Long Non-Coding RNA XLOC_008466 Functions as an Oncogene in Human Non-Small Cell Lung Cancer by Targeting miR-874.

BACKGROUND: The therapy and prognosis of lung cancer are difficult because of multiple genetic and epigenetic alterations. Long non-coding RNAs (lncRNAs) have been verified as new mediators of cancer development and progression by virtue of their various functions. Here, we focused on the lncRNA XLOC_008466 based on previous microarray data. However, whether aberrant expression of XLOC_008466 in human non-small cell lung cancer (NSCLC) is correlated with malignancy, metastasis or prognosis has not been elucidated.

METHODS: We performed real-time PCR, CCK-8, flow cytometry, trans-well, western blotting, luciferase reporter assays, RNA immunoprecipitation (RIP) assay and surface plasmon resonance (SPR) assay to detect the function of XLOC_008466 in NSCLC.

RESULTS: Up-regulation of XLOC_008466 in NSCLC patients was related to lymph node metastasis and the TNM stage. In vitro, down-regulation of XLOC_008466 inhibited cell proliferation and invasion of A549 and H460 cells in vitro, but promoted cell apoptosis. Experiments on mechanisms revealed that XLOC_008466 functioned as a ceRNA, directly binding to miR-874, and could affect cell proliferation, apoptosis and invasion through regulation of miR-874 expression as well as by increasing matrix metalloproteinase 2 (MMP2) and X-linked inhibitor of apoptosis (XIAP) expression.

CONCLUSIONS: XLOC_008466 functions as an oncogene in NSCLC by regulating the miR-874-MMP2/XIAP axis, which indicates that XLOC_008466 may be a useful marker and potential therapeutic target in NSCLC.