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Background FBXW7 m6A modification plays an important role in lung adenocarcinoma (LUAD) progression; however, the underlying mechanisms remain unclear. Methods The correlation between FBXW7 and various genes related to m6A modification was analyzed using The Cancer Genome Atlas database. The regulatory effects of METTL3 on FBXW7 mRNA m6A modification were examined in a cell model, and the underlying mechanism was determined by methylated RNA immunoprecipitation, RNA immunoprecipitation, luciferase reporter, and mutagenesis assays. In vitro experiments were performed to further explore the biological effects of METTL3-mediated FBXW7 m6A modification on LUAD development. Results Decreased FBXW7 expression was accompanied by downregulated METTL3 expression in human LUAD tissues and was associated with a worse prognosis for LUAD in The Cancer Genome Atlas database. m6A was highly enriched in METTL3-mediated FBXW7 transcripts, and increased m6A modification in the coding sequence region increased its translation. Functionally, METTL3 overexpression or knockdown affected the apoptosis and proliferation phenotype of LUAD cells by regulating FBXW7 m6A modification and expression. Furthermore, FBXW7 overexpression in METTL3-depleted cells partially restored LUAD cell suppression in vitro and in vivo. Conclusions Our findings reveal that METTL3 positively regulates FBXW7 expression and confirm the tumor-suppressive role of m6A-modified FBXW7, thus providing insight into its epigenetic regulatory mechanisms in LUAD initiation and development.

Background: Lung cancer has the highest mortality rate among cancers worldwide, with non-small cell lung cancer (NSCLC) the most common type. Increasing evidence shows that PHB2 is highly expressed in other cancer types; however, the effects of PHB2 in NSCLC are currently poorly understood. Method: PHB2 expression and its clinical relevance in NSCLC tumor tissues were analyzed using a tissue microarray. The biological role of PHB2 in NSCLC was investigated in vitro and in vivo using immunohistochemistry and immunofluorescence staining, gene expression knockdown and overexpression, cell proliferation assay, flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, wound healing assay, Transwell assay, western blot analysis, qRT-PCR, coimmunoprecipitation, and mass spectrometry analysis. Results: Our major finding is that PHB2 facilitates tumorigenesis in NSCLC by interacting with and stabilizing RACK1, which further induces activation of downstream tumor-promoting effectors. PHB2 was found to be overexpressed in NSCLC tumor tissues, and its expression was correlated with clinicopathological features. Furthermore, PHB2 overexpression promoted proliferation, migration, and invasion, whereas PHB2 knockdown enhanced apoptosis in NSCLC cells. The stimulating effect of PHB2 on tumorigenesis was also verified in vivo. In addition, PHB2 interacted with RACK1 and increased its expression through posttranslational modification, which further induced activation of the Akt and FAK pathways. Conclusions: Our results reveal the effects of PHB2 on tumorigenesis and its regulation of RACK1 and RACK1-associated proteins and downstream signaling in NSCLC. We believe that the crosstalk between PHB2 and RACK1 provides us with a great opportunity to design and develop novel therapeutic strategies for NSCLC.

Background: Immunotherapy has dramatically changed the treatment landscape of cancer. Immunotherapies targeting the programmed death 1/programmed death ligand 1 pathway have been shown to lead to durable responses in patients with a variety of cancers. However, combination approaches are required to extend this benefit beyond a subset of patients. Studies have suggested that anti-angiogenic therapy can elicit or enhance tumor immunity response.Therefore, we hypothesised that combining immunotherapy with anti-angiogenic treatment may have a synergistic effect and may enhance the efficacy of both treatments.Methods: We evaluated the combination of bevacizumab (anti-vascular endothelial growth factor monoclonal antibody) and pembrolizumab (anti-programmed death 1 monoclonal antibody) in two mouse models of human non-small cell lung cancer cell lines (H1299 and A549). We monitored tumour growth and examined changes in the tumour vasculature, along with the frequency and phenotype of tumour-infiltrating lymphocytes.Results: The combination of bevacizumab and pembrolizumab synergistically inhibited tumour growth in vivo without overt toxicity in both cell lines. Combination therapy reprogrammed the immune microenvironment by increasing CD8+ cytotoxic T cell infiltration, thereby turning tumours with different phenotypes into inflamed (‘hot’) tumours. This is potentially mediated by vascular normalisation and endothelial cell activation, as demonstrated by a reduction in the number of microvessels and an increase in adhesion molecules.Conclusions: Taken together, our preclinical studies demonstrate that the combination of bevacizumab and pembrolizumab had a synergistic anti-tumour effect and provides a theoretical basis for translating basic research into clinical applications.