Renal cell carcinoma (RCC) patients with hypercalcemia (HC) have worse outcomes. HC often involves PTHrP, and the role of HIF-2 is incompletely understood. Leveraging RCC tumorgraft (TG) models of HC, which were characterized by tumor cell autonomous inflamatory/immune signatures, we show that HIF-2 inhibition with PT2399 frequently normalized calcium, downregulated circulating PTHrP and reduced HIF-2 binding to the PTHLH (PTHrP) promoter. Likely contributing to the selective induction of PTHrP in a subset of HIF-2-dependent tumors, the PTHLH locus was generally more accessible in TG(HC). However, PTHLH chromatin accessibility was grossly unaffected by PT2399, unlike elsewhere (including EPO locus in a TG with paraneoplastic polycythemia). As in TGs, paraneoplastic HC in patients was associated with clear cell (cc)RCC (and sarcomatoid/rhabdoid differentiation) and was rapidly corrected by PT2977/belzutifan, which unlike bisphosphonates, downregulated PTHrP. Our data supports evaluating HIF-2 antagonists for ccRCC patients with paraneoplastic HC, which may serve as a predictive biomarker.
Cancer discovery. 2025 Oct 09 [Epub ahead of print]
Arijit Mal, Bingqing Xie, Zane Gray, Charlotte Small, Susmita G Ramanand, Yunpeng Gao, Vanina Toffessi Tcheuyap, Sashi Debnath, Alana Christie, Jeffrey Miyata, Brooklyn Jackson, Hua Zhong, Boning Gao, Jay Lohrey, Naim M Maalouf, Sangeetha M Reddy, John D Minna, Ivan Pedrosa, Xiankai Sun, Ram S Mani, Payal Kapur, James Brugarolas
The University of Texas Southwestern Medical Center, Dallas, Texas, United States., The University of Texas Southwestern Medical Center, Dallas, TX, United States., The University of Texas Southwestern Medical Center, dallas, TX, United States., The University of Texas MD Anderson Cancer Center, Houston, TX, United States., UT Southwestern Medical Center, Dallas, Texas, United States., The University of Texas Southwestern Medical Center, Dallas, United States.