Clear cell Renal Cell Carcinoma (ccRCC) is characterized by VHL inactivation1,2. Because no other gene is mutated as frequently, and VHL mutations are truncal3, VHL inactivation is regarded as the governing event4. VHL loss activates HIF-2, and constitutive HIF-2 restores tumorigenesis in VHL-reconstituted ccRCC cells5. HIF-2 is implicated in angiogenesis and multiple other processes6–9, but angiogenesis is the main target of drugs like sunitinib10. HIF-2, a transcription factor, has been regarded as undruggable11. A structure-based design approach identified a selective HIF-2 antagonist (PT2399) that we evaluate using a tumorgraft (TG)/PDX platform12,13. PT2399 dissociated HIF-2 (an obligatory heterodimer [HIF-2α/HIF-1β])14 in human ccRCC suppressing tumorigenesis in 56% (10/18) lines. PT2399 had greater activity than sunitinib, was active in sunitinib-progressing tumors, and was better tolerated. Unexpectedly, some VHL-mutant ccRCCs were resistant. Resistance occurred despite HIF-2 dissociation in tumors and evidence of Hif-2 inhibition in the mouse as determined by suppression of circulating erythropoietin, a HIF-2 target15 and possible pharmacodynamic marker. We identified a HIF-2-dependent gene signature in sensitive tumors. Illustrating drug specificity, gene expression was largely unaffected by PT2399 in resistant tumors. Sensitive tumors exhibited a distinguishing gene expression signature, and generally higher HIF-2α levels. Prolonged PT2399 treatment led to resistance. We identified a binding site and second site suppressor mutation in HIF-2α and HIF-1β respectively. Both mutations preserved HIF-2 dimers despite treatment with PT2399. Finally, an extensively pretreated patient with a sensitive TG had disease control for >11 months with the close analogue PT2385. We validate HIF-2 as a target in ccRCC, show that some ccRCC are, unexpectedly, HIF-2 independent, and set the stage for biomarker-driven clinical trials.

Background: Hyperuricemia is an independent risk factor for renal progression in IgA nephropathy (IgAN). However, no study has evaluated the effect of allopurinol on the clinical outcome in hyperuricemic IgAN. Methods: First,a retrospective cohort study of 353 IgAN patients was conducted to explore the relationship between uric acid (UA) and the progression of renal disease over a mean period of 5 years. Then, 40 hyperuricemic IgAN patients were randomized to receive allopurinol (100–300 mg/day) or usual therapy for 6 months. The study outcomes were renal disease progression and/or blood pressure. Results: Hyperuricemia independently predicted renal survival at 1, 3, and 5 years after adjustment for different baseline estimated glomerular filtration rates. In the randomized controlled trial, allopurinol did not significantly alter renal progression or proteinuria. The antihypertensive drug dosage was reduced in 7 of 9 cases with hypertension in the allopurinol group compared to 0 of 9 cases in the control group (p < 0.01). UA levels correlated with mean arterial pressure in normotensive patients (r = 0.388, p < 0.001). Conclusion: Hyperuricemia predicts the progression of IgAN independently of baseline estimated glomerular filtration rate. Allopurinol may improve the control of blood pressure. Further studies are required to explore the effects of lowering UA on renal protection in IgAN.

BackgroundProgrammed cell death 1 (PD-1) blockade induces tumor regression in patients with advanced esophageal squamous cell carcinoma (ESCC); however, little is known about the efficacy of PD-1 blockade as neoadjuvant therapy in resectable ESCC. We aim to assess the safety and feasibility of using the combination of neoadjuvant PD-1 blockade with chemotherapy in patients with ESCC.MethodsPatients with previously untreated, resectable (stage II or III) ESCC were enrolled. Each patient received two 21-day cycles of neoadjuvant treatment with camrelizumab, nab-paclitaxel, and carboplatin before undergoing surgical resection approximately 6–9 weeks after the first cycle.ResultsBetween January 2020 and September 2020, 37 patients were screened, of whom 23 were enrolled. The neoadjuvant therapeutic regimen had an acceptable side effect profile, and no delays in surgery were observed. Severe (grade 3–4) treatment-related adverse events included neutropenia (9 of 23, 39.1%) and leukopenia (2 of 23, 8.7%). The objective response and disease control rates were 90.5% and 100%, respectively. Twenty patients received surgery, and R0 resection was achieved in all cases. Five (25%) patients had a pathological complete response (PCR) and 10 (50%) patients had a major pathological response. The proportion of patients with a high tumor mutation burden and a high expression of programmed death-ligand 1 (PD-L1) in primary tumor was significantly higher in the PCR group than in the non-PCR group (p=0.044). The number of infiltrating PD-L1+ CD163+ cells was significantly lower in the PCR group than in the non-PCR group after treatment (p=0.017).ConclusionsNeoadjuvant camrelizumab plus carboplatin and nab-paclitaxel had manageable treatment-related adverse effects and induced an objective response in 90.5% of patients, demonstrating its antitumor efficacy in resectable ESCC.Trial registration numberChiCTR2000028900.

Background and purpose: Icariin may be the active ingredient in Herba Epimedii, a Chinese herb commonly used for treatment of osteoporosis. The present study aims to delineate the mechanism(s) by which icariin prevents bone loss after ovariectomy (OVX) in vivo and stimulates osteoblastic functions in vitro. Experimental approach: Ovariectomized or sham-operated C57BL/6 mice were treated with vehicle, 17b-oestradiol or icariin for 6 weeks. Total and trabecular bome mineral density (BMD) as well as polar stress-strain index of distal femur were measured by peripheral computed tomography. The mRNA expressions of OPG and RANKL in tibia were studied by RT-PCR. Interactions between the oestrogen receptor (ER) antagonist ICI182,780 and icariin were studied in UMR 106 cells. The functional transactivation of ERa and ERb as well as ERa phosphorylation by icariin were also assessed. Key results: Icariin suppressed the loss of bone mass and strength in distal femur and increased the mRNA expression ratio of OPG/RANKL in tibia, following OVX. Icariin increased ER-dependent cell proliferation, alkaline phosphatase (ALP) activity, gene expression of OPG and the OPG/RANKL ratio in UMR 106 cells. Icariin did not activate ERE-luciferase activity in UMR 106 cells, via the ERa or the ERb-mediated pathway, but it did increase ERa phosphorylation at Ser118. Conclusions and implications:Our results indicate that icariin exerts anabolic effects in bone possibly by activating ER in a ligand-independent manner. Its ability to prevent OVX-induced bone loss without inducing uterotrophic effects supports its use as an alternative regimen for management of postmenopausal osteoporosis.