Immunometabolic Stress and Immune Suppression in Clear-Cell Renal Cell Carcinoma: Perspectives in Therapeutic Strategy.

Solid tumors frequently experience hypoxia during tumor progression, resulting in profound metabolic alterations. This phenomenon is particularly pronounced in clear-cell renal cell carcinoma (ccRCC) because of loss of the von Hippel-Lindau (VHL) tumor suppressor gene and constitutive activation of hypoxia-inducible factor (HIF) signaling. ccRCC is the most common subtype of kidney cancer, and durable therapeutic responses remain limited despite advances in immune checkpoint inhibition. Owing to its strong pseudohypoxic phenotype and extensive metabolic rewiring, ccRCC is widely regarded as a metabolic disease. These alterations generate a unique immune landscape characterized by abundant immune-cell infiltration together with profound T-cell dysfunction and exhaustion. This paradoxical "immune-hot yet immunosuppressed" phenotype is largely driven by hypoxia-associated immunometabolic reprogramming within tumor cells and the tumor microenvironment (TME). Several metabolic pathways are critically involved in this process, including lactate acidosis, arginine (Arg) depletion, tryptophan (Trp) depletion, kynurenine (Kyn)-mediated T-cell exhaustion, and adenosine-driven immune suppression. This review summarizes the current understanding of hypoxia-driven immunometabolic interactions in ccRCC and discusses how targeting these pathways may improve future therapeutic strategies against this aggressive malignancy.