Two correlated variants (r² = 0.99 in controls), rs11894252 (P = 1.8 × 10⁻⁸) and rs7579899 (P = 2.3 × 10⁻⁹), map to EPAS1 on 2p21, which encodes hypoxia-inducible-factor-2 alpha, a transcription factor previously implicated in RCC.
In this issue of Cancer Discovery, Mathew and colleagues report that miR-30c-2-3p and miR-30a-3p downregulation in ccRCC promotes increased expression of HIF2α.
To explore the HIF-1α, HIF-2α and c-Myc baseline expression as potential predictors of sunitinib outcome as well as the effectiveness and safety with sunitinib in patients with metastatic ccRCC in routine clinical practice.
We demonstrate that functional delivery of a HIF2α-specific RNAi trigger resulted in HIF2α gene silencing and subsequent tumor growth inhibition and degeneration in an established orthotopic ccRCC xenograft model.<i></i>.
In kidney cancer, HIF-2α is believed to be the most important driver for development and progression of clear cell renal cell carcinoma (ccRCC), highlighting the therapeutic potential of HIF-2 antagonists in this disease.
HIF-1α, HIF-2α and CAIX were up-regulated in 88.2% (15/17), 100% (17/17) and 88.2% (15/17) of tumors respectively and their expression is independent of VHL status. hnRNP A2/B1 and osteopontin expression was variable in CCRCCs and had no association with VHL genetic status.
Two recent independent studies published in <i>Nature</i> show robust responses of clear cell renal cell carcinoma (ccRCC) cell lines, preclinical ccRCC xenograft models and, remarkably, a patient with progressive ccRCC despite receiving multiple lines of treatment, to the long-awaited, recently developed inhibitors of hypoxia-inducible factor 2-alpha (HIF2α).
We demonstrate that HIF2α promotes lipid storage, ER homeostasis, and cell viability in ccRCC via upregulation of the LD coat protein PLIN2, revealing a novel function for the well-documented "clear-cell" phenotype and identifying ER stress as a targetable vulnerability created by HIF2α/PLIN2 suppression in this common renal malignancy.
Design and Activity of Specific Hypoxia-Inducible Factor-2α (HIF-2α) Inhibitors for the Treatment of Clear Cell Renal Cell Carcinoma: Discovery of Clinical Candidate ( S)-3-((2,2-Difluoro-1-hydroxy-7-(methylsulfonyl)-2,3-dihydro-1 H-inden-4-yl)oxy)-5-fluorobenzonitrile (PT2385).
Herein, we provide mechanistic evidence that HIF-2α can be degraded in cytoplasm under hypoxic conditions via the 26S proteasome and that MDM2 is the E3 ligase which induces the hypoxic degradation of HIF-2α in PI-3K-dependent manner in VHL-deficient RCC cells.
Identification of CDCP1 as a hypoxia-inducible factor 2α (HIF-2α) target gene that is associated with survival in clear cell renal cell carcinoma patients.
These studies validate HIF2α as a therapeutic target in ccRCC, reveal variable sensitivity to HIF2α antagonism, and provide the foundation for predictive biomarker-driven clinical trials.
Hypoxia-inducible factor 2alpha (HIF-2α) antagonists -PT2385, and PT2399 have been shown to have promising results in the management of clear cell renal cell carcinoma by targeting the HIF-2α pathway in recent and ongoing clinical trials (PT2799).
Herein, we summarize the molecular background behind the use of HIF-2α inhibitors in ccRCC and give an overview of the development of new agents in this setting.
Taken together, the findings of this study suggest that the protein levels of HIF2A and VEGFA in tumor tissue may serve as independent prognostic factors in ccRCC. ccRCC patients with increased intratumoral HIF2A and VEGFA protein levels, and unaltered VHL protein levels, are not likely to benefit from sunitinib treatment following nephrectomy; however, this hypothesis requires verification by large‑scale replication studies.