3.1 MUC18 serves as a Crucial Biomarker for Tumors
The expression difference of MUC18 between tumor and normal tissues was
evaluated by pairing TCGA and GTEx data. MUC18 was upregulated in 8
cancers—head and neck squamous cell carcinoma (HNSC), kidney renal
clear cell carcinoma (KIRC), lymphoid neoplasm diffuses large B-cell
lymphoma (DLBC), cholangiocarcinoma (CHOL), glioblastoma multiforme
(GBM), liver hepatocellular carcinoma (LIHC), pancreatic adenocarcinoma
(PAAD), and thymoma (THYM)—compared with normal tissues (Figure 1A).
Analysis of the pancancer cohort from the GEPIA2 database revealed that
patients with high MUC18 expression in the Mesothelioma (MESO, HR=2.8),
GBM (HR=1.5), Brain Lower Grade Glioma (LGG, HR=2.2), and Cervical
squamous cell carcinoma and endocervical adenocarcinoma (CESC, HR=1.6)
cohorts had significantly reduced OS, and patients with high MUC18
expression in the Adrenocortical carcinoma (ACC, HR=2.8), Kidney
Chromophobe (KICH, HR=12), LGG (HR=1.5), and Uveal Melanoma (UVM,
HR=3.2) cohorts had significantly reduced DFS, suggesting that high
MUC18 expression adversely affects the prognosis of patients with these
tumors (Figure 1B).