Recently, long noncoding RNAs (lncRNAs) are attracting wide attention in the field of cancer research because of its important role in cancer diagnosis and prognosis. But studies on the biological effects and relevant mechanisms of lncRNAs in non‐small cell lung cancer (NSCLC) remain few and need to be enriched. Our study discussed the expression and biological effects of LncRNA NR2F2‐AS1, and further explored its possible molecular mechanisms. As a result, elevated expression of NR2F2‐AS1 was detected in NSCLC tissues and cells and was remarkably associated with the tumor, node, metastasis (TNM) stage and the status of lymphatic metastasis of patients. Down‐regulated NR2F2‐AS1 contributed to the promotion of cell apoptosis and the inhibition of cell proliferation and invasion in A549 and SPC‐A‐1 cells in vivo and vitro. Through bioinformatics analysis, NR2F2‐AS1 functions as a ceRNA directly binding to miR‐320b, BMI1 was a direct target of miR‐320b. Combined with the following cellular experiments, the data showed that NR2F2‐AS1 may influence the NSCLC cell proliferation, invasion and apoptosis through regulating miR‐320b targeting BMI1.

N6-methyladenosine (m6A) is the most abundant mRNA modification in mammals and has been implicated in various biological processes. However, its role in hepatocellular carcinoma (HCC) remains largely unknown. In this study, we investigated the alterations of 19 main m6A regulatory genes in HCC and their association with clinicopathological features, including survival. The mutation, copy number variation (CNV) and clinical data of HCC patients were retrieved from The Cancer Genome Atlas (TCGA) database. We found that the m6A regulators had high frequent alterations in HCC. The alterations of m6A regulators were significantly associated with clinicopathological features as well as TP53 alteration. Patients with any mutation of the m6A regulatory genes had worse overall survival (OS) and disease free survival (DFS). Deletion of METTL16 or ALKBH5 predicted poor OS and DFS of HCC patients. Moreover, deletion of METTL16 was an independent risk factor for DFS. Low METT16 expression was association with activation of multiple metabolic pathways in HCC. Finally, by RT-PCR, we confirmed that METTL16 was downregulated in HCC, and that lower METTL16 expression was associated with poor OS. In conclusion, we reported a significant association between alterations of m6A regulators and clinicopathological features, and highlighted the importance of METTL16 among the 19 m6A regulators in HCC pathogenesis. These findings will provide new insights into the role of m6A modification in HCC.

Abstract. plays an important role in both the immune response and tumor progression, while microRNAs act as tumor regulators to mediate tumorigenesis. However, the underlying molecular mechanisms remain unknown. In the present study, we investigated the relationship between Gal-9 and microRNA-mediated regulation in liver cancer. We examined Gal-9 expression using qRT-PCR and western blot analysis and found that it was markedly upregulated in human liver cancer cells compared with the level in normal hepatocytes. We co-cultured peripheral blood mononuclear cells (PBMCs) and tumor cells and observed that Gal-9 induced lymphocyte apoptosis and tumor cell immune escape using flow cytometric analysis and WST-1 assay. We found that miR-22 was downregulated in liver cancer tissues and cell lines and confirmed that miR-22 directly targeted the Gal-9 3'UTR and negatively regulated Gal-9 expression by luciferase reporter assay and transfection of microRNA mimics. We also observed that the Gal-9/miR-22 axis may influence lymphocyte apoptosis and tumor cell proliferation. These studies contribute to a further understanding of the microRNA-mediated regulation of the Gal-9 pathway and elucidate novel therapeutic targets for liver cancer.

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