The pan-cancer landscape of crosstalk between chemokines and the tumor immune microenvironment

Background: Chemokines are a subfamily of cytokines known for their ability to promote cell migration, particularly that of immune cells. Chemokines are necessary for immune system function and have attracted considerable attention on account of their roles in regulation of the tumor immune microenvironment.Methods: Chemokine genes were obtained from the TISIDB database, and we examined the correlation, gene alteration, differential expression, and prognostic value of these genes in 33 tumor types based on Cancer Genome Atlas and Genotype-Tissue Expression data. The chemokine score of each sample was calculated using the “ssGSEA” function of the R package “GSVA.” We also evaluated the correlation between chemokine scores and a tumor immune microenvironment index and assessed the influence of chemokine scores on the response of cancer patients to immune checkpoint inhibitor therapy.Results: We found that tumor samples with high chemokine scores were immune-activated, and further analysis using three immunotherapy cohorts revealed that patients with high chemokine scores were sensitive to anti-PD-1 therapy.Conclusions: Our results indicate that chemokines are closely associated with the tumor microenvironment, and consequently, patients with high chemokine scores may be suitable for treatment using immune checkpoint inhibitors.