Abstract 1387: SETD2 loss promotes macrophage infiltration and metastasis in RCC

Abstract Across human cancer, tumors that are high grade, poorly differentiated, and have undergone epithelial-to-mesenchymal transition (EMT) carry a worse prognosis with a high likelihood of metastasizing to distant organs. Despite significant research efforts, metastatic cancers and relapse remain the primary cause of cancer related deaths. In renal cell carcinoma (RCC), metastasis is present in one-third of patients at the time of diagnosis, and one-third of patients who initially present with locally advanced disease eventually develop local or distant recurrence following resection of the primary tumor, highlighting the need for new RCC therapies and further insight into the metastatic process. Using RCC patient biopsies, we found that patients with more epithelial tumors have a significantly lower risk of recurrence. Additionally, tumors that had a mesenchymal protein signature had significantly increased macrophage infiltration, which was significantly associated with a higher stage at diagnosis and worse overall survival, suggesting that macrophages may play an important role in EMT and metastasis in ccRCC. Whole exome sequencing of these patient samples revealed that mutational loss of SETD2, a histone methyltransferase that is lost in about 20% of RCC patients, correlated strongly with increased macrophage infiltration within the primary tumor and was necessary for the correlation between macrophages and EMT. SETD2 loss in syngeneic kidney cancer mouse models confirmed that SETD2 loss within tumor cells resulted in increased EMT, macrophages within the primary tumor microenvironment (TME), and spontaneous metastasis, further supporting the role of macrophages in promoting metastasis in the absence of SETD2. Further characterization of the gene signatures and immune cell infiltrate in RCC will lead to a better understanding of metastasis in an oncogene- and tissue-specific manner and thus lead to more efficacious therapies for metastatic patients. Citation Format: Emily N. Arner, Melissa M. Wolf, Logan Vlach, Jeffrey C. Rathmell, W. Kimryn Rathmell. SETD2 loss promotes macrophage infiltration and metastasis in RCC abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1387.