Integrative Analysis of the Role of MRPL21 in Human Pan-Cancer and Its Relationship with the Progression of Lung Adenocarcinoma

Mitochondrial ribosomal protein L21 (MRPL21) is essential for normal cell function and may play a significant role in cancer development. In this study, we performed a comprehensive pan-cancer analysis to explore MRPL21's function across different cancers, utilizing multiple online data platforms such as TCGA. Our analysis covered its clinical significance and biological functions, including expression levels, survival and diagnostic analysis, gene mutations, multidimensional immune-correlation analysis, tumor heterogeneity, and cancer-associated signaling pathways. Additionally, we constructed a prognostic nomogram for lung adenocarcinoma (LUAD) patients based on MRPL21 and validated its biological function through in vitro experiments. Our findings revealed that MRPL21 is commonly overexpressed in various cancers and is associated with poor prognosis. It significantly impacts cancer-related pathways, particularly those related to cell cycle activation. Moreover, MRPL21 is critical in the tumor microenvironment and is closely linked to immune infiltration across several cancer types. Its expression correlates with essential factors such as tumor mutational burden, microsatellite instability, immune checkpoint, and methylation patterns. In LUAD, MRPL21 was identified as an independent risk factor and demonstrated that MRPL21 promotes LUAD progression. Overall, MRPL21 holds potential as both a diagnostic and prognostic marker in cancer and could serve as a promising therapeutic target, particularly for LUAD.