tbuckley/cabot-search huggingface dataset:
In Vivo <i>Ryr</i> 2 Editing Corrects Catecholaminergic Polymorphic Ventricular Tachycardia
Authors: Xiaolu Pan, Leonne Philippen, Satadru K. Lahiri, Ciaran Lee, So Hyun Park, Tarah A. Word, Na Li, Kelsey E. Jarrett, Rajat Gupta, Julia O. Reynolds, Jean Lin, Gang Bao, William R. Lagor, Xander H.T. Wehrens
Journal: Circulation Research (2018)

Rationale: Autosomal-dominant mutations in ryanodine receptor type 2 ( RYR2 ) are responsible for ≈60% of all catecholaminergic polymorphic ventricular tachycardia. Dysfunctional RyR2 subunits trigger inappropriate calcium leak from the tetrameric channel resulting in potentially lethal ventricular tachycardia. In vivo CRISPR/Cas9-mediated gene editing is a promising strategy that could be used to eliminate the disease-causing Ryr2 allele and hence rescue catecholaminergic polymorphic ventricular tachycardia. Objective: To determine if somatic in vivo genome editing using the CRISPR/Cas9 system delivered by adeno-associated viral (AAV) vectors could correct catecholaminergic polymorphic ventricular tachycardia arrhythmias in mice heterozygous for RyR2 mutation R176Q (R176Q/+). Methods and Results: Guide RNAs were designed to specifically disrupt the R176Q allele in the R176Q/+ mice using the SaCas9 ( Staphylococcus aureus Cas9) genome editing system. AAV serotype 9 was used to deliver Cas9 and guide RNA to neonatal mice by single subcutaneous injection at postnatal day 10. Strikingly, none of the R176Q/+ mice treated with AAV-CRISPR developed arrhythmias, compared with 71% of R176Q/+ mice receiving control AAV serotype 9. Total Ryr2 mRNA and protein levels were significantly reduced in R176Q/+ mice, but not in wild-type littermates. Targeted deep sequencing confirmed successful and highly specific editing of the disease-causing R176Q allele. No detectable off-target mutagenesis was observed in the wild-type Ryr2 allele or the predicted putative off-target site, confirming high specificity for SaCas9 in vivo. In addition, confocal imaging revealed that gene editing normalized the enhanced Ca 2+ spark frequency observed in untreated R176Q/+ mice without affecting systolic Ca 2+ transients. Conclusions: AAV serotype 9–based delivery of the SaCas9 system can efficiently disrupt a disease-causing allele in cardiomyocytes in vivo. This work highlights the potential of somatic genome editing approaches for the treatment of lethal autosomal-dominant inherited cardiac disorders, such as catecholaminergic polymorphic ventricular tachycardia.
Abstract 265: Epi-magnolin suppresses EGF-induced neoplastic cell transformation by inhibition of Akt/mTOR signaling pathway in JBC Cl41 cells
Authors: Cheol-Jung Lee, Sun-Mi Yoo, Seung-Min Kim, Seon-Yeon Cho, Juhee Park, Yu-Mi Shin, Yong-Yeon Cho, Hye Suk Lee
Journal: Cancer Research (2018)

Abstract The phosphatidylinositol-3-kinase (PI3K)/Akt/the mammalian target of rapamycin (mTOR) signaling pathway is frequently activated in human cancer and plays a pivotal role in cell proliferation and transformation. In this study, we reveal epi-magnolin, a phytochemical found in Magnolia flos, as an inhibitor of Akt/mTOR signaling pathway. Epi-magnolin inhibits EGF-induced Akt phosphorylation at Thr308 and Ser473, but not extracellular signal-regulated kinases (ERKs)/ribosomal S6 kinase 2 (RSK2) signaling pathway. Moreover, we demonstrate that epi-magnolin suppresses JB6 cell proliferation by impairing EGF-induced G1/S cell cycle transition in a dose-dependent manner. Notably, epi-magnolin abrogates phosphorylation of c-Jun at Ser63 and 73 as well as total c-Jun protein level, which leads to downregulation of AP-1 transactivation activity. The inhibition effect of Akt/mTOR signaling pathway and AP-1 transactivation activity by epi-magnolin suppressed EGF-induced anchorage-independent cell transformation. Based on these results, epi-magnolin might be a chemopreventive agent by targeting Akt/mTOR signaling pathway. Key words: chemoprevention, cell transformation, Akt/mTOR signaling pathway Citation Format: Cheol-Jung Lee, Sun-Mi Yoo, Seung-Min Kim, Seon-Yeon Cho, Juhee Park, Yu-Mi Shin, Yong-Yeon Cho, Hye Suk Lee. Epi-magnolin suppresses EGF-induced neoplastic cell transformation by inhibition of Akt/mTOR signaling pathway in JBC Cl41 cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 265.
Revision of migrated self-expandable metal stent by the remOVE device
Authors: Tiffany Chua, Norio Fukami
Journal: Endoscopy (2018)

Self-expandable metal stents (SEMS) provide longer patency duration compared with plastic stents for malignant biliary obstruction [1]. Tumor in-/overgrowth, and stent migration can cause reocclusion of the biliary tract. Herein we describe the revision of a distally migrated and stenosed biliary SEMS using the remOVE system (Ovesco Endoscopy, Tübingen, Germany), a device used to fragment and retrieve over-the-scope clips (OTSC) ([Video 1]).
Abstract 3410: Copy number estimation from whole-exome sequencing in tumors
Authors: Shawn Anderson, Zhiwei Che, Raja Keshavan, Andrea O'Hara, Dong Lin, Yuzhuo Wang, Colin Collins, Soheil Shams
Journal: Cancer Research (2018)

Abstract At the Vancouver Prostate Centre (VPC), a personalized medicine approach is the focus to the understanding and treatment of prostate and other cancers. As a part of this approach, the xenograft program is used to identify and validate mechanisms and drivers of progress and therapeutic targets. VPC frequently uses Next-Generation Sequencing (NGS) technologies for copy number (CN) analysis. Many CN from NGS algorithms require a matched normal reference for CN estimation, however, a matched normal may not be possible for many reasons including unavailability of patient blood sample and poor quality of the matched sample in question. The correct CN algorithm for NGS data is critical to overcome these obstacles. Here we will share our results from analysis of Whole Exome Sequencing (WES) of prostate cancer patient-derived xenograft (PC PDX) samples using Nexus Copy Number software with BioDiscovery's BAM MSR algorithm. A pooled reference can be created using unmatched normal samples; however, when normal samples are not available, tumor samples from within the batch and/or run can be used to create a reference. BAM MSR derives CN and B-Allele Frequency (BAF) from WES, whole-exome sequencing (WGS), and targeted panels using a pooled reference. Due to an absence of normal samples, randomly selected tumor samples were used to build a reference file, which was used for baseline CNV results. By using a recursive refinement method, which incorporated evaluation of B-allele frequency (BAF) patterns among the pooled samples, a subset of tumor samples was selected to create a refined pooled reference using BAM MSR. All tumor samples were then subjected to CN estimation, which included adjustment based on tumor ploidy. While creating a normal reference including PC PDX tumor samples may seem counter intuitive due to enrichment of cancer cells and replacement of stromal component with mouse origin (e.g. fibroblasts, endothelium and immune cells), and high early recurrent copy number signatures, the BAM MSR algorithm was able to get results comparable to previous aCGH results. This is of special importance because the lack of normal tissues is commonplace in cancer research. Citation Format: Shawn Anderson, Zhiwei Che, Raja Keshavan, Andrea O'Hara, Dong Lin, Yuzhuo Wang, Colin Collins, Soheil Shams. Copy number estimation from whole-exome sequencing in tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3410.
Reduced Atherosclerotic Lesions in P2Y1/Apolipoprotein E Double-Knockout Mice
Authors: BéatriceHechler, MoniqueFreund, CatherineRavanat, StéphanieMagnenat, Jean-PierreCazenave, ChristianGachet
Journal: Circulation (2008)

Background— The P2Y1 receptor plays a key role in arterial thrombosis and is widely expressed in many cell types involved in atherosclerosis. The aim of this study was to evaluate its potential involvement in the development of atherosclerotic lesions. Methods and Results— Apolipoprotein E–deficient (ApoE−/−) and P2Y1−/−/ApoE−/− mice were maintained on regular chow for 17 or 30 weeks before analysis of atherosclerotic lesions. At 17 weeks, lesions in the aortic sinus and entire aorta were smaller in P2Y1−/−/ApoE−/− compared with those in ApoE−/− animals. At 30 weeks, the aortic sinus lesions in P2Y1−/−/ApoE−/− mice were still diminished in size and displayed reduced inflammation, reflected by decreased macrophage infiltration and diminished VCAM-1 immunostaining, compared with those in ApoE−/− mice. They also had a lower smooth muscle cell content. Unexpectedly, bone marrow transplantation showed that the absence of the P2Y1 receptor in blood cells only led to no significant modification of the lesion com...
Abstract 5908: Resistance mechanisms to TP53-MDM2 inhibition identified by in vivo piggyBac transposon mutagenesis screen
Authors: Emilie A. Chapeau
Journal: Cancer Research (2018)

Abstract Inhibitors of MDM2-TP53 interaction are predicted to be effective in tumors where the TP53 gene is wild-type by preventing TP53 protein degradation. One such setting is represented by the frequent CDKN2A deletion in human cancer that, through inactivation of p14ARF, activates MDM2 protein, which in turn degrades TP53 tumor suppressor. Here we utilized piggyBac transposon insertional mutagenesis to anticipate resistance mechanisms that occur under intermittent high dose treatment with the MDM2-TP53 inhibitor HDM201. Constitutive piggyBac mutagenesis in Arf-/- mice provided a collection of spontaneous tumors with characterized insertional genetic landscapes. Tumors were allografted in large cohorts of mice to assess HDM201 pharmacological effects. 16 out of 21 allograft models were sensitive to HDM201 but ultimately relapsed under treatment. When tumors with acquired resistance to HDM201 were compared to untreated tumors, 87 genes were found differentially and significantly targeted by piggyBac transposon. Resistant tumors displayed a complex clonality pattern suggesting emergence of several resistant subclones. Among the most frequent alterations conferring resistance, we observed somatic and insertional loss-of-function mutations in Trp53 in 54% of tumors, and transposon-mediated gain-of-function alterations in Bcl-xL, Mdm4, and two TP53-family members, resulting in expression of the TP53 dominant negative truncations ΔNTrp63 and ΔNTrp73. Enhanced BCL-xL and MDM4 proteins expression was confirmed in resistant tumors, as well as in HDM201 resistant patient-derived tumor xenografts. Interestingly, concomitant inhibition of MDM2 and BCL-xL demonstrated significant synergy in p53 wild-type cell lines in vitro. Moreover, we performed an additional piggyBac screen with daily HDM201 treatment, at lower dose. Surprisingly, we identified Bcl-XL expression as a unique mechanism of resistance in intermittent high dose scheduling. These data suggested that different apoptotic inductions between the two HDM201 dose regimens (intermittent high dose/daily lower dose) likely play a role in the way the resistance to HDM201 takes place. Collectively, our study has identified several potential mechanisms by which TP53 wild-type tumors may escape MDM2 targeted therapy, and provide evidence that Bcl-XL inhibition may be beneficial for relapsing patients that were treated with HDM201 intermittent scheduling. Citation Format: Emilie A. Chapeau. Resistance mechanisms to TP53-MDM2 inhibition identified by in vivo piggyBac transposon mutagenesis screen [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5908.
Abstract 12980: Circulating Level of the Growth-Differentiation Factor-15 Is Increased in Dogs With Heart Failure and Normalized After Long-term Therapy With Elamipretide
Authors: Hani N Sabbah, Ramesh C Gupta, Vinita Singh-Gupta, Kefei Zhang, Jiang Xu
Journal: Circulation (2016)

Introduction: Growth-differentiation factor-15 (GDF15) is a stress-responsive cytokine produced in pathological states associated with tissue injury and inflammation. Increased level of GDF15 is an independent predictor of adverse prognosis (disease progression and mortality) in heart failure (HF). As a prognostic biomarker, GDF15 is independent of established biomarkers including BNP, troponins, or C-reactive protein (CRP). We previously showed that increased plasma levels of nt-pro BNP, tumor necrosis factor-α, interleukin-6 and CRP are normalized in dogs with HF following long-term therapy with Elamipretide (ELA, Bendavia TM ), a novel mitochondria targeting peptide. We also showed that therapy with ELA also prevents progressive LV dysfunction in dogs with HF. Hypothesis: This study tested the hypothesis that plasma level of GDF15 is increased in dogs with HF and is normalized after long-term therapy with ELA. Methods: Venous blood samples were obtained from 14 dogs at baseline (normal state) prior to induction of HF, after the induction of HF by intracoronary microembolizations but prior to any therapy and again at 3 months after initiating therapy with either subcutaneous ELA (0.5 mg/kg/day, n=7) or saline v/v (Control, n=7). Plasma levels of GDF15 were measured using a dog specific commercially available enzyme-linked immunosorbent assay (ELISA) kit (MyBiosource, San Diego, CA). Results: In untreated HF control dogs, plasma level of GDF15 was 326±32 pg/ml at baseline and increased to 744±124 pg/ml (p&lt;0.05) when dogs were in HF and remained elevated at 3 months after initiating therapy with saline (728± 77 pg/ml). In dogs treated with ELA, plasma level of GDF15 was 314±29 pg/ml at baseline, increased to 875±71 pg/ml (p&lt;0.05) when dogs were in HF and was restored to near normal levels at 3 months after initiating therapy with ELA (556±25 pg/ml, p&lt;0.05 vs. pre-treatment). Conclusions: Circulating levels of GDF15 are increased in dogs with coronary microembolizations-induced HF. Long-term treatment with ELA reverses this increase, suggesting that inflammation-mediated injury may be reduced in dogs with HF treated with ELA. Restoring GDF15 by ELA therapy may be a useful indicator of beneficial response to therapy in patients with chronic HF.
Abstract 273: Upregulation of 15-hydroxyprostaglandin dehydrogenase expression by 15-Deoxy-Δ12,14-prostaglandin J2 through inactivation of DNA methyltransferase 1
Authors: Hye-Ok Jang, Hye-Rim Kim Kim, Ha-Na Lee, Do-Hee Kim, Young-Joon Surh, Hye-Kyung Na
Journal: Cancer Research (2018)

Abstract 15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the oxidation of prostaglandin E2 (PGE2) to a biologically inactive keto metabolite 15-keto-PGE2. However, the molecular mechanisms underlying regulation of 15-PGDH expression remain largely elusive. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand of peroxisome proliferator-activated receptor γ, has been reported to have anti-inflammatory and anti-carcinogenic activities. In the present study, we have found that 15-PGJ2 upregulates expression and catalytic activity of 15-PGDH in human breast cancer (MDA-MB-231) cells. 15d-PGJ2 treatment decreased the CpG methylation in the 15-PGDH promoter in MDA-MB-231 cells as determined by the bisulfite genome sequencing and methyl-specific PCR. 15d-PGJ2 inhibited catalytic activity of methyltransferase 1 (DNMT1) but did not influence DNMT expression. 15d-PGJ2 increased the expression of c-Fos which is a functional subunit of AP-1. Chromatin-immunoprecipitation analysis revealed that 15d-PGJ2 significantly attenuated DNMT1 binding to the site for AP-1 transcription factor present in the 15-PGDH promoter regions, while increasing c-Fos binding. Biotin-tagged 15d-PGJ2 directly bound to DNMT1, and reduced its catalytic activity. A non-electrophilic analogue 9,10-dihydro-15d-PGJ2 failed to suppress the methylation of CpG islands present in 15-PGDH promoter and did not affect both DNMT1 activity and 15-PGDH expression. This findings suggests that the α,β-unsaturated carbonyl group of 15d-PGJ2 is essential for its inactivation of DNMT1 and expression of 15-PGDH. In conclusion, 15d-PGJ2 directly interacts with DNMT1 and consequently suppresses DNMT1-mediated hypermethylation of 15-PGDH promoter, leading to upregulation of 15-PGDH expression. Citation Format: Hye-Ok Jang, Hye-Rim Kim Kim, Ha-Na Lee, Do-Hee Kim, Young-Joon Surh, Hye-Kyung Na. Upregulation of 15-hydroxyprostaglandin dehydrogenase expression by 15-Deoxy-Δ12,14-prostaglandin J2 through inactivation of DNA methyltransferase 1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 273.
Abstract 5288: MPNST treatment and diagnosis in NF1: A health economic model
Authors: Lydia Turkson, Hannah Mamuszka, Kyla Grimshaw, Erica Marie Marshall
Journal: Cancer Research (2018)

Abstract Biomarkers have many applications along the care process in rare cancers and have potential to optimize treatment decisions. However, many diagnostic tests struggle to gain market access and appropriate value in terms of payer coverage because of a lack of evidence on their health economic benefit to patients. CMS reimbursement guidelines, of cost-plus pricing for diagnostics does not always work for niche small rare disease subpopulations. Nor does it reflect the lifelong value of effective patient care. To address this, we have developed a cost benefit model for early diagnostic intervention, based on retrospective data to determine mutation status and monitor for disease progression in people diagnosed with neurofibromatosis type 1 (NF1) and soft tissue tumors. NF1 is an autosomal dominant hereditary cancer syndrome that affects around 1:2,500 people and is caused by mutations in the NF1 gene. 50% of patients can have few to many neurofibroma which vary in clinical behavior from benign to malignant. About 10% of people can develop malignant peripheral nerve sheath tumors (MPNSTs) thought to develop from pre-existing benign neurofibroma. Currently, there is no reliable way of knowing which individual and which tumors are malignant. MPNSTs are often difficult to diagnose in the early phases with current imaging methods like CT or MRI. Overall, these patients face a lifetime risk of cancer up to 16-26% higher than the normal population. Once metastasizes MPNSTs are associated with poor prognosis, less than 25% survival rate at 5 years. We built a model used retrospective anonymized patient treatment records to demonstrate cost and risk based benefits to patients, payers and clinical practitioners, on the effect of early intervention versus late on treatment cost, and patient outcome in the long-term care process. For NF1 patients. In conclusion, our model proposes a new framework to engage healthcare insurers and managed care physician groups in the US to quantify the health economic benefits of prognostic biomarker tests in patient populations with a lifelong genetic predisposition to cancer. Citation Format: Lydia Turkson, Hannah Mamuszka, Kyla Grimshaw, Erica Marie Marshall. MPNST treatment and diagnosis in NF1: A health economic model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5288.
Abstract 3764: Porcupine inhibitor RXC004 enhances immune response in pre-clinical models of cancer
Authors: Inder Bhamra, Richard Armer, Matilda Bingham, Catherine Eagle, Alicia Edmenson Cook, Caroline Phillips, Simon Woodcock
Journal: Cancer Research (2018)

Abstract Background: RXC004, a potent and selective porcupine (PORCN) inhibitor, is being investigated in a safety and tolerability study in cancer patients with solid tumours (CT 2017-000720-98). In addition to the tumour targeting role of RXC004 and other Wnt pathway inhibitors, we present pre-clinical data which suggests further potential for RXC004 in modulating the immune system of the tumour microenvironment. Materials and Methods: To evaluate the potential of a novel porcupine inhibitor, RXC004, as an immunomodulatory anti-cancer agent, sub cutaneous B16F10 melanoma (C57BL/6 mice) and CT26 colorectal (BALB/c mice) murine tumour models were utilised. Mice in both models were treated with RXC004 alone or in combination with mouse anti-PD-1 antibody. Flow cytometry analysis was utilised to measure key immune cell populations in the tumour microenvironment. To probe the underlying mechanism of immune modulation in these models and to provide a link to the emerging clinical data suggesting a role for Wnt pathway activation in immune escape, human monocytic cells were isolated from PBMCs and human dendritic cells were derived in vitro. The Wnt pathway was induced in derived Dendritic cells and expression of IDO was measured. Results: In the murine CT26 model, RXC004 treatment reduced tumour size when dosed in combination with anti-PD-1 antibody, causing regression and cures in some animals. Furthermore, flow cytometry showed RXC004 in combination with anti-PD-1 antibody increased the proportion of CD8+ cytotoxic T cells as well as decreasing FoxP3+ regulatory T cells when compared to the monotherapy anti-PD-1 arm. In a syngeneic murine melanoma B16F10 model, RXC004 monotherapy at a dose of 5mg/kg QD orally significantly inhibited tumour growth, as did RXC004 combined with anti-PD-1. RXC004 had no effect on the proliferation of B16F10 cells in vitro, suggesting this was not caused by the compound directly affecting B16 cell proliferation. Flow cytometry analysis of the B16 tumours showed significant immune modulatory effects in the tumour microenvironment. In addition to mouse model data, Wnt pathway activation in human dendritic cells was shown to increase IDO expression. Conclusion: Taken together, data from murine syngeneic mouse models corroborate literature data suggesting that inhibiting the Wnt pathway may promote the immune response against human cancers. Citation Format: Inder Bhamra, Richard Armer, Matilda Bingham, Catherine Eagle, Alicia Edmenson Cook, Caroline Phillips, Simon Woodcock. Porcupine inhibitor RXC004 enhances immune response in pre-clinical models of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3764.