN group (P = 0.004 and 0.026, respectively). Furthermore, the expression levels of miR-2861 and miR-451 in lateral lymph node (LLN) metastasis were significantly greater than those in central lymph node (CLN) metastasis (P = 0.007 and 0.001, respectively). Upregulated expression of miR-2861 and miR-451 in PTC with LN metastasis represents a unique miRNA signature associated with the prognosis and progression of PTC.