Albumin promoter-driven FlpO expression induces efficient genetic recombination in mouse liver

Tissue-specific gene manipulations are widely used in genetically engineered mouse models. A single recombinase system, such as the one using Alb-Cre, has been commonly used for liver-specific genetic manipulations. However, most diseases are complex, involving multiple genetic changes and various cell types. A dual recombinase system is required for conditionally modifying different genes sequentially in the same cell or inducing genetic changes in different cell types within the same organism. A FlpO cDNA was inserted between the last exon and 3'-UTR of the mouse albumin gene in a bacterial artificial chromosome (BAC-Alb-FlpO). The founders were crossed with various reporter mice to examine the efficiency of recombination. Liver cancer tumorigenesis was investigated by crossing the FlpO mice with FSF-KrasG12D mice and p53frt mice (KPF mice). BAC-Alb-FlpO mice exhibited highly efficient recombination capability in both hepatocytes and intrahepatic cholangiocytes. No recombination was observed in the duodenum and pancreatic cells. BAC-Alb-FlpO-mediated liver-specific expression of mutant KrasG12D and conditional deletion of p53 gene caused the development of liver cancer. Remarkably, liver cancer in these KPF mice manifested a distinctive mixed hepatocellular carcinoma and cholangiocarcinoma phenotype. A highly efficient and liver-specific BAC-Alb-FlpO mouse model was developed. In combination with other Cre lines, different genes can be manipulated sequentially in the same cell, or distinct genetic changes can be induced in different cell types of the same organism.NEW & NOTEWORTHY A liver-specific Alb-FlpO mouse line was generated. By coupling it with other existing CreERT or Cre lines, the dual recombinase approach can enable sequential gene modifications within the same cell or across various cell types in an organism for liver research through temporal and spatial gene manipulations.

A simple and effective genotyping workflow for rapid detection of CRISPR genome editing

Genetically engineered mouse models play a pivotal role in the modeling of diseases, exploration of gene functions, and the development of novel therapies. In recent years, clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)-mediated genome editing technology has revolutionized the process of developing such models by enabling precise genome modifications of the multiple interested genes simultaneously. Following genome editing, an efficient genotyping methodology is crucial for subsequent characterization. However, current genotyping methods are laborious, time-consuming, and costly. Here, using targeting the mouse trypsinogen genes as an example, we introduced common applications of CRISPR-Cas9 editing and a streamlined cost-effective genotyping workflow for CRISPR-edited mouse models, in which Sanger sequencing is required only at the initial steps. In the F0 mice, we focused on identifying the presence of positive editing by PCR followed by Sanger sequencing without the need to know the exact sequences, simplifying the initial screening. In the F1 mice, Sanger sequencing and algorithms decoding were used to identify the precise editing. Once the edited sequence was established, a simple and effective genotyping strategy was established to distinguish homozygous and heterozygous status by PCR from tail DNA. The genotyping workflow applies to deletions as small as one nucleotide, multiple-gene knockout, and knockin studies. This simplified, efficient, and cost-effective genotyping shall be instructive to new investigators who are unfamiliar with characterizing CRISPR-Cas9-edited mouse strains.NEW & NOTEWORTHY This study presents a streamlined, cost-effective genotyping workflow for clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) edited mouse models, focusing on trypsinogen genes. It simplifies initial F0 mouse screening using PCR and Sanger sequencing without needing exact sequences. For F1 mice, precise editing is identified through Sanger sequencing and algorithm decoding. The workflow includes a novel PCR strategy for distinguishing homozygous and heterozygous statuses in subsequent generations, effective for small deletions, multiple-gene knockouts, and knockins.

PTEN Deficiency Induces an Extrahepatic Cholangitis-Cholangiocarcinoma Continuum via Aurora kinase A in Mice

BACKGROUND & AIMS

The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aim to evaluate the role of PTEN in the pathogenesis of eCCA and find novel therapies for this disease.

METHODS

The Pten gene in the biliary epithelial cells were genetically deleted using the Cre-loxp system. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry (IHC), RT-PCR, cell culture, and RNAseq. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. Experimental therapy was tested using an Aurka inhibitor.

RESULTS

We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as one month old. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated the disease progression, potentially through downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expressions of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression.

CONCLUSIONS

Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum through an Aurka-dependent manner. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA.

IMPACT AND IMPLICATIONS

The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition (EMT), cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted the disease progression. This model shall be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.

Development and validation of novel immune-inflammation-based clinical predictive nomograms in HER2-negative advanced gastric cancer

Purpose

To explore the predictive value of multiple immune-inflammatory biomarkers including serum VEGFA and systemic immune-inflammation index (SII) in HER2-negative advanced gastric cancer (AGC) and establish nomograms for predicting the first-line chemotherapeutic efficacy, progression-free survival (PFS) and overall survival (OS) of patients with this fatal disease.

Methods

From November 2017 to April 2022, 102 and 34 patients with a diagnosis of HER2-negative AGC at the First Affiliated Hospital of Bengbu Medical College were enrolled as development and validation cohorts, respectively. Univariate and multivariate analyses were performed to evaluate the clinical value of the candidate indicators. The variables were screened using LASSO regression analysis. Predictive models were developed using significant predictors and are displayed as nomograms.

Results

Baseline VEGFA expression was significantly higher in HER2-negative AGC patients than in nonneoplastic patients and was associated with malignant serous effusion and therapeutic efficacy (all p<0.001). Multivariate analysis indicated that VEGFA was an independent predictor for first-line therapeutic efficacy and PFS (both p<0.01) and SII was an independent predictor for first-line PFS and OS (both p<0.05) in HER2-negative AGC patients. The therapeutic efficacy model had an R2 of 0.37, a Brier score of 0.15, and a Harrell's C-index of 0.82 in the development cohort and 0.90 in the validation cohort. The decision curve analysis indicated that the model added more net benefits than VEGFA assessment alone. The PFS/OS models had Harrell's C-indexes of 0.71/0.69 in the development cohort and 0.71/0.62 in the validation cohort.

Conclusion

The established nomograms integrating serum VEGFA/SII and commonly available baseline characteristics provided satisfactory performance in predicting the therapeutic efficacy and prognosis of HER2-negative AGC patients.

A mouse model for high-efficient Flp-recombinase-mediated genetic manipulation in the pancreas

BACKGROUND

Tissue and cell-specific gene targeting has been widely employed in biomedical research. In the pancreas, the commonly used Cre recombinase recognizes and recombines loxP sites. However, to selectively target different genes in distinct cells, a dual recombinase system is required.

METHOD

We developed an alternative recombination system mediated by FLPo, which recognizes frt DNA sequences for pancreatic dual recombinase-mediated genetic manipulation. An IRES-FLPo cassette was targeted between the translation stop code and 3-UTR of the mouse pdx1 gene in a Bacterial Artificial Chromosome using recombineering technology. Transgenic BAC-Pdx1-FLPo mice were developed by pronuclear injection.

RESULTS

Highly efficient recombination activity was observed in the pancreas by crossing the founder mice with Flp reporter mice. When the BAC-Pdx1-FLPo mice were bred with conditional FSF-KRasG12D and p53 F/F mice, pancreatic cancer developed in the compound mice. The characteristics of pancreatic cancer resembled those derived from conditional LSL-KRasG12D and p53 L/L mice controlled by pdx1-Cre.

CONCLUSIONS

We have generated a new transgenic mouse line expressing FLPo, which enables highly efficient pancreatic-specific gene recombination. When combined with other available Cre lines, this system can be utilized to target different genes in distinct cells for pancreatic research.

Upregulation of the ERRγ-VDAC1 axis underlies the molecular pathogenesis of pancreatitis

Emerging evidence suggest that transcription factors play multiple roles in the development of pancreatitis, a necroinflammatory condition lacking specific therapy. Estrogen-related receptor γ (ERRγ), a pleiotropic transcription factor, has been reported to play a vital role in pancreatic acinar cell (PAC) homeostasis. However, the role of ERRγ in PAC dysfunction remains hitherto unknown. Here, we demonstrated in both mice models and human cohorts that pancreatitis is associated with an increase in ERRγ gene expression via activation of STAT3. Acinar-specific ERRγ haploinsufficiency or pharmacological inhibition of ERRγ significantly impaired the progression of pancreatitis both in vitro and in vivo. Using systematic transcriptomic analysis, we identified that voltage-dependent anion channel 1 (VDAC1) acts as a molecular mediator of ERRγ. Mechanistically, we showed that induction of ERRγ in cultured acinar cells and mouse pancreata enhanced VDAC1 expression by directly binding to specific site of the Vdac1 gene promoter and resulted in VDAC1 oligomerization. Notably, VDAC1, whose expression and oligomerization were dependent on ERRγ, modulates mitochondrial Ca2+ and ROS levels. Inhibition of the ERRγ-VDAC1 axis could alleviate mitochondrial Ca2+ accumulation, ROS formation and inhibit progression of pancreatitis. Using two different mouse models of pancreatitis, we showed that pharmacological blockade of ERRγ-VDAC1 pathway has therapeutic benefits in mitigating progression of pancreatitis. Likewise, using PRSS1R122H-Tg mice to mimic human hereditary pancreatitis, we demonstrated that ERRγ inhibitor also alleviated pancreatitis. Our findings highlight the importance of ERRγ in pancreatitis progression and suggests its therapeutic intervention for prevention and treatment of pancreatitis.

Hematopoietic progenitor kinase 1 inhibits the development and progression of pancreatic intraepithelial neoplasia

Ras plays an essential role in the development of acinar to ductal metaplasia (ADM) and pancreatic ductal adenocarcinoma (PDAC). However, mutant Kras is an inefficient driver for PDAC development. The switching mechanisms from low Ras activity to high Ras activity that is required for development and progression of pancreatic intraepithelial neoplasia (PanIN) are unclear. In this study, we found that HPK1 was upregulated during pancreatic injury and ADM. HPK1 interacted with the SH3 domain and phosphorylated Ras GTPase activating protein (RasGAP) and upregulated RasGAP activity. Using the transgenic mouse models of HPK1 or M46, a kinase-dead mutant of HPK1, we showed that HPK1 inhibited Ras activity and its downstream signaling and regulated acinar cell plasticity. M46 promoted the development of ADM and PanINs. Expression of M46 in KrasG12D;Bac mice promoted the infiltration of myeloid-derived suppressor cells and macrophages, inhibited the infiltration of T cells, and accelerated the progression of PanINs to invasive and metastatic PDAC, while HPK1 attenuated mutant Kras-driven PanIN progression. Our results showed that HPK1 plays an important role in ADM and the progression of PanINs by regulating Ras signaling. Loss of HPK1 kinase activity promotes an immunosuppressive tumor microenvironment and accelerates the progression of PanINs to PDAC.

Simple risk score to predict the likelihood of a positive EUS in idiopathic acute pancreatitis

BACKGROUND AND AIMS

We sought to derive a risk score, DORM65, of known variables to predict the likelihood of a positive EUS in patients with idiopathic acute pancreatitis (IAP).

METHODS

A retrospective cohort study of 180 patients with IAP was performed across 3 tertiary care centers between January 2018 and December 2021. Multivariate logistic regression modeling was performed to predict a positive EUS. Accuracy of the models was assessed by the area under the receiver-operating characteristic curve (AUROCC).

RESULTS

The diagnostic yield of EUS was 58.9% (95% confidence interval [CI], 51.7-66.1). The DORM65 scores of 5 predictors present before EUS with the best discrimination were a delayed EUS (defined as ≥82 days from the last episode of AP), obesity, not having had a repeated transabdominal US, male sex, and age ≥65 years at the time of EUS. For those at the lowest risk score group, the positive EUS rate was 13.0% compared with 100% in those at the highest risk group (relative risk, 7.67; P < .001). A score of 3 or more had a positive predictive value of 86.0% with a sensitivity of 34.9% and specificity of 91.9%. The model had a high predictive accuracy (AUROCC, .774; 95% CI, .707-.841). Adding 3 additional predictors (no cholecystectomy, no MRCP, and a single episode of AP) did not increase the accuracy significantly (AUROCC, .805; 95% CI, .742-.867).

CONCLUSIONS

DORM65 is easily calculated and accurately predicts a positive EUS in patients with IAP. Further validation is needed.

Selecting an Appropriate Experimental Animal Model for Cholangiocarcinoma Research

Cholangiocarcinoma (CCA) is a highly aggressive biliary tree malignancy with intrahepatic and extra-hepatic subtypes that differ in molecular pathogeneses, epidemiology, clinical manifestations, treatment, and prognosis. The overall prognosis and patient survival remains poor because of lack of early diagnosis and effective treatments. Preclinical in vivo studies have become increasingly paramount as they are helpful not only for the study of the fundamental molecular mechanisms of CCA but also for developing novel and effective therapeutic approaches of this fatal cancer. Recent advancements in cell and molecular biology have made it possible to mimic the pathogenicity of human CCA in chemical-mechanical, infection-induced inflammatory, implantation, and genetically engineered animal models. This review is intended to help investigators understand the particular strengths and weaknesses of the currently used in vivo animal models of human CCA and their related modeling techniques to aid in the selection of the one that is the best for their research needs.

Abstract 3821: Rapid acceleration of KRAS-mutant pancreatic carcinogenesis via remodeling of tumor immune microenvironment by PPARD

Pancreatic intraepithelial neoplasia (PanIN) is a precursor of pancreatic ductal adenocarcinoma (PDAC), which commonly occurs in the general populations with aging. Although most PanIN lesions (PanINs) harbor oncogenic KRAS mutations that initiate pancreatic tumorigenesis, PanINs rarely progress to PDAC. Critical factors that promote this progression, especially targetable ones, remain poorly defined. We show that peroxisome proliferator-activated receptor-delta (PPARD), a lipid nuclear receptor, is upregulated in PanINs in humans and mice. Furthermore, PPARD ligand activation by a high-fat diet or GW501516 (a highly selective, synthetic PPARD ligand) in mutant KRASG12D (KRASmu) pancreatic epithelial cells strongly accelerates PanIN progression to PDAC. This PPARD activation induces KRASmu pancreatic epithelial cells to secrete CCL2, which recruits immunosuppressive macrophages and myeloid-derived suppressor cells into pancreas via the CCL2/CCR2 axis to orchestrate an immunosuppressive tumor microenvironment and subsequently drive PanIN progression to PDAC. Our data identify PPARD signaling as a potential molecular target to prevent PDAC development in subjects harboring PanINs.

Citation Format: Yi Liu, Yasunori Deguchi, Daoyan Wei, Micheline J. Moussalli, Fuyao Liu, Eriko Deguchi, Donghui Li, Huamin Wang, Lovie Ann Valentin, Jennifer K. Colby, Jing Wang, Xiaofeng Zheng, Haoqiang Ying, Mihai Gagea, Baoan Ji, Jiaqi Shi, James C. Yao, Xiangsheng Zuo, Imad Shureiqi. Rapid acceleration of KRAS-mutant pancreatic carcinogenesis via remodeling of tumor immune microenvironment by PPARD [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3821.

Abstract LB568: Protein phosphatase 4 deficiency protects mice against cerulein-induced acute pancreatitis

Background: Pancreatitis is an inflammatory disease of the pancreas that causes significant morbidity and mortality and is one of the major risk factors for pancreatic cancer. Protein phosphatase 4 (PP4) has been reported to be overexpressed in breast, lung and pancreatic cancers. PP4 plays an important role in the regulation of centrosome maturation, DNA repair, NF-κB, and c-jun-NH2-kinase (JNK) signaling pathways. However, the expression and functions of PP4 in pancreatitis have not been studied.

Methods: To examine the functions of PP4 in cerulein-induced acute pancreatitis (AP), we crossed PP4flox/+ mice with pancreatic acinar cell specific cre, CreERT, which was driven by a full length pancreatic acinar specific elastase I promoter. PP4flox/flox, CreERT mice and control mice were treated with 8 hourly intraperitoneal injections of cerulein (50 µg/kg/h). The pancreata were harvested at different time points for histopathological examination and molecular analysis.

Results: PP4 expression was increased at both protein and mRNA levels in mouse pancreas with AP. Compared to CreERT mice, PP4flox/flox, CreERT mice demonstrated significantly less edema, less inflammation, less necrosis or loss of pancreatic acinar cells in pancreas after cerulein treatment. The serum amylase and lipase levels were lower in cerulein-treated PP4flox/flox, CreERT mice compared with controls. The pancreata of PP4flox/flox, CreERT mice exhibited decreased STAT3 Tyr705 phosphorylation and decreased NF-κB activation cerulein-treated PP4flox/flox, CreERT mice than control mice.

Conclusion: Our findings demonstrated that PP4 plays an important role in cerulein-induced AP through STAT3 and NF-κB signaling pathways. Inhibition of PP4 may help to reduce the pancreatic injuries and to prevent the development of chronic pancreatitis, which increases the risk of pancreatic cancer.

Citation Format: Hua Wang, Reza Abbasgholizadeh, Rohan Moniruzzaman, Baoan Ji, Anirban Maitra, Huamin Wang. Protein phosphatase 4 deficiency protects mice against cerulein-induced acute pancreatitis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB568.

Aurora kinase a inhibitor MLN8237 suppresses pancreatic cancer growth

Pancreatic ductal adenocarcinoma (PDAC) is notorious for high mortality due to limited options of appropriate chemotherapy drugs. Here we report that Aurora kinase-A expression is elevated in both human and mouse PDAC samples. MLN8237, an inhibitor of Aurora kinase-A, efficiently reduced the proliferation and motility of PDAC cells in vitro as well as tumor growth in orthotropic xenograft model and genetic pancreatic cancer animal models (p53/LSL/Pdx-Cre mice) in vivo. MLN8237 exhibited tumor inhibitory effect through inhibiting proliferation and migration, and inducing apoptosis and senescence. These results provide the molecular basis for a novel chemotherapy strategy for PDAC patients.

Rapid acceleration of KRAS-mutant pancreatic carcinogenesis via remodeling of tumor immune microenvironment by PPARδ

Pancreatic intraepithelial neoplasia (PanIN) is a precursor of pancreatic ductal adenocarcinoma (PDAC), which commonly occurs in the general populations with aging. Although most PanIN lesions (PanINs) harbor oncogenic KRAS mutations that initiate pancreatic tumorigenesis; PanINs rarely progress to PDAC. Critical factors that promote this progression, especially targetable ones, remain poorly defined. We show that peroxisome proliferator-activated receptor-delta (PPARδ), a lipid nuclear receptor, is upregulated in PanINs in humans and mice. Furthermore, PPARδ ligand activation by a high-fat diet or GW501516 (a highly selective, synthetic PPARδ ligand) in mutant KRASG12D (KRASmu) pancreatic epithelial cells strongly accelerates PanIN progression to PDAC. This PPARδ activation induces KRASmu pancreatic epithelial cells to secrete CCL2, which recruits immunosuppressive macrophages and myeloid-derived suppressor cells into pancreas via the CCL2/CCR2 axis to orchestrate an immunosuppressive tumor microenvironment and subsequently drive PanIN progression to PDAC. Our data identify PPARδ signaling as a potential molecular target to prevent PDAC development in subjects harboring PanINs.

Pancreatic Disorders in Patients with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) can involve multiple organ systems, and pancreatic manifestations of IBD are not uncommon. The incidence of several pancreatic diseases is more frequent in patients with Crohn's disease and ulcerative colitis than in the general population. Pancreatic manifestations in IBD include a heterogeneous group of disorders and abnormalities ranging from mild, self-limited disorders to severe diseases. Asymptomatic elevation of amylase and/or lipase is common. The risk of acute pancreatitis in patients with IBD is increased due to the higher incidence of cholelithiasis and drug-induced pancreatitis in this population. Patients with IBD commonly have altered pancreatic histology and chronic pancreatic exocrine dysfunction. Diagnosing acute pancreatitis in patients with IBD is challenging. In this review, we discuss the manifestations and possible causes of pancreatic abnormalities in patients with IBD.

Ptf1a Promoter-Driven Cre Expression During Spermatogenesis Causes Germline Recombination

OBJECTIVES

Two independently developed Ptf1a-Cre mouse lines, Ptf1atm1(cre)Hnak and Ptf1atm1(Cre)Cvw, are widely used in pancreatic research. Recently, Ptf1atm1(cre)Hnak line was reported to transmit unwanted paternal recombination. We aimed to investigate whether this exists in the Ptf1atm1(Cre)Cvw line.

METHODS

Ptf1atm1(Cre)Cvw mice were crossed with R26-LSL-LacZ reporter mice. DNA recombination and gene expression were examined by recombination-specific polymerase chain reaction, reverse transcription-polymerase chain reaction, and X-Gal staining.

RESULTS

R26 locus recombination was detected in the pancreas as well as the testes and sperm of the double transgenic mice. Positive ptf1a mRNA expression from testes revealed that there was endogenous Ptf1a promoter activity in this extrapancreatic tissue. Of the 15 progenies that inherited LacZ from the male double transgenic mice, 4 (26.7%) were positive for complete whole-body recombination. The presence of recombination in R26 only mice suggested that the recombination occurred before meiosis.

CONCLUSIONS

Paternal germline recombination exists in the Ptf1atm1(Cre)Cvw mouse line. Ptf1a promoter-driven Cre expression during spermatogenesis before meiosis is the cause of germline recombination. Therefore, when male Ptf1a-Cre mice are used in compound mice breeding, it is necessary to genotype not only floxed alleles but also recombined alleles to examine unwanted recombinations.

Venous thromboembolism risk in rheumatoid arthritis patients: a systematic review and updated meta-analysis

OBJECTIVE

Rheumatoid arthritis (RA) patients are prone to develop thromboembolic complications due to the chronic inflammatory nature of RA. Only one systematic review and meta-analysis has attempted to evaluate venous thromboembolism risk in RA patients. However, this review has become outdated due to the recent publication of several high-quality retrospective cohort studies. The aim of the study was to evaluate the risks of deep vein thrombosis, pulmonary embolism, and overall venous thromboembolism event incidence in RA patients.

MATERIALS AND METHODS

Five databases (Web of Science, EMBASE, CENTRAL, Scopus, and MEDLINE) were systematically searched according to PRISMA guidelines for eligible studies. With the available literature, we conducted a random-effect meta-analysis to evaluate odds ratios of deep vein thrombosis, pulmonary embolism, and venous thromboembolism incidence in RA patients and healthy controls.

RESULTS

We found 12 eligible studies detailing 272,884 RA patients and 2,280,454 age and sex-matched healthy controls. Meta-analysis revealed elevated risks for deep vein thrombosis (Odd's ratio: 2.25), pulmonary embolism (2.15), and overall venous thromboembolism incidence (2.23) in RA patients.

CONCLUSIONS

This meta-analysis provides evidence concerning the elevated risks of deep vein thrombosis, pulmonary embolism, and venous thromboembolism in RA patients. The findings herein may aid in developing clinical awareness and assisting best practice guideline development for RA patients with thromboembolic complications.

Dissecting VEGF-induced acute versus chronic vascular hyperpermeability: Essential roles of dimethylarginine dimethylaminohydrolase-1

Vascular endothelial cell growth factor (VEGF) is a key regulator of vascular permeability. Herein we aim to understand how acute and chronic exposures of VEGF induce different levels of vascular permeability. We demonstrate that chronic VEGF exposure leads to decreased phosphorylation of VEGFR2 and c-Src as well as steady increases of nitric oxide (NO) as compared to that of acute exposure. Utilizing heat-inducible VEGF transgenic zebrafish (Danio rerio) and establishing an algorithm incorporating segmentation techniques for quantification, we monitored acute and chronic VEGF-induced vascular hyperpermeability in real time. Importantly, dimethylarginine dimethylaminohydrolase-1 (DDAH1), an enzyme essential for NO generation, was shown to play essential roles in both acute and chronic vascular permeability in cultured human cells, zebrafish model, and Miles assay. Taken together, our data reveal acute and chronic VEGF exposures induce divergent signaling pathways and identify DDAH1 as a critical player and potentially a therapeutic target of vascular hyperpermeability-mediated pathogenesis.

Pancreas-specific CHRM3 activation causes pancreatitis in mice

Hyperstimulation of the cholecystokinin 1 receptor (CCK1R), a G protein-coupled receptor (GPCR), in pancreatic acinar cells is commonly used to induce pancreatitis in rodents. Human pancreatic acinar cells lack CCK1R but express cholinergic receptor muscarinic 3 (M3R), another GPCR. To test whether M3R activation is involved in pancreatitis, a mutant M3R was conditionally expressed in pancreatic acinar cells in mice. This mutant receptor loses responsiveness to its native ligand, acetylcholine, but can be activated by an inert small molecule, clozapine-N-oxide (CNO). Intracellular calcium and amylase were elicited by CNO in pancreatic acinar cells isolated from mutant M3R mice but not WT mice. Similarly, acute pancreatitis (AP) could be induced by a single injection of CNO in the transgenic mice but not WT mice. Compared with the cerulein-induced AP, CNO caused more widespread acinar cell death and inflammation. Furthermore, chronic pancreatitis developed at 4 weeks after 3 episodes of CNO-induced AP. In contrast, in mice with 3 recurrent episodes of cerulein-included AP, pancreas histology was restored in 4 weeks. Furthermore, the M3R antagonist ameliorated the severity of cerulein-induced AP in WT mice. We conclude that M3R activation can cause the pathogenesis of pancreatitis. This model may provide an alternative approach for pancreatitis research.

Exome Sequencing of Pancreatic Acinar Carcinoma Identified Distinctive Mutation Patterns

OBJECTIVES

Pancreatic acinar cell carcinoma (ACC) is a rare pancreatic cancer. The advancement of treatment is hampered because of the limited knowledge of its molecular mechanism.

METHODS

Whole-exome sequencing was performed on DNA extracted from 11 pure ACC surgical samples. Potential germline variants were removed on the basis of polymorphic databases, alternative allele frequency, coverage depth, and Catalogue of Somatic Mutations in Cancer (COSMIC) annotations after variant calling procedure. Mutation profiles and signatures were assessed through the Mutational Patterns package.

RESULTS

A median of 34 somatic mutations were detected (range, 19-60). Three novel recurrent small deletions were identified. Common pancreatic ductal adenocarcinoma mutations or neuroendocrine tumor mutants were not found. FAT atypical cadherin 4, mucin 5B, titin, and zinc finger homeobox 3 were consistently mutated across 4 independent ACC studies. A high contribution of COSMIC mutational signature 1 was seen in ACC, indicating deamination of 5-methylcytosine. The majority of the patients had COSMIC signatures 6, 15, or 20, relating to defective DNA mismatch repair. Six patients showed COSMIC mutational signature 10 because of the altered activity of DNA polymerase epsilon.

CONCLUSIONS

Distinct mutational signatures pathways were found in ACC and targeting them may improve clinical outcome.

[Use of alternative pancreatic fistula risk score system for patients with clinical relevant postoperative pancreatic fistula after laparoscopic pancreaticoduodenectomy]

Objective: To examine the application value of alternative pancreatic fistula risk score system(a-FRS) for patients with clinically relevant postoperative pancreatic fistula(CR-POPF) after laparoscopic pancreaticoduodenectomy(LPD). Methods: Clinical data of 400 patients who underwent LPD at Department of Hepatobiliary and Pancreatic Surgery,Jilin University First Hospital,from April 2015 to August 2019 were retrospectively analyzed.There were 217 males and 183 females, with age of (M(Q_R)) 58 (53) years (range:26 to 93 years) and body mass index of (23.0±2.7) kg/m² (range:19.4 to 27.1 kg/m²).Preoperative CA19-9 was (171.6±212.7) U/ml (range:32.1 to 762.6 U/ml), and preoperative CA125 was (18.6±22.9) U/ml (range:9.0 to 112.3 U/ml).Univariate analysis and multivariate Logistic regression analysis were implemented to find independent risk factors in CR-POPF.According to 3 indicators of a-FRS system(pancreatic texture,main pancreatic duct diameter,and body mass index),receiver operator characteristic curve was used to prospectively analyze the clinical value of CR-POPF. Results: CR-POPF occurred in 60 patients(15.0%) among the 400 LPD patients,including 54 patients(13.5%) with grade B pancreatic fistula and 6 patients(1.5%) with grade C pancreatic fistula.Univariate and multivariate Logistic regression analysis results showed that soft pancreas,diameter of main pancreatic duct ≤3 mm,and body mass index>23 kg/m² were the independent risk factors for CR-POPF after LPD.The incidence of CR-POPF was 1.9% in the group with low pancreatic fistula risk(0 to 5%),5.9% with moderate pancreatic fistula risk(>5% to 20%),and 80.7% with high pancreatic fistula risk(>20%).a-FRS prospectively predicted the sensitivity and specificity of CR-POPF after LPD was 76.7% and 96.8%,positive predictive value was 80.7%,negative predictive value was 95.9%,positive likelihood ratio was 23.66,negative likelihood ratio was 0.24,and area under the curve was 0.735(95%CI:0.668-0.799). Conclusion: a-FRS system has great clinical application value in predicting CR-POPF after LPD,which can provide basis for early risk prediction of CR-POPF and timely related clinical intervention.

POS0696 SAFETY AND EFFICACY OF BELIMUMAB IN OLDER ADULTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS OF AN INTEGRATED ANALYSIS

Background:

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease characterised by persistent B-cell activation. Belimumab (BEL), a monoclonal antibody that inhibits B-lymphocyte stimulator, is approved in patients aged ≥5 years with active autoantibody-positive SLE; however, safety and efficacy data of BEL in older adults are limited.

Objectives:

Assess the safety and efficacy of BEL in older adults with SLE.

Methods:

A meta-analysis (GSK study 116559) was performed on the subpopulation of patients aged ≥65 years and compared with the overall population pooled from six controlled, repeat-dose (CRD) BEL trials in adults with SLE (GSK studies: 110752, 110751, LBSL02 [safety only], 112341, 113750, and 115471). Additional safety data were obtained from GSK study 115467.

In each trial, patients were randomised to BEL or placebo (PBO) and received ≥1 treatment dose (GSK studies 110752 and 110751: intravenous [IV] BEL 1 or 10 mg/kg; LBSL02: IV BEL 1, 4, or 10 mg/kg; GSK study 112341: subcutaneous BEL 200 mg; GSK studies 113750, 115471, and 115467: IV BEL 10 mg/kg) plus standard therapy. Safety assessments included: incidence of serious adverse events (SAE), mortality and adverse events of special interest (AESI). The primary efficacy analysis for the CRD trials was the SLE Responder Index 4 (SRI4) response rate.

Results:

Older adults (CRD studies: N=63; study 115467: N=156) had lower disease activity and more organ damage compared with the overall populations, and a greater proportion were of white race compared with the overall population in the CRD studies. There were no clinically relevant differences in the incidence of SAE or death between older adults and the overall populations (Table 1). Rates of AESI (post-infusion/injection systemic reactions [PISR], serious infections of special interest, malignancies, psychiatric events) were generally similar or lower in older adults compared with the overall populations with no imbalances between BEL and PBO in older adults (Table 1). No malignancies were reported in older adults. The SRI4 response rate in older adults favoured BEL vs PBO (OR [95% CI], 1.49 [0.49, 4.58]), consistent with the overall populations of the individual CRD studies (110752 and 110751 pooled [10 mg/kg IV]: 1.68 [1.32, 2.15]; 112341: 1.68 [1.25, 2.25]; 113750: 1.99 [1.40, 2.82]; 115471: 1.42 [0.94, 2.15]).

Conclusion:

In patients with SLE, the safety and efficacy of BEL in older adults were generally consistent with the overall population and suggest a favourable benefit–risk profile. Due to the small number of older adults analysed, these data should be interpreted with caution.

Funding:

GSK

Table 1.

SAE, deaths, and AESI

N (%)*Study 115467CRD studies†Older adults(N=156)Overall(N=4003)Older adults(N=63)Overall(N=4170)PBON=82BELN=74PBON=2001BELN=2002PBON=27BELN=36PBON=1355BELN=2815SAE9 (11.0)6 (8.1)222 (11.1)220 (11.0)5 (18.5)10 (27.8)230 (17.0)421 (15.0)Death‡1 (1.2)1 (1.4)11 (0.5)12 (0.6)006 (0.4)16 (0.6)AESI PISR§,‖,¶----02 (5.6)110 (8.1)286 (10.2)  Serious PISR002 (<0.1)8 (0.4)002 (0.1)13 (0.5)Infections of SI (opportunistic, herpes zoster, tuberculosis, sepsis)§02 (2.7)50 (2.5)36 (1.8)1 (3.7)097 (7.2)173 (6.1)Serious infections of SI02 (2.7)17 (0.8)17 (0.8)0017 (1.3)40 (1.4)Malignancies ex. non-melanoma skin cancer§005 (0.2)5 (0.2)002 (0.1)8 (0.3)Depression(inc. mood disorders /anxiety)/suicide/self-injury§,¶,**-‖---3 (11.1)3 (8.3)92 (6.8)210 (7.5)Serious depression/ suicide/self-injury01 (1.4)6 (0.3)18 (0.9)1 (3.7)05 (0.4)9 (0.3)

*Patients counted once/category; †Pooled data from all studies except 115467; ‡Study 115467: fatal SAEs that started during on-treatment period; death may have occurred after period end. CRD studies: all deaths during double-blind period; §Per custom MedDRA query; ‖Occurring on/within 3 days of infusion/injection; ¶Study 115467: only serious PISR and serious depression/suicide/self-injury events collected; **Per standard MedDRA query.

MedDRA, Medical Dictionary for Regulatory Activities; SI, special interest

Acknowledgements:

Medical writing assistance was provided by Helen Taylor, Fishawack Indicia Ltd., UK, part of Fishawack Health, and was funded by GSK.

Disclosure of Interests:

David d’cruz Speakers bureau: GSK, Consultant of: GSK, Eli Lilly, Gina Eriksson Shareholder of: GSK, Employee of: GSK, Yulia Green Shareholder of: GSK, Employee of: GSK, Anne Hammer Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Paige Meizlik Shareholder of: GSK, Employee of: GSK, David Roth Shareholder of: GSK, Employee of: GSK

Downregulation of GSTM2 enhances gemcitabine chemosensitivity of pancreatic cancer in vitro and in vivo

Glutathione-S-transferases (GSTs) not only show cytoprotective role and their involvement in the development of anticancer drug resistance, but also transmit signals that control cell proliferation and apoptosis. However, the role of GST isoforms in chemotherapy resistance remains elusive in pancreatic cancer. Here, we demonstrated that gemcitabine treatment increased the GSTM2 expression in pancreatic cancer cell lines. Knockdown of GSTM2 by siRNA elevated apoptosis and decreased viability of pancreatic cancer cells treated with gemcitabine. Moreover, in vivo experiments further showed that shRNA induced GSTM2 downregulation enhanced drug sensitivity of gemcitabine in orthotopic pancreatic tumor mice. We also found that GSTM2 levels were lower in tumor tissues than in non-tumor tissues and higher GSTM2 expression was significantly associated with longer overall survival. In conclusion, our findings indicate that GSTM2 expression is essential for the survival of pancreatic cancer cells undergoing gemcitabine treatment and leads to chemo resistance. Downregulation of GSTM2 in pancreatic cancer may benefit gemcitabine treatment. GSTM2 expression in patients also shows significant correlation with overall survival. Thus, our study suggests that GSTM2 is a potential target for chemotherapy optimization and prognostic biomarker of pancreatic cancer.

[The value of "posterior approach, uncinate process priority, artery first" in laparoscopic pancreatoduodenectomy]

Objective: To explore the value of "posterior approach, uncinate process priority, artery first" in laparoscopic pancreatoduodenectomy. Methods: The clinical data of 200 patients who underwent laparoscopic pancreatoduodenectomy from January 2018 to April 2019 in the Second Department of Hepatobiliary and Pancreatic Surgery, the First Hospital of Jilin University were analyzed retrospectively. Meanwhile, the advantages of "posterior approach, uncinate process priority, artery first" were analyzed. Results: Two hundred patients were treated with "posterior approach, uncinate process priority, artery first". The average total operation time was (260.2±50.1) min, sample cutting time was (86.6±18.7) min, intraoperative bleeding volume was 50 (50-100) ml, average number of lymph node dissection was (19.2±7.4), and average hospitalization time was (17.9±9.9) days. Conclusion: The "posterior approach, uncinate process first, artery first" approach not only protects the variant hepatic artery, but also allows early detection of SMA, clarifies the positional relationship between the tumor and SMA, realizes R0 resection, and reduces the amount of bleeding during operation and shortens the operation time, which is safe and feasible in clinical setting.

Trypsin activity governs increased susceptibility to pancreatitis in mice expressing human PRSS1R122H

Currently, an effective targeted therapy for pancreatitis is lacking. Hereditary pancreatitis (HP) is a heritable, autosomal-dominant disorder with recurrent acute pancreatitis (AP) progressing to chronic pancreatitis (CP) and a markedly increased risk of pancreatic cancer. In 1996, mutations in PRSS1 were linked to the development of HP. Here, we developed a mouse model by inserting a full-length human PRSS1R122H gene, the most commonly mutated gene in human HP, into mice. Expression of PRSS1R122H protein in the pancreas markedly increased stress signaling pathways and exacerbated AP. After the attack of AP, all PRSS1R122H mice had disease progression to CP, with similar histologic features as those observed in human HP. By comparing PRSS1R122H mice with PRSS1WT mice, as well as enzymatically inactivated Dead-PRSS1R122H mice, we unraveled that increased trypsin activity is the mechanism for R122H mutation to sensitize mice to the development of pancreatitis. We further discovered that trypsin inhibition, in combination with anticoagulation therapy, synergistically prevented progression to CP in PRSS1R122H mice. These animal models help us better understand the complex nature of this disease and provide powerful tools for developing and testing novel therapeutics for human pancreatitis.

OP0164 BLISS-LN: A RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED PHASE 3 TRIAL OF INTRAVENOUS BELIMUMAB IN PATIENTS WITH ACTIVE LUPUS NEPHRITIS

Background:

Lupus nephritis (LN), a serious manifestation of systemic lupus erythematosus (SLE), affects nearly 70% of patients (pts) in high-risk groups. To preserve renal function, LN requires fast and effective treatment. Despite medical advances, progression rates at 15 years to end-stage renal disease (ESRD) remain >40% for pts with diffuse proliferative LN. Belimumab (BEL), approved in pts aged ≥5 years with active SLE, improved renal parameters in pts with baseline renal involvement in apost hocanalysis of Phase 3 trials data.

Objectives:

To assess efficacy and safety of intravenous (IV) BEL vs placebo (PBO), plus standard therapy (ST), in pts with active LN.

Methods:

BLISS-LN is a Phase 3, randomised, double-blind, PBO-controlled, 104-week study (GSK Study BEL114054,NCT01639339). Adults with SLE and biopsy-proven LN (class III, IV, and/or V) were randomised (1:1) to monthly BEL 10 mg/kg IV or PBO, plus ST. Primary endpoint: Primary Efficacy Renal Response (PERR); defined as urine protein creatinine ratio [uPCR] ≤0.7; estimated glomerular filtration rate [eGFR] within 20% of the pre-flare value or ≥60 ml/min/1.73m2; no rescue therapy) at Week (Wk) 104. Key secondary endpoints: Complete Renal Response (CRR; defined as uPCR <0.5; eGFR within 10% of the pre-flare value or ≥90 ml/min/1.73m2; no rescue therapy) at Wk 104; PERR at Wk 52; time to renal-related event (defined as ESRD/doubling of serum creatinine/renal worsening/renal disease-related treatment failure) or death. Other endpoints: time to PERR/CRR sustained through Wk 104; SLEDAI-S2K score <4 points at Wk 104; safety.

Results:

Overall, 448 pts were randomised (efficacy: 223/group; safety: 224/group). Significantly more BEL (43%) than PBO (32.3%) pts achieved PERR at Wk 104 (OR 1.55, 95% CI 1.04, 2.32; p=0.0311). More BEL than PBO pts achieved key secondary and other efficacy endpoints (Table).

Overall, 214 (95.5%) BEL and 211 (94.2%) PBO pts had ≥1 adverse event (AE); 58 (25.9%) BEL and 67 (29.9%) PBO pts had ≥1 serious AE; 29 (12.9%) pts in each group had ≥1 AE resulting in study treatment discontinuation; 4 (1.8%) BEL and 3 (1.3%) PBO pts developed on-treatment fatal AEs.

Conclusion:

In the largest LN study to date, data from BLISS-LN demonstrate that BEL plus ST significantly improves LN renal responses compared with ST alone with a favourable safety profile.

Study funding: GSK.

Table.Endpoint, n (%)PBO(n=223)BEL(n=223)OR/HR (95% CI) vs PBOp-valueCRR at Wk 104*44 (19.7)67 (30.0)OR 1.74(1.11, 2.74)0.0167PERR at Wk 52*79 (35.4)104 (46.6)OR 1.59(1.06, 2.38)0.0245Time to PERR throughWk 104†72 (32.3)96 (43.0)HR 1.46(1.07, 1.98)0.0157Time to CRR throughWk 104†44 (19.7)67 (30.0)HR 1.58(1.08, 2.31)0.0189Time to renal-related event or death†63 (28.3)35 (15.7)HR 0.51(0.34, 0.77)0.0014SLEDAI-S2K score <4 points at Wk 104*41 (18.4)62 (27.8)OR 1.76(1.11, 2.78)0.0164

*PBO and BEL columns represent the n (%) responders

†Data presented as n (cumulative incidence)

Disclosure of Interests:

Richard Furie Grant/research support from: GSK, Consultant of: GSK, Brad H Rovin Grant/research support from: GSK, Consultant of: GSK, Frederic Houssiau Grant/research support from: UCB, Consultant of: GSK, Zahir Amoura Grant/research support from: GSK, Roche, Consultant of: GSK, Astra Zeneca, Amgen, Mittermayer Santiago: None declared, Gabriel Contreras Grant/research support from: Genentech, Merck, Consultant of: Genentech, Merck, Ana Malvar Consultant of: GSK and Roche, chi chiu mok: None declared, Amit Saxena Consultant of: GSK, AZ, BMS, Xueqing Yu: None declared, Y.K. Onno Teng Grant/research support from: GSK, Consultant of: GSK, Aurinia Pharmaceuticals, Novartis, Carly Barnett Shareholder of: GSK, Employee of: GSK, Susan Burriss Shareholder of: GSK, Employee of: GSK, Yulia Green Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Christi Kleoudis Shareholder of: GSK, Consultant of: GSK, Employee of: Parexel, David Roth Shareholder of: GSK, Employee of: GSK

THU0503 PLUTO TRIAL: SENSITIVITY ANALYSES OF SRI4 RESPONSE WITH BELIMUMAB VS PLACEBO IN PAEDIATRIC PATIENTS WITH CHILDHOOD-ONSET SYSTEMIC LUPUS ERYTHEMATOSUS (CSLE)

Background:

Belimumab (BEL) is the first treatment approved in children ≥5 years of age with cSLE. This recent approval was based on favourable results of the PLUTO trial, evaluating efficacy and safety of intravenous (IV) BEL, plus standard SLE therapy (SST), vs placebo (PBO), in children with cSLE.1

Objectives:

To evaluate the SLE Responder Index 4 (SRI4) sensitivity of response for the comparison of BEL vs PBO at Week (Wk) 52.

Methods:

In PLUTO (NCT01649765; GSK study BEL114055), an ongoing Phase 2, randomised, PBO-controlled, double-blind study, patients (pts) 5–17 years of age with active cSLE were randomised to monthly BEL 10 mg/kg IV, or PBO, plus SST, for 52 weeks. The primary efficacy endpoint was the SRI4 response rate at Wk 52. Pre-specified sensitivity analyses supporting the primary efficacy endpoint for the intention-to-treat (ITT) population included unadjusted, last observation carried forward (LOCF), completer responses, and response using SLE Disease Activity Index (SLEDAI) 2K proteinuria scoring rule (4-point score for proteinuria >0.5 g/24 h), all at Wk 52. Completers were pts who completed 52 weeks of treatment. Any pts who withdrew or received protocol-prohibited medication or a dose of allowable medication that resulted in treatment failure prior to the Wk 52 visit had missing data handled using LOCF (missing values imputed using the last previous non-missing value). Statistics are descriptive.

Results:

Overall, 93 pts were randomised (BEL, n=53; PBO, n=40). Majority (94.6%) of pts were female, mean (standard deviation [SD]) age was 14.0 (2.49) years and mean (SD) disease duration was 2.4 (1.93) years. By Wk 52, numerically more BEL (52.8%) than PBO (43.6%) pts were SRI4 responders; difference vs PBO 9.24; odds ratio (OR; 95% confidence interval [CI]) vs PBO 1.49 (0.64, 3.46). For each sensitivity analysis (unadjusted, LOCF, completer, and SLEDAI 2K responses) the odds of being a responder at Wk 52 were higher for pts receiving BEL vs PBO (Table).

Table.

Sensitivity analyses: SRI4 response at Wk 52

PBO(n=40)BEL(n=53)Unadjusted response (ITT), n*3953 n (%)17 (43.6)28 (52.8) Observed difference vs PBO9.24 OR (95% CI)†vs PBO1.45 (0.63, 3.33)LOCF response (ITT), n*3953 n (%)18 (46.2)30 (56.6) Observed difference vs PBO10.45 OR (95% CI)‡vs PBO1.51 (0.65, 3.52)Completer response (completers), n*3045 n (%)17 (56.7)27 (60.0) Observed difference vs PBO3.33 OR (95% CI)‡vs PBO1.16 (0.44, 3.09)Response using SLEDAI 2K (ITT), n*3953 n (%)17 (43.6)28 (52.8) Observed difference vs PBO9.24 OR (95% CI)‡vs PBO1.49 (0.64, 3.46)

*One pt was excluded because they did not have a baseline Safety of Estrogens in Lupus National Assessment (SELENA)-SLEDAI assessment;†calculated from a logistic regression model for the comparison between BEL and PBO without adjustment for any covariates;‡calculated from a logistic regression model for the comparison between BEL and PBO with covariates treatment group, baseline age (5–11 years vs 12–17 years), and baseline SELENA-SLEDAI score (≤12 vs ≥13)

Conclusion:

The results of the SRI4 primary efficacy endpoint sensitivity analyses further support a favourable effect for BEL vs PBO.

References:

[1]Brunner HI,et al.Arthritis Rheumatol.2018;70(59): 3224–5, Abst. 2867

Acknowledgments:

We acknowledge all PLUTO investigators (PRINTO, PRCSG and otherwise affiliated). Study funding: GSK.

Disclosure of Interests:

Nicolino Ruperto Consultant of: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GSK, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi and Takeda, Hermine Brunner Consultant of: Hoffman-La Roche, Novartis, Pfizer, Sanofi Aventis, Merck Serono, AbbVie, Amgen, Alter, AstraZeneca, Baxalta Biosimilars, Biogen Idec, Boehringer, Bristol-Myers Squibb, Celgene, EMD Serono, Janssen, MedImmune, Novartis, Pfizer, and UCB Biosciences, Speakers bureau: GSK, Roche, and Novartis, Masaaki Mori Grant/research support from: Abbvie Japan, Asahikasei Pharmaceutical, Ayumi Pharmaceutical, CSL Behring, Chugai Pharmaceutical, Japan Blood Products Organization, MSD K.K., Nippon Kayaku, UCB Japan, Consultant of: Daiichi Sankyo, Taisho Pharmaceutical, Jacqueline Clinch Consultant of: Alexion, Speakers bureau: Alexion, Reema Syed: None declared, Naomi Iwata Speakers bureau: Sanofi K.K, Damon Bass Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Anne Hammer Shareholder of: GSK, Employee of: GSK, Mohamed Okily Shareholder of: GSK, Employee of: GSK, Gina Eriksson Shareholder of: GSK, Employee of: GSK, Holly Quasny Shareholder of: GSK, Employee of: GSK

SAT0505 PLUTO TRIAL OF INTRAVENOUS BELIMUMAB IN PAEDIATRIC PATIENTS WITH CHILDHOOD-ONSET SYSTEMIC LUPUS ERYTHEMATOSUS (cSLE): PATIENT RESPONSES OVER TIME

Background:

Belimumab (BEL) is a human monoclonal antibody that specifically inhibits B-cell activating factor (BAFF). PLUTO is an ongoing trial evaluating efficacy and safety of intravenous (IV) BEL in children ≥5 years of age with cSLE. Efficacy, and safety endpoints of PLUTO have been reported;1briefly, numerically more BEL vs PBO pts met the primary and major secondary efficacy endpoints. We present patient (pt) response to BEL over time.

Objectives:

To evaluate changes in SLE Responder Index (SRI) 4 and SRI6 responses, and disease activity over 52 weeks, in paediatric pts receiving BEL, or placebo (PBO), plus standard SLE therapy (SST).

Methods:

PLUTO (GSK Study BEL114055,NCT01649765) is a Phase 2, randomised, double-blind, placebo-controlled study. Pts 5–17 years of age with active cSLE were randomised to monthly BEL 10 mg/kg IV, or PBO, plus SST. Endpoints assessed: SRI4 and SRI6 response rate, mean percentage and absolute change from baseline in Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLE Disease Activity Index (SLEDAI) and Physicians’ Global Assessment (PGA) scores, and percentage of pts with no new British Isles Lupus Assessment Group (BILAG) 1A/2B organ domain scores compared with baseline, all by study visit. The last-observation-carried-forward (LOCF) principle (missing values imputed using the last available non-missing value) was applied to pts who withdrew or received protocol-prohibited medication or a dose of allowable medication that resulted in treatment failure prior to the Week (Wk) 52 visit. Descriptive statistics were used.

Results:

A total of 93 pts (94.6% female, mean [SD] age 14.0 [2.49] years) were randomised for the intention-to-treat (ITT) population: 53 to BEL and 40 to PBO. Mean (SD) BEL and PBO baseline scores were 10.3 (3.34) and 10.4 (3.63) for SELENA-SLEDAI and 1.3 (0.43) and 1.4 (0.42) for PGA, respectively. Pt number with at least BILAG 1A/2B organ domain involvement at baseline was 37 (69.8%) for BEL and 29 (72.5%) for PBO. SRI4 and SRI6 responses over 52 weeks were mostly numerically higher with BEL than PBO; more BEL than PBO pts were SRI4 and SRI6 responders at Wk 52 (Figure 1). Unadjusted mean (SE) percentage changes from baseline over time in SELENA-SLEDAI and PGA scores generally favoured BEL over PBO, as did unadjusted mean (SE) absolute changes (Figure 2). Wk 52 adjusted mean (95% CI) percentage treatment difference vs PBO was -4.0% (-21.8, 13.9) for SELENA-SLEDAI and -6.1% (-23.9, 11.7) for PGA, while Wk 52 adjusted mean (95% CI) treatment difference vs PBO was -0.7 (-2.4, 1.1) for SELENA-SLEDAI and -0.1 (-0.3, 0.1) for PGA. Over the study duration, numerically more BEL than PBO pts had no new BILAG 1A/2B organ domain scores (Figure 2).

Figure 1.

SRI4 and SRI6 response by study visit

Figure 2.

SELENA-SLEDAI and PGA score mean percentage and absolute change from baseline, and no new BILAG 1A/2B organ domain scores compared with baseline, all by study visit

Conclusion:

In line with the main analyses performed at Wk 52,1further analyses of responses over time in SRI4, SRI6 and disease activity generally favoured BEL over PBO. Combined, these results continue to support the efficacy profile of IV BEL in the treatment of children with cSLE.

References:

[1]Brunner HI,et al.Arthritis Rheumatol.2018;70(59): 3224–5, Abst. 2867

Acknowledgments:

We acknowledge all PLUTO investigators (PRINTO, PRCSG and otherwise affiliated). Study funding: GSK.

Disclosure of Interests:

Nicolino Ruperto Consultant of: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GSK, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi and Takeda, Liza McCann: None declared, Syuji Takei Grant/research support from: Eisai, Consultant of: Novartis, Bristol-Myers Squibb, Speakers bureau: GSK, Sanofi, Tanabe-Mitsubishi, Novartis, Chugai, Ono, Abbvie, Eli-Lilly, Bristol-Myers Squibb, Clarissa Pilkington: None declared, Damon Bass Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Anne Hammer Shareholder of: GSK, Employee of: GSK, Mohamed Okily Shareholder of: GSK, Employee of: GSK, Gina Eriksson Shareholder of: GSK, Employee of: GSK, Holly Quasny Shareholder of: GSK, Employee of: GSK, Hermine Brunner Consultant of: Hoffman-La Roche, Novartis, Pfizer, Sanofi Aventis, Merck Serono, AbbVie, Amgen, Alter, AstraZeneca, Baxalta Biosimilars, Biogen Idec, Boehringer, Bristol-Myers Squibb, Celgene, EMD Serono, Janssen, MedImmune, Novartis, Pfizer, and UCB Biosciences, Speakers bureau: GSK, Roche, and Novartis

SAT0193 A PHASE 3, OPEN-LABEL, CONTINUATION STUDY EVALUATING LONG-TERM SAFETY AND EFFICACY OF BELIMUMAB IN PATIENTS FROM JAPAN AND KOREA WITH SYSTEMIC LUPUS ERYTHEMATOSUS, FOR UP TO 7 YEARS

Background:

Systemic lupus erythematosus (SLE) is an autoimmune disorder more prevalent in the Asian population vs Caucasians. Belimumab (BEL), a monoclonal antibody targeting B-lymphocyte stimulator, is approved in patients (pts) ≥5 years with active, autoantibody-positive SLE.

Objectives:

Evaluate long-term safety and efficacy of intravenous (IV) BEL + standard SLE therapy (SST) in pts with SLE in Japan/Korea.

Methods:

In this Phase 3, multicentre, open-label (OL) study (BEL114333;NCT01597622), eligible (≥18 years of age) completers of the double-blind phase of GSK study BEL113750 in Japan and South Korea or the subcutaneous OL phase of GSK Study BEL112341 in Japan, received monthly BEL 10 mg/kg IV plus SST. Primary endpoints: safety assessments. Key secondary endpoints: SRI4 response rate at each scheduled visit (observed data), defined as a ≥4-point reduction from baseline in SELENA-SLEDAI score, no worsening in PGA (<0.3-point increase from baseline) and no new BILAG 1A/2B organ domain scores; time to first severe SFI flare over time. Endpoints were analysed relative to first BEL dose (parent or current study). No follow-up data were collected after study withdrawal.

Results:

Overall, 142 pts were enrolled (Japan n=72; Korea n=70), 104 (73.2%) completed the study, 1 (0.7%) died and 37 (26.1%) withdrew.

Overall, 139 (97.9%) pts had ≥1 adverse event (AE) (Table). Most frequent AEs included: nasopharyngitis (60.6%); headache (28.2%); cough, herpes zoster and viral upper respiratory tract infection (18.3% each). Serious AEs (SAEs) occurred in 48 (33.8%) pts. Most common SAEs were infections and infestations, reported in 24 (16.9%) pts (Table). During this study, the annual incidence of AEs, including SAEs and AESI, remained stable or declined, with no trends of clinical concerns regarding the incidence of Grade 3 or 4 values for laboratory parameters. There was 1 transient positive immunogenicity result of no clinical concern.

Table.

The proportion of SRI4 responders was 47.8% at Year 1 (Week 24) and tended to increase numerically up to 84.6% at Year 7 (Week 48). The proportion of pts with a ≥4-point decrease from baseline in SELENA-SLEDAI score numerically increased from 51.5% at Year 1 (Week 24) to 84.6% at Year 7 (Week 48). Proportion of pts with no PGA worsening was 91.3-100% and the proportion with no new BILAG 1A/2B organ domain scores was 93.3-100% up to Year 7 (Week 48). A total of 21 (14.8%) pts had 24 severe SFI flares.

Conclusion:

BEL was well tolerated as add-on therapy to SST for ≤7 years in pts with SLE from Japan/Korea. Safety results were consistent with the known BEL safety profile.

Study funding: GSK.

Disclosure of Interests:

Yoshiya Tanaka Grant/research support from: Received research grants from Asahi-Kasei, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Ono, Speakers bureau: Received speaking fees and/or honoraria from Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Teijin, Sang-Cheol Bae: None declared, Damon Bass Shareholder of: GSK, Employee of: GSK, Myron Chu Shareholder of: GSK, Employee of: GSK, Paula Curtis Shareholder of: GSK, Employee of: GSK, Kathleen DeRose Shareholder of: GSK, Employee of: GSK, Beulah Ji Shareholder of: GSK, Employee of: GSK, Regina Kurrasch Shareholder of: GSK, Employee of: GSK, Jenny Lowe Shareholder of: GSK, Employee of: GSK, Paige Meizlik Shareholder of: GSK, Employee of: GSK, David Roth Shareholder of: GSK, Employee of: GSK

Adipose-Derived Biogenic Nanoparticles for Suppression of Inflammation

Extracellular vesicles secreted from adipose-derived mesenchymal stem cells (ADSCs) have therapeutic effects in inflammatory diseases. However, production of extracellular vesicles (EVs) from ADSCs is costly, inefficient, and time consuming. The anti-inflammatory properties of adipose tissue-derived EVs and other biogenic nanoparticles have not been explored. In this study, biogenic nanoparticles are obtained directly from lipoaspirate, an easily accessible and abundant source of biological material. Compared to ADSC-EVs, lipoaspirate nanoparticles (Lipo-NPs) take less time to process (hours compared to months) and cost less to produce (clinical-grade cell culture facilities are not required). The physicochemical characteristics and anti-inflammatory properties of Lipo-NPs are evaluated and compared to those of patient-matched ADSC-EVs. Moreover, guanabenz loading in Lipo-NPs is evaluated for enhanced anti-inflammatory effects. Apolipoprotein E and glycerolipids are enriched in Lipo-NPs compared to ADSC-EVs. Additionally, the uptake of Lipo-NPs in hepatocytes and macrophages is higher. Lipo-NPs and ADSC-EVs have comparable protective and anti-inflammatory effects. Specifically, Lipo-NPs reduce toll-like receptor 4-induced secretion of inflammatory cytokines in macrophages. Guanabenz-loaded Lipo-NPs further suppress inflammatory pathways, suggesting that this combination therapy can have promising applications for inflammatory diseases.

Transgenic Expression of PRSS1R122H Sensitizes Mice to Pancreatitis

BACKGROUND & AIMS

Mutations in the trypsinogen gene (PRSS1) cause human hereditary pancreatitis. However, it is not clear how mutant forms of PRSS1 contribute to disease development. We studied the effects of expressing mutant forms of human PRSS1 in mice.

METHODS

We expressed forms of PRSS1 with and without the mutation encoding R122H (PRSS1^R122H) specifically in pancreatic acinar cells under control of a full-length pancreatic elastase gene promoter. Mice that did not express these transgenes were used as controls. Mice were given injections of caerulein to induce acute pancreatitis or injections of lipopolysaccharide to induce chronic pancreatitis. Other groups of mice were fed ethanol or placed on a high-fat diet to induce pancreatitis. Pancreata were collected and analyzed by histology, immunoblots, real-time polymerase chain reaction, and immunohistochemistry. Trypsin enzymatic activity and chymotrypsin enzymatic activity were measured in pancreatic homogenates. Blood was collected and serum amylase activity was measured.

RESULTS

Pancreata from mice expressing transgenes encoding PRSS1 or PRSS1^R122H had focal areas of inflammation; these lesions were more prominent in mice that express PRSS1^R122H. Pancreata from mice that express PRSS1 or PRSS1^R122H had increased levels of heat shock protein 70 and nuclear factor (erythroid-derived 2)-like 2, and reduced levels of chymotrypsin C compared with control mice. Increased expression of PRSS1 or PRSS1^R122H increased focal damage in pancreatic tissues and increased the severity of acute pancreatitis after caerulein injection. Administration of lipopolysaccharide exacerbated inflammation in mice that express PRSS1^R122H compared to mice that express PRSS1 or control mice. Mice that express PRSS1^R122H developed more severe pancreatitis after ethanol feeding or a high-fat diet than mice that express PRSS1 or control mice. Pancreata from mice that express PRSS1^R122H had more DNA damage, apoptosis, and collagen deposition and increased trypsin activity and infiltration by inflammatory cells than mice that express PRSS1 or control mice.

CONCLUSIONS

Expression of a transgene encoding PRSS1^R122H in mice promoted inflammation and increased the severity of pancreatitis compared with mice that express PRSS1 or control mice. These mice might be used as a model for human hereditary pancreatitis and can be studied to determine mechanisms of induction of pancreatitis by lipopolysaccharide, ethanol, or a high-fat diet.

Oncogenic KRAS Reduces Expression of FGF21 in Acinar Cells to Promote Pancreatic Tumorigenesis in Mice on a High-Fat Diet

BACKGROUND & AIMS

Obesity is a risk factor for pancreatic cancer. In mice, a high-fat diet (HFD) and expression of oncogenic KRAS lead to development of invasive pancreatic ductal adenocarcinoma (PDAC) by unknown mechanisms. We investigated how oncogenic KRAS regulates the expression of fibroblast growth factor 21, FGF21, a metabolic regulator that prevents obesity, and the effects of recombinant human FGF21 (rhFGF21) on pancreatic tumorigenesis.

METHODS

We performed immunohistochemical analyses of FGF21 levels in human pancreatic tissue arrays, comprising 59 PDAC specimens and 45 nontumor tissues. We also studied mice with tamoxifen-inducible expression of oncogenic KRAS in acinar cells (Kras^G12D/+ mice) and fElas^CreERT mice (controls). Kras^G12D/+ mice were placed on an HFD or regular chow diet (control) and given injections of rhFGF21 or vehicle; pancreata were collected and analyzed by histology, immunoblots, quantitative polymerase chain reaction, and immunohistochemistry. We measured markers of inflammation in the pancreas, liver, and adipose tissue. Activity of RAS was measured based on the amount of bound guanosine triphosphate.

RESULTS

Pancreatic tissues of mice expressed high levels of FGF21 compared with liver tissues. FGF21 and its receptor proteins were expressed by acinar cells. Acinar cells that expressed Kras^G12D/+ had significantly lower expression of Fgf21 messenger RNA compared with acinar cells from control mice, partly due to down-regulation of PPARG expression-a transcription factor that activates Fgf21 transcription. Pancreata from Kras^G12D/+ mice on a control diet and given injections of rhFGF21 had reduced pancreatic inflammation, infiltration by immune cells, and acinar-to-ductal metaplasia compared with mice given injections of vehicle. HFD-fed Kras^G12D/+ mice given injections of vehicle accumulated abdominal fat, developed extensive inflammation, pancreatic cysts, and high-grade pancreatic intraepithelial neoplasias (PanINs); half the mice developed PDAC with liver metastases. HFD-fed Kras^G12D/+ mice given injections of rhFGF21 had reduced accumulation of abdominal fat and pancreatic triglycerides, fewer pancreatic cysts, reduced systemic and pancreatic markers of inflammation, fewer PanINs, and longer survival-only approximately 12% of the mice developed PDACs, and none of the mice had metastases. Pancreata from HFD-fed Kras^G12D/+ mice given injections of rhFGF21 had lower levels of active RAS than from mice given vehicle.

CONCLUSIONS

Normal acinar cells from mice and humans express high levels of FGF21. In mice, acinar expression of oncogenic KRAS significantly reduces FGF21 expression. When these mice are placed on an HFD, they develop extensive inflammation, pancreatic cysts, PanINs, and PDACs, which are reduced by injection of FGF21. FGF21 also reduces the guanosine triphosphate binding capacity of RAS. FGF21 might be used in the prevention or treatment of pancreatic cancer.

Elevated intracellular trypsin exacerbates acute pancreatitis and chronic pancreatitis in mice

Intra-acinar trypsinogen activation occurs in the earliest stages of pancreatitis and is believed to play important roles in pancreatitis pathogenesis. However, the exact role of intra-acinar trypsin activity in pancreatitis remains elusive. Here, we aimed to examine the specific effects of intra-acinar trypsin activity on the development of pancreatitis using a transgenic mouse model. This transgenic mouse model allowed for the conditional expression of a mutant trypsinogen that can be activated specifically inside pancreatic acinar cells. We found that expression of this active mutated trypsin had no significant effect on triggering spontaneous pancreatitis. Instead, several protective compensatory mechanisms, including SPINK1 and heat shock proteins, were upregulated. Notably, these transgenic mice developed much more severe acute pancreatitis, compared with control mice, when challenged with caerulein. Elevated tissue edema, serum amylase, inflammatory cell infiltration and acinar cell apoptosis were dramatically associated with increased trypsin activity. Furthermore, chronic pathological changes were observed in the pancreas of all transgenic mice, including inflammatory cell infiltration, parenchymal atrophy and cell loss, fibrosis, and fatty replacement. These changes were not observed in control mice treated with caerulein. The alterations in pancreata from transgenic mice mimicked the histological changes common to human chronic pancreatitis. Taken together, we provided in vivo evidence that increased intra-acinar activation of trypsinogen plays an important role in the initiation and progression of both acute and chronic pancreatitis. NEW & NOTEWORTHY Trypsinogen is activated early in pancreatitis. However, the roles of trypsin in the development of pancreatitis have not been fully addressed. Using a genetic approach, we showed trypsin activity is critical for the severity of both acute and chronic pancreatitis.

Single-stage treatment of chronically infected total hip arthroplasty with cementless reconstruction: results in 126 patients with broad inclusion criteria

AIMS

Single-stage revision is not widely pursued due to restrictive inclusion criteria. In this study, we evaluated the results of single-stage revision of chronically infected total hip arthroplasty (THA) using broad inclusion criteria and cementless implants.

PATIENTS AND METHODS

Between 2010 and 2016, 126 patients underwent routine single-stage revision with cementless reconstruction with powdered vancomycin or imipenem poured into the medullary cavity and re-implantation of cementless components. For patients with a culture-negative hip, fungal infections, and multidrug-resistant organisms, a direct intra-articular infusion of pathogen-sensitive antibiotics was performed postoperatively. Recurrence of infection and clinical outcomes were evaluated. Three patients died and 12 patients (none with known recurrent infection) were lost to follow-up. There were 111 remaining patients (60 male, 51 female) with a mean age of 58.7 (sd 12.7; 20 to 79).

RESULTS

Of these 111 patients, 99 (89.2%) were free of infection at a mean follow-up time of 58 months (24 to 107). A recurrent infection was observed in four of the 23 patients (17.4%) with culture-negative infected hip. The success rate in patients with multidrug-resistant organisms was 84.2% (16/19). The mean postoperative Harris hip score was 79.6 points (63 to 92) at the most recent assessment.

CONCLUSION

Routine single-stage revision with cementless reconstruction can be a viable option for the treatment of chronically infected THA. The results of this study will add to the growing body of evidence supporting routine use of single-stage revision for the treatment of chronically infected THA. Cite this article: Bone Joint J 2019;101-B:396-402.

Neuropilin-1 maintains dimethylarginine dimethylaminohydrolase 1 expression in endothelial cells, and contributes to protection from angiotensin II-induced hypertension

Dimethylarginine dimethylaminohydrolases (DDAHs) are known to degrade asymmetric dimethylarginine, an endogenous inhibitor of NOS, and maintain vascular homeostasis; however, the regulatory pathways of DDAHs remain unclear. In this study, we aimed to define the role of transmembrane glycoprotein neuropilin-1 (NRP1) in the expression of DDAHs and investigate the potential roles of NRP1 in regulation of blood pressure. Short hairpin RNA-mediated knockdown of NRP1 reduced the level and mRNA stability of DDAH1 but not DDAH2 in HUVECs, whereas overexpression of NRP1 increased the mRNA stability of DDAH1. Meanwhile, mesenteric arteries and lung vascular endothelial cells of tamoxifen-inducible endothelial cell-specific NRP1 knockout mice exhibited decreased expression of DDAH1 and slightly increased expression of DDAH2. Mechanistically, the regulation of NRP1 on DDAH1 expression is mediated by a posttranscriptional mechanism involving miR-219-5p in HUVECs. Although the endothelial cell-specific NRP1 knockout mice did not exhibit any significant change in blood pressure at the basal level, they were more sensitive to low-dose angiotensin II infusion-induced increases in blood pressure. Our results show that NRP1 is required for full expression of DDAH1 in endothelial cells and that NRP1 contributes to protection from low-dose angiotensin II-induced increases in blood pressure.-Wang, Y., Wang, E., Zhang, Y., Madamsetty, V. S., Ji, B., Radisky, D. C., Grande, J. P., Misra, S., Mukhopadhyay, D. Neuropilin-1 maintains dimethylarginine dimethylaminohydrolase 1 expression in endothelial cells, and contributes to protection from angiotensin II-induced hypertension.

Transgenic expression of cyclooxygenase-2 in pancreatic acinar cells induces chronic pancreatitis

Replacement of the exocrine parenchyma by fibrous tissue is a main characteristic of chronic pancreatitis. Understanding the mechanisms of pancreatic fibrogenesis is critical for the development of preventive and therapeutic interventions. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin synthesis, is expressed in patients with chronic pancreatitis. However, it is unknown whether COX-2 can cause chronic pancreatitis. To investigate the roles of pancreatic acinar COX-2 in fibrogenesis and the development of chronic pancreatitis, COX-2 was ectopically expressed specifically in pancreatic acinar cells in transgenic mice. Histopathological changes and expression levels of several profibrogenic factors related to chronic pancreatitis were evaluated. COX-2 was expressed in the pancreas of the transgenic mice, as detected by Western blot analysis. Immunohistochemical staining showed COX-2 was specifically expressed in pancreatic acinar cells. COX-2 expression led to progressive changes in the pancreas, including pancreas megaly, persistent inflammation, collagen deposition, and acinar-to-ductal metaplasia. Quantitative RT-PCR and immunostaining showed that profibrogenic factors were upregulated and pancreatic stellate cells were activated in the COX-2 transgenic mice. Expression of COX-2 in pancreatic acinar cells is sufficient to induce chronic pancreatitis. Targeting this pathway may be valuable in the prevention of chronic pancreatitis. NEW & NOTEWORTHY COX-2 expression is observed in pancreatic tissues of human chronic pancreatitis. In this study, we showed that COX-2 expression caused the development of chronic pancreatitis in transgenic mice, supporting the idea that COX-2 inhibition may be an effective preventive and therapeutic strategy.

[Effects of sevoflurane and desflurane on pharmacodynamics of rocuronium in children]

Objective: To observe the intraoperative influences on pharmacodynamics of rocuronium in children inhaling sevoflurane and desflurane for 40 min balance. Methods: Ninety children (ASAⅠ-Ⅱ) undergoing elective surgery with general anesthesia in Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University from July 2015 to May 2016 were randomly assigned into six groups (n=15): Sevoflurane group (group S1 and S2), Desflurane group (group D1 and D2) and Propofol group (group P1 and P2). Children in group D1, S1 and P1 were allocated to research the dose-effect relationship of rocuronium, children in group D2, S2 and P2 were allocated to research the time-effect relationship of rocuronium. TOF-Watch SX monitor was used to exert a train-of-four stimulation (TOF) at ulnar nerve in wrist, then the adductor pollicis muscle appeared muscle twitch 4 times in turn which was recorded T(1, )T(2, )T(3) and T(4) respectively. After the success of the muscle relaxant calibration, 1.3 MAC sevoflurane and desflurane were inhaled and maintained for 40 min respectively in children in Sevoflurane group (group S1 and S2) and Desflurane group (group D1 and D2), Plasma target controlled infusion of 3.5-4.0 μg/ml propofol was always administered in Propofol group (group P1 and P2). 75 μg/kg rocuronium was injected each time in group S1, D1 and P1 respectively. Maximum inhibited effect of T(1) was recorded after every injection until inhibition of T(1) more than 95% eventually. The method of cumulative dose four times was used to calculate the efficiency curve of rocuronium[median effective dose (ED(50)), 90% effective dose (ED(90)) and 95% effective dose (ED(95))]. 0.6 mg/kg rocuronium was injected respectively through vein in group S2, D2 and P2. The recovery times of muscle relaxant were recorded which including time of T(1) disappeared (onset time), T(1) from 0% to 5% (peak effect time), T(1) from 0% to 25% (clinical effect time), T(1) from 25% to 75% (recovery index), T(1) from 0% to 70% (internal effect time), T(4)/T(1) (TOFr) from 0% to 70% and 90%. Results: ED(50, )ED(90) and ED(95) in group D1 were 128.73, 212.45 and 245.78 μg/kg respectively. ED(50, )ED(90) and ED(95) in group S1 were 132.46, 218.94 and 252.30 μg/kg respectively. ED(50, )ED(90) and ED(95) in group P1 were 230.56, 381.02 and 439.55 μg/kg respectively. ED(50, )ED(90) and ED(95) in group D1 and S1 were significantly lower than those in group P1 (all P<0.05), but there was no significant difference between D1 and S1 group (P>0.05). Compared with group P2, the shorter onset time, the longer peak effect time and clinical effect time was observed in group D2 and S2, the longer recovery index, internal effect time and TOFr from 0% to 70% and 90% was observed in group S2 (all P<0.01). Conclusions: 1.3 MAC sevoflurane and desflurane inhaling for 40 min significantly reduces ED(50) and ED(95) of rocuronium, prolongs the onset time and action time of rocuronium in children. Sevoflurane can significantly prolong the recovery characteristics of rocuronium.

Abstract GS1-05: Tandem duplicator phenotypes define 50% of triple negative breast cancers

Background. We recently discovered a unique chromotype, the Tandem Duplicator Phenotype (TDP), characterized by hundreds of somatic tandem duplications (TDs) scattered throughout the genome of a large percentage of triple negative breast cancers (TNBCs). Importantly, we observed that the TDP associates with a better response to cisplatin therapy in vitro and in vivo, suggesting that it is a tractable and quantitative biomarker of response to platinum-based therapy. Here, we expand on our initial findings by analyzing Whole-Genome (WG) sequences of over 2,700 tumors.

Methods. TD coordinates from WG sequences relative to 2717 tumors were assembled from over 30 independent studies representing several cancer types, including 254 TNBCs. WG sequencing of mouse breast tumors was carried out using standard Illumina protocols. The number, distribution and span-size of somatic TDs from a training set of 992 tumors were used to develop a TDP classifier that identifies highly recurrent but clearly distinct TDP profiles. The TDP classifier was then applied to the remaining tumor sequences. WG mutation and copy number datasets were investigated to identify the genetic drivers associated with each TDP profile, and the genomic consequences of different TDPs were evaluated through identification of genomic hotspots for gene duplication and transection.

Results. We describe six different TDPs featuring distinct TD span size distributions, with peaks at 10Kb (group 1), 300Kb (group 2) and 3Mb (group 3), or different combinations of these (mix12, mix13 and mix23). More than half of all TNBC display a TDP. Of these, 55% classify as group 1, 14% as group 2 and 15% as group mix12. Whereas all TDP groups show a higher TP53 mutation rate compared to non-TDP tumors, each TDP profile is characterized by specific additional gene perturbations, with loss of BRCA1 occurring in groups 1, mix12 and mix13; CCNE1 amplification in group 2; and CDK12 mutations in group mix23. We show that different TDPs are subject to the perturbation of specific oncogenic networks resulting from the duplication of oncogenes by larger TDs (&gt;300Kb) or the disruption of tumor suppressors via double transections by shorter TDs (10Kb). Indeed, tumor suppressor genes such as PTEN, RB1 and MLL3 are frequently disrupted by TDs in TNBC TDP group 1 tumors, whereas TNBC TDP group 2 tumors commonly feature duplication of oncogenes such as MYC and MALAT1. Finally, through WG analyses of 18 mouse models (GEMMs) of breast cancer, we provide the first mechanistic evidence of the driving role of conjoint loss of TP53 and BRCA1, but not of BRCA2, in inducing the TDP group 1 profile.

Conclusions. Our study shows a definitive genetic induction of one specific form of TDP (group 1) characterized by 10kb TD span. Different TDP profiles are characterized by alternative somatic genetic origins but always couple with disruptive TP53 mutations. The consequences of the massive TD formation in TDP TNBCs suggest a systems strategy to tumor induction involving heterogeneous combinations of oncogenes and tumor suppressors. That these TDP forms, accounting for ˜50% of TNBC, are associated with significant sensitivity to cisplatin suggest that this chromotype may identify TNBC patients who would benefit from upfront platinum-based chemotherapy.

Citation Format: Liu ET, Menghi F, Barthel F, Yadav V, Tang M, Ji B, Carter G, Jonkers J, Verhaak R. Tandem duplicator phenotypes define 50% of triple negative breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS1-05.

Critical Role for GAB2 in Neuroblastoma Pathogenesis through the Promotion of SHP2/MYCN Cooperation

Growing evidence suggests a major role for Src-homology-2-domain-containing phosphatase 2 (SHP2/PTPN11) in MYCN-driven high-risk neuroblastoma, although biologic confirmation and a plausible mechanism for this contribution are lacking. Using a zebrafish model of MYCN-overexpressing neuroblastoma, we demonstrate that mutant ptpn11 expression in the adrenal gland analog of MYCN transgenic fish promotes the proliferation of hyperplastic neuroblasts, accelerates neuroblastomagenesis, and increases tumor penetrance. We identify a similar mechanism in tumors with wild-type ptpn11 and dysregulated Gab2, which encodes a Shp2 activator that is overexpressed in human neuroblastomas. In MYCN transgenic fish, Gab2 overexpression activated the Shp2-Ras-Erk pathway, enhanced neuroblastoma induction, and increased tumor penetrance. We conclude that MYCN cooperates with either GAB2-activated or mutant SHP2 in human neuroblastomagenesis. Our findings further suggest that combined inhibition of MYCN and the SHP2-RAS-ERK pathway could provide effective targeted therapy for high-risk neuroblastoma patients with MYCN amplification and aberrant SHP2 activation.

Abstract 2961: Targeting stromal-derived Dickkopf-3 (DKK3) for the treatment of pancreatic ductal adenocarcinoma (PDAC)

Introduction: We and others have shown that pancreatic stellate cells (PSCs) in the tumor-associated stroma of PDAC promote tumor progression and resistance to therapy but the precise mechanisms are unclear. We investigated the role of PSC-derived DKK3, a member of the Dickkopf family of glycoproteins, in PDAC progression, metastasis and response to chemotherapy.

Methods: We evaluated expression of DKK3 in human PDAC tissue and cell lines, human PSCs and in a genetically engineered mouse model (GEMM) of PDAC. The paracrine and autocrine effects of DKK3 on PDAC and PSCs were examined by treatment with exogenous DKK3 and gain- and loss of function assays for proliferation, migration, invasion, and gemcitabine-induced apoptosis. The effects of DKK3 on PDAC progression and metastasis were determined by shRNA neutralization and genetic ablation in orthotopic xenograft models and the KPC autochthonous model of PDAC. We developed novel monoclonal antibodies (mAbs) against DKK3 and tested their ability to neutralize DKK3 and prolong survival in mouse models of PDAC.

Results: DKK3 was expressed at 4.5 times higher levels in human PDAC by Affymetrix profiling compared to normal pancreas and was present in 99% (118/119) of samples on a tissue microarray with moderate to high expression in 59%. In a GEMM of PDAC, DKK3 appeared early with preneoplastic PanIN lesions with increased expression in invasive carcinoma. DKK3 was strongly expressed by PSCs with minimal to no expression in PDAC cells and knockdown by shRNA reduced PSC proliferation and migration by 60% and 84% compared to controls (p&lt;0.001). Treatment of Panc1 and BxPC3 cells with DKK3 stimulated migration and invasion by 100-300% (p&lt;0.001) and proliferation of DKK3-silenced Panc1 cells was decreased by 80% (p&lt;0.001). Overexpression of DKK3 in L3.6pl cells increased colony formation in gemcitabine by &gt;90% (p&lt;0.001) with 65% reduction in apoptosis (p&lt;0.01), indicating that DKK3 contributes to PDAC resistance to chemotherapy. When we ablated DKK3 in KPC mice by breeding with DKK3-knockout mice, tumor growth was inhibited and survival increased by 45% (p=0.0002). In addition, fewer PanIN lesions developed in DKK3-null mice suggesting that DKK3 may contribute to the early developmental stages of PDAC. DKK3 neutralizing mAbs abrogated DKK3-mediated induction of PDAC cell migration, invasion and resistance to gemcitabine in vitro. Furthermore, treatment with DKK3 mAb significantly inhibited primary tumor growth, reduced peritoneal metastases and prolonged survival in an orthotopic model of PDAC by 43% compared to control mAb (p=0.005; HR 0.24, 95% CI 0.01-0.30).

Conclusions: These data are the first report, to our knowledge, of a tumor-promoting function of DKK3 and our results suggest that neutralization of DKK3 may be an effective approach as a primary treatment for PDAC and to enhance responsiveness to chemotherapy.

Citation Format: Liran Zhou, Hongmei Husted, Todd Moore, Mason Lu, Defeng Deng, Yan Liu, Vijaya Ramachandran, Thiruvengadam Arumugam, Baoan Ji, Huamin Wang, Jeffrey E. Lee, Craig D. Logsdon, Rosa F. Hwang. Targeting stromal-derived Dickkopf-3 (DKK3) for the treatment of pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2961. doi:10.1158/1538-7445.AM2017-2961

Chronic inflammation initiates multiple forms of K-Ras-independent mouse pancreatic cancer in the absence of TP53

Chronic inflammation (CI) is a risk factor for pancreatic cancer (PC) including the most common type, ductal adenocarcinoma (PDAC), but its role and the mechanisms involved are unclear. To investigate the role of CI in PC, we generated genetic mouse models with pancreatic specific CI in the presence or absence of TP53. Mice were engineered to express either cyclooxygenase-2 (COX-2) or IκB kinase-2 (IKK2), and TP53^+/+ or TP53^f/f specifically in adult pancreatic acinar cells by using a full-length pancreatic elastase promoter-driven Cre. Animals were followed for >80 weeks and pancreatic lesions were evaluated histologically and immunohistochemically. The presence of K-ras mutations was assessed by direct sequencing, locked nuclei acid (LNA)-based PCR, and immunohistochemistry. We observed that sustained COX-2/IKK2 expression caused histological abnormalities of pancreas, including increased immune cell infiltration, proliferation rate and DNA damage. A minority of animals with CI developed pre-neoplastic lesions, but cancer was not observed in any TP53^+/+ animals within 84 weeks. In contrast, all animals with CI-lacking TP53 developed various subtypes of PC, including acinar cell carcinoma, ductal adenocarcinoma, sarcomatoid carcinoma and neuroendocrine tumors, and all died within 65 weeks. No evidence of K-ras mutations was observed. Variations in the activity of the Hippo, pERK and c-Myc pathways were found in the diverse cancer subtypes. In summary, chronic inflammation is extremely inefficient at inducing PC in the presence of TP53. However, in the absence of TP53, CI leads to the development of several rare K-ras-independent forms of PC, with infrequent PDAC. This may help explain the rarity of PDAC in persons with chronic inflammatory conditions.

Neuropilin-1 modulates interferon-γ-stimulated signaling in brain microvascular endothelial cells

Inflammatory response of blood-brain barrier (BBB) endothelial cells plays an important role in pathogenesis of many central nervous system inflammatory diseases, including multiple sclerosis; however, the molecular mechanism mediating BBB endothelial cell inflammatory response remains unclear. In this study, we first observed that knockdown of neuropilin-1 (NRP1), a co-receptor of several structurally diverse ligands, suppressed interferon-γ (IFNγ)-induced C-X-C motif chemokine 10 expression and activation of STAT1 in brain microvascular endothelial cells in a Rac1-dependent manner. Moreover, endothelial-specific NRP1-knockout mice, VECadherin-Cre-ERT2/NRP1^flox/flox mice, showed attenuated disease progression during experimental autoimmune encephalomyelitis, a mouse neuroinflammatory disease model. Detailed analysis utilizing histological staining, quantitative PCR, flow cytometry and magnetic resonance imaging demonstrated that deletion of endothelial NRP1 suppressed neuron demyelination, altered lymphocyte infiltration, preserved BBB function and decreased activation of the STAT1-CXCL10 pathway. Furthermore, increased expression of NRP1 was observed in endothelial cells of acute multiple sclerosis lesions. Our data identify a new molecular mechanism of brain microvascular endothelial inflammatory response through NRP1-IFNγ crosstalk that could be a potential target for intervention of endothelial cell dysfunction in neuroinflammatory diseases.

Animal models of gastrointestinal and liver diseases. Animal models of acute and chronic pancreatitis

Animal models of pancreatitis are useful for elucidating the pathogenesis of pancreatitis and developing and testing novel interventions. In this review, we aim to summarize the most commonly used animal models, overview their pathophysiology, and discuss their strengths and limitations. We will also briefly describe common animal study procedures and refer readers to more detailed protocols in the literature. Although animal models include pigs, dogs, opossums, and other animals, we will mainly focus on rodent models because of their popularity. Autoimmune pancreatitis and genetically engineered animal models will be reviewed elsewhere.