HMGA1-mediated miR-671-5p targets APC to promote metastasis of clear cell renal cell carcinoma through Wnt signaling

This study aimed to investigate the effect of miR-671-5p on metastasis of clear cell renal cell carcinoma (ccRCC) and underlying mechanism involved. The migration and invasion of ccRCC cells were determined by transwell and boyden assays in vitro and in vivo. Genes mRNA and protein expression were detected by quantitative polymerase chain reaction (qPCR) and western blot analysis, respectively. The target gene of miRNA was confirmed by luciferase reporter assays. Transcriptional regulation of miRNA by transcription factor was detected by chromatin immunoprecipitation assay (ChIP). The expression of miRNA in clinical specimens were detected by in situ hybridization (ISH). miR-671-5p promoted migration and invasion of ccRCC in vivo and in vitro. Moreover, miR-671-5p directly targeted APC to activate Wnt signaling, thus inducing the epithelial-mesenchymal transition (EMT) in ccRCC. Intriguingly, miR-671-5p expression was transcriptionally enhanced by HMGA1. Consistently, bioinformatics analysis suggested that HMGA1 was positively correlated with miR-671 expression, however, miR-671 was negatively correlated with APC. In situ hybridization analysis showed that miR-671-5p was upregulated in ccRCC compared with paracarcinoma and correlated with poor prognosis of ccRCC patients. In addition, univariate and multivariate analysis indicated that miR-671-5p expression was an independent prognostic factor for overall survival in ccRCC patients. Our data suggest that miR-671-5p is a tumor enhancer in regulating of ccRCC metastasis, and miR-671-5p may be utilized as a factor for the clinical diagnosis and prognosis of ccRCC.