Prognostic Value of Fatty Acid Synthase FASN in Renal Clear Cell Carcinoma and Bioinformatics Analysis of Immune Correlation

Objective: In this study, the expression, genetic variation, immune infiltration, functional enrichment of FASN in ccRCC and its correlation with prognosis were analyzed by bioinformatics. Methods: : The changes of FASN in renal clear cell carcinoma were analyzed by using R language and bioinformatics database. UALCAN, GEPIA2 and HPA were used to analyze the characteristics and prognostic correlation of FASN in KIRC clinical data, and to evaluate the protein expression level of FASN. TIMER2 and TISIDB website were used to analyze the expression difference and prognosis of FASN in pan-cancer. Analysis of genetic variation in FASN using cBioPortal database and R language; further explore the relationship between FASN and tumor immune infiltration by TIMER2 and TISCH; Metascape was used to integrate the functional enrichment analysis of KEGG and GO genes of FASN and related genes. Results: : The expression of FASN gene in ccRCC changed to varying degrees, which was significantly correlated with tumor staging and grading, and was significantly correlated with OS and DFS in patients with ccRCC. FASN protein phosphorylation has significant changes in ccRCC. FASN has significant indigenous significance in gene expression, prognosis, genetic mutation and MSI/TMB in pan-cancer. FASN was co-localized with various immune cells in KIRC single cell sequencing analysis. FASN is mainly involved in lipid metabolism, SREBF activation gene expression, PPAR signaling pathway, and fatty acid biosynthesis. Conclusion: The expression of FASN is closely related to the clinical prognosis, tumor immune cell infiltration and tumor lipid metabolism of patients with renal clear cell carcinoma, which may mediate the occurrence and development mechanism of ccRCC.