SP1-induced up-regulation of lncRNA SNHG14 as a ceRNA promotes migration and invasion of clear cell renal cell carcinoma by regulating N-WASP

Clear cell renal cell carcinoma (ccRCC) is one of the leading causes of genitourinary cancer-related death, largely due to the metastasis of ccRCC. Previous profiling study showed that lncRNAs are critical regulators in lots of cancers. However, the roles of specific lncRNAs in ccRCC migration and invasion are still unknown. In this study, we utilized the high-throughput genome sequencing to identify the potential differentially expressed lncRNAs in ccRCC and further determined the underlying regulatory mechanism. We found that lncRNA SNHG14 was significantly up-regulated in ccRCC cell lines in contrast to normal renal epithelial cells. By performing bioinformatics analysis and luciferase reporter assays, we revealed that the transcription factor SP1 can bind to the promoter region of SNHG14, resulting in the overexpression of SNHG14 in ccRCC. Functionally, enhanced expression of lncRNA SNHG14 promoted cell migration and invasion through promoting N-WASP protein level. More importantly, RT-qPCR and in situ RNA FISH analysis showed that SNHG14 was predominantly abundant in the cytoplasm of ccRCC cells. The subsequent RNA immunoprecipitation assay, and gain or loss-function assays showed that SNHG14 functioned as ceRNA to regulate N-WASP expression and cell motility ability via a miR-203-dependent manner. Our results imply that SNHG14 is a critical lncRNA that promotes ccRCC migration and invasion via sponging miR-203 and elevating N-WASP. Therefore, SNHG14 could serve as a promising therapeutic target for ccRCC.