MUC20 as a novel prognostic biomarker in ccRCC correlating with tumor immune microenvironment modulation

Tumor microenvironment (TME) broadly participates in genesis development of clear cell renal cell carcinoma (ccRCC). To recognize the immune and stromal modulation in TME, we screened the differentially expressed TME-related genes generated by the ESTIMATE algorithm in ccRCC specimens. Following the construction of protein-protein interaction (PPI) network and univariate COX regression, mucin 20 (MUC20) was judged to be a predictive factor. Further analysis, including immunohistochemistry (IHC) showed that MUC20 was positively correlated with survival and negatively correlated with the clinicopathologic characteristics (grade, clinical and TNM stages) in ccRCC patients. Gene Set Enrichment Analysis suggested that the low-expression MUC20 group was primarily enriched in immune-related activities, inflammation and epithelial-mesenchymal transition. Based on the CIBERSORT analysis for tumor-infiltrating immune cells (TICs), MUC20 was positively correlated with CD8⁺ T cells and resting mast cells and negatively correlated with activated CD4⁺ memory T cells, Treg cells, and plasma cells, implying that MUC20 may contribute to immune component in TME. Additionally, the patients with low MUC20 expression had better response to immune checkpoint blockades (ICBs) and 17 potential anticancer drugs were screened regarding calculating IC₅₀ value. Thus, MUC20 may contain a value of prognosis assessment for ccRCC patients and indicate the immune modulation status of TME, which provided a novel insight for comprehensive immunotherapy.