Comprehensive Pan-cancer Analysis of CMPK2 as Biomarker and Prognostic Indicator for Immunotherapy.

INTRODUCTION: UMP-CMP kinase 2 (CMPK2) is involved in mitochondrial DNA synthesis which can be oxidized and released into the cytoplasm in innate immunity. It initiates the assembly of NLRP3 inflammasomes and mediates various pathological processes such as human immunodeficiency virus infection and systemic lupus erythematosus. However the role of CMPK2 in tumor progression and tumor immunity remains unclear.

METHOD: In this study we conducted a systematical analysis of CMPK2 across 33 different cancers based on datasets such as Genotype Tissue-Expression (GTEx) The Cancer Genome Atlas (TCGA) the Cancer Cell Line Encyclopedia (CCLE) and Tumor Immune Syngeneic Mouse (TISMO). Our focus encompassed the characterization of CMPK2 expression patternsclinical significance potential regulatory mechanisms and its relationship with the tumor immune profile including responsiveness to immune checkpoint inhibitor treatment. CMPK2 expression was elevated in 23 cancers and decreased in two cancers. Receiver operating characteristic curve analysis indicated that CMPK2 expression had a high diagnostic value for 16 cancers. Kaplan-Meier survival analysis showed that high CMPK2 expression was associated with Lower Overall Survival (OS)Disease- Specific Survival (DSS) and Progression-Free Interval (PFI) in Kidney Cutaneous Chromophobe (KICH) Uterine Corpus Endometrial Carcinoma (UCEC) and Uveal Melanoma (UVM) and the opposite was true in Skin Cutaneous Melanoma (SKCM). Immune microenvironment-related analysis revealed strong associations between CMPK2 expression and immune cell infiltration as well as immune checkpoint expression across various tumors.

RESULT: Notably in four mouse immunotherapy cohorts CMPK2 expression in treated mouse tumors was post-treatment. In five clinical immunotherapy cohorts patients with high CMPK2 expression show better responses to immunotherapy. Furthermore the methylation level of the CMPK2 gene was closely correlated to its expression and tumor prognosis. Among these cancers the clinical and immunological indications of SKCM are particularly closely related to CMPK2 expression.

CONCLUSION: Our analysis preliminarily describes the complex function of CMPK2 in cancer progression and immune microenvironment highlighting its potential as a diagnostic and therapeutic target for immunotherapy.