High CS Expression Leads to Poor Prognosis Associated with Immune Invasion of Lung Adenocarcinoma

Abstract Background Citrate synthase (CS) is the initial rate-limiting enzyme in tricarboxylic acid cycle. We found that its expression is up-regulated in many cancers. Previous studies on the relationship between the expression of CS and (LUAD) have not been reported till date. Methods we systematically analyzed several online databases, such as TCGA and GEO database, TIMER database, Kaplan Meier plotter, Ualcan database and Linkedomics database. Results we found that it was highly expressed in patients with LUAD. The high expression of CS caused poor prognosis in LUAD patients, and it was associated with some clinical traits. This indicates that it may be an independent prognostic factor. At the same time, we found that high CS expression was associated with the decline of immune-infiltrating B cells. While exploring the mechanism, we found that highly expressed CS mainly interacts with ATP5B and KPNB1 proteins. Moreover, CS is highly expressed in regulating the cell cycle, P53 binding site and oxygen binding pathways. Conclusions Our results confirmed CS was associated with LUAD and affected immune cell infiltration in LUAD. This provided a basis for further use of CS as a new therapeutic target and prognostic indicator of patients with LUAD.