Low Expression of PRRG2 in Kidney Renal Clear Cell Carcinoma: An Immune Infiltration-Associated Prognostic Biomarker

Abstract Background: Kidney renal clear cell carcinoma (KIRC) is a highly prevalent and lethal type of cancer, and one of the primary approaches to address it is the development of suitable biomarkers. The objective of this study is to investigate the prognostic value of proline-rich γ-carboxyglutamic acid protein 2 (PRRG2) in KIRC and its correlation with immune cell infiltration. Methods: The study comprehensively clarified the prognostic value and potential function of PRRG2 in KIRC. PRRG2 expression was analyzed and correlated with sex, age, metastasis, and pathological stage in KIRC patients. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) were used to explore the involvement of PRRG2 in the immune response. The correlation between PRRG2 expression and immune cell infiltration was also analyzed. Finally, the confirmation of cellular and tissue identity was achieved through the utilization of immunohistochemical staining and quantitative real-time PCR. Results: The study reveals a significant reduction in PRRG2 expression among KIRC patients. Low PRRG2 expression is associated with gender, age, metastasis, and pathological staging, and significantly predicts poor prognosis in KIRC patients. GO, KEGG, and GSEA results indicate the involvement of PRRG2 in immune response. PRRG2 expression is significantly correlated with the infiltration level of immune cells and the expression of different immune cell markers. Conclusion: PRRG2 may potentially impact prognosis in KIRC patients by regulating immune infiltration, thus rendering PRRG2 a promising candidate prognostic biomarker for KIRC-associated immune infiltration.