Telomerase-Related Gene Expression Networks Predicting Survival in Hepatocellular Carcinoma and Renal Clear Cell Carcinoma

Background: Telomerase is a ribonucleic multimeric reverse transcriptase complex protecting the chromosomal ends from erosion and thereby from cellular senescence. The prognostic value of the components of this complex and their interrelationships with the immune system are not well understood. Objectives: We aimed to examine 15 telomerase-related genes across 7489 tumor samples from the TCGA database. Methods: The mRNA expression of these genes was analyzed using Kaplan–Meier statistics and hierarchical clustering analyses, alone or in combination with tumor infiltration counts for 11 immune cell types. As an additional analysis, univariable and multivariable Cox regression analyses have been performed. Results: Thirteen of 21 tumor types showed significant associations between gene expression in tumors and survival times of patients. Most gene correlations were found in hepatocellular carcinoma and renal clear cell carcinoma. In hepatocellular carcinoma, a high expression of DKC1, NHP2, GAR1, WRAP53, and ACD was associated with shorter survival. In renal clear cell carcinoma, TERT, DKC1, and PARN correlated with shorter survival, and NAF1, TERF2, POT1, and TINF2 with longer survival. DKC1 was the only gene significantly associated with poor prognosis in both tumor types. The telomerase-related genes correlated with patterns of immune cell infiltration, which influenced the survival of patients. The associations of mutation burden and neoantigen load with survival varied depending on the gene and patient groups. In renal clear cell carcinoma, TERT, DKC1, and PARN showed strong interactions with immune cell infiltration and neoantigen load. Conclusions: The combination of telomerase-related gene expression and immune-cell infiltration was associated with overall survival in hepatocellular carcinoma and renal clear cell carcinoma and warrants further evaluation as prognostic markers.