Macrophage HIF-1α Is an Independent Prognostic Indicator in Kidney Cancer
Sophie J. Cowman, Daniel G. Fuja, Xian-De Liu, Rebecca S. Tidwell, Neelima Kandula, Deepika Sirohi, Archana Agarwal, Lyska L. Emerson, Sheryl R. Tripp, Jeffrey S. Mohlman, Miekan Stonhill, Guillermina Garcia, Christopher J. Conley, Adam A. Olalde, Timothy Sargis, Adela Ramírez‐Torres, José A. Karam, Christopher G. Wood, Kanishka Sircar, Pheroze Tamboli, Kenneth M. Boucher, Benjamin L. Maughan, Benjamin T. Spike, Thai H. Ho, Neeraj Agarwal, Eric Jonasch, Mei Yee Koh
Abstract
Abstract Purpose: Clear cell renal cell carcinoma (ccRCC) is frequently associated with inactivation of the von Hippel–Lindau tumor suppressor, resulting in activation of HIF-1α and HIF-2α. The current paradigm, established using mechanistic cell-based studies, supports a tumor promoting role for HIF-2α, and a tumor suppressor role for HIF-1α. However, few studies have comprehensively examined the clinical relevance of this paradigm. Furthermore, the hypoxia-associated factor (HAF), which regulates the HIFs, has not been comprehensively evaluated in ccRCC. Experimental Design: To assess the involvement of HAF/HIFs in ccRCC, we analyzed their relationship to tumor grade/stage/outcome using tissue from 380 patients, and validated these associations using tissue from 72 additional patients and a further 57 patients treated with antiangiogenic therapy for associations with response. Further characterization was performed using single-cell mRNA sequencing (scRNA-seq), RNA-in situ hybridization (RNA-ISH), and IHC. Results: HIF-1α was primarily expressed in tumor-associated macrophages (TAMs), whereas HIF-2α and HAF were expressed primarily in tumor cells. TAM-associated HIF-1α was significantly associated with high tumor grade and increased metastasis and was independently associated with decreased overall survival. Furthermore, elevated TAM HIF-1α was significantly associated with resistance to antiangiogenic therapy. In contrast, high HAF or HIF-2α were associated with low grade, decreased metastasis, and increased overall survival. scRNA-seq, RNA-ISH, and Western blotting confirmed the expression of HIF-1α in M2-polarized CD163-expressing TAMs. Conclusions: These findings highlight a potential role of TAM HIF-1α in ccRCC progression and support the reevaluation of HIF-1α as a therapeutic target and marker of disease progression.