Citations

Abstract Introduction: Atrial fibrillation (AF) represents a cardiovascular syndrome which can lead to embolic stroke. Several AF clinical trials have shown a decrease risk of stroke with anticoagulation using warfarin. Currently, there are two approaches for anticoagulation in AF patients. For outpatients, warfarin is used with an INR goal 2.0–3.0. For inpatients requiring cardioversion, unfractionated heparin (UFH, IV) is used as a bridge to therapeutic warfarin. More recently, anticoagulation with a low molecular weight heparin, enoxaparin, has been reported to give a more predictable anticoagulant response than UFH in TEEguided cardioversion. The present study compares the markers of inflammation and thrombin generation in patients included in the ACUTE II study. Methods: This was a randomized multicenter trial of 155 patients from 17 clinical sites, the anticoagulant activity of LMWH (enoxaparin, 1 mg/kg sc bid, Sanofi-Aventis, n=76) was compared to that of UFH (APTT 1.5 – 2.5 x control, n=79). Blood samples were drawn at enrollment (baseline), day 2 (peri cardioversion) and day 4 in both groups. Day 2 and day 4 samples were taken 3–4 hours after the injection of LMWH in patients in the LMWH group. Blood samples were evaluated for inflammation: C-reactive protein (CRP), CD 40 ligand (CD 40L), monocyte chemotactic protein 1 (MCP-1) and anticoagulant effect: thrombin antithrombin complex (TAT) and prothrombin fragment (F 1.2). Results: The APTT and anti-Xa levels indicated therapeutic anticoagulation was achieved (previously reported). In addition, both TAT and F1.2 levels were increased at baseline and were significantly decreased with LMWH (p<0.01) in comparison to UFH. The CRP, CD40L, MCP-1 were decreased after treatment in both groups of patients. These results suggest that AF patients treated with LMWH demonstrate a stronger anticoagulant effect as measured by a significant reduction in the markers of thrombin generation. Furthermore, anticoagulation with either UFH of LMWH results in a decrease in inflammation which was not different between groups. Conclusion: In the ACUTE II trial, anticoagulation with LMWH in AF patients may be a better alternate than UFH during TEE-guided cardioversion due to a a stronger anticoagulant.

Abstract Purpose: Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease urgently requiring new treatments. Overexpression of the protein transporter exportin-1 (XPO1) leads to mislocalization of tumor-suppressor proteins (TSP) and their inactivation. Earlier, we showed that blocking XPO1 by CRISPR/Cas9 validated Selective Inhibitor of Nuclear Export (SINE) compounds (selinexor and analogs) restores the antitumor activity of multiple TSPs leading to suppression of PDAC in vitro and in orthotopic models. Experimental Design: We evaluate the synergy between SINE compounds and standard-of-care treatments in preclinical models and in a PDAC Phase Ib trial. Results: SINE compounds synergize with gemcitabine (GEM) and nanoparticle albumin–bound (nab)-paclitaxel leading to suppression of PDAC cellular growth and cancer stem cell (CSC) spheroids disintegration. Label-free quantitative proteome profiling with nuclear and cytoplasmic enrichment showed superior enhancement in nuclear protein fraction in combination treatment. Selinexor inhibited the growth of PDAC CSC and two patient-derived (PDX) subcutaneous xenografts. Selinexor–GEM–nab-paclitaxel blocked PDX and orthotopic tumor growth. In a phase 1b study (NCT02178436), 9 patients were exposed to selinexor (60 mg oral) with GEM (1,000 mg/m2 i.v.) and nab-paclitaxel (125 mg/m2 i.v.) on days 1, 8, and 15 of 28-day cycle. Two patients showed partial response, and 2 had stable disease. An outstanding, durable objective response was observed in one of the responders with progression-free survival of 16 months and overall survival of 22 months. Conclusions: Our preclinical and ongoing clinical study lends support to the use of selinexor–GEM–nab-paclitaxel as an effective therapy for metastatic PDAC.

Background: Variations in cardiac troponin concentrations by age, sex, and time between samples in patients with suspected myocardial infarction are not currently accounted for in diagnostic approaches. We aimed to combine these variables through machine learning to improve the assessment of risk for individual patients. Methods: A machine learning algorithm (myocardial-ischemic-injury-index [MI 3 ]) incorporating age, sex, and paired high-sensitivity cardiac troponin I concentrations, was trained on 3013 patients and tested on 7998 patients with suspected myocardial infarction. MI 3 uses gradient boosting to compute a value (0–100) reflecting an individual’s likelihood of a diagnosis of type 1 myocardial infarction and estimates the sensitivity, negative predictive value, specificity and positive predictive value for that individual. Assessment was by calibration and area under the receiver operating characteristic curve. Secondary analysis evaluated example MI 3 thresholds from the training set that identified patients as low risk (99% sensitivity) and high risk (75% positive predictive value), and performance at these thresholds was compared in the test set to the 99th percentile and European Society of Cardiology rule-out pathways. Results: Myocardial infarction occurred in 404 (13.4%) patients in the training set and 849 (10.6%) patients in the test set. MI 3 was well calibrated with a very high area under the receiver operating characteristic curve of 0.963 [0.956–0.971] in the test set and similar performance in early and late presenters. Example MI 3 thresholds identifying low- and high-risk patients in the training set were 1.6 and 49.7, respectively. In the test set, MI 3 values were <1.6 in 69.5% with a negative predictive value of 99.7% (99.5–99.8%) and sensitivity of 97.8% (96.7–98.7%), and were ≥49.7 in 10.6% with a positive predictive value of 71.8% (68.9–75.0%) and specificity of 96.7% (96.3–97.1%). Using these thresholds, MI 3 performed better than the European Society of Cardiology 0/3-hour pathway (sensitivity, 82.5% [74.5–88.8%]; specificity, 92.2% [90.7–93.5%]) and the 99th percentile at any time point (sensitivity, 89.6% [87.4–91.6%]); specificity, 89.3% [88.6–90.0%]). Conclusions: Using machine learning, MI 3 provides an individualized and objective assessment of the likelihood of myocardial infarction, which can be used to identify low- and high-risk patients who may benefit from earlier clinical decisions. Clinical Trial Registration: URL: https://www.anzctr.org.au . Unique identifier: ACTRN12616001441404.

Abstract Over 30% of patients with renal cell carcinoma (RCC) present with metastases, with median survival of 2 years. Kidney injury molecule 1 (KIM-1) is a cell-surface glycoprotein expressed by &gt;85% of RCC tumours and may serve as an early biomarker for RCC detection. Here we sought to determine if tumour KIM-1 plays a role in RCC cell extravasation and metastasis to lungs. Methods: We overexpressed KIM-1 in Renca cells (murine RCC) using stable transfection of an expression plasmid, or silenced endogenous KIM-1 in human 769-P and 786-O RCC cells using shRNA. We studied extravasation using the chorioallantoic membrane (CAM) model. We injected ~1x105 Renca or 769-P cells into blood vessels of chicken embryos (n=6), and measured percentage of cells that exited the capillary bed into surrounding spaces after 24 hours. To study lung metastasis, we injected ~5x105 Renca or 786-O cells intravenously through the tail vein of syngeneic BALB/c (n=10/group) or immune deficient Rag1-/- [BALB/c] (n=5/group) mice, and manually counted metastatic nodules in excised lungs after 17 days. Finally, we analyzed the publicly available Cancer Genome Atlas Illumina RNA-Seq dataset to determine if KIM-1 mRNA expression predicts overall survival in patients with clear cell RCC. Results: In CAM experiments, extravasation efficiency was significantly decreased in KIM-1pos 769-P cells compared to KIM-1neg 769-P cells (30.08% vs. 47.94%; p=0.0004), and in KIM-1pos Renca cells compared to KIM-1neg Renca cells (47.78% vs 60.73%; p=0.042). BALB/c mice injected with Kim-1pos Renca cells or Kim-1pos 786-O cells had significantly fewer lung metastases compared to mice injected with Kim-1neg Renca cells or Kim-1neg 786-O cells, respectively (257 vs 429, p=0.02; 131 vs 339 p=0.001). The inhibitory effect of KIM-1 expression in Renca and 786-O cells on numbers of lung metastases was similar in Rag1-/- mice, suggesting that the observed effects were not dependent on adaptive immunity. In the TCGA database, patients with the lowest vs. highest tertile of KIM-1 RCC expression has significantly higher mortality (unadjusted HR 1.82, 95% CI 1.23-2.70; p=0.0034). Conclusion: KIM-1 is a negative regulator of cell extravasation and inhibits the development of lung metastases in mice, and KIM-1 expression in human RCC may predict better survival. Deciphering the underlying mechanisms may lead to novel therapies. Citation Format: Jasper C. Lee, Marie A. Sarabusky, Audrey Champagne, Fabrice Lucien, Lakshman Gunaratnam. Kidney injury molecule-1 regulates metastasis in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4604.

Background Mutations in genes encoding ion channels or sarcomeric proteins are an important cause of hereditary cardiac disease. However, the severity of the resultant disease varies considerably even among those with an identical mutation. Such clinical variation is often thought to be explained largely by differences in genetic background or ‘modifier genes’. We aimed to test the prediction that identical genetic backgrounds result in largely similar clinical expression of a cardiac disease causing mutation, by studying the clinical expression of mutations causing cardiac disease in monozygotic twins. Methods We compared first available clinical information on 46 monozygotic twin pairs and 59 control pairs that had either a hereditary cardiomyopathy or channelopathy. Results Despite limited power of this study, we found significant heritability for corrected QT interval (QTc) in long QT syndrome (LQTS). We could not detect significant heritability for structural traits, but found a significant environmental effect on thickness of the interventricular septum in hypertrophic cardiomyopathy. Conclusions Our study confirms previously found robust heritability for electrical traits like QTc in LQTS, and adds information on low or lacking heritability for structural traits in heritable cardiomyopathies. This may steer the search for genetic modifiers in heritable cardiac disease.

Abstract Context von Hippel-Lindau (VHL) disease, comprising renal cancer, hemangioblastoma, and/or pheochromocytoma (PHEO), is caused by missense or truncating variants of the VHL tumor-suppressor gene, which is involved in degradation of hypoxia-inducible factors (HIFs). However, the role of synonymous VHL variants in the disease is unclear. Objective We evaluated a synonymous VHL variant in patients with familial PHEO or VHL disease without a detectable pathogenic VHL mutation. Design We performed genetic and transcriptional analyses of leukocytes and/or tumors from affected and unaffected individuals and evaluated VHL splicing in existing cancer databases. Results We identified a synonymous VHL variant (c.414A>G, p.Pro138Pro) as the driver event in five independent individuals/families with PHEOs or VHL syndrome. This variant promotes exon 2 skipping and hence, abolishes expression of the full-length VHL transcript. Exon 2 spans the HIF-binding domain required for HIF degradation by VHL. Accordingly, PHEOs carrying this variant display HIF hyperactivation typical of VHL loss. Moreover, other exon 2 VHL variants from the The Cancer Genome Atlas pan-cancer datasets are biased toward expression of a VHL transcript that excludes this exon, supporting a broader impact of this spliced variant. Conclusion A recurrent synonymous VHL variant (c.414A>G, p.Pro138Pro) confers susceptibility to PHEO and VHL disease through splice disruption, leading to VHL dysfunction. This finding indicates that certain synonymous VHL variants may be clinically relevant and should be considered in genetic testing and surveillance settings. The observation that other coding VHL variants can exclude exon 2 suggests that dysregulated splicing may be an underappreciated mechanism in VHL-mediated tumorigenesis.

OPLAH is cardioprotective for myocardial infarction, and its substrate 5-oxoproline is a putative circulating marker for heart failure.