Evolution of the structure of lipid nanoparticles for nucleic acid delivery: From in situ studies of formulation to colloidal stability

The development of lipid nanoparticle (LNP) based therapeutics for delivery of RNA has triggered the advance of new strategies for formulation, such as high throughput microfluidics for precise mixing of components into well-defined particles. In this study, we have characterised the structure of LNPs throughout the formulation process using in situ small angle x-ray scattering in the microfluidic chip, then by sampling in the subsequent dialysis process. The final formulation was investigated with small angle x-ray (SAXS) and neutron (SANS) scattering, dynamic light scattering (DLS) and cryo-TEM. The effect on structure was investigated for LNPs with a benchmark lipid composition and containing different cargos: calf thymus DNA (DNA) and two model mRNAs, polyadenylic acid (polyA) and polyuridylic acid (polyU). The LNP structure evolved during mixing in the microfluidic channel, however was only fully developed during the dialysis. The colloidal stability of the final formulation was affected by the type of incorporated nucleic acids (NAs) and decreased with the degree of base-pairing, as polyU induced extensive particle aggregation. The main NA LNP peak in the SAXS data for the final formulation were similar, with the repeat distance increasing from polyU Collapse

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MESH Headings

• Scattering, Small Angle
• Lipids/chemistry
• X-Ray Diffraction
• Nanoparticles/chemistry
• DNA
• RNA, Messenger
• RNA, Small Interfering/chemistry
• Liposomes

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Affiliation(s)

Jennifer Gilbert Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden
Federica Sebastiani Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; Department of Pharmacy, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
Marianna Yanez Arteta Advanced Drug Delivery, Pharmaceutical Sciences, R&D, AstraZeneca, 431 83, Gothenburg, Sweden
Ann Terry MAX IV Laboratory, Lund University, Fotongatan 2, 224 84 Lund, Sweden
Anna Fornell MAX IV Laboratory, Lund University, Fotongatan 2, 224 84 Lund, Sweden
Robert Russell National Deuteration Facility (NDF), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, 2232 Sydney, NSW, Australia
Najet Mahmoudi ISIS Neutron and Muon Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, UK
Tommy Nylander Division of Physical Chemistry, Department of Chemistry, Lund University, 221 00 Lund, Sweden; NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden; LINXS Institute of Advanced Neutron and X-Ray Science, Lund, Sweden; School of Chemical Engineering and Translational Nanobioscience Research Center, Sungkyunkwan University, Suwon, Republic of Korea.

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On the interactions between RNA and titrateable lipid layers: implications for RNA delivery with lipid nanoparticles

Characterising the interaction between cationic ionisable lipids (CIL) and nucleic acids (NAs) is key to understanding the process of RNA lipid nanoparticle (LNP) formation and release of NAs from LNPs. Here, we have used different surface techniques to reveal the effect of pH and NA type on the interaction with a model system of DOPC and the CIL DLin-MC3-DMA (MC3). At only 5% MC3, differences in the structure and dynamics of the lipid layer were observed. Both pH and %MC3 were shown to affect the absorption behaviour of erythropoietin mRNA, polyadenylic acid (polyA) and polyuridylic acid (polyU). The adsorbed amount of all studied NAs was found to increase with decreasing pH and increasing %MC3 but with different effects on the lipid layer, which could be linked to the NA secondary structure. For polyA at pH 6, adsorption to the surface of the layer was observed, whereas for other conditions and NAs, penetration of the NA into the layer resulted in the formation of a multilayer structure. By comparison to simulations excluding the secondary structure, differences in adsorption behaviours between polyA and polyU could be observed, indicating that the NA's secondary structure also affected the MC3-NA interactions.

Definitive Chemoradiation with Concurrent Carboplatin and Paclitaxel for HPV-Mediated Oropharyngeal Cancer (p16+ OPSCC): Survival and Local Control

PURPOSE/OBJECTIVE(S)

Standard therapy for locally advanced p16+ OPSCC with cisplatin and bilateral nodal RT results in substantial acute and late toxicities. De-intensification strategies are under active investigation, including the de-escalation of RT dose and field size and use of less toxic RT sensitizing agents. We present our single-institution experience with definitive chemoRT using weekly carboplatin and paclitaxel and modified RT.

MATERIALS/METHODS

A retrospective review of 139 consecutive patients with non-metastatic p16+ OPSCC treated with definitive chemoRT from 2013 to 2019 was performed. IMRT dose ranged from 60 to 70 Gy (median 69.96 Gy) to gross disease and 44 to 59.4 Gy (median 54.45 Gy) to elective nodal sites. Modified RT included dose reduction from 70 Gy EQD2 to 60-67.8 Gy EQD2 (2.0-2.2 Gy/fraction) and/or field modified contralateral neck. All patients received concurrent weekly paclitaxel (30 mg/m2) and carboplatin (AUC 1); 34 (24.5%) received induction chemotherapy. Patients were classified as low or intermediate risk based on HPV status, smoking history, and nodal staging per RTOG 0129 risk stratification. OS, local and regional RFS, and DSS were estimated using Kaplan-Meier method.

RESULTS

Median FU was 40.5 months. Of 139 pts, 96 were low and 43 were intermediate risk. Median age 61 yrs (range, 40-81 yrs). 125 pts were male and 14 were female. TNM staging: 29 pts (20.9%) were T1 (22 N1, 7 N2), 68 (48.9%) T2 (4 N0, 52 N1, 12 N2), 27 (19.4%) T3 (5 N0, 15 N1, 7 N2), and 15 (10.8%) T4 (2 N0, 2 N1, 10 N2, 1 N3). Median smoking history of 22.5 pack-yrs (range, 0.25-150 pack-yrs); 59 never smoked. LR recurrence was noted in 6/96 (6.3%) low risk and 7/43 (16.3%) intermediate risk pts. DM developed in 11/96 (11.5%) low risk and 8/43 (18.6%) intermediate risk pts. Synchronous LR recurrence and DM were noted in 1/96 (1%) low risk and 2/43 (4.7%) intermediate risk pts. The 3-year LRC was 93.6% (95% CI, 86.3-97.1) in the low-risk and 77.8% (95% CI, 61.4-87.8) in the intermediate-risk group. The 3-year OS was 95.4% (95% CI, 88.3-98.3) in the low-risk and 77.6% (95% CI, 61.3 to 87.7) in the intermediate-risk group. The 3-year DSS was 96.6% (95% CI, 89.7-98.9) in the low-risk and 86.8% (95% CI, 71.0-94.3) in the intermediate-risk group.

CONCLUSION

Definitive chemoRT for p16+ OPSCC with concurrent carboplatin and paclitaxel and a modified RT regimen designed to minimize acute and late effects of therapy demonstrated comparable outcomes to standard cisplatin-based chemoRT, such as report on RTOG 0129, with a high rate of LRC at 3 years. Our analysis suggests a role for a less intensive regimen using paclitaxel and carboplatin as a less toxic, effective alternative to cisplatin in the curative management of p16+ OPSCC, particularly in low-risk patients. Strategies for combating distant metastases are needed. Toxicity analysis planned to be presented separately.

Structural insights on ionizable Dlin-MC3-DMA lipids in DOPC layers by combining accurate atomistic force fields, molecular dynamics simulations and neutron reflectivity

Ionizable lipids such as the promising Dlin-MC3-DMA (MC3) are essential for the successful design of lipid nanoparticles (LNPs) as drug delivery agents. Combining molecular dynamics simulations with experimental data, such as neutron reflectivity experiments and other scattering techniques, is essential to provide insights into the internal structure of LNPs, which is not fully understood to date. However, the accuracy of the simulations relies on the choice of force field parameters and high-quality experimental data is indispensable to verify the parametrization. For MC3, different parameterizations in combination with the CHARMM and the Slipids force fields have recently emerged. Here, we complement the existing efforts by providing parameters for cationic and neutral MC3 compatible with the AMBER Lipid17 force field. Subsequently, we carefully assess the accuracy of the different force fields by providing a direct comparison to neutron reflectivity experiments of mixed lipid bilayers consisting of MC3 and DOPC at different pHs. At low pH (cationic MC3) and at high pH (neutral MC3) the newly developed MC3 parameters in combination with AMBER Lipid17 for DOPC give good agreement with the experiments. Overall, the agreement is similar compared to the Park-Im parameters for MC3 in combination with the CHARMM36 force field for DOPC. The Ermilova-Swenson MC3 parameters in combination with the Slipids force field underestimate the bilayer thickness. While the distribution of cationic MC3 is very similar, the different force fields for neutral MC3 reveal distinct differences ranging from strong accumulation in the membrane center (current MC3/AMBER Lipid17 DOPC), over mild accumulation (Park-Im MC3/CHARMM36 DOPC) to surface accumulation (Ermilova-Swenson MC3/Slipids DOPC). These pronounced differences highlight the importance of accurate force field parameters and their experimental validation.

Cation and buffer specific effects on the DNA-lipid interaction

Knowledge of DNA - lipid layer interactions is key for the development of biosensors, synthetic nanopores, scaffolds, and gene-delivery systems. These interactions are strongly affected by the ionic composition of the solvent. We have combined quartz crystal microbalance (QCM) and ellipsometry measurements to reveal how pH, buffers and alkali metal chloride salts affect the interaction of DNA with lipid bilayers (DOTAP/DOPC 30:70 in moles). We found that the thickness of the DNA layer adsorbed onto the lipid bilayer decreased in the order citrate > phosphate > Tris > HEPES. The effect of cations on the thickness of the DNA layer decreased in the order (K⁺ > Na⁺ > Cs⁺ ∼ Li⁺). Rationalization of the experimental results requires that adsorption, due to cation specific charge screening, is driven by the simultaneous action of two mechanisms namely, the law of matching water affinities for kosmotropes (Li⁺) and ion dispersion forces for chaotropes (Cs⁺). The outcome of these two opposing mechanisms is a ^"bell-shaped" specific cations sequence. Moreover, a superimposed buffer specificity, which goes beyond the simple effect of pH regulation, further modulated cation specificity. In summary, DNA-lipid bilayer interactions are maximized if citrate buffer (50 mM, pH 7.4) and KCl (100 mM) are used.

Can virtual reality technology be considered as a part of the surgical care pathway?

INTRODUCTION

Virtual reality (VR) is emerging as a new technology in the healthcare sector. It has been shown to enhance the patient's experience and satisfaction in various settings. This review aims to give a brief description of the use of VR and establish validity of its applications to improve the patient's pathway through surgery.

METHODS

A literature search was conducted using the PubMed and Embase™ databases to identify fields in which VR technology has been trialled in relation to surgery. The search terms 'virtual reality' and 'surgery' were employed.

RESULTS

Although benefits relating to VR use have been identified in mental health, obesity management, and physical and cognitive rehabilitation, those in surgery have been less well documented. There are, however, some important but limited benefits reported in managing surgery related stress and improving preoperative patient education as well as VR being an adjunct to some level of postoperative analgesia.

CONCLUSIONS

The current applications of VR in relation to surgical care fall into four main categories: preoperative education, supporting mental health, postoperative pain management, and pre and postoperative patient optimisation. Future studies and validation of VR applications should be carried out so the technology can be utilised throughout the entire patient pathway as VR surgical care bundles.

Effect of encapsulated protein on the dynamics of lipid sponge phase: a neutron spin echo and molecular dynamics simulation study

Lipid membranes are highly mobile systems with hierarchical, time and length scale dependent, collective motions including thickness fluctuations, undulations, and topological membrane changes, which play an important role in membrane interactions. In this work we have characterised the effect of encapsulating two industrially important enzymes, β-galactosidase and aspartic protease, in lipid sponge phase nanoparticles on the dynamics of the lipid membrane using neutron spin echo (NSE) spectroscopy and molecular dynamics (MD) simulations. From NSE, reduced membrane dynamics were observed upon enzyme encapsulation, which were dependent on the enzyme concentration and type. By fitting the intermediate scattering functions (ISFs) with a modified Zilman and Granek model including nanoparticle diffusion, an increase in membrane bending rigidity was observed, with a larger effect for β-galactosidase than aspartic protease at the same concentration. MD simulations for the system with and without aspartic protease showed that the lipids relax more slowly in the system with protein due to the replacement of the lipid carbonyl-water hydrogen bonds with lipid-protein hydrogen bonds. This indicates that the most likely cause of the increase in membrane rigidity observed in the NSE measurements was dehydration of the lipid head groups. The dynamics of the protein itself were also studied, which showed a stable secondary structure of protein over the simulation, indicating no unfolding events occurred.

Patient Preferences for Discussing and Acting on Health-Related Needs in Primary Care

Background:

Addressing social needs, health behaviors, and mental health may help patients more than traditional medical care. However, these root causes of poor health are difficult to address and the role of primary care is unclear. This qualitative study assesses patient’s willingness and motivations to discuss and accept assistance for these needs from their primary care team.

Methods:

In July and August of 2020, semi-structured virtual interviews were conducted with family medicine patients (n = 6) and residents of low resource neighborhoods (n = 11) in Richmond, Virginia. Interviews were conducted over Zoom. We conducted a qualitative analysis of patient and resident interview transcripts. A rapid qualitative analysis approach and immersion-crystallization processes were used to identify themes and categories.

Results:

Interviewees reported varying degrees of comfort discussing topics with their health care team. They were less comfortable discussing needs they considered outside the realm of “traditional primary care” including finances, transportation, and housing, but interviewees expressed willingness to discuss these needs under certain conditions. Important factors were a strong patient-clinician relationship to create a trusted and safe space for discussion, adequate time for discussion during visits, communication of practices’ ability to provide resources to help patients, and ensuring appropriate high quality referrals.

Conclusions:

Primary care provides opportunity for identifying and addressing needs that adversely impact health. Some needs are more sensitive for patients to work with their care team on, though, there was willingness to work on any need when a strong provider relationship and clinic structure for providing support were in place. This study highlights critical care delivery factors which may be used to enhance patient comfort accepting support for their needs and ultimately improve clinical care and chronic disease management.

379 Improving Flow: A Quality Improvement Project on The Processing of Vascular Surgical Microbiology Samples

Aim

Tissue samples taken during vascular surgical operations are commonly sent for microbiological analysis, owing to the relatively high incidence and serious consequences of infection in these cases. Delays in obtaining results from these samples can hinder clinical management, leading to prolonged inpatient stay and adverse clinical outcomes. The aim of this audit was to identify causes for delay in obtaining microbiology results and to improve the service.

Method

A closed loop quality improvement project performed at a tertiary vascular centre in London. We initially identified all tissue microbiology samples sent from vascular surgical operations performed during April 2019 and record the time when samples reach microbiology laboratory and the time when results were made available. Re-audit data was collected in November 2019.

Results

Initial audit showed that on average, results were available for clinicians 9.1 days after the sample was taken and 7.3 days after the sample had reached the laboratory. Samples required an average of 44 hours to transit to the laboratory and notably there is delay if surgery is performed on Friday (71 hours). Additionally, one sample was missing. Following utilization of the urgent sample pathway and raising awareness amongst staff, re-audit data showed significant reduction in average time of transit (33 hours) with much reduced transit time on Friday (36 hours). Results were available 7.7 days following sample date, compared to 9.1 days before.

Conclusions

Utilization of existing pathway and staff training can reduce delays in microbiology sample processing. However, further analysis is necessary to ensure sustained improvement.

653 DRAFFT Dodging? Fixation Methods for Distal Radial Fractures Since 2014 In A UK Trauma Unit

Introduction

The 2014 randomised, controlled Distal Radius Acute Fracture Fixation Trial (DRAFFT) compared K-wires to internal fixation for management of dorsally displaced distal radius fractures. The authors found no clinical difference between the two fixation methods, concluding ‘The results of this trial will reverse the trend towards locking-plate fixation for this injury’. Our study aimed to measure local change in practice since 2014.

Method

From the DRAFFT CONSORT diagram, we calculated just 10.7% of eligible cases required locking plate fixation. 300 patients, 50 per year from 2014-19 meeting DRAFFT eligibility criteria undergoing fixation, were randomly selected from an electronic trauma database. Radiographs were reviewed to see whether patients received internal fixation or K-wires.

Results

Age and sex distributions of the study sample were not significantly different to the DRAFFT population (p < 0.05). Over 60% of recruited patients received internal fixation each year. No increasing trend in use of K-wires was detected (p = 0.27). No trend was observed in either fixation method adjusting for intra versus extra-articular fractures (p = 0.36).

Conclusions

Local practice remains unchanged in fixation of dorsally displaced distal radius fractures since 2014. Internal fixation remains the most prevalent surgery, and there has been no detectable increase in use of K-wires.

Retention Strategies for Medications for Opioid Use Disorder in Adults: A Rapid Evidence Review

OBJECTIVES

Although medications for opioid use disorder (MOUD) save lives, treatment retention remains challenging. Identification of interventions to improve MOUD retention is of interest to policymakers and researchers. On behalf of the Agency for Healthcare Research and Quality, we conducted a rapid evidence review on interventions to improve MOUD retention.

METHODS

We searched MEDLINE and the Cochrane Library from February 2009 through August 2019 for systematic reviews and randomized trials of care settings, services, logistical support, contingency management, health information technology (IT), extended-release (XR) formulations, and psychosocial interventions that assessed retention at least 3 months.

RESULTS

Two systematic reviews and 39 primary studies were included; most did not focus on retention as the primary outcome. Initiating MOUD in soon-to-be-released incarcerated people improved retention following release. Contingency management may improve retention using antagonist but not agonist MOUD. Retention with interventions integrating medical, psychiatric, social services, or IT did not differ from in-person treatment-as-usual approaches. Retention was comparable with XR- compared to daily buprenorphine formulations and conflicting with XR-naltrexone monthly injection compared to daily buprenorphine. Most psychosocial interventions did not improve retention.

DISCUSSION

Consistent but sparse evidence supports criminal justice prerelease MOUD initiation, and contingency management interventions for antagonist MOUD. Integrating MOUD with medical, psychiatric, social services, delivering through IT, or administering via XR-MOUD formulations did not worsen retention. Fewer than half of the studies we identified focused on retention as a primary outcome. Studies used different measures of retention, making it difficult to compare effectiveness. Additional inquiry into the causes of low retention would inform future interventions.Registration: PROSPERO: CRD42019134739.

GalliForm, a database of Galliformes occurrence records from the Indo-Malay and Palaearctic, 1800-2008

Historical as well as current species distribution data are needed to track changes in biodiversity. Species distribution data are found in a variety of sources, each of which has its own distinct bias toward certain taxa, time periods or places. We present GalliForm, a database that comprises 186687 galliform occurrence records linked to 118907 localities in Europe and Asia. Records were derived from museums, peer-reviewed and grey literature, unpublished field notes, diaries and correspondence, banding records, atlas records and online birding trip reports. We describe data collection processes, georeferencing methods and quality-control procedures. This database has underpinned several peer-reviewed studies, investigating spatial and temporal bias in biodiversity data, species' geographic range changes and local extirpation patterns. In our rapidly changing world, an understanding of long-term change in species' distributions is key to predicting future impacts of threatening processes such as land use change, over-exploitation of species and climate change. This database, its historical aspect in particular, provides a valuable source of information for further studies in macroecology and biodiversity conservation.

Thin Layer Chromatographic Method for Determination of Deoxynivalenol in Wheat: Collaborative Study

A collaborative study of a rapid method for the determination of deoxynivalenol (DON) in winter wheat was successfully completed. The method involves sample extraction with acetonitrile-water (84 + 16), cleanup using a disposable column of charcoal, Celite, and alumina, and detection by thin layer chromatography after spraying with an aluminum chloride solution. Each of the 15 collaborators analyzed 12 samples, 2 of which were naturally contaminated, and 10 to which DON was added, in duplicate, at levels of 0,50,100,300, and 1000 ng/ g. Average recoveries of DON ranged from 78 to 96% with repeatabilities of 30-64% and reproducibilities of 33-87%. The results of the study show that false positives were not a problem and that all of the analysts could detect DON at the 300 ng/g level or higher. The method has been adopted official first action.

Periphyton bioconcentrates pesticides downstream of catchment dominated by agricultural land use

Periphyton provides important ecosystem services in aquatic environments, including supporting diverse consumers. We studied pesticide bioconcentration in periphyton in a coastal marsh on Lake Erie. The marsh is within a protected area (Rondeau Provincial Park) but receives discharge from tributaries draining intensively farmed land. Periphyton bioconcentrated 20 pesticide chemicals above levels observed in adjacent water or sediment. Average bioconcentration factors ranged from 12 times for the herbicide dicamba to 6864 times for the fungicide boscalid on a dry-weight basis. Bioconcentration factors were not linearly related to pesticides' log K_ow, log K_oc, or water solubility (simple linear regressions, p > 0.43). The removal of pesticides from ambient water represents another valuable ecosystem service provided by periphyton. However, we caution that bioconcentration of pesticides in periphyton provides a mechanism through which contemporary and legacy pesticides may enter wetland food webs.

Study of the Reproducibility Characteristics of a Liquid Chromatographic Method for the Determination of Fumonisins B1 and B2 in Corn: IUPAC Collaborative Study

An interlaboratory study of the reproducibility characteristics of a liquid chromatographic method for the determination of fumonisins B1 and B2 in corn was conducted in 11 laboratories in the United States, South Africa, Italy, Japan, United Kingdom, and The Netherlands. Each laboratory was supplied with 12 coded, blind duplicates of 6 samples of naturally contaminated corn containing different amounts of fumonisins B1 and B2 . Samples are extracted with methanol-water (3 + 1), extracts are centrifuged, and supernatants are cleaned up on strong-anion-exchange cartridges, which were supplied to participants. Solutions are derivatized with o-phthaldialdehyde, and individual fumonisins are determined by reversed-phase liquid chromatography with fluorescence detection. Quantitation is by comparison with the supplied fumonisin standards. The within-laboratory repeatability was determined by statistical analysis of data after exclusion of outliers. Relative standard deviations for within-laboratory repeatability varied from 7.7 to 25.5% for fumonisin B1 at concentrations between 200 and 2000 ng/g and from 12.5 to 36.8% for fumonisin B2 at concentrations between 70 and 740 ng/g. Relative standard deviations for betweenlaboratory reproducibility varied from 18.0 to 26.7% for fumonisin B1 and from 28.0 to 45.6% for fumonisin B2 at the concentrations mentioned above. These measures of variability indicate that the method is suitable for adoption as an official method provided that the accuracy characteristics are verified collaboratively.

Low-fat/high-fibre diet prehabilitation improves anastomotic healing via the microbiome: an experimental model

BACKGROUND

Both obesity and the presence of collagenolytic bacterial strains (Enterococcus faecalis) can increase the risk of anastomotic leak. The aim of this study was to determine whether mice chronically fed a high-fat Western-type diet (WD) develop anastomotic leak in association with altered microbiota, and whether this can be mitigated by a short course of standard chow diet (SD; low fat/high fibre) before surgery.

METHODS

Male C57BL/6 mice were assigned to either SD or an obesogenic WD for 6 weeks followed by preoperative antibiotics and colonic anastomosis. Microbiota were analysed longitudinally after operation and correlated with healing using an established anastomotic healing score. In reiterative experiments, mice fed a WD for 6 weeks were exposed to a SD for 2, 4 and 6 days before colonic surgery, and anastomotic healing and colonic microbiota analysed.

RESULTS

Compared with SD-fed mice, WD-fed mice demonstrated an increased risk of anastomotic leak, with a bloom in the abundance of Enterococcus in lumen and expelled stool (65-90 per cent for WD versus 4-15 per cent for SD; P = 0·010 for lumen, P = 0·013 for stool). Microbiota of SD-fed mice, but not those fed WD, were restored to their preoperative composition after surgery. Anastomotic healing was significantly improved when WD-fed mice were exposed to a SD diet for 2 days before antibiotics and surgery (P < 0·001).

CONCLUSION

The adverse effects of chronic feeding of a WD on the microbiota and anastomotic healing can be prevented by a short course of SD in mice. Surgical relevance Worldwide, enhanced recovery programmes have developed into standards of care that reduce major complications after surgery, such as surgical-site infections and anastomotic leak. A complementary effort termed prehabilitation includes preoperative approaches such as smoking cessation, exercise and dietary modification. This study investigated whether a short course of dietary prehabilitation in the form of a low-fat/high-fibre composition can reverse the adverse effect of a high-fat Western-type diet on anastomotic healing in mice. Intake of a Western-type diet had a major adverse effect on both the intestinal microbiome and anastomotic healing following colonic anastomosis in mice. This could be reversed when mice received a low-fat/high-fibre diet before operation. Taken together, these data suggest that dietary modifications before major surgery can improve surgical outcomes via their effects on the intestinal microbiome.

Correction to: Effects of New Zealand blackcurrant extract on sport climbing performance

The authors would like to correct the following errors in the online publication of the article. Incorrect values for % changes for climb duration were provided in the abstract, results and discussion session. The  % changes in climb duration was 15% with intake of New Zealand blackcurrant extract and -15% for the placebo condition. This correction does not change the conclusions derived from the study.

Immobilisation of β-galactosidase within a lipid sponge phase: structure, stability and kinetics characterisation

In the formulation of an active enzyme enclosed in a matrix for controlled delivery, it is a challenge to achieve a high protein load and to ensure high activity of the protein. For the first time to our knowledge, we report the use of a highly swollen lipid sponge (L₃) phase for encapsulation of the large active enzyme, β-galactosidase (β-gal, 238 kDa). This enzyme has large relevance for applications in, e.g. the production of lactose free milk products. The formulation consisted of diglycerol monooleate (DGMO), and a mixture of mono-, di- and triglycerides (Capmul GMO-50) stabilised by polysorbate 80 (P80). The advantage of this type of matrix is that it can be produced on a large scale with a fairly simple and mild process as the system is in practice self-dispersing, yet it has a well-defined internal nano-structure. Minor effects on the sponge phase structure due to the inclusion of the enzyme were observed using small angle X-ray scattering (SAXS). The effect of encapsulation on the enzymatic activity and kinetic characteristics of β-galactosidase activity was also investigated and can be related to the enzyme stability and confinement within the lipid matrix. The encapsulated β-galactosidase maintained its activity for a significantly longer time when compared to the free solution at the same temperature. Differences in the particle size and charge of sponge-like nanoparticles (L₃-NPs) with and without the enzyme were analysed by dynamic light scattering (DLS) and zeta-potential measurements. Moreover, all the initial β-galactosidase was encapsulated within L₃-NPs as revealed by size exclusion chromatography.

Effects of New Zealand blackcurrant extract on sport climbing performance

PURPOSE

Blood flow to skeletal muscles and removal of metabolic by-products during a sport climb are essential to optimise performance and recovery. New Zealand blackcurrant (NZBC) extract has enhanced blood flow and performance in other exercise modalities. We examined the effect of NZBC extract on sport climbing performance and recovery.

METHODS

The study employed a double-blind, randomised, crossover design. Male sport climbers (n = 18, age 24 ± 6 years, height 179 ± 6 cm, mass 71.4 ± 7.8 kg, French grade 6a-8b) undertook 7 days supplementation of NZBC extract (600 mg day^-1 CurraNZ™ containing 210 mg anthocyanins) or a placebo (PL). Climbing ability was assessed through hang time (HT), pull-ups and total climbing time (TCT) in 3 intermittent climbing bouts on a Treadwall M6 rotating climbing wall to exhaustion with 20 min recovery between climbs. Heart rate (HR), blood lactate (BL), forearm girth (FG) and hand grip strength (HGS) were recorded.

RESULTS

NZBC extract had no effect on pull-ups but provided a trend for higher HT and significantly improved TCT (+23%) compared to PL (-11%) over three climbs. HR, BL, FG and HGS all indicated that 20 min was insufficient for physiological recovery between the three climbing bouts indicating accumulative fatigue regardless of supplement condition.

CONCLUSION

Despite indices of progressive fatigue across three bouts of climbing, NZBC extract facilitated not only a maintenance of TCT but an improved climbing endurance as compared with the PL condition. Blackcurrant anthocyanin-derived metabolites seem to affect physiological responses that facilitate sport climbing performance.

Improving Quality of Radiotherapy Care Across Ontario Using a Community of Practice Approach

Background: Communities of Practice (CoPs) are defined as “a group of people who share a concern, a set of problems, or a passion about a topic, and who deepen their knowledge and expertise by interacting on an ongoing basis”. This concept was developed by Wegner and Lave in 1991, based on the theory that learning is more than just acquiring knowledge, but rather involves being socialized into a practice and developing an identity within a community. Cancer Care Ontario (CCO) is the provincial governments advisor on the cancer system and this work documents CCO's use of CoPs to help advance the quality of care in radiotherapy in Ontario, Canada. Aim: After the divestment of radiotherapy care from a centralised structure into individual hospitals in 2003/2004, there was a marked decrease in communication between the 14 Regional Cancer Centres (RCCs) in Ontario. As a means to rebuild the sense of community among radiation medicine programs (encompassing oncologists, physicists and radiation therapists), and to facilitate communication between the RCCs, the Radiation Treatment Program (RTP) at CCO developed and organized a CoP program. The three aims were knowledge creation, knowledge transfer and exchange (KTE), and community building. The ultimate goal was to improve the safety and quality of radiotherapy by reducing variation in practice between centers. Methods: Seven CoPs have been established since 2010; 3 are disease specific (head and neck, gynecologic and lung cancers) with multidisciplinary representation from oncologists, physicists, and radiation therapists. The other 4 CoPs are single-discipline (radiation therapy, physics, radiation safety officers, clinical specialist radiation therapists) to allow for practice specific knowledge-sharing and innovation. All CoPs are led and driven by volunteer members who identify and prioritize key quality issues and select corresponding projects to pursue. Results: CCO's CoPs have produced several knowledge products, including endorsed clinical guidance documents (5), and practical implementation tools (5), with over 20 additional products currently in development. Members have delivered numerous international and national KTE presentations and hosted 51 workshops. CoP guidance documents have 1: Improved safety ( “Implementation Strategy for Radiation Safety Straps” with 100% implementation across RCCs) 2: Standardized care ( “Contouring Nomenclature - Head and Neck Cancer”) with adoption of recommendations province-wide 3: Supported infrastructure improvements (“ MRI Simulation guideline document”). Conclusion: Overall, the RTP's CoP program has been effective in achieving its main three aims: knowledge creation, KTE, and community building. This approach of a member-driven voluntary CoP should be explored and modeled in other healthcare settings as a means to develop and share knowledge, reduce variation in care, standardize practice and improve patient care.

Vocal tract modelling in fallow deer: are male groans nasalized?

Males of several species of deer have a descended and mobile larynx, resulting in an unusually long vocal tract, which can be further extended by lowering the larynx during call production. Formant frequencies are lowered as the vocal tract is extended, as predicted when approximating the vocal tract as a uniform quarter wavelength resonator. However, formant frequencies in polygynous deer follow uneven distribution patterns, indicating that the vocal tract configuration may in fact be rather complex. We CT-scanned the head and neck region of two adult male fallow deer specimens with artificially extended vocal tracts and measured the cross-sectional areas of the supra-laryngeal vocal tract along the oral and nasal tracts. The CT data were then used to predict the resonances produced by three possible configurations, including the oral vocal tract only, the nasal vocal tract only, or combining the two. We found that the area functions from the combined oral and nasal vocal tracts produced resonances more closely matching the formant pattern and scaling observed in fallow deer groans than those predicted by the area functions of the oral vocal tract only or of the nasal vocal tract only. This indicates that the nasal and oral vocal tracts are both simultaneously involved in the production of a non-human mammal vocalization, and suggests that the potential for nasalization in putative oral loud calls should be carefully considered.

Rapid Evidence Review of Mobile Applications for Self-management of Diabetes

BACKGROUND

Patients with diabetes lack information on which commercially available applications (apps) improve diabetes-related outcomes. We conducted a rapid evidence review to examine features, clinical efficacy, and usability of apps for self-management of type 1 and type 2 diabetes in adults.

METHODS

Ovid/Medline and the Cochrane Database of Systematic Reviews were searched for systematic reviews and technology assessments. Reference lists of relevant systematic reviews were examined for primary studies. Additional searches for primary studies were conducted online, through Ovid/Medline, Embase, CINAHL, and ClinicalTrials.gov . Studies were evaluated for eligibility based on predetermined criteria, data were extracted, study quality was assessed using a risk of bias tool, information on app features was collected, and app usability was assessed. Results are summarized qualitatively.

RESULTS

Fifteen articles evaluating 11 apps were identified: six apps for type 1 and five apps for type 2 diabetes. Common features of apps included setting reminders and tracking blood glucose and hemoglobin A1c (HbA1c), medication use, physical activity, and weight. Compared with controls, use of eight apps, when paired with support from a healthcare provider or study staff, improved at least one outcome, most often HbA1c. Patients did not experience improvements in quality of life, blood pressure, or weight, regardless of app used or type of diabetes. Study quality was variable. Of the eight apps available for usability testing, two were scored "acceptable," three were "marginal," and three were "not acceptable."

DISCUSSION

Limited evidence suggests that use of some commercially available apps, when combined with additional support from a healthcare provider or study staff, may improve some short-term diabetes-related outcomes. The impact of these apps on longer-term outcomes is unclear. More rigorous and longer-term studies of apps are needed.

REGISTRATION

This review was funded by the Agency for Healthcare Research and Quality (AHRQ). The protocol is available at: http://www.effectivehealthcare.ahrq.gov/topics/diabetes-mobile-devices/research-protocol .

Adrenal insufficiency, steroid sick day rules and the paediatric endocrine nurse

Clinical governance processes are important for improving patient care. Patients with adrenal insufficiency are at significant risk if they have an adrenal crisis and require steroid therapy. Families should receive education on managing illness or stress, that is, steroid sick day rules. Most of this education is delivered by children's nurses. Two local cases of mortality related to adrenal insufficiency were reviewed and a questionnaire audit was undertaken to compare the steroid sick day rules education provided to patients and their families with published standards. Most training (75%) was delivered by nurses. Most families/patients (94%) had received written information on oral dosing for steroid sick day rules, and were confident about when/how to double up oral steroid doses (78%). Fewer families recalled being given written information about the emergency hydrocortisone injection (53%), and fewer were confident about how to give the injection (46%). Several important changes and modifications to clinical practice have been implemented in response to the clinical governance findings. These include setting up notification 'red flags' on patients' electronic records and holding specialist family teaching sessions on steroid sick day rules.

Characteristics of Referrals to an Inpatient Hospice and a Survey of General Practitioner Perceptions of Palliative Care

In order to determine symptoms, drug prescribing and physical problems of patients referred to an inpatient hospice, case notes from 130 consecutive first admissions (95 general practitioner (GP) referrals, 35 consultant referrals) were analysed. GP referrals were more likely to be constipated, require care and be discharged to home. Consultant referrals were more gravely ill, dependent and more likely to die in the hospice. On admission 76 (58%) patients were receiving opiates with co-prescription of opiate and laxative occurring in 41 % (31/76) of the cases. The prescription of laxatives with the symptoms of constipation occurred in 62% (26/42) of the cases on admission. A telephone survey of 79 referring GPs revealed that 37% had attended neither a course nor a lecture relevant to palliative care in the past 3 years. GPs experienced difficulties frequently or always in: (a) managing pain (8/79); (b) managing other symptoms (25/79); (c) helping patients and relatives cope with their emotional distress (18/79); and (d) coping with their own emotional responses to death and dying (5/79).

In conclusion, the differences demonstrated between the GP and consultant referrals have implications for purchasers. The high incidence of possible opiate-induced side-effects and the difficulties with symptom control expressed by some GPs indicate a continuing need for effective educational input.

Abstract P3-05-06: Prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and its relation to stromal tumor infiltrating lymphocytes (sTILs) in triple negative breast cancer (TNBC)

Background: While TNBC remains the most aggressive type of breast cancer (BC), substantial heterogeneity in biology and outcomes exists among TNBC subtypes. Historically, risk stratification of TNBC has been based on anatomic factors such as tumor size, nodal involvement and presence of distant metastases. However, these features alone fail to accurately predict outcomes. Tumor immune infiltration (sTILs) and distribution of immune cell subsets in the perip heral blood (NLR) have emerged as variables reported to be associated with outcomes in TNBC. We sought to evaluate whether NLR and sTILs provided independent prognostic information in TNBC.

Methods: From a cohort of 9,982 women who underwent BC surgery at Mayo Clinic, Rochester, MN between Jan 1985 and Dec 2012, we identified 605 centrally-confirmed TNBC tumors. Patients (pts) with prior BC, bilateral BC, non-invasive disease, stage IV, neoadjuvant therapy, endocrine therapy, or adenoid cystic histology were excluded. For eligible tumors, clinical and pathologic variables were evaluated, including peripheral blood NLR and central assessment of sTILs per the 2014 International TILs Working Group recommendations. We calculated the Pearson correlation coefficient (PCC) between NLR and sTILs and constructed Cox Proportional Hazards Models to evaluate their association with invasive-disease free (IDFS) and overall survival (OS). NLR and sTILs were both analyzed as continuous variables.

Results: Most pts had T1-2 (95%) and N0-1 disease (86%). Median OS follow-up was 10.6yrs. Median IDFS was 12yrs (95%CI 10.2-16.7) and median OS was 18.8yrs (95%CI 15.6-20.8). NLR and sTILs were available in 408 and 599 pts, respectively. The median NLR and sTIL content were 2.29 (0.14-10.50) and 20% (0-90%), respectively. NLR and sTILs were poorly correlated (PCC 0.0237). On univariate analysis (UVA), a higher NLR was associated with worse IDFS (HR 1.13; 95%CI 1.02-1.26, p=0.02) and OS (HR 1.17; 95%CI 1.04-1.31, p=0.01). Each 1% increment in sTILs was associated with improved IDFS (HR 0.99; 95%CI 0.98-0.99, p&lt;0.001) and OS (HR 0.99, 95%CI 0.98-1.00, p&lt;0.001). Among pts with high sTILs (≥20%), a higher NLR remained significantly associated with worse IDFS (HR 1.21; 95%CI 1.05-1.38, p=0.007) and OS (HR 1.25; 95%CI 1.09-1.44, p=0.001). In contrast, among pts with low sTILs (&lt;20%), NLR was not associated with IDFS (HR 1.07; 95%CI 0.89-1.28, p=0.49) or OS (HR 1.07; 95%CI 0.88-1.30, p=0.49). The interaction test between NLR and sTILs did not reach statistical significance. A multivariate analysis (MVA; including age, menopausal status, histologic subtype, grade, tumor size, nodal stage, Ki-67, NLR, sTILs, adjuvant chemotherapy, type of surgery and adjuvant radiation) showed that sTILs remained independently associated with IDFS (HR 0.99, 95%CI 0.97-1.0, p=0.019) and OS (HR 0.99, 95% CI 0.97-1.0, p=0.044), whereas NLR did not.

Conclusions: A lower NLR and a higher sTIL content were each associated with improved IDFS and OS among pts with nonmetastatic TNBC on UVA. However, when evaluated on a MVA, only sTILs remained independently associated with IDFS and OS. Our data suggest that the effect of sTILs on outcomes may not be modified by the NLR.

Citation Format: Leon-Ferre RA, Polley M-Y, Liu H, Gilbert J, Cafourek V, Hillman D, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari K, Couch FJ, Visscher DW, Goetz MP. Prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and its relation to stromal tumor infiltrating lymphocytes (sTILs) in triple negative breast cancer (TNBC) [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 P3-05-06.

Abstract P1-06-07: Mayo clinic TNBC outcome calculator: A clinical calculator to predict disease relapse and survival in women with triple-negative breast cancer

Purpose: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype with substantial risks of disease recurrence. While cytotoxic chemotherapy is commonly administered and reduces recurrence, disease outcomes vary considerably and few prognostic tools are available for risk stratification for TNBC patients. We constructed and validated clinical calculators for invasive-disease free survival (IDFS) and overall survival (OS) for TNBC and compared their performance against AJCC-based models which include only tumor size and nodal status.

Methods: From a surgical cohort of 9,982 patients who underwent breast cancer surgery at Mayo Clinic between January 1985 and December 2012, 605 centrally reviewed TNBC patients were identified and used to construct Cox models for IDFS and OS. Patients treated with neoadjuvant chemotherapy were excluded. Variables considered included age, menopausal status, tumor size, nodal status, Nottingham grade, type of breast surgery (mastectomy vs. lumpectomy), adjuvant radiation therapy, adjuvant chemotherapy, Ki67, stromal tumor infiltrating lymphocytes (sTILs), and neutrophil-to-lymphocyte ratio (NLR). Missing values were imputed using single imputation with all variables (including outcomes) included in the imputation model. Backward step-down procedure was used for model selections. The final models were internally validated for calibration and discrimination using bootstrapping methods and compared with AJCC-based models.

Results: For both IDFS and OS, higher sTIL's, less extensive nodal involvement, use of adjuvant chemotherapy, and lower NLR were significant predictors of improved clinical outcomes. Premenopausal status and younger age were additionally predictive of improved IDFS and OS, respectively. Models for IDFS and OS have good calibration and are associated with bias-corrected C-indices of 0.68 and 0.71, respectively, as compared with C-indices of 0.59 and 0.62 for AJCC-based models.

Conclusions: Our data indicate that a clinical calculator that includes sTIL's, NLR, menopausal status, age, nodal involvement as well as chemotherapy use can provide significantly greater prediction of clinical risk than tumor size and nodal status alone. These tools may be used to identify TNBC patients at elevated risk of disease relapse and to aid physician's communication with patients regarding their long-term disease outlook and planning treatment strategies. External validation is required to further evaluate broader applicability of this tool, which was developed utilizing a single-institutional experience.

Citation Format: Polley M-YC, Leon-Ferre RA, Liu H, Gilbert J, Cafourek V, Hillman DW, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari K, Couch F, Visscher DW, Goetz MP. Mayo clinic TNBC outcome calculator: A clinical calculator to predict disease relapse and survival in women with triple-negative breast cancer [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 P1-06-07.

The rise and potential fall of pancreas transplantation

BACKGROUND

The aim of this review is to bring pancreatic transplantation out of the specialist realm, informing practitioners about this important procedure, so that they feel better equipped to refer suitable patients for transplantation and manage, counsel and support when encountering them within their own speciality.

SOURCES OF DATA

Narrative review conducted in May 2017. OVID interface searching EMBASE and MEDLINE databases, using Timeframe: Inception to June 1, 2017. Articles were assessed for clinical relevance and most up to date content with articles written in english as the only inclusion criteria. Other sources, used included conference proceedings/presentations, unpublished data from our institution (Oxford Transplant Centre).

AREAS OF AGREEMENT

Pancreas transplantation has evolved from an experimental procedure to the gold standard of care for patients with type 1 diabetes and uraemia. Currently, it remains the most effective method of establishing and maintaining euglycemia over the longer term, halting and potentially reversing many of the secondary complications associated with diabetes. Significant improvements to quality of life and better life expectancy make it in the longer term, a lifesaving procedure compared to waiting candidates.

AREAS OF CONTROVERSY

The future of solid organ pancreas transplantation remains uncertain, with extensive comorbidity and advances in alternative therapies makes the long-term growth of the procedure questionable.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

Therapies to alleviate problems associated with ischaemia reperfusion injury, graft pancreatitis and more effective monitoring methods for detecting and treating organ rejection are the key areas of growth.

Validation of Molecular Markers for Use With Adapted Sources of Fusarium Head Blight Resistance in Wheat

Genetic control of resistance to Fusarium head blight (FHB) is quantitative, making phenotypic selection difficult. Genetic markers to resistance are helpful to select favorable genotypes. This study was conducted to determine if Fhb1 and Fhb5 present in the Sumai 3 source of FHB resistance occur in Sumai 3-derived North American spring wheat cultivars and to understand the appropriateness of using markers to select for the favorable alleles at these loci in breeding. Sumai 3-derived parents Alsen, ND3085, ND744, Carberry, and Glenn were used in crosses to generate 14 doubled haploid breeding populations. The parents and progeny were genotyped with five Fhb1 and three Fhb5 microsatellite markers. Progeny were selected based on performance relative to parents and other control cultivars in FHB nurseries near Portage la Prairie and Carman, MB. χ² and t test analyses were performed on marker and FHB data. The χ² test frequently determined the proportion of lines carrying molecular variants associated with FHB resistance increased following nursery selection for FHB. Similarly, the t test regularly demonstrated that selection for FHB resistance lowered the mean level of disease associated with resistant marker haplotypes. The study affirmed FHB resistance sources Alsen, Carberry, ND3085, and ND744 have Fhb1 and Fhb5 loci like Sumai 3, but no evidence was found that Glenn carries Fhb1 and Fhb5 resistance alleles. The results justified use of Fhb1 and Fhb5 markers for marker assisted selection in populations derived from Alsen, Carberry, ND3085, and ND744, but not Glenn. Combined or individual application of Xgwm493 and Xgwm533 in selection of genotypes carrying Fhb1, and Xgwm150, Xgwm304, and Xgwm595 for Fhb5 will enhance FHB resistance in wheat.

Transplantation of Kidneys From Donors With Acute Kidney Injury: Friend or Foe?

The gap between supply and demand in kidney transplantation has led to increased use of marginal kidneys; however, kidneys with acute kidney injury are often declined/discarded. To determine whether this policy is justified, we analyzed outcomes of donor kidneys with acute kidney injury (AKI) in a large UK cohort. A retrospective analysis of the UK Transplant Registry evaluated deceased donors between 2003 and 2013. Donors were classified as no AKI, or AKI stage 1-3 according to Acute Kidney Injury Network (AKIN) criteria. Relationship of AKI with delayed graft function/primary nonfunction (DGF/PNF), estimated glomerular filtration rate (eGFR), and graft-survival at 90 days and 1 year was analyzed. There were 11 219 kidneys (1869 [17%] with AKI) included. Graft failure at 1 year is greater for donors with AKI than for those without (graft survival 89% vs. 91%, p = 0.02; odds ratio (OR) 1.20 [95% confidence interval (CI): 1.03-1.41]). DGF rates increase with donor AKI stage (p < 0.005), and PNF rates are significantly higher for AKIN stage 3 kidneys (9% vs. 4%, p = 0.04) Analysis of association between AKI and recipient eGFR suggests a risk of inferior eGFR with AKI versus no AKI (p < 0.005; OR 1.25 [95% CI: 1.08-1.31]). We report a small reduction in 1-year graft-survival of kidneys from donors with AKI. We conclude that AKI stage 1 or 2 kidneys should be used; however, caution is advised for AKI stage 3 donors.

Safe food and feed through an integrated toolbox for mycotoxin management: the MyToolBox approach

There is a pressing need to mobilise the wealth of knowledge from the international mycotoxin research conductedover the past 25-30 years, and to perform cutting-edge research where knowledge gaps still exist. This knowledgeneeds to be integrated into affordable and practical tools for farmers and food processors along the chain inorder to reduce the risk of mycotoxin contamination of crops, feed and food. This is the mission of MyToolBox – a four-year project which has received funding from the European Commission. It mobilises a multi-actorpartnership (academia, farmers, technology small and medium sized enterprises, food industry and policystakeholders) to develop novel interventions aimed at achieving a significant reduction in crop losses due tomycotoxin contamination. Besides a field-to-fork approach, MyToolBox also considers safe use options ofcontaminated batches, such as the efficient production of biofuels. Compared to previous efforts of mycotoxin reduction strategies, the distinguishing feature of MyToolBox is to provide the recommended measures to theend users along the food and feed chain in a web-based MyToolBox platform (e-toolbox). The project focuseson small grain cereals, maize, peanuts and dried figs, applicable to agricultural conditions in the EU and China. Crop losses using existing practices are being compared with crop losses after novel pre-harvest interventionsincluding investigation of genetic resistance to fungal infection, cultural control (e.g. minimum tillage or cropdebris treatment), the use of novel biopesticides suitable for organic farming, competitive biocontrol treatment and development of novel modelling approaches to predict mycotoxin contamination. Research into post-harvestmeasures includes real-time monitoring during storage, innovative sorting of crops using vision-technology, novelmilling technology and studying the effects of baking on mycotoxins at an industrial scale.

Abstract 4168: Mig-6 ablation cooperates with oncogenic Kras in promoting mouse lung tumorigenesis

Lung tumorigenesis is a stochastic multistep process, during which different gene mutations accumulate, and Kras is an oncogene with the most frequent mutation in the Caucasian lung adenocarcinoma. Although Mig-6 (mitogen-inducible gene 6) has been shown to be a tumor suppressor gene in lung, skin and uterus, the interplay between Mig-6 and Kras in lung tumorigenesis remains elusive. Here, we found Mig-6 expression was down-regulated in oncogenic KrasG12D-induced lung tumors and Mig-6d/dKrasG12D mice showed an earlier onset of pulmonary tumor development and a significantly reduced life span as compared to KrasG12D mice though no obvious lung phenotype was observed in Mig-6d/d mice. Meanwhile, ablation of Mig-6 can change the lung epithelial cell fate in KrasG12D mice. Furthermore, lung tumor tissues of Mig-6d/dKrasG12D mice showed decreased cellular apoptosis, elevated EGF/Akt signaling and increased severity of inflammation as compared to those of KrasG12D mice. Thus, ablation of Mig-6 cooperated with oncogenic Kras in promoting lung tumorigenesis and this novel murine model of lung cancer can be applied for future study.

Citation Format: Jian Liu, Sung-Nam Cho, Nili Jin, Seyed Javad Moghaddam, Jennifer Gilbert, Ignacio Wistuba, Francesco J. DeMayo. Mig-6 ablation cooperates with oncogenic Kras in promoting mouse lung tumorigenesis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4168.