STAT1-induced upregulation of LINC00467 promotes the proliferation migration of lung adenocarcinoma cells by epigenetically silencing DKK1 to activate Wnt/β-catenin signaling pathway

Abstract

Long non-coding RNAs (lncRNAs) have been reported as essential regulators in human cancers, including lung adenocarcinoma (LUAD). In the present study, we found that lncRNA long intergenic non-protein coding RNA 467 (LINC00467) was expressed higher in TCGA LUAD samples and predicted poor prognosis in LUAD patients. High expression of LINC00467 was further detected in LUAD cell lines. Functionally, high expression level of LINC00467 promoted LUAD cell proliferation and migration, indicating that LINC00467 exerted oncogenic functions in LUAD progression. Considering the upregulation of LINC00467 in LUAD, we further detected the activator of LINC00467 promoter. Combining with bioinformatics analysis and mechanism experiments, we determined that LINC00467 was activated by STAT1 in LUAD. Moreover, high expression of LINC00467 was found to be associated with the activation of Wnt/β-catenin signaling pathway. Rescue assays demonstrated that dickkopf WNT signaling pathway inhibitor 1 (DKK1; an inhibitor of Wnt/β-catenin signaling pathway) and Wnt/β-catenin signaling involved in DKK1-mediated LUAD cell proliferation and migration. Furthermore, LINC00467 was located in the nucleus of LUAD cell lines and negatively regulated DKK1 in LUAD cells. Mechanistically, we determined that LINC00467 epigenetically silenced DKK1 by recruiting enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) to DKK1 promoter. Collectively, we determined that STAT1-induced upregulation of LINC00467 promoted LUAD progression by epigenetically silencing DKK1 to activate Wnt/β-catenin signaling pathway.

Keywords: DKK1; LINC00467; LUAD; STAT1; Wnt/β-catenin signaling pathway.