Characterization of the fatty acid metabolism gene signature in gastric cancer to assist precision treatment in chemotherapy

Objective: This project evaluated the efficacy of fatty acid metabolism (FAM) in gastric cancer (GC) with pII/III stage to explore potential therapeutic strategies. Methods Clinical features, transcriptome expression and follow-up information were downloaded from TCGA and GEO databases. "Limma" package serves to analyze differentially expressed genes (DEG). We applied "clusterprofiler" package to carry out GO and KEGG aggregation analysis on DEG. The "maftools" package was used to analyze gene transformation and association. "Coef" refers to the non-zero correlation coefficient estimated according to lasso cox regression analysis. The half maximum inhibitory concentration (IC50) is calculated according to the "prrophytic" package. We also used the "rms" package to structure nomograms. Results A digital model of the risk score was established by using ten FAM genes. Compare to the low-risk group, the high-risk group has a worse prognosis (p < 0.001). ROC, univariate and multivariable cox analysis all verified the above results. We also constructed nomograms based on age, sex, pathological TNM stage and risk scores. The high-risk score sample is not particularly sensitive to 5-Fu chemotherapy, and the Tumor immune dysfunction and rejection (TIDE) index of the high-risk group is higher, which indicates that the high-risk group may be more prone to immune escape. Conclusion The FAM gene model believes that the low-risk groups have better 5-Fu drug sensitivity, lower probability of immune escape, and better prognosis.