AURKB-mediated phosphorylation of metabolic enzyme CD73 drives immune suppression and renal cell carcinoma progression

Aberrant tumor metabolism plays a crucial role in establishing and sustaining an immunosuppressive microenvironment. CD73, a key enzyme in the purine metabolism pathway, is frequently overexpressed in tumors, leading to elevated extracellular adenosine (ADO) levels. This accumulation suppresses antitumor immune responses by promoting immune cell exhaustion, ultimately contributing to immunotherapy resistance. However, the mechanisms underlying CD73 upregulation in tumors remain poorly defined. Here, we identify aurora kinase B (AURKB) as a critical regulator of CD73 overexpression in renal cell carcinoma (RCC), orchestrating immune evasion and resistance to immune checkpoint therapy. AURKB is highly expressed in RCC, with its prognostic significance being especially evident in tumors with strong immunogenicity. Mechanistically, AURKB enhances CD73 expression, thereby promoting T cell dysfunction and immune suppression. Mass cytometry (CyTOF) analysis revealed that AURKB inhibition facilitates immune infiltration and alleviates immune exhaustion. We further demonstrate that AURKB directly interacts with CD73 and phosphorylates it at serine 429, which inhibits STUB1-mediated ubiquitination and proteasomal degradation of CD73. Targeting AURKB to modulate the post-translational stability of CD73 restores antitumor immunity and synergizes with immune checkpoint blockade in vivo. Collectively, this study uncovers a previously unrecognized AURKB–CD73 axis and provides a mechanistically informed strategy to enhance immunotherapy efficacy in RCC.