The association of microRNAs (miRs) with cancer progression has been established in many cancers including esophageal squamous cell carcinoma (ESCC). A public microarray database showed that the expression of miR-150 was lower in ESCC than in normal esophageal mucosa. Here, we focused on ZEB1, epithelial-mesenchymal-transition (EMT)-inducer, as a target gene of miR-150 based on in silico predictions. The purpose of this study was to clarify the clinicopathological significance of miR-150 in ESCC, and to investigate miR-150′s EMT-regulatory ability. Quantitative RT-PCR was used to evaluate miR-150 expression in 108 curative resected ESCC samples to determine the clinicopathological significance. Moreover, we examined the in vitro and in vivo function of miR-150 via degradation of ZEB1. MiR-150 expression was significantly lower in cancer tissues compared to adjacent non-cancerous tissues (P < 0.001). Low expression of miR-150 in ESCC contributed to malignant potential, such as tumor depth, lymph node metastasis, lymphatic invasion, venous invasion, clinical staging, and poor prognosis (P < 0.05). In vitro assays showed that EMT-inducer-ZEB1 is a new direct target of miR-150. Moreover, miR-150 induced MET-like changes in TE-8 cells through ZEB1 degradation (e.g., E-cadherin expression, vimentin repression, epithelial morphology, and suppression of migration ability), and significantly inhibited tumorigenicity and tumor growth in a mouse xenograft model. Analysis of the regulation of ZEB1 by miR-150 could provide new insights into preventing metastasis and also suggests novel targeted therapeutic strategies in ESCC. (Cancer Sci 2013; 104: 48-54) P rogress in perioperative management and definitive or adjuvant therapy has led to improved survival of esophageal squamous cell carcinoma (ESCC) patients. However, for patients with advanced disease, prognosis remains poor.(1-3) Local ESCCs directly invade other organs, presenting serious obstacles to radical resection, a characteristic which enhances local recurrence. Moreover, ESCCs cause early lymphatic and hematogenous disseminations more frequently compared to other solid gastrointestinal cancers.(4,5) Therefore, clinical indicators that accurately predict ESCC progression and prognosis are essential for improving patient survival.Recently, microRNAs (miRs) have attracted attention for their involvement in the regulation of gene expression. miRs are small non-coding RNAs, approximately 18-25 nucleotides in length, which partially bind to the 3′-untranslated region (3′-UTR) of target mRNAs, leading to mRNA degradation and/or translational repression.(6) Many miRs play an essential role in cellular processes, such as proliferation, differentiation, apoptosis, and cancer progression, depending on their specific gene targets. To find cancer-associated miRs in ESCC, we re-analyzed GSE6188 in the Gene Expression Omnibus public microarray database.(7) In this way, we detected five downregulated miRs in ESCC compared to normal esophageal mucosa (Fig. S1). First, we examin...

We used adult rat cardiac myocytes to examine the acute effects of 0.1-5.0% (vol/vol)

CD47 inhibits phagocytosis and its overexpression is correlated with poor prognosis in patients with several types of cancer. It has also been reported that CD47 expression in multiple sclerosis is regulated by microRNAs. However, the regulatory mechanism of CD47 in cancer tissues has not been yet clarified. Re-analysis of a public microarray database revealed that miR-133a is downregulated in esophageal squamous cell carcinoma (ESCC). Moreover, in silico algorithms predicted that miR-133a is a regulator of CD47. The purpose of this study was to clarify the clinical significance of CD47 and its regulatory mechanism by miR-133a in ESCC. Quantitative real-time RT-PCR was used to evaluate CD47 and miR-133a expression in 102 cases of curative resected ESCC and adjacent non-cancerous tissue. The regulation of CD47 by miR-133a was examined with precursor miR-133a-transfected cells. A mouse xenograft model was used to investigate the ability of miR-133a to suppress tumor progression. High expression levels of CD47 were associated with lymph node metastasis (P=0.049). Multivariate analysis showed that CD47 expression was an independent prognostic factor (P=0.045). miR-133a expression was significantly lower in cancer tissues compared to adjacent non-cancerous tissues (P<0.001). In vitro assays showed that miR-133a is a direct regulator of CD47. miR‑133a significantly inhibited tumorigenesis and growth in vivo. CD47 expression is a novel prognostic marker in ESCC that is directly inhibited by the miR-133a tumor suppressor. This correlation could provide new insight into the mechanism of cancer progression and a promising candidate for target therapy in ESCC.

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