Metabolic Contributions of Individual Cellular Compartments to the Diversity of the Tumor Microenvironment in Renal Cell Carcinoma

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PROJECT SUMMARY Deregulating cellular energetics and avoiding immune destruction are considered hallmarks of cancer. Stimulating anti-tumor immunity is now a chief goal of cancer therapy. The success of immune checkpoint blockade (ICB) therapy demonstrates the tremendous promise of this paradigm, but still only a minority of patients have durable responses with this modality of therapy. I propose that altered metabolic programs in the tumor microenvironment (TME) may be linked to dysfunctional anti-tumor immune responses. By revealing these interactions, there may be new opportunities to improve the efficacy of immunotherapy. I have generated novel data demonstrating that myeloid cells across tumor models uptake significantly more glucose in the TME, while transformed cells appear to be glutamine consuming. Renal Cell Carcinomas (RCC) are metabolically altered tumors that are characterized by a complex and abundant immune cell infiltrate. It is well established by our group and others that these tumor-infiltrating T cells are metabolically compromised and have limited antitumor capacity. Even though ICB has improved RCC patient survival, only a minority of patients have complete responses with these T cell stimulating agents. The unique genetics of RCC may contribute to this aforementioned suppressive TME. In clear cell RCCs, the loss of the tumor suppressor von Hippel Lindau (VHL) is a necessary event for tumorigenesis. Additionally, in a subset of aggressive Type II papillary RCCs, the loss of fumarate hydratase (FH) or other defects in the tricarboxylic acid cycle are required for tumor formation. These genetic events were defined by my mentor WK Rathmell and others. These genetic events across RCC results in accumulation of the oncogenic transcription factors (TFs) hypoxia inducible factor 1 and 2. With accumulation of these TFs, RCC tumor cells shift their energetic requirements by decreasing their reliance on the tricarboxylic acid cycle and mitochondrial respiration while increasing cellular glycolysis. Therefore, RCC is uniquely posed to further study the impact of tumor cell metabolism on lymphoid and myeloid cell fate and function. This project will apply novel immunocompetent, non-immunogenic CRISPR/Cas9 models to study the effect of RCC genetic events (VHL and FH loss) on immune infiltration and activation. In these models, I will also examine the differential outcomes of inhibiting glucose and glutamine uptake on immune cell fitness and function in the TME. This work will be complemented by studies that employ in vitro primary human RCC organoid models to examine the impact of genetic and chemical perturbations on human tumor resident immune cell metabolism. This study will ultimately shed light on the heterotypic nature of tumor metabolism. By understanding the divergent metabolic capacities of the key cell types in the heterogenous TME, this work will increase our capability to support anti-tumor capacity of infiltrating immune cells. These data will aid future pharmacological strategies that can increase our ability to induce clinically significant anti-tumor immune responses in larger cohorts of patients.