Bex, A. | bioRxiv Science

bioRxiv2026

Distinct functions of PBRM1 and BAP1 reconcile the course of kidney cancer evolution and disease progression

Clear cell renal cell carcinoma (ccRCC) progresses along two predominant evolutionary trajectories, defined by PBRM1 ([~]40%) or BAP1 ([~]15%) mutations on a VHL-inactivated background. They have distinct patterns of evolutionary tempo and mode, and vastly different clinical outcomes, yet the underlying genotype-specific molecular phenotypic programmes are unknown. We established a patient-derived preclinical model biobank that captures the genetic diversity of ccRCC. Through integrative analyses of preclinical models and tumour bulk and single cell profiling, we identified transcriptional and epigenetic changes specific to PBRM1- and BAP1-driven ccRCC. Modelling PBRM1 loss in vitro demonstrates that it reinforces renal lineage identity and maintains progenitor-like cell state. In contrast, BAP1 loss drives inflammatory signalling and chromosomal instability. These insights reconcile the distinct evolutionary modes (branched versus punctuated), tempo (slow versus fast) and clinical outcomes associated with PBRM1 and BAP1 mutations, respectively, establishing a framework for patient stratification and genotype-directed therapeutic development.

cancer biology↗

bioRxiv2020

T cells expanded from renal cell carcinoma are tumor-reactive but fail to produce IFN-γ, TNF-α or IL-2

Metastatic renal cell carcinoma (RCC) has a poor prognosis. Recent advances have shown beneficial responses to immune checkpoint inhibitors, such as anti-PD-1 or anti-PD-L1 antibodies. As only a subset of RCC patients respond, alternative strategies should be explored. Patients refractory to anti-PD-1 therapy may benefit from autologous tumor infiltrating lymphocyte (TIL) therapy. Even though efficient TIL expansion was reported from RCC lesions, it is not well established how many RCC TIL products are tumor-reactive, how well they produce pro-inflammatory cytokines in response to autologous tumors, and whether their response correlates with the presence of specific immune cells in the tumor lesions. We here compared the immune infiltrate composition of RCC lesions with that of autologous kidney tissue of 18 RCC patients. T cell infiltrates were increased in the tumor lesions, and CD8+ T cell infiltrates were primarily of effector memory phenotype. Nine out of 16 (56%) tested TIL products we generated were tumor-reactive, as defined by CD137 upregulation after exposure to autologous tumor digest. Tumor reactivity was found in particular in TIL products originating from tumors with a high percentage of infiltrated T cells compared to autologous kidney, and coincided with increased ex vivo CD25 expression on CD8+ T cells. Importantly, although TIL products had the capacity to produce the key effector cytokines IFN-{gamma}, TNF- or IL-2, they failed to do so in response to autologous tumor digests. In conclusion, TIL products from RCC lesions contain tumor-reactive T cells. Their lack of tumor-specific cytokine production requires further investigation of immunosuppressive factors in RCC and subsequent optimization of RCC-derived TIL culture conditions.

immunology↗