The Mechanism Of MicroRNA-744-5p Inhibiting Osteosarcoma And The Bioinformatics Analysis Of Key Genes In Osteosarcoma Prognosis

Background and objectiveOsteosarcoma(OS)is highly aggressive malignant tumor.The 5-year overall survival rate for patients with metastatic OS is only 30%.The benefits of surgery,radiotherapy,chemotherapy and other treatments for OS patients have reached the bottleneck period,and more molecular mechanism studies are urgently needed to seek molecular targets for diagnosis and treatment.MicroRNAs(miRNAs)participate in the regulation of various physiological processes through post-transcriptional regulation of target genes,including:development,cell differentiation,apoptosis,glucose metabolism,fat metabolism,aging,and hormone secretion.At the same time,miRNAs are involved in regulating the pathological processes of various diseases,including tumors,inflammation,diabetes,and hypertension.However,to date,the specific roles of miRNAs in the malignant progression of OS have not been fully elucidated.This topic intends to explore the effect of miRNA on the proliferation and metastasis of OS cells and its molecular mechanism,and analyze the key genes of OS prognosis,aiming to provide new ideas for molecular targeted therapy of OS.Methods1.Identification of miRNA-744-5p and the analysis of its clinical relevance(1)The GSE65071 dataset was downloaded from the GEO database,the differentially expressed miRNAs were screened,and qRT-PCR was used to detect the expression of miR-744-5p in OS tissues and cell lines.(2)The correlation between miR-744-5p and clinical characteristics such as tumor stage,size,metastasis,and survival prognosis of patients with OS was analyzed.2.The effect of miRNA-744-5p on the biological behavior of OS cells(1)Plate cloning assay,EdU uptake assay,Transwell assay and Western blot were used to detect the effect of miRNA-744-5p on the proliferation and metastasis of OS cells in vitro.(2)The effect of miR-744-5p on the proliferation and metastasis of OS cells in vivo was observed in nude mice by subcutaneous tumorigenesis and lung metastasis by tail vein injection.3.The mechanism of miRNA-744-5p promoting the proliferation and metastasis of OS cells(1)Bioinformatics analysis,qRT-PCR,Western blot and dual-luciferase reporter gene experiments were used to screen and verify the expression regulation of miR-744-5p signaling axis on target mRNA.(2)Functional rescue experiments were performed to detect the effect of miR-744-5p/target mRNA signaling axis on the malignant biological behavior of OS cells.4.Bioinformatics analysis of key genes in OS prognosis.(1)The OS mRNA chip dataset was downloaded from the GEO database to obtain differential genes.The OS transcriptome data and clinical data were downloaded from TCGA,and the overall survival(OS)of the differential genes was analyzed using Kaplan-Meier,and the differential genes significantly associated with OS were used as prognosis-related genes.(2)KEGG and GO were used to analyze the functional pathways of prognosis-related genes.(3)The STRING database and Cytoscape software were used to construct a protein interaction network and screen for key prognostic genes.Results1.The expression of miR-744-5p was down-regulated in OS cancer tissues and cells.2.The low expression level of miR-744-5p was negatively correlated with tumor stage,size,distant metastasis and poor prognosis.3.In vitro experiments,high expression of miR-744-5p can inhibit the proliferation,migration,and invasion of OS cells;in vivo experiments,high expression of miR-744-5p can inhibit the growth and metastasis of subcutaneous transplanted tumors in nude mice.4.miR-744-5p inhibits the proliferation,migration and invasion of OS cells by targeting TGFB1 to regulate the MAPK signaling pathway.5.OS prognosis-related genes are mainly mediated through immune response,leukocyte activation and other processes,mediating immune-related pathways to improve or reduce patient prognosis.6.The key prognostic genes are TYROBP and ITGAM.Low expression of TYROBP or ITGAM was associated with a worse prognosis.ConclusionThe high expression of miR-744-5p activates the p38 MAPK signaling pathway by targeting TGFB1,thereby inhibiting the proliferation and metastasis of OS,which can be used as a potential molecular target for targeted therapy of OS.The low expression of TYROBP and ITGAM is associated with poor prognosis in patients with OS,suggesting that it may be a molecular target for prognosis monitoring of OS.