DLEU1 promotes oral squamous cell carcinoma progression through activating interferon-stimulated genes [microarray]

Long noncoding RNAs (lncRNAs) are deeply involved in cancer development, and we have previously reported that DLEU1 (deleted in lymphocytic leukemia 1) is frequently overexpressed in oral squamous cell carcinoma (OSCC) cells, where it plays an oncogenic role. In this study, we aimed to further clarify the molecular function of DLEU1 in the pathogenesis of OSCC. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis revealed that knockdown of DLEU1 induced substantial changes in the levels of histone H3 lysine 4 trimethylation (H3K4me3) and H3K27 acetylation (H3K27ac) in OSCC cells. Notably, depletion of DLEU1 significantly downregulated levels of H3K4me3/H3K27ac and expression of a number of interferon-stimulated genes (ISGs) including IFIT1, IFI6 and OAS1, while ectopic DLEU1 expression activated these genes. Western blot analysis and reporter assay suggested that DLEU1 upregulates ISGs through activating the JAK-STAT signaling in OSCC cells. Moreover, IFITM1, one of the ISGs induced by DLUE1, is frequently overexpressed in primary OSCC tumors, and knockdown of IFITM1 attenuated OSCC cell proliferation, migration and invasion. Our data suggest that DLEU1 exerts its oncogenic function through, at least in part, activating a series ISGs in OSCC cells. Ca9-22 cells were infected with a DLEU1 lentiviral vector or a control vector and were selected with 6mg/ml of Blasticidin for 2 weeks.