Lipid metabolism in cancer refers to the alterations in how cancer cells process and utilize lipids, a type of fat molecule. It was investigated how lipid metabolism relates to osteosarcoma. Genes relevant to lipid metabolism were gathered to create lipid metabolism-associated clusters and locate the dangerous marker. We investigated FAAH's prognostic significance, route annotation, immunotherapy response, and medication prediction. Besides, FAAH is proven to be a potent, dangerous marker that may promote growth and migration and inhibit the apoptosis of osteosarcoma. FAAH exhibits higher expression levels in tumor tissues as compared to normal tissues. In conclusion, FAAH is identified in this work as a potentially dangerous gene and immunotherapy determinant. This study requires more investigation to determine how FAAH influences the immune response in osteosarcoma.

Background: Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the progressive deterioration of articular cartilage, significantly impacting the quality of life in middle-aged and elderly populations. The Ras and Hippo signaling pathways play critical roles in regulating cell proliferation, differentiation, and stress responses; however, their interactive mechanisms in OA remain unclear. This study aimed to identify key genes associated with these two pathways using bioinformatic approaches and to elucidate their potential mechanisms in OA. Methods: Transcriptomic data of OA along with Ras signaling pathway-related genes (RSPRGs) and Hippo signaling pathway-related genes (HSPRGs) were obtained from public databases. Differentially expressed genes (DEGs) were identified, and key genes were screened through machine learning, expression validation, and receiver operating characteristic (ROC) curve analysis. Functional insights were further explored via gene set enrichment analysis (GSEA), subcellular localization, immune infiltration analysis, regulatory network construction, and drug prediction. Finally, the expression of key genes was validated in clinical samples. Results: KIT and CSF1R were identified as key genes. GSEA indicated their involvement in pathways such as the lysosome pathway. Subcellular localization predicted that KIT and CSF1R are distributed in the nucleus, extracellular region, and plasma membrane. Immune infiltration analysis revealed that KIT showed a positive correlation with eosinophils and a negative correlation with immature dendritic cells, while CSF1R was positively correlated with macrophages and negatively correlated with CD56ᵇʳⁱᵍʰᵗ natural killer cells. Drug prediction suggested interactions between the key genes and several therapeutic agents, including avapritinib and IMC-CS4. Subsequently, we validated our findings in cartilage tissue samples and discovered that compared to the control group, both CSF1R mRNA and protein expression was significantly upregulated in OA tissue, while KIT expression was significantly downregulated.The same results were also validated in immunofluorescence staining of chondrocytes. Conclusion: This study identified KIT and CSF1R as key genes in OA, providing new theoretical insights and potential targets for mechanistic research and targeted therapy.

This study aimed to evaluate the clinical efficacy of hip arthroscopic luggage-tag suture repair for the treatment of acetabular labral tears. This single-