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BACKGROUND The majority of patients diagnosed with clear cell renal cell carcinoma (ccRCC) have low‐risk disease with a < 10% chance of ccRCC‐specific death. DNA sequencing revealed that mutations in BAP1 (BRCA1 associated protein‐1) occur in 5% to 15% of ccRCC cases and are associated with poor outcomes. The vast majority of BAP1 mutations abolish protein expression. In this study, we used a highly sensitive and specific immunohistochemistry (IHC) assay to test whether BAP1 expression is an independent marker of ccRCC‐specific survival, particularly in patients with low‐risk disease. METHODS BAP1 expression was assessed, using IHC, in 1479 patients who underwent nephrectomy to treat clinically localized ccRCC. A centralized pathologist dichotomized patients as either BAP1‐positive or BAP1‐negative. The authors employed Kaplan‐Meier and Cox regression models to associate BAP1 expression with cancer‐specific survival. RESULTS A total of 10.5% of tumors were BAP1‐negative, 84.8% of tumors were BAP1‐positive, and 4.6% of tumors had ambiguous staining for BAP1. Patients with BAP1‐negative tumors have an increased risk of ccRCC‐related death (hazard ratio [HR] = 3.06; 95% confidence interval [CI] = 2.28‐4.10; P = 6.77 × 10 −14 ). BAP1 expression remained an independent marker of prognosis after adjusting for the UCLA integrated staging system (UISS) (HR = 1.67; 95% CI = 1.24‐2.25; P < .001). Finally, BAP1 was an independent prognostic marker in low‐risk patients with a Mayo Clinic stage, size, grade, and necrosis (SSIGN) score of ≤ 3 (HR = 3.24; 95% CI = 1.26‐8.33; P = .015). CONCLUSIONS This study used a large patient cohort to demonstrate that BAP1 expression is an independent marker of prognosis in patients with low‐risk (SSIGN≤ 3) ccRCC. Cancer 2014;1059–1067 . © 2014 American Cancer Society .

Background— Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak V O 2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF. Methods and Results— RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak V O 2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and V E /V CO 2 was higher. Conclusions— AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00763867.

Lipid droplets (LDs) are lipid storage organelles that in hepatocytes may be catabolized by autophagy for use as an energy source, but the membrane-trafficking machinery regulating such a process is poorly characterized. We hypothesized that the large GTPase Dynamin 2 (Dyn2), well known for its involvement in membrane deformation and cellular protein trafficking, could orchestrate autophagy-mediated LD breakdown. Accordingly, depletion or pharmacologic inhibition of Dyn2 led to a substantial accumulation of LDs in hepatocytes. Strikingly, the targeted disruption of Dyn2 induced a dramatic four- to fivefold increase in the size of autolysosomes. Chronic or acute Dyn2 inhibition combined with nutrient deprivation stimulated the excessive tubulation of these autolysosomal compartments. Importantly, Dyn2 associated with these tubules along their length, and the tubules vesiculated and fragmented in the presence of functional Dyn2. These findings provide new evidence for the participation of the autolysosome in LD metabolism and demonstrate a novel role for dynamin in the function and maturation of an autophagic compartment.

Abstract Increased angiogenesis and tumor-induced immune evasion are two mechanisms by which clear cell renal cell carcinoma (ccRCC) proliferate and metastasize; however, the relationship between these pathways in human ccRCC is poorly understood. We conducted a nested case–control study using 98 archived tumor samples from patients diagnosed with primary ccRCC between 1990 and 2006, half of which were identified by immunohistochemistry (IHC) as either programmed death ligand 1 (PDL-1)–positive or PDL-1–negative. RNAs were extracted from the formalin-fixed paraffin-embedded tumor slides and the expression of the VEGFA, VEGFR1, VEGFR2, and PDL-1 genes was quantified. We assessed the presence of tumor-infiltrating lymphocytes (TIL) by IHC for CD3, and then analyzed the relationship among VEGFA, VEGFR1, VEGFR2, CD3, and PDL-1. When analyzed as a continuous variable, PDL-1 protein expression by IHC inversely correlates with the expression of the three VEGF-related genes: VEGFA (r = −0.23; P = 0.01), VEGFR1 (r = −0.34; P &lt; 0.001), and VEGFR2 (r = −0.23; P = 0.01). When dichotomized, the PDL-1–positive cohort trended toward a lower expression of VEGFA (fold change = 0.72; P = 0.056) and VEGFR1 (fold change = 0.69; P = 0.057). In addition, there was a significant and positive relationship between the presence of TIL as assessed by IHC for CD3 and PDL-1 by IHC (r = 0.25; P = 0.015), and there was a trend toward an inverse relationship between TIL and VEGFA gene expression (r = −0.18; P = 0.089). In conclusion, this is the first demonstration of an inverse association between the angiogenesis and PDL-1 pathways in tumor samples from primary ccRCC, and this relationship may be related to the immunosuppressive effects of VEGF signaling. Cancer Immunol Res; 1(6); 378–85. ©2013 AACR.

Abstract Interleukin (IL)-10 is elevated in cancer and is thought to contribute to immune tolerance and tumor growth. Defying these expectations, the adoptive transfer of IL-10–expressing T cells to mice with polyposis attenuates microbial-induced inflammation and suppresses polyposis. To gain better insights into how IL-10 impacts polyposis, we genetically ablated IL-10 in T cells in APCΔ468 mice and compared the effects of treatment with broad-spectrum antibiotics. We found that T cells and regulatory T cells (Treg) were a major cellular source of IL-10 in both the healthy and polyp-bearing colon. Notably, T cell–specific ablation of IL-10 produced pathologies that were identical to mice with a systemic deficiency in IL-10, in both cases increasing the numbers and growth of colon polyps. Eosinophils were found to densely infiltrate colon polyps, which were enriched similarly for microbiota associated previously with colon cancer. In mice receiving broad-spectrum antibiotics, we observed reductions in microbiota, inflammation, and polyposis. Together, our findings establish that colon polyposis is driven by high densities of microbes that accumulate within polyps and trigger local inflammatory responses. Inflammation, local microbe densities, and polyp growth are suppressed by IL-10 derived specifically from T cells and Tregs. Cancer Res; 73(19); 5905–13. ©2013 AACR.

The dynamin family of large GTPases has been implicated in vesicle formation from both the plasma membrane and various intracellular membrane compartments. The dynamin-like protein DLP1, recently identified in mammalian tissues, has been shown to be more closely related to the yeast dynamin proteins Vps1p and Dnm1p (42%) than to the mammalian dynamins (37%). Furthermore, DLP1 has been shown to associate with punctate vesicles that are in intimate contact with microtubules and the endoplasmic reticulum (ER) in mammalian cells. To define the function of DLP1, we have transiently expressed both wild-type and two mutant DLP1 proteins, tagged with green fluorescent protein, in cultured mammalian cells. Point mutations in the GTP-binding domain of DLP1 (K38A and D231N) dramatically changed its intracellular distribution from punctate vesicular structures to either an aggregated or a diffuse pattern. Strikingly, cells expressing DLP1 mutants or microinjected with DLP1 antibodies showed a marked reduction in ER fluorescence and a significant aggregation and tubulation of mitochondria by immunofluorescence microscopy. Consistent with these observations, electron microscopy of DLP1 mutant cells revealed a striking and quantitative change in the distribution and morphology of mitochondria and the ER. These data support very recent studies by other authors implicating DLP1 in the maintenance of mitochondrial morphology in both yeast and mammalian cells. Furthermore, this study provides the first evidence that a dynamin family member participates in the maintenance and distribution of the ER. How DLP1 might participate in the biogenesis of two presumably distinct organelle systems is discussed.