Background Clear cell renal cell carcinoma (ccRCC) is metabolically primed for ferroptosis, yet the prognostic relevance and mechanistic contribution of ferroptosis-related genes remain incompletely defined. This study aimed to identify ferroptosis-associated biomarkers with prognostic value and to clarify their functional relevance in ccRCC progression. Methods We integrated single-cell RNA sequencing, bulk RNA-seq, spatial transcriptomics, and machine-learning-based feature selection to identify ferroptosis-related prognostic genes in ccRCC. A four-gene risk model and an integrated nomogram were constructed and evaluated in independent cohorts. PANX2 was prioritized for experimental validation using stable knockdown models, RNA sequencing, lipid peroxidation and iron probes, redox assays, Western blot, luciferase reporter assays, xenografts, and an immunocompetent murine renal carcinoma model. Results A four-gene prognostic signature (CA9, PVT1, RRM2, and PANX2) was identified and used to construct a risk model with consistent predictive performance in the training and external validation cohorts. Among these genes, PANX2 was predominantly enriched in epithelial tumor compartments and had not been functionally characterized in ccRCC. PANX2 knockdown inhibited ccRCC cell proliferation, reduced antioxidant capacity, increased intracellular Fe2+ accumulation and lipid peroxidation, and sensitized cells to erastin-induced ferroptotic death. Mechanistically, PANX2 loss was associated with reduced Akt/mTOR pathway activity and diminished SLC7A11 expression; rescue with an Akt activator or SLC7A11 overexpression attenuated ferroptosis-associated phenotypes. In an immunocompetent murine renal carcinoma model, PANX2 knockdown was accompanied by increased infiltration of CD45+ leukocytes, CD3+ T cells, and CD8+ T cells, supporting a potential link between PANX2-dependent ferroptosis resistance and the tumor immune contexture. Conclusions This study identifies PANX2 as a ccRCC-relevant suppressor of ferroptosis and supports the involvement of a PANX2-Akt/mTOR-SLC7A11-associated signaling axis in redox homeostasis and tumor progression. The ferroptosis-related prognostic model and nomogram may support risk stratification, while PANX2 represents a candidate therapeutic vulnerability that warrants further mechanistic and translational validation.
Xing-Lin Li, Yiqi Xiong, Jiyin Wang et al.· Frontiers in Immunology· 0 citations
BACKGROUND
Clear cell renal cell carcinoma (ccRCC) is characterized by intratumoral heterogeneity and a complex immune microenvironment, which contribute to disease progression and therapeutic resistance. Although ribosomal proteins have been implicated in tumor biology, the clinical relevance, microenvironmental impact, and biological role of ribosomal protein lateral stalk subunit P0 (RPLP0) in ccRCC remain unclear.
METHODS
We performed a comprehensive investigation integrating bulk transcriptomics (TCGA, GEO, ICGC, ArrayExpress), proteomics (CPTAC, HPA), single-cell RNA sequencing, and spatial transcriptomics to characterize RPLP0 expression, prognostic value, immunological relevance, and spatial distribution in ccRCC. The biological functions of RPLP0 were validated experimentally using clinical tissues (qRT-PCR, immunofluorescence) and ccRCC cell lines. Proliferation, migration, and invasion were assessed via CCK-8, wound healing, and Transwell assays following siRNA-mediated knockdown, with epithelial-mesenchymal transition (EMT) markers evaluated by Western blot.
RESULTS
RPLP0 was ubiquitously expressed in normal tissues but significantly upregulated in ccRCC at both the mRNA and protein levels, which was validated in clinical specimens and cell lines. High RPLP0 expression was associated with advanced tumor stage, metastasis, and poor clinical outcomes, and was identified as an independent prognostic factor. Functional enrichment analyses revealed that RPLP0 was closely linked to ribosome-related processes, DNA damage response, cell cycle regulation, and epithelial-mesenchymal transition. Immune analyses demonstrated that elevated RPLP0 expression correlated with M2 macrophages, as well as with enhanced expression of immune checkpoint and antigen presentation-related genes. Single-cell and spatial transcriptomic analyses revealed the preferential enrichment of RPLP0 in the malignant compartment, with spatial transcriptomics further demonstrating a positive correlation with macrophages. Drug sensitivity analyses based on pRRophetic predictions showed that RPLP0-high tumors were associated with higher estimated IC50 values for several targeted therapies, suggesting a potential association between elevated RPLP0 expression and predicted reduced drug sensitivity. Mechanistically, RPLP0 knockdown in vitro significantly inhibited ccRCC cell proliferation, migration, and invasion, and reversed EMT progression by downregulating mesenchymal markers and upregulating the epithelial marker.
CONCLUSIONS
These findings indicate that RPLP0 is aberrantly upregulated in ccRCC, promoting tumor progression, migration, and invasion by facilitating the EMT process. Furthermore, its close association with immune activation and spatial heterogeneity highlights its potential as a robust prognostic biomarker and a regulator of tumor-microenvironment interactions.
Bin Wang, Hongquan Liu, Yicheng Guo et al.· BMC Cancer· 0 citations