Citations

Abstract Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of only 9%, due in part to its robust metastatic capability. Metastatic invasion is a particularly energy-intensive cellular process; thus, novel therapeutic strategies could include targeting the energy source for tumor cell invasion and migration. Excess lipids, present due to increased fatty acid synthesis or obesity, could provide a fuel source for cancer progression and metastasis. Neutral lipids are stored in organelles called lipid droplets (LDs). How LDs contribute to PDAC tumor cell invasion and metastasis remains unknown. We hypothesize that PDAC cells can store excess lipid to drive metastatic invasion. Indeed, introduction of excess exogenous fatty acids augments LD production and accumulation in PDAC cells and leads to enhanced PDAC cell motility and invasion in vitro. LDs are metabolized by the concerted action of lipases. Importantly, we have found that treatment of tumor cells with lipase inhibitors blocks tumor cell invasion, indicating that utilization of stored lipids via lipase-mediated LD breakdown is required for invasive migration. Hormone sensitive lipase (HSL) is a lipolytic enzyme, best characterized in adipose tissue, that is critical to the breakdown and utilization of LDs in vitro and in vivo. We have made the surprising observation that oncogenic KRas downregulates expression of HSL in pancreatic cancer cells, which shifts the cells towards lipid storage. In PDAC, mutational activation of the oncogene KRas occurs in 95% of tumors and contributes to metabolic rewiring of tumor cells. Our data suggest that the metabolic shift induced by mutant KRas is comprised of decreased LD utilization via downregulation of HSL. Indeed, re-expression of HSL shifts tumor cell metabolism towards elevated oxidative phosphorylation. Importantly, KRas-mutant cells still require the catalytic activity of HSL for tumor cell invasion, even though HSL expression is downregulated. Using redox ratio imaging, we have found that migratory cells selectively utilize oxidative phosphorylation during the process of migration to metabolize stored lipid droplets and fuel invasive migration. Finally, depletion of LD stores via overexpression of HSL blocks tumor cell invasion in vitro and metastasis in mice, even in the context of oncogenic KRas. These data indicate that regulation of HSL is important for both lipid storage and maintaining cancer cell invasiveness. Therefore, we propose a novel mechanism by which oncogenic KRas mediates HSL activity in a tunable manner, thereby altering the metabolism of PDAC cells and leading to increased metastatic ability. This abstract is also being presented as Poster B47. Citation Format: Cody Rozeveld, Ryan Schulze, Lizhi Zhang, Gina L Razidlo. KRas modulates pancreatic cancer cell metabolism and invasive potential through the lipase HSL [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr PR09.

Objective: Anemia is common during critical illness and often persists after hospital discharge; however, its potential association with physical outcomes after critical illness is unclear. Our objective was to assess the associations between hemoglobin at intensive care unit (ICU) and hospital discharge with physical status at 3-month follow-up in acute respiratory distress syndrome (ARDS) survivors. Methods: This is a secondary analysis of a multisite prospective cohort study of 195 mechanically ventilated ARDS survivors from 13 ICUs at 4 teaching hospitals in Baltimore, Maryland. Multivariable regression was utilized to assess the relationships between ICU and hospital discharge hemoglobin concentrations with measures of physical status at 3 months, including muscle strength (Medical Research Council sumscore), exercise capacity (6-minute walk distance [6MWD]), and self-reported physical functioning (36-Item Short-Form Health Survey [SF-36v2] Physical Function score and Activities of Daily Living [ADL] dependencies). Results: Median (interquartile range) hemoglobin concentrations at ICU and hospital discharge were 9.5 (8.5-10.7) and 10.0 (9.0-11.2) g/dL, respectively. In multivariable regression analyses, higher ICU discharge hemoglobin concentrations (per 1 g/dL) were associated with greater 3-month 6MWD mean percent of predicted (3.7% [95% confidence interval 0.8%-6.5%]; P = .01) and fewer ADL dependencies (−0.2 [−0.4 to −0.1]; P = .02), but not with percentage of maximal muscle strength (0.7% [−0.9 to 2.3]; P = .37) or SF-36v2 normalized Physical Function scores (0.8 [−0.3 to 1.9]; P = .15). The associations of physical outcomes and hospital discharge hemoglobin concentrations were qualitatively similar, but none were statistically significant. Conclusions: In ARDS survivors, higher hemoglobin concentrations at ICU discharge, but not hospital discharge, were significantly associated with improved exercise capacity and fewer ADL dependencies. Future studies are warranted to further assess these relationships.

The gene encoding SAP97 ( DLG1) joins a growing list of genes encoding ion channel interacting proteins (ChIPs) identified as potential channelopathy-susceptibility genes because of their ability to regulate the trafficking, targeting, and modulation of ion channels that are critical for the generation and propagation of the cardiac electrical impulse. In this study we provide the first data supporting DLG1-encoded SAP97’s candidacy as a minor Brugada syndrome susceptibility gene.

INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 369 nominally genome-wide significant loci ( P < 5 × 10 −8 ) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 360 loci for which replication data were available, 241 loci influencing surface area and 66 influencing thickness remained significant after replication, with 237 loci passing multiple testing correction ( P < 8.3 × 10 −10 ; 187 influencing surface area and 50 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation ( r G = −0.32, SE = 0.05, P = 6.5 × 10 −12 ), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 46 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function. Identifying genetic influences on human cortical structure. ( A ) Measurement of cortical surface area and thickness from MRI. ( B ) Genomic locations of common genetic variants that influence global and regional cortical structure. ( C ) Our results support the radial unit hypothesis that the expansion of cortical surface area is driven by proliferating neural progenitor cells. ( D ) Cortical surface area shows genetic correlation with psychiatric and cognitive traits. Error bars indicate SE. IMAGE CREDITS: (A) K. COURTNEY; (C) M. R. GLASS

Abstract BACKGROUND In treating glioblastoma, irradiation of the neural progenitor cell (NPC) niches is controversial. Lower hippocampal doses may limit neurocognitive toxicity, but higher doses to the subventricular zones (SVZ) may improve survival. OBJECTIVE To prospectively evaluate the impact of limiting radiation dose to the NPC niches on tumor progression, survival, and cognition in patients with glioblastoma. METHODS Patients with glioblastoma received resection followed by standard chemoradiation. Radiation dose to the NPC niches, including the bilateral hippocampi and SVZ, was minimized without compromising tumor coverage. The primary outcome was tumor progression in the spared NPC niches. Follow-up magnetic resonance imaging was obtained bimonthly. Neurocognitive testing was performed before treatment and at 6- and 12-mo follow-up. Cox regression evaluated predictors of overall and progression-free survival. Linear regression evaluated predictors of neurocognitive decline. RESULTS A total of 30 patients enrolled prospectively. The median age was 58 yr. Median mean doses to the hippocampi and SVZ were 49.1 and 41.8 gray (Gy) ipsilaterally, and 16.5 and 19.9 Gy contralaterally. Median times to death and tumor progression were 16.0 and 7.6 mo, and were not significantly different compared to a matched historical control. No patients experienced tumor progression in the spared NPC-containing regions. Overall survival was associated with neurocognitive function ( P ≤ .03) but not dose to the NPC niches. Higher doses to the hippocampi and SVZ predicted greater decline in verbal memory ( P ≤ .01). CONCLUSION In treating glioblastoma, limiting dose to the NPC niches may reduce cognitive toxicity while maintaining clinical outcomes. Further studies are needed to confirm these results.

Background: Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks. METHODS: Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18–80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes. RESULTS: ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2–4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05–3.98; P = .0386), BMI ≥40 (2.16 [1.12–4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30–39: 1.75 [1.09–2.79], P = .02; MELD ≥40: 2.73 [1.53–4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75–5.34], P < .001), living donors (2.13 [1.16–3.89], P = .014), and reoperation (1.87 [1.13–3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA. CONCLUSIONS: We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with improved survival for patients with colorectal peritoneal metastases (CR-PM). However, the role of neoadjuvant chemotherapy (NAC) prior to CRS-HIPEC is poorly understood. A retrospective review of adult patients with CR-PM who underwent CRS+/-HIPEC from 2000–2017 was performed. Among 298 patients who underwent CRS+/-HIPEC, 196 (65.8%) received NAC while 102 (34.2%) underwent surgery first (SF). Patients who received NAC had lower peritoneal cancer index score (12.1 + 7.9 vs. 14.3 + 8.5, p = 0.034). There was no significant difference in grade III/IV complications (22.4% vs. 16.7%, p = 0.650), readmission (32.3% vs. 23.5%, p = 0.114), or 30-day mortality (1.5% vs. 2.9%, p = 0.411) between groups. NAC patients experienced longer overall survival (OS) (median 32.7 vs. 22.0 months, p = 0.044) but similar recurrence-free survival (RFS) (median 13.8 vs. 13.0 months, p = 0.456). After controlling for confounding factors, NAC was not independently associated with improved OS (OR 0.80) or RFS (OR 1.04). Among patients who underwent CRS+/-HIPEC for CR-PM, the use of NAC was associated with improved OS that did not persist on multivariable analysis. However, NAC prior to CRS+/-HIPEC was a safe and feasible strategy for CR-PM, which may aid in the appropriate selection of patients for aggressive cytoreductive surgery.

1502 Background: High-grade gliomas (HGG, WHO grades III-IV) are morphologically and genetically diverse, with survivals ranging from months to decades. Although WHO 2000 grading criteria are well established for pure astrocytomas [anaplastic astrocytoma (AA) and glioblastoma (GBM)], those for oligodendroglial neoplasms [anaplastic oligoastrocytoma (AOA) and oligodendroglioma (AO)] remain subjective, there being a debate regarding the existence of a grade IV variant based on the finding of necrosis, particularly with pseudopalisading (PPN). Methods: Overall survival of 916 adult (>20 yr) patients diagnosed between 1990 and 2005 with supratentorial HGG (77 AA, 481 GBM, 183 AOA, 175 AO) was analyzed by uni- (log-rank) and multivariate (Cox proportional hazards) models for significance of the following factors: microvascular proliferation, necrosis, patient age, surgery (stereotactic vs. open), location, primary vs. secondary tumor, year of diagnosis, and chromosome 1p and 19q losses by fluorescence in situ hybridization. Results: Necrosis was a statistically significant predictor of poor survival on multivariate analyses in AOA (P=0.035), but not in AO (log-rank P=0.048, Cox P=0.9), while PPN showed a trend towards significance on multivariate analysis only in AOA (P=0.096). Other independent predictors on multivariate analysis included age, grade, surgery type, and year of diagnosis for AA/GBM and age, primary tumor, and 1p/19q codeletion for both AOA and AO (P<0.05). Median survival for AOA patients whose tumors featured necrosis (20.7 mo) was significantly worse than their counterparts lacking necrosis (>104 mo); survival of the latter was more similar to that of AO (83.5 mo), whereas in the former it was better than GBM (10.5 mo) (log-rank P<0.0001). Conclusions: Stratification of oligoastrocytomas, but not of pure oligodendrogliomas, into grades III (AOA) and IV (GBM with oligodendroglial features) on the basis of necrosis is prognostically justified and is more accurate than the current approach of using a single anaplastic grade. These data provide impetus for the modification of present WHO criteria. No significant financial relationships to disclose.

Abstract Background Since the introduction of percutaneous endoscopic gastrostomy in the 1980s, the prevalence of home enteral nutrition (HEN) support has increased significantly. Despite these increases, many patients are unable to tolerate standard polymeric formulas (SPFs), resulting in significant healthcare resource utilization. Peptide‐based diets (PBDs) have emerged as a viable option in SPF‐intolerant patients; however, data in the HEN population are lacking. Methods Retrospective review of our prospectively maintained HEN database was conducted to assess tolerance, efficacy, and impact on healthcare utilization in patients on PBDs. Results From January 1, 2016, to May 1, 2018, 95 patients were placed on PBDs, with 53 patients being started directly and 42 patients being transitioned from SPFs. In patients transitioned to PBDs, symptoms of nausea and vomiting, diarrhea, abdominal pain, and distention improved significantly. Healthcare utilization also declined significantly, including mean number of phone calls (1.8 ± 1.6 to 1.1 ± 0.9, P = 0.006), mean number of emergency room visits (0.3 ± 0.6 to 0.09 ± 0.3, P = 0.015), and mean number of provider visits (1.3 ± 1.3 to 0.3 ± 0.5, P < 0.0001). Conclusions Overall, PBDs were well tolerated and resulted in significant improvements in symptoms of gastrointestinal distress and healthcare utilization in patients intolerant to SPFs.

Background and Aims Vacuolar H+‐ATP complex (V‐ATPase) is a multisubunit protein complex required for acidification of intracellular compartments. At least five different factors are known to be essential for its assembly in the endoplasmic reticulum (ER). Genetic defects in four of these V‐ATPase assembly factors show overlapping clinical features, including steatotic liver disease and mild hypercholesterolemia. An exception is the assembly factor vacuolar ATPase assembly integral membrane protein (VMA21), whose X‐linked mutations lead to autophagic myopathy. Approach and Results Here, we report pathogenic variants in VMA21 in male patients with abnormal protein glycosylation that result in mild cholestasis, chronic elevation of aminotransferases, elevation of (low‐density lipoprotein) cholesterol and steatosis in hepatocytes. We also show that the VMA21 variants lead to V‐ATPase misassembly and dysfunction. As a consequence, lysosomal acidification and degradation of phagocytosed materials are impaired, causing lipid droplet (LD) accumulation in autolysosomes. Moreover, VMA21 deficiency triggers ER stress and sequestration of unesterified cholesterol in lysosomes, thereby activating the sterol response element‐binding protein–mediated cholesterol synthesis pathways. Conclusions Together, our data suggest that impaired lipophagy, ER stress, and increased cholesterol synthesis lead to LD accumulation and hepatic steatosis. V‐ATPase assembly defects are thus a form of hereditary liver disease with implications for the pathogenesis of nonalcoholic fatty liver disease.