Pan-cancer analysis identifies RPL6 as a potential prognostic and immunotherapeutic biomarker and in vitro experimental verification in hepatocellular carcinoma

To systematically evaluate the prognostic significance, immune-regulatory role and therapeutic potential of RPL6 across 33 cancer types and to functionally validate its oncogenic role in hepatocellular carcinoma. To evaluate the mRNA expression levels of RPL6 across 33 distinct tumour types, we accessed various public databases, which included TIMER, Genotype-Tissue Expression (GTEx) and the Cancer Genome Atlas (TCGA). To evaluate the impact of RPL6 on overall survival (OS) and disease-free survival (DFS) in patients with these malignancies, we used the Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database. Moreover, cBioPortal was used to investigate alterations in the RPL6 gene within various tumor tissues. Further analyses were conducted utilizing the R programming language to investigate the association between RPL6 and various clinical features, such as the tumor microenvironment (TME), genes related to immune regulation, immune checkpoint indicators, tumor mutational burden (TMB), microsatellite instability (MSI), methylation of DNA, RNA methylation, and tumor stemness score. Gene Set Enrichment Analysis (GSEA) was also conducted to further understand the molecular mechanisms regulated by RPL6. Furthermore, we performed in vitro validation studies to explore the biological role of RPL6 in hepatocellular carcinoma(HCC). RPL6 exhibited markedly distinct expression levels when comparing cancerous and normal tissues. The expression of RPL6 was linked to patient outcomes, tumor mutational burden (TMB), microsatellite instability (MSI), and tumor stemness score in specific types of cancers. Additionally, RPL6 plays a role in regulating immune functions and impacting the tumor microenvironment. A deeper examination of RPL6 mutation locations and types revealed that the highest mutation rate occurred in endometrial cancer, with the predominant mutations being missense alterations. Through a series of cell behavioral assays, we demonstrated that RPL6 significantly influences the initiation and progression of hepatocellular carcinoma. Our associative, multi-omics analysis identifies RPL6 as a potential prognostic and immune-related candidate for multiple cancers; however, this remains a bioinformatics-based hypothesis that awaits functional confirmation and large-scale clinical sample validation.