The functions and prognostic values of chemokine and chemokine receptors in gastric cancer.

Chemokine and chemokine receptors (CCRs) play a significant role in tumor infiltration of immune cells, tumor angiogenesis and distant metastasis. In this study, we explored the importance of CCRs in gastric cancer (GC) by analyzing the datasets from TCGA database. First, we analyzed the characteristics of the CCRs mutations. Then, we screened the differentially expressed CCRs and performed GO functional annotation and KEGG pathway analyses to explore their potential biological functions. Using multivariate Cox regression analyses, we constructed a prediction model based on four-CCRs (CCL15, CCL21, CCR3 and ACKR3) signature, and we found that the risk score of the model was an independent prognostic factor of GC. Next, a nomogram was constructed to assess the prognosis of GC patients. GSEA indicated that the high-risk group was significantly enriched in immune response and immune system process. Moreover, GSVA was employed to investigate the up- and down-regulated signaling pathways in the high- and low-risk groups. The correlation between risk score and immune-cell infiltration indicated that the four-CCRs signature might play a pivotal role in GC immune microenvironment. In conclusion, we revealed the potential molecular mechanisms of CCRs in GC and constructed a prediction model which might guide personalized treatment and prognosis for GC patients.