The phosphatidylinositol 3 kinase （PI3K）/AKT pathway is genetically targeted in more pathway components and in more tumor types than any other growth factor signaling pathway, and thus is frequently ...activated as a cancer driver. More importantly, the PI3K/AKT pathway is composed of multiple bifurcating and converging kinase cascades, providing many potential targets for cancer therapy. Renal cell carcinoma （RCC） is a high-risk and high-mortality cancer that is notoriously resistant to traditional chemotherapies or radiotherapies. The PI3K/AKT pathway is modestly mutated but highly activated in RCC, representing a promising drug target. Indeed, PI3K pathway inhibitors of the rapalog family are approved for use in RCC. Recent large-scale integrated analyses of a large number of patients have provided a molecular basis for RCC, reiterating the critical role of the PI3K/AKT pathway in this cancer. In this review, we summarize the genetic alterations of the PI3K/AKT pathway in RCC as indicated in the latest large-scale genome sequencing data, as well as treatments for RCC that target the aberrant activated PI3K/AKT pathway.
Clear cell renal carcinoma (ccRCC) is a heterogeneous disease with a variable post-surgical course. To assemble a comprehensive ccRCC tumor microenvironment (TME) atlas, we performed single-cell RNA ...sequencing (scRNA-seq) of hematopoietic and non-hematopoietic subpopulations from tumor and tumor-adjacent tissue of treatment-naive ccRCC resections. We leveraged the VIPER algorithm to quantitate single-cell protein activity and validated this approach by comparison to flow cytometry. The analysis identified key TME subpopulations, as well as their master regulators and candidate cell-cell interactions, revealing clinically relevant populations, undetectable by gene-expression analysis. Specifically, we uncovered a tumor-specific macrophage subpopulation characterized by upregulation of TREM2/APOE/C1Q, validated by spatially resolved, quantitative multispectral immunofluorescence. In a large clinical validation cohort, these markers were significantly enriched in tumors from patients who recurred following surgery. The study thus identifies TREM2/APOE/C1Q-positive macrophage infiltration as a potential prognostic biomarker for ccRCC recurrence, as well as a candidate therapeutic target.
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•We present a robust pipeline for scRNA-seq analysis by protein activity inference•Our pipeline identifies a C1Q+TREM2+APOE+ macrophage population enriched in ccRCC•Protein activity signature of these cells is prognostic of post-surgical recurrence•C1Q+ Macrophage association with recurrence is validated by immunohistochemistry
Analysis of the tumor microenvironment using tumor and tumor-adjacent tissue of treatment-naive clear cell renal carcinoma resections from patients by combining single-cell sequencing and single-cell protein activity uncovers a tumor-specific infiltrating macrophage subpopulation associated with disease recurrence.
Over the last several decades, an improved understanding of von Hippel–Lindau disease and its underlying biology has informed the successful development of numerous anti-cancer agents, particularly ...for the treatment of advanced renal cell carcinoma. Most recently, this has culminated in the first regulatory approval for a systemic therapy for VHL disease-associated neoplasms. This review will trace the clinical development of systemic therapies for VHL disease and additionally highlight anticipated challenges and opportunities for future VHL systemic therapy.
Abstract Background Sunitinib and everolimus are standard first-line and second-line therapies, respectively, in clear cell renal cell carcinoma (ccRCC). Objective To conduct a randomized phase 2 ...trial comparing sunitinib and everolimus in non–clear cell RCC (non-ccRCC). Design, setting, and participants Patients with metastatic, non-ccRCC, or ccRCC with >20% sarcomatoid features (ccSRCC) were randomized to receive sunitinib or everolimus with crossover at disease progression. Outcome measurement and statistical analysis Primary end point was progression-free survival (PFS) in first-line therapy; 108 patients were needed to show improvement in median PFS (mPFS) from 12 wk with sunitinib to 20 wk with everolimus. Results and limitations Interim analysis of 68 patients (papillary 27 , chromophobe 12 , unclassified 10 , translocation 7 , ccSRCC 12 ) prompted early trial closure. The mPFS in first-line therapy was 6.1 mo with sunitinib and 4.1 mo with everolimus ( p = 0.6); median overall survival (mOS) was not reached with sunitinib and was 10.5 mo with everolimus, respectively ( p = 0.014). At final analysis, mOS was 16.2 and 14.9 mo with sunitinib and everolimus, respectively ( p = 0.18). There were four partial responses (PRs) in first-line therapy (sunitinib: 3 of 33 9%; everolimus, 1 of 35 2.8%) and four PRs in second-line therapy (sunitinib: 2 of 21 9.5%; everolimus, 2 of 23 8.6%), with mPFS of 1.8 mo and 2.8 mo, respectively. In patients without sarcomatoid features in their tumors ( n = 49), mOS was 31.6 mo with sunitinib and 10.5 mo with everolimus ( p = 0.075). Genomic profiling of a chromophobe RCC from a patient with a PR to first-line everolimus revealed a somatic TSC2 mutation. Conclusions In this trial, everolimus was not superior to sunitinib. Both agents demonstrated modest efficacy, underscoring the need for better therapies in non-ccRCC. Patient summary This randomized phase 2 trial provides the first head-to-head comparison of everolimus and sunitinib in patients with metastatic non–clear cell renal cell carcinoma (non-ccRCC). The observed very modest efficacy underscores the need to develop more effective therapies for non-ccRCC.
A non-immunogenic tumor microenvironment (TME) is a significant barrier to immune checkpoint blockade (ICB) response. The impact of Polybromo-1 (PBRM1) on TME and response to ICB in renal cell ...carcinoma (RCC) remains to be resolved. Here we show that PBRM1/Pbrm1 deficiency reduces the binding of brahma-related gene 1 (BRG1) to the IFNγ receptor 2 (Ifngr2) promoter, decreasing STAT1 phosphorylation and the subsequent expression of IFNγ target genes. An analysis of 3 independent patient cohorts and of murine pre-clinical models reveals that PBRM1 loss is associated with a less immunogenic TME and upregulated angiogenesis. Pbrm1 deficient Renca subcutaneous tumors in mice are more resistance to ICB, and a retrospective analysis of the IMmotion150 RCC study also suggests that PBRM1 mutation reduces benefit from ICB. Our study sheds light on the influence of PBRM1 mutations on IFNγ-STAT1 signaling and TME, and can inform additional preclinical and clinical studies in RCC.
Posttranslational modifications (PTMs) of tubulin specify microtubules for specialized cellular functions and comprise what is termed a “tubulin code.” PTMs of histones comprise an analogous “histone ...code,” although the “readers, writers, and erasers” of the cytoskeleton and epigenome have heretofore been distinct. We show that methylation is a PTM of dynamic microtubules and that the histone methyltransferase SET-domain-containing 2 (SETD2), which is responsible for H3 lysine 36 trimethylation (H3K36me3) of histones, also methylates α-tubulin at lysine 40, the same lysine that is marked by acetylation on microtubules. Methylation of microtubules occurs during mitosis and cytokinesis and can be ablated by SETD2 deletion, which causes mitotic spindle and cytokinesis defects, micronuclei, and polyploidy. These data now identify SETD2 as a dual-function methyltransferase for both chromatin and the cytoskeleton and show a requirement for methylation in maintenance of genomic stability and the integrity of both the tubulin and histone codes.
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•Dynamic microtubules are methylated during mitosis and cytokinesis•SETD2 methylates α-tubulin at lysine 40, the same lysine that is acetylated•Loss of microtubule methylation causes genomic instability
Tubulin and histones share a methyltransferase, suggesting a new basis for known tumorigenic mutations in the enzyme.
To date, real-world evidence around the clinical and economic burden related to von Hippel-Lindau (VHL) disease is limited. Therefore, this study characterized the prevalence, healthcare resource ...utilization (HRU), and economic burden of von Hippel-Lindau-associated central nervous system hemangioblastoma (VHL-CNS-Hb) and pancreatic neuroendocrine tumors (VHL-pNET) in the United States (US).
Patients with VHL-CNS-Hb or VHL-pNET were identified from Optum's de-identified Clinformatics® Data Mart Database (2007-2020) and matched 1:5 to control patients without VHL disease or CNS-Hb/pNET. Prevalence rates of VHL-CNS-Hb and VHL-pNET (standardized by age and sex) in 2019 were estimated. HRU and healthcare costs (2020 US dollars) were compared between the VHL-CNS-Hb/VHL-pNET and control cohorts.
In 2019, US prevalence rates of VHL-CNS-Hb and VHL-pNET were estimated to be 1.12 cases per 100,000 (3,678 patients) and 0.12 cases per 100,000 (389 patients), respectively. Patients with VHL-CNS-Hb (N = 220) had more inpatient, outpatient, and emergency department visits and $49,645 higher annual healthcare costs than controls (N = 1,100). Patients with VHL-pNET (N = 20) had more inpatient and outpatient visits and $56,580 higher annual healthcare costs than controls (N = 100). Costs associated with surgical removal of CNS-Hb and pNET were particularly high.
In this retrospective, claims-based study, both VHL-CNS-Hb and VHL-pNET were associated with substantial HRU and healthcare costs, particularly tumor reduction surgery-related costs. These findings provide important insight for healthcare payers regarding the expected real-world costs that enrollees with VHL-CNS-Hb and VHL-pNET may incur over the course of their disease.
Purpose The purpose of this guideline is to provide a clinical framework for follow-up of clinically localized renal neoplasms undergoing active surveillance, or following definitive therapy. ...Materials and Methods A systematic literature review identified published articles in the English literature between January 1999 and 2011 relevant to key questions specified by the Panel related to kidney neoplasms and their follow-up (imaging, renal function, markers, biopsy, prognosis). Study designs consisting of clinical trials (randomized or not), observational studies (cohort, case-control, case series) and systematic reviews were included. Results Guideline statements provided guidance for ongoing evaluation of renal function, usefulness of renal biopsy, timing/type of radiographic imaging and formulation of future research initiatives. A lack of studies precluded risk stratification beyond tumor staging; therefore, for the purposes of postoperative surveillance guidelines, patients with localized renal cancers were grouped into strata of low- and moderate- to high-risk for disease recurrence based on pathological tumor stage. Conclusions Evaluation for patients on active surveillance and following definitive therapy for renal neoplasms should include physical examination, renal function, serum studies and imaging and should be tailored according to recurrence risk, comorbidities and monitoring for treatment sequelae. Expert opinion determined a judicious course of monitoring/surveillance that may change in intensity as surgical/ablative therapies evolve, renal biopsy accuracy improves and more long-term follow-up data are collected. The beneficial impact of careful follow-up will also need critical evaluation as further study is completed.
Deficient DNA mismatch repair (dMMR) induces a hypermutator phenotype that can lead to tumorigenesis; however, the functional impact of the high mutation burden resulting from this phenotype remains ...poorly explored. Here, we demonstrate that dMMR-induced destabilizing mutations lead to proteome instability in dMMR tumors, resulting in an abundance of misfolded protein aggregates. To compensate, dMMR cells utilize a Nedd8-mediated degradation pathway to facilitate clearance of misfolded proteins. Blockade of this Nedd8 clearance pathway with MLN4924 causes accumulation of misfolded protein aggregates, ultimately inducing immunogenic cell death in dMMR cancer cells. To leverage this immunogenic cell death, we combined MLN4924 treatment with PD1 inhibition and found the combination was synergistic, significantly improving efficacy over either treatment alone.
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•Abundant destabilizing mutations lead to proteome instability in MSI cancers•MSI cancers rely on Nedd8-mediated clearance of destabilized/misfolded proteins•Inhibiting neddylation with MLN4924 induces immunogenic cell death•Potentiating MLN4924 therapy's immunogenicity with anti-PD1 provides potent synergy
McGrail et al. find that the abundance of destabilizing mutations in microsatellite unstable (MSI) tumors causes proteome instability and accumulation of misfolded proteins. To compensate, MSI tumors rely on a Nedd8-mediated pathway to clear misfolded aggregates, which can be therapeutically targeted by MLN4924.
Summary Background Population pharmacokinetic data suggest axitinib plasma exposure correlates with efficacy in metastatic renal-cell carcinoma. Axitinib dose titration might optimise exposure and ...improve outcomes. We prospectively assessed the efficacy and safety of axitinib dose titration in previously untreated patients with metastatic renal-cell carcinoma. Methods In this randomised, double-blind, multicentre, phase 2 study, patients were enrolled from 49 hospitals and outpatient clinics in the Czech Republic, Germany, Japan, Russia, Spain, and USA. Patients with treatment-naive metastatic renal-cell carcinoma received axitinib 5 mg twice daily during a 4 week lead-in period. Those patients with blood pressure 150/90 mm Hg or lower, no grade 3 or 4 treatment-related toxic effects, no dose reductions, and no more than two antihypertensive drugs for 2 consecutive weeks were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1), and then randomly assigned (1:1) to either masked titration with axitinib to total twice daily doses of 7 mg, and then 10 mg, if tolerated, or placebo titration. Patients who did not meet these criteria continued without titration. The primary objective was comparison of the proportion of patients achieving an objective response between randomised groups. Safety analyses were based on all patients who received at least one dose of axitinib. This ongoing trial is registered with ClinicalTrials.gov , number NCT00835978. Findings Between Sept 2, 2009, and Feb 28, 2011, we enrolled 213 patients, of whom 112 were randomly assigned to either the axitinib titration group (56 patients) or the placebo titration group (56 patients). 91 were not eligible for titration, and ten withdrew during the lead-in period. 30 patients (54%, 95% CI 40–67) in the axitinib titration group had an objective response, as did 19 patients (34%, 22–48) in the placebo titration group (one-sided p=0·019). 54 (59%, 95% CI 49–70) of non-randomised patients achieved an objective response. Common grade 3 or worse, all-causality adverse events in treated patients were hypertension (ten 18% of 56 in the axitinib titration group vs five 9% of 56 in the placebo titration group vs 45 49% of 91 in the non-randomised group), diarrhoea (seven 13% vs two 4% vs eight 9%), and decreased weight (four 7% vs three 5% vs six 7%). One or more all-causality serious adverse events were reported in 15 (27%) patients in the axitinib titration group, 13 (23%) patients in the placebo titration group, and 35 (38%) non-randomised patients. The most common serious adverse events in all 213 patients were disease progression and dehydration (eight each 4%), and diarrhoea, vomiting, pneumonia, and decreased appetite (four each 2%). Interpretation The greater proportion of patients in the axitinib titration group achieving an objective response supports the concept of individual axitinib dose titration in selected patients with metastatic renal-cell carcinoma. Axitinib shows clinical activity with a manageable safety profile in treatment-naive patients with this disease. Funding Pfizer Inc.
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