FOXF2-Mediated lncRNA LINC02532 Promotes Gastric Cancer Cell Migration and Invasion By Decreasing SOX7 mRNA Stability

Abstract

Background LncRNAs are known to play a crucial role in the initiation and progression of human diseases, especially cancers. Our previous study demonstrated that dysregulation of LINC02532 facilitated the malignant phenotype of gastric cancer (GC). However, the potential molecular mechanisms regarding the upstream and downstream regulation of LINC02532 in GC progression remain unclear. Methods RNA-Seq and clinical data from public databases were used for gene expression and clinical analyses. The subcellular location of LINC02532 was predicted by the bioinformatics tools and further validated by the RNA-Fluorescence in situ hybridization (FISH) assay. The effect of FOXF2/LINC02532/SOX7 axis in GC cell migration and invasion was evaluated using in vitro and in vivo assays. The transcriptional regulation role of FOXF2 and the mRNA stability of SOX7 were explored by dual-luciferase reporter assay and Actinomycin-D drug assay. Results We found that high LINC02532 expression was associated with poor prognosis of GC. Furthermore, a Cox regression model indicated that LINC02532 was an independent prognostic factor for GC patients. Using in vitro and in vivo assays, we found that LINC02532 promoted GC cell migration and invasion, as well as tumour growth and metastasis in nude mice. Mechanistically, LINC02532 decreased SOX7 mRNA stability by binding to its 3’UTR, resulting in reduced SOX7 expression. In addition, FOXF2 was identified as a transcriptional factor of LINC02532 and was shown to repress LINC02532 expression by negative transcriptional regulation. Conclusions Together, these findings show that LINC02532 promotes GC progression through epithelial–mesenchymal transition (EMT). Cross-talk between the FOXF2/LINC02532/SOX7 axis may provide a novel target for the treatment and prognostic prediction of GC.