miR-516b functions as a tumor suppressor by directly modulating CCNG1 expression in esophageal squamous cell carcinoma.

miR-516b, as a tumor suppressor in several tumors, its regulatory role in esophageal squamous cell carcinoma (ESCC) hasn't been previously reported. This study was to investigate the potential role of miR-516b in ESCC. miR-516b expression was measured in ESCC tumor specimens and matched adjacent non-cancerous tissues from 80 ESCC patients. The association between miR-516b and clinicopathological features of these patients was analyzed. The effect of miR-516b was evaluated by cell proliferation, migration, invasion and apoptosis assays in ESCC cell line EC9706 and TE-9. The role of miR-516b in vivo was further studied by constructing ESCC xenograft mice model. The direct target of miR-516b was predicted by public miRNA database and confirmed by luciferase reporter assay. The regulation of miR-516b on the target gene was further confirmed in vitro and in vivo. The expressions of proteins related to cell cycle and apoptosis were analyzed by western blot analysis, and cell migration and invasion were assessed by transwell assays. miR-516b expression was reduced in ESCC tissues and cells, and correlated with advanced TNM stage, depth of invasion, lymphatic metastasis and poorer overall survival in ESCC patients. miR-516b was upregulated by miR-516b mimics repressing cell proliferation, and inducing G1 cell cycle arrest and apoptosis. miR-516b upregulation also suppressed the growth of ESCC xenograft tumor in nude mice and the invasion of ESCC cells via regulating the epithelial-mesenchymal transition pathway. CCNG1 was identified as a direct downstream target of miR-516b. The results demonstrated miR-516b functions as a tumor suppressor by directly modulating CCNG1 expression in ESCC cells, and may be a novel therapeutic and prognostic biomarker for ESCC.

Zhao Y ，Wang Y ，Xing G 《-》

Plasma miR-185 is decreased in patients with esophageal squamous cell carcinoma and might suppress tumor migration and invasion by targeting RAGE.

The receptor for advanced-glycation end products (RAGE) is upregulated in various cancers and has been associated with tumor progression, but little is known about its expression and regulation by microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC). Here, we describe miR-185, which represses RAGE expression, and investigate the biological role of miR-185 in ESCC. In this study, we found that the high level of RAGE expression in 29 pairs of paraffin-embedded ESCC tissues was correlated positively with the depth of invasion by immunohistochemistry, suggesting that RAGE was involved in ESCC. We used bioinformatics searches and luciferase reporter assays to investigate the prediction that RAGE was regulated directly by miR-185. Besides, overexpression of miR-185 in ESCC cells was accompanied by 27% (TE-11) and 49% (Eca-109) reduced RAGE expression. The effect was further confirmed in RAGE protein by immunofluorescence in both cell lines. The effects were reversed following cotransfection with miR-185 and high-level expression of the RAGE vector. Furthermore, the biological role of miR-185 in ESCC cell lines was investigated using assays of cell viability, Ki-67 staining, and cell migration and invasion, as well as in a xenograft model. We found that overexpression of miR-185 inhibited migration and invasion by ESCC cells in vitro and reduced their capacity to develop distal pulmonary metastases in vivo partly through the RAGE/heat shock protein 27 pathway. Interestingly, in clinical specimens, the level of plasma miR-185 expression was decreased significantly (P = 0.002) in patients with ESCC [0.500; 95% confidence interval (CI) 0.248-1.676] compared with healthy controls (2.410; 95% CI 0.612-5.671). The value of the area under the receiver-operating characteristic curve was 0.73 (95% CI 0.604-0.855). In conclusion, our findings shed novel light on the role of miR-185/RAGE in ESCC metastasis, and plasma miR-185 has potential as a novel diagnostic biomarker in ESCC.

Jing R ，Chen W ，Wang H ，Ju S ，Cong H ，Sun B ，Jin Q ，Chu S ，Xu L ，Cui M ... -  《-》

microRNA-messenger RNA regulatory network of esophageal squamous cell carcinoma and the identification of miR-1 as a biomarker of patient survival.

Emerging evidence indicates that microRNAs (miRNAs) play an important role in tumor carcinogenesis and progression by targeting gene expression. The goal of this study was to comprehensively analyze the vital functional miRNAs and their target genes in esophageal squamous cell carcinoma (ESCC) and to explore the clinical significance and mechanisms of miR-1 in ESCC. First, the miRNA and messenger RNA (mRNA) expression profiles of ESCC were determined with microarray technology. Using an integrated analysis of miRNAs and their target genes with multistep bioinformatics methods, the miRNA-mRNA regulatory network in ESCC was constructed. Next, miR-1 expression in 292 ESCC patients and its relationship with clinicopathological features and prognosis were detected by in situ hybridization. Furthermore, the biological functions of miR-1 were determined with in vitro and in vivo functional experiments. Finally, real-time quantitative reverse transcription polymerase chain reaction, Western blot analysis, and luciferase reporter assays were performed to verify the target genes of miR-1. In this study, 67 miRNAs and 2992 genes were significantly differentially expressed in ESCC tissues compared with their expression in adjacent normal tissues, and an miRNA-mRNA regulatory network comprising 59 miRNAs and 162 target mRNAs was identified. Low miR-1 expression was correlated with pathological T stage, lymph node metastasis, vessel invasion, and poor clinical outcome. miR-1 suppressed ESCC cell proliferation and invasion and promoted ESCC cell apoptosis. Fibronectin 1 (FN1) was verified as a direct target of miR-1. Taken together, the present results suggest that miR-1 may be a valuable prognostic predictor for ESCC, and the miR-1/FN1 axis may be a therapeutic target.

Wei Q ，Li X ，Yu W ，Zhao K ，Qin G ，Chen H ，Gu Y ，Ding F ，Zhu Z ，Fu X ，Sun M ... -  《-》

Downregulation of MiR-31 stimulates expression of LATS2 via the hippo pathway and promotes epithelial-mesenchymal transition in esophageal squamous cell carcinoma.

Gao Y ，Yi J ，Zhang K ，Bai F ，Feng B ，Wang R ，Chu X ，Chen L ，Song H ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

miR-483-3p plays an oncogenic role in esophageal squamous cell carcinoma by targeting tumor suppressor EI24.

microRNAs (miRNAs), through negatively regulating their target genes, influence the development and progression of many cancers. Previously, we found miR-483 was overexpressed in esophageal squamous cell carcinoma (ESCC) tissues, and its overexpression was negatively correlated with the prognosis and positively correlated with multidrug resistance of ESCC, but whether it could affect the biological role of proliferation and migration in ESCC cell lines is unknown. In the present study, we found miR-483-3p was overexpressed in ESCC cell lines as compared with the normal esophageal squamous epithelial cell line. Functional experiments in vitro showed that miR-483-3p could promote the proliferation, migration, transformation of cell cycle from G1 phase to G2 phase of ESCC cells and could inhibit cells' sensitivity to chemotherapy drugs. Nude mouse tumorigenicity assay indicated that miR-483-3p could promote the growth of ESCC cells in vivo. Western blot assay showed that ectopic expression of miR-483-3p in ESCC cells could downregulate the protein level of etoposide induced 2.4 (EI24), which is a tumor suppressor and has not been reported in ESCC. Luciferase reporter assay demonstrated that EI24 was a direct target of miR-483-3p. Collectively, our study demonstrated that miR-483-3p could promote ESCC progression at least in part through directly targeting EI24, supplying a potential strategy for miRNA-based ESCC therapy.

Ma J ，Hong L ，Xu G ，Hao J ，Wang R ，Guo H ，Liu J ，Zhang Y ，Nie Y ，Fan D ... -  《-》