MicroRNAs are important regulators during human growth and development. Emerging evidence indicates that microRNAs play important roles in colorectal cancer. The aim of this study is to reveal the biological function and direct target gene of miR-483 in colorectal cancer. The biological function of miR-483 on the proliferation and migration of colon cancer cells was then examined by Edu assay and transwell assay, respectively. Our findings revealed that miR-483 mimic could significantly inhibit cell proliferation and migration. The target gene of miR-483 was predicted by target scan software and identified by a dual fluorescence reporter system which showed that TRAF1 was a direct target gene of miR-483 in SW480 cell line. These data suggest that miR-483 is a colorectal cancer suppressor which could inhibit cell proliferation and migration, possibly via targeting TRAF1. The miR-483 could be a potential treatment target for colorectal cancer.

5-Azacytidine is a well-known anticancer drug that is clinically used in the treatment of breast cancer, melanoma and colon cancer. It has been reported that 5-azacytidine suppresses the biological behavior of esophageal cancer cells. However, corresponding mechanisms remain unclear. In this study, using Transwell invasion and cell proliferation assays, we demonstrated that 5-azacytidine significantly inhibited the metastasis and proliferation of EC9706 cells, and upregulated the expression of cadherin 1 (CDH1) and SRY-box containing gene 17 (SOX17). Moreover, the inhibition of the metastasis of the 5-azacytidine-treated EC9706 cells was impaired following transfection with siRNA targeting CDH1 (CDH1 siRNA), and the inhibition of cell proliferation was attenuated following the downregulation of SOX17 by siRNA targeting SOX17 (SOX17 siRNA). Furthermore, 5-azacytidine remarkably reduced the CDH1 and SOX17 promoter methylation levels, suggesting that 5-azacytidine upregulates the expression of SOX17 and CDH1 by inhibiting the methylation of the SOX17 and CDH1 promoter. The findings of our study confirm that 5-azacytidine suppresses the proliferation and metastasis of EC9706 esophageal cancer cells by upregulating the expression of CDH1 and SOX17. The expression levels of CDH1 and SOX17 negatively correlate with the promoter methylation levels. CDH1 and SOX17 are potential indicators of the clinical application of 5-azacytidine.

Colon cancer is a common gastrointestinal cancer in China. In recent years, the mortality rate caused by colon cancer showed an upward trend, with invasion and metastasis as the main reasons. Thus, looking for factors triggering tumor cell invasion and metastasis, and effectively blocking them, are a hot research focus and a difficult problem in current research. In the processes of tumor invasion and metastasis, heparan sulfate proteoglycan (HPSG) and its soluble enzyme heparanase (HPA1) play an important role. Syndecan1 is a group of transmembrane heparan sulfate proteoglycan (HPSG), and involved in adhesion between the extracellular matrix and cells, the reduction or absence of its expression can promote tumor growth, invasion, and metastasis [1] . HPA1 is a recently discovered important enzyme functioning in tumors and is the only glucuronic acid incision enzyme that can degrade HPSG in vivo. HPA1 is capable of degrading HPSG in certain areas, therefore promotes tumor invasion and metastasis [2] .