Growing evidence suggested that long non-coding RNA (lncRNA) played a crucial role in the progression of ulcerative colitis (UC). Therefore, the purpose of this study is to understand how the lncRNA CBR3-AS1, which has been found to be up-regulated in UC, contributes to the bio-progression of the disease. To determine the concentration and relationship of the lncRNA CBR3-AS1, miRNA-145-5p, and FN1 in the LPS-induced Caco-2 model cells, qRT-PCR was employed in this study. Starbase was used to predict the target sites of the lncRNA CBR3-AS1 and the miRNA-145-5p, and Targetscan was used to predict the probable linking points of the FN1 and the miRNA-145-5p, which was confirmed by a twofold luciferase reporter test. The vitality of Caco-2 cells was determined using the CCK-8 and FCM tests. Using the ELISA kit, TNF, IFN, IL-6, and IL-17 were identified. The results of the experiment show that in Caco-2 cells treated with 10 ng/mL LPS, LncRNA CBR3-AS1 was up-regulated. Additionally, Caco-2 cells' LPS-induced apoptosis and inflammatory response were inhibited by lncRNA CBR3-AS1 inhibition. Dual-luciferase reporter experiments demonstrated that miRNA-145-5p and lncRNA CBR3-AS1 might connect. Moreover, miRNA-145-5p, which was shown to be poorly expressed in UC, was found to suppress inflammatory and apoptotic responses in Caco-2 cells activated by LPS. It's significant that FN1 was confirmed to be miRNA-145-5p's downstream target. Sh-CBR3-AS1's inhibitory effects were reversed by miRNA-145-5p knockdown, and the effects of the miRNA-145-5p inhibitor were reversed by sh-FN1. In conclusion, LncRNA CBR3-AS1 may offer a unique method for treating UC by suppressing the function of miRNA-145-5p, which is implicated in the development of UC.
Background Radiotherapy is commonly used for locoregionally advanced NSCLC, but radioresistance is a clinical challenge. The long non-coding RNA CBR3-AS1 mediates radioresistance in NSCLC, yet the underlying molecular mechanism is unclear. This study aims to explore whether and how N6-methyladenosine (m6A) modification regulates CBR3-AS1 expression and promotes NSCLC radioresistance. Methods Integrative bioinformatics analyses were used to investigate the m6A methyltransferases that were associated with CBR3-AS1 expression and radioresistance of patients using data from The Cancer Genome Atlas of lung adenocarcinoma and squamous cell carcinoma. Clinical samples of 133 patients with NSCLC was collected to validate the correlation of the methyltransferase with radioresistance. The functional role and molecular mechanism of the methyltransferase in radioresistance was investigated through a series of in vitro experiments including m6A MeRIP-PCR, lentivirus transfection, RNA immunoprecipitation, Luciferase reporter, Colony formation, Transwell invasion, Flow cytometry, ELISA and TUNEL assay and in vivo experiments. Results The methyltransferase RNA binding motif protein 15 (RBM15) was identified as it was significantly positively correlated with CBR3-AS1 expression and overall survival of NSCLC patients receiving radiotherapy. The clinical samples demonstrated that the high protein expression of RBM15 was significantly enriched in patients with radioresistance as well as associated with poor prognosis of patients receiving radiotherapy. In vitro, RBM15 silencing enhanced the effects of radiation on the growth and invasion inhibition, and apoptosis induction of NSCLC cells; RBM15 overexpression had the opposite effects. Mechanistically, RBM15 induced CBR3-AS1 upregulation via an m6A-IGF2BP3-dependent mechanism, inducing CXCL1 expression by sponging miR-409-3p to recruit myeloid-derived suppressor cells (MDSCs) and inhibit T cell activity. In vivo, RBM15 silencing suppressed MDSC invasiveness and enhanced CD8 + and CD4 + T cell infiltration, causing NSCLC cells to overcome radioresistance. Conclusion Our study identifies methyltransferase RBM15 as a potential therapeutic target for NSCLC radioresistance whose inhibition reverses resistance through limiting MDSC recruitment via the m6A-IGF2BP3-CBR3-AS1/miR-409-3p/CXCL1 axis. Graphical