miR-215 promotes cell migration and invasion of gastric cancer by targeting Retinoblastoma tumor suppressor gene 1.

BACKGROUND: Gastric cancer (GC) is one of the most common malignant tumor and has high mortality worldwide. microRNAs (miRNAs) play critical roles in carcinogenesis. Previous studied showed that miR-215 was involved in tumorigenesis and progression. This study was designed to clarify the biological function of miR-215 in GC.

METHODS: qRT-PCR was used to detect the miR-215 expression in GC tissues and 6 human GC cell lines (AGS, SGC-7901, NCI-N87, GES-1, MKN-45 and BGC-823) as well. Transwell assay was used to investigate the biological function of miR-215 in GC. Luciferase reporter assay was used to confirm its effect on the regulation of the target gene Retinoblastoma tumor suppressor gene 1 (RB1).

RESULTS: miR-215 was frequently up-regulated in GC tissues compared to adjacent non-tumor tissues and GC cell lines. miR-215 expression level was correlated with the progression of tumor invasion and tumor-node-metastasis (TNM) stage. Over-expression miR-215 in GC cell lines promoted cell migration and invasion. Besides, miR-215 could down-regulate the expression of RB1 in vitro via directly binding to its 3'-untranslated region (UTR), while the expression of RB1 would suppress the miR-215-indueced GC cell migration and invasion.

CONCLUSIONS: miR-215 promoted cell migration and invasion of gastric cancer by directly targeting RB1.