Comprehensive single-cell and spatial transcriptome landscapes of ferroptosis regulators in ccRCC reveal intercellular interactions within malignant cells and DERL3 + plasma cells via JAK2/STAT3/GPX4 axis

Clear cell renal cell carcinoma (ccRCC) ranks among the most common malignant tumors affecting the urinary tract. However, the role of ferroptosis mediated by plasma cells in ccRCC remains poorly understood. In this study, we combined single-cell RNA sequencing (scRNA-seq), spatial transcriptomic RNA sequencing (spRNA-seq), bulk RNA sequencing (RNA-seq) analysis to investigate the comprehensive landscapes of ferroptosis regulators within ccRCC. Expression profiles of ferroptosis markers, drivers and suppressors were depicted in scRNA-seq data via Addmodule Score and Percentage Feature Set algorithms. The marker genes and RNA-seq data were utilized to construct the Plasma Signature (Plasma.Sig), predicting overall survival (OS) of ccRCC patients with machine learning (ML) algorithms. In vitro and in vivo experiments were conducted to validate our bioinformatics findings. Through scRNA-seq and spRNA-seq analyses, we identified a subpopulation of DERL3 + plasma cells with close intercellular interactions with malignant cells, which is also correlated with ferroptosis suppressors in ccRCC. Utilizing marker genes of DERL3 + plasma cells, we developed the Plasma.Sig to predict OS of ccRCC patients accurately and specifically. By bulk RNA-seq analysis, we demonstrated that high DERL3 expression was associated with poor prognosis in ccRCC. Co-culture experiments revealed that knockdown of DERL3 in plasma cells decreased GPX4 expression in ccRCC tumor cells at both mRNA and protein levels. Furthermore, DERL3 knockdown impaired tumor cell proliferation, enhanced lipid peroxidation, and significantly induced ferroptosis in ccRCC tumor cells through the JAK2/STAT3 signaling pathway. Notably, combining DERL3 targeting with anti-PD-1 therapy enhanced the efficacy of immunotherapy in subcutaneous tumor model of ccRCC. Using multi-omics approaches, we identify that targeting DERL3 in plasma cells modulates tumor ferroptosis via the JAK2/STAT3 axis and potentiates immunotherapy response in ccRCC. Our findings highlight ferroptosis-targeting strategies combined with immunotherapy as a promising therapeutic approach for ccRCC. Not applicable.