The novel application of the Lightning Process to treat Long COVID in primary care - Case report

As a result of the COVID-19 pandemic, Long COVID (LC) is now prevalent in many countries. Little evidence exists regarding how this chronic condition should be treated, but guidelines suggest for most people it can be managed symptomatically in primary care. The Lightning Process is a trademarked positive psychology focused self-management programme which has shown to be effective in reducing fatigue and accompanying symptoms in other chronic conditions including Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. Here we outline its novel application to two patients with LC who both reported improvements in fatigue and a range of physical and emotional symptoms post-treatment and at 3 months follow-up.

The Royal College of Surgeons of England Damage Control Orthopaedic Trauma Skills course (DCOTS): resuscitative knowledge and confidence in surgical skills are reliably maintained at six months post course

INTRODUCTION

Since 2012, the Damage Control Orthopaedic Trauma Skills course (DCOTS) has trained more than 250 surgeons in the principles and practice of damage control orthopaedics and early appropriate care. This Royal College of Surgeons of England (RCS England) course takes place at the RCS England Partner cadaver laboratory at Brighton and Sussex Medical School. Trauma is a leading cause of morbidity and mortality in the UK, and the course has tried to pass on the lessons of war and conflict from its military faculty and hard-won lessons of "developed world" trauma from its experienced civilian faculty.

METHODS

Participating surgeons were invited to score their self-reported confidence before attending the DCOTS course, immediately afterwards and again 6 months later. A modified four-point Likert scale was used, with responses from 1 = No Confidence to 4 = Very Confident. Damage control resuscitation principles with damage control surgery showed the greatest retained increase at 6 months - 100% - which is extremely satisfying.

RESULTS

Self-reported confidence in pelvic external fixation was initially 93% dropping to 85%, which is also considered good to excellent. For pelvic packing, confidence was 90% at the end of the course, up from 19% precourse. This dropped to 62%, which was still considered good but low for the high standards of the course. This may relate to UK trainees' lack of familiarity with the concept.

CONCLUSIONS

Three of the main skills taught on the DCOTS are effectively retained at 6 months post course.

ACLR and military service: time to rethink?

Anterior cruciate ligament (ACL) rupture is a common injury that affects young, active individuals, normally managed with reconstruction in this age group. Current UK Armed Forces policy precludes prospective applicants from joining with an anterior cruciate ligament reconstruction (ACLR). This isdue to the perceived risk of premature osteoarthritis (OA), graft rupture or clinical failure, all of which could make the service person medically non-deployable.The most recent evidence shows that an ACL rupture without associated significant meniscal or osteochondral defect has a similar likelihood of developing OA as to that of the uninjured knee after reconstruction at 20 years postoperatively.Applicants should be considered for service following an ACL rupture without significant concurrent meniscal or osteochondral defect who have undergone ACLR and 18 months of rehabilitation. We recommend these applicants to be graded P2 Medically Fully Deployable (MFD) as per the Joint Service Publication (JSP) guidance for service personnel who undergo ACLR.

Scale-up of the Internet-based Professional Learning to help teachers promote Activity in Youth (iPLAY) intervention: a hybrid type 3 implementation-effectiveness trial

BACKGROUND

Whole-of-school programs have demonstrated success in improving student physical activity levels, but few have progressed beyond efficacy testing to implementation at-scale. The purpose of our study was to evaluate the scale-up of the 'Internet-based Professional Learning to help teachers promote Activity in Youth' (iPLAY) intervention in primary schools using the RE-AIM framework.

METHODS

We conducted a type 3 hybrid implementation-effectiveness study and collected data between April 2016 and June 2021, in New South Wales (NSW), Australia. RE-AIM was operationalised as: (i) Reach: Number and representativeness of students exposed to iPLAY; (ii) Effectiveness: Impact of iPLAY in a sub-sample of students (n = 5,959); (iii) Adoption: Number and representativeness of schools that received iPLAY; (iv) Implementation: Extent to which the three curricular and three non-curricular components of iPLAY were delivered as intended; (v) Maintenance: Extent to which iPLAY was sustained in schools. We conducted 43 semi-structured interviews with teachers (n = 14), leaders (n = 19), and principals (n = 10) from 18 schools (11 from urban and 7 from rural locations) to determine program maintenance.

RESULTS

Reach: iPLAY reached ~ 31,000 students from a variety of socio-economic strata (35% of students were in the bottom quartile, almost half in the middle two quartiles, and 20% in the top quartile).

EFFECTIVENESS

We observed small positive intervention effects for enjoyment of PE/sport (0.12 units, 95% CI: 0.05 to 0.20, d = 0.17), perceptions of need support from teachers (0.26 units, 95% CI: 0.16 to 0.53, d = 0.40), physical activity participation (0.28 units, 95% CI: 0.10 to 0.47, d = 0.14), and subjective well-being (0.82 units, 95% CI: 0.32 to 1.32, d = 0.12) at 24-months. Adoption: 115 schools received iPLAY.

IMPLEMENTATION

Most schools implemented the curricular (59%) and non-curricular (55%) strategies as intended. Maintenance: Based on our qualitative data, changes in teacher practices and school culture resulting from iPLAY were sustained.

CONCLUSIONS

iPLAY had extensive reach and adoption in NSW primary schools. Most of the schools implemented iPLAY as intended and effectiveness data suggest the positive effects observed in our cluster RCT were sustained when the intervention was delivered at-scale.

TRIAL REGISTRATION

ACTRN12621001132831.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

ImmunoCluster provides a computational framework for the nonspecialist to profile high-dimensional cytometry data

High-dimensional cytometry is an innovative tool for immune monitoring in health and disease, and it has provided novel insight into the underlying biology as well as biomarkers for a variety of diseases. However, the analysis of large multiparametric datasets usually requires specialist computational knowledge. Here, we describe ImmunoCluster (https://github.com/kordastilab/ImmunoCluster), an R package for immune profiling cellular heterogeneity in high-dimensional liquid and imaging mass cytometry, and flow cytometry data, designed to facilitate computational analysis by a nonspecialist. The analysis framework implemented within ImmunoCluster is readily scalable to millions of cells and provides a variety of visualization and analytical approaches, as well as a rich array of plotting tools that can be tailored to users' needs. The protocol consists of three core computational stages: (1) data import and quality control; (2) dimensionality reduction and unsupervised clustering; and (3) annotation and differential testing, all contained within an R-based open-source framework.

A systematic review of the evidence base for the Lightning Process

BACKGROUND

The Lightning Process (LP), a mind-body training programme, has been applied to a range of health problems and disorders. Studies and surveys report a range of outcomes creating a lack of clarity about the efficacy of the intervention.

OBJECTIVE

This systematic review evaluates the methodological quality of existing studies on the LP and collates and reviews its reported efficacy.

DATA SOURCES

Five databases, PsycINFO, PubMed, CINAHL, Embase, ERIC (to September 2018), and Google and Google Scholar were searched for relevant studies.

STUDY SELECTION

Studies of the LP in clinical populations published in peer-reviewed journals or in grey literature were selected. Reviews, editorial articles and studies/surveys with un-reported methodology were excluded.

DATA EXTRACTION

Searches returned 568 records, 21 were retrieved in full text of which 14 fulfilled the inclusion criteria (ten quantitative studies/surveys and four qualitative studies).

DATA SYNTHESIS AND CONCLUSIONS

The review identified variance in the quality of studies across time; earlier studies demonstrated a lack of control groups, a lack of clarity of aspects of the methodology and potential sampling bias. Although it found a variance in reported patient outcomes, the review also identified an emerging body of evidence supporting the efficacy of the LP for many participants with fatigue, physical function, pain, anxiety and depression. It concludes that there is a need for more randomised controlled trials to evaluate if these positive outcomes can be replicated and generalised to larger populations.

Combat Application Tourniquet fares well in a chemical, biological, radiological or nuclear dress state

INTRODUCTION

There is a need for a military tourniquet to control catastrophic haemorrhage in a chemical, biological, radiological or nuclear (CBRN) threat environment. No published data exist as to the efficacy of tourniquets while wearing British military CBRN individual protective equipment (IPE).

METHODS

12 volunteers from the counter CBRN instructors' course allowed testing on 24 legs. A Combat Application Tourniquet (C-A-T) was applied to all volunteers at the level of the midthigh. 12 legs were tested while wearing CBRN IPE (both operator and simulated casualty), and the control group of 12 legs was tested while wearing conventional combat dress state (both operator and simulated casualty). The order of leg laterality and dress state were sequenced according to a prerandomised system. Efficacy was measured via use of an ultrasound probe at the popliteal artery. Tourniquets were considered effective if arterial flow was completely occluded on ultrasound imaging. Data were collected on time to successful application, failure of tourniquets and pain scores as rated by the visual analogue scale (1-10).

RESULTS

There were no failures of tourniquet application in the CBRN group, and two failures (17%) in the control group. Failures were pain threshold exceeded (n=1) and tourniquet internal strap failure (n=1). The mean application time for the CBRN group was 28.5 s (SD 11.7) and 23.7 s (SD 9.8) for the conventional combat group. There was no statistically significant difference (p=0.27). The median CBRN pain score was 2.0 (IQR 2.0-3.5). The median control pain score was 4.0 (IQR 3-6). This was a statistically significant difference (p=0.002).

CONCLUSION

C-A-Ts applied to simulated casualties in CBRN IPE at the midthigh are at least as efficacious as those applied to the midthigh in a conventional combat dress state. The pain experienced was less in CBRN IPE than when in a conventional combat dress state.

Abstract P6-11-01: Field testing of a point-of-care decision support tool for contralateral prophylactic mastectomy

Background: The majority of women undergoing contralateral prophylactic mastectomy (CPM) overestimate their risk of developing a contralateral breast cancer and incorrectly believe the CPM will substantially improve their overall survival. Using the results of our published micro-simulation decision-analytic model (Davies et al. Breast Cancer Res, 2016), we created and tested a CPM decision support tool to provide patients and breast cancer surgeons with individualized estimates of contralateral breast cancer risk and overall mortality.

Methods: The CPM decision support tool had four entry parameters from the micro-simulation model (age, family history of breast cancer, estrogen receptor status, and stage), and a visual depiction of outcomes using icon arrays for chances of developing a contralateral breast cancer and overall mortality with and without CPM. A user-centered design strategy was used with input and iterative refinement from stakeholders, i.e., breast cancer surgeons, patient advocates and breast cancer survivors. The tool was field-tested at MD Anderson Cancer Center with 5 breast cancer surgeons each using the tool with 5 breast cancer patients considering CPM (25 total). Patients completed a knowledge survey immediately before and after viewing the tool and the Decisional Conflict Scale (DCS) after viewing the tool. Surgeons completed the System Usability Scale (SUS) and ratings of the acceptability of the tool.

Results: The mean age of patients was 58 years. All patients reported the tool was helpful in making a decision about CPM and would recommend it to others. Knowledge of breast cancer and key CPM facts increased from before to after using the tool (64% vs. 75%, respectively, P<0.05). The mean score on the DCS was 10.5 (standard deviation =14.3) indicating patients were overall sure about the CPM choice. The majority (72%) of patients were unsure of their interest in CPM before viewing the tool. After viewing the tool, 13 (52%) of patients indicated they did not want CPM, 4 (16%) indicated they wanted CPM, and 8 (32%) remained unsure. Surgeons rated the tool as having a positive impact on the decision-making process and SUS scores were highly favorable (mean 93 on 0-100 scale, with 100 indicating highest usability).

Conclusion: The CPM decision tool had high overall patient satisfaction and improved knowledge about CPM without affecting decisional conflict. Decision support tools may be used to improve the quality of decision-making about CPM by providing surgeons and their patients with useful individualized information about CPM's impact on relevant clinical outcomes, which may lower the incidence of CPM.

Citation Format: Brewster AM, Cantor S, Davies K, Bedrosian I, Parker P, Garrison S, Volk RJ. Field testing of a point-of-care decision support tool for contralateral prophylactic mastectomy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-11-01.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Surveillance of Arboviruses in Primates and Sloths in the Atlantic Forest, Bahia, Brazil

From 2006 through 2014, we conducted seroepidemiological surveys on non-human primates and sloths to investigate the possible circulation of arboviruses in Bahia Atlantic Forest, Brazil. We collected a total of 196 samples from 103 Leontopithecus chrysomelas, 7 Sapajus xanthosternos, 22 Bradypus torquatus and 7 Bradypus variegatus. Serum samples were tested using neutralization test and hemagglutination inhibition test to detect total antibodies against 26 different arboviruses. The overall prevalence of arboviruses was 36.6% (51/139), with the genus Flavivirus having the highest prevalence (33.1%; 46/139), followed by Phlebovirus (5.0%; 7/139), Orthobunyavirus (4.3%; 6/139) and Alphavirus (0.7%; 1/139). Monotypic reactions suggest that the wild animals were exposed naturally to at least twelve arboviruses. Added results from the neutralization test, animals were exposed to thirteen arboviruses. Most of these viruses are maintained in transmission cycles independent of human hosts, although antibodies against dengue virus serotypes 1, 2 and 3 were found in this study. To our knowledge, this is the first study reporting exposure to arboviruses in L. chrysomelas, S. xanthosternos and B. torquatus. Our results also highlight that the Southern Bahia Atlantic Forest has a variety of vertebrate hosts and potential vectors, which may support the emergence or re-emergence of arboviruses, including those pathogenic to humans.

Prospective use of unmanned aerial vehicles for military medical evacuation in future conflicts

In order to continue to deliver outstanding medical care on the battlefield, the UK Defence Medical Services must continue to adapt, overcome and actively embrace change. One potential area is the rapid proliferation and sophistication of automated and remote systems such as unmanned aerial vehicles (UAVs). UAVs are already used to deliver blood to remote military locations in Afghanistan and defibrillators to those that need them in the USA and Sweden. An area of future opportunity would be to facilitate rapid evacuation of wounded personnel from high intensity, high threat, remote and austere areas directly to specialist care. Such a capability would reduce threat to human life while allowing rapid extraction of casualties from high risk or inaccessible environments straight back to Role 3 care, all of which in these situations is either not possible or carries too much risk using conventional aerial assets. The article aims to highlight a potential future capability, stimulate debate and reflection, all of which is essential for innovation and future organisational development. The potential uses and benefits of UAVs are highlighted including both the challenges and rewards of utilising UAVs for casualty evacuation. Key benefits are reduced risk to human life, cost, ability to insert into areas conventional aircraft cannot and the rapidity of transfer. Challenges are likely to be airspace management, decisions on appropriate level of care to deliver during transit and ultimately user acceptability. The article also highlights that in order to maximise our ability to exploit new technologies, all arms and trades within the military must be involved in collective research and development. Furthermore, sensible corroboration with private companies will further enhance our ability to acquire products that best serve our needs.

Gene expression modules in primary breast cancers as risk factors for organotropic patterns of first metastatic spread: a case control study

BACKGROUND

Metastases from primary breast cancers can involve single or multiple organs at metastatic disease diagnosis. Molecular risk factors for particular patterns of metastastic spread in a clinical population are limited.

METHODS

A case-control design including 1357 primary breast cancers was used to study three distinct clinical patterns of metastasis, which occur within the first six months of metastatic disease: bone and visceral metasynchronous spread, bone-only, and visceral-only metastasis. Whole-genome expression profiles were obtained using whole genome (WG)-DASL assays from formalin-fixed paraffin-embedded (FFPE) samples. A systematic protocol was developed for handling FFPE samples together with stringent data quality controls to identify robust expression profiling data. A panel of published and novel gene sets were tested for association with these specific patterns of metastatic spread and odds ratios (ORs) were calculated.

RESULTS

Metasynchronous metastasis to bone and viscera was found in all intrinsic breast cancer subtypes, while immunohistochemically (IHC)-defined receptor status and specific IntClust subgroups were risk factors for visceral-only or bone-only first metastases. Among gene modules, those related to proliferation increased the risk of metasynchronous metastasis (OR (95% CI) = 2.3 (1.1-4.8)) and visceral-only first metastasis (OR (95% CI) = 2.5 (1.2-5.1)) but not bone-only metastasis (OR (95% CI) = 0.97 (0.56-1.7)). A 21-gene module (BV) was identified in estrogen-receptor-positive breast cancers with metasynchronous metastasis to bone and viscera (area under the curve = 0.77), and its expression increased the risk of bone and visceral metasynchronous spread in this population. BV was further orthogonally validated with NanoString nCounter in primary breast cancers, and was reproducible in their matched lymph nodes metastases and an external cohort.

CONCLUSION

This case-control study of WG-DASL global expression profiles from FFPE tumour samples, after careful quality control and RNA selection, revealed that gene modules in the primary tumour have differing risks for clinical patterns of metasynchronous first metastases. Moreover, a novel gene module was identified as a putative risk factor for metasynchronous bone and visceral first metastatic spread, with potential implications for disease monitoring and treatment planning.

STAT4 expression and activation is increased during mitosis in vitro and in vivo in skin- and mucosa-derived cell types: implications in neoplastic and inflammatory skin diseases

BACKGROUND

The signal transducer and activator of transcription-4 (STAT4/Stat4) is a transcription factor known to convey signals from interleukin-12, interleukin-23, and interferon-alpha/beta to the nucleus, resulting in activation of dendritic cells, T-helper cell differentiation and production of interferon-gamma.

OBJECTIVE

To demonstrate a novel role for STAT4 in cell mitosis.

RESULTS

Phosphoserine STAT4 (pSerSTAT4) is increased in cells undergoing mitosis and is distributed throughout the cytoplasm during this stage of the cell cycle, whilst phosphotyrosine STAT4 (pTyrSTAT4) is confined to the chromosomal compartment. This distinct pattern of pSerSTAT4 during mitosis is seen in vitro in human keratinocytes and in other cell types. This is also present in vivo in cells undergoing mitosis in normal skin, psoriasis and squamous cell carcinoma. Inhibition of STAT4 phosphorylation by lisofylline and depletion of STAT4 by RNA interference results in a delay in progression of mitosis and leads to a reduction in cells completing cytokinesis.

CONCLUSION

Our data demonstrate that STAT4 plays a role in enabling the normal and timely division of cells undergoing mitosis.

Group O low titre only emergency donor panels for small combat teams

INTRODUCTION

Military elements increasingly operate in small teams in remote areas with no immediate blood product support. Planners and operators may endorse collection of fresh whole blood from pretested donors in emergency situations. The biggest risk of transfusion is the accidental use of ABO incompatible blood which can be fatal. The risk may be mitigated by using only group O LOw (OLO) titre donors with plasma containing low levels of the naturally occurring antibody to group A and B red cells. This paper reviews the ABO blood group distribution in potential blood donors from a high readiness UK medical regiment and explores the feasibility of using only group OLO donors in small teams.

METHODS

A retrospective review of routine volunteer blood donor samples was undertaken at 6 monthly intervals during a 2-year period. Personnel were tested in groups when available during training to create multiple donor panels to simulate small teams.

RESULTS

206 donation samples were collected from 157 potential donors. All donors were acceptable based on the lifestyle questionnaire, serology and microbiology screen. Of the 206 samples reviewed, 85 (41%) were group O (D pos and D neg). 14 group O (16.5%) were shown to have high titre of anti-A or B. Therefore, 71, that is, 34% overall were suitable as OLO donors. The donor panel size varied from 15 to 44. The absolute number of OLO donors in each panel ranged from 4 to 17 and the number of O neg donors was 0-3.

CONCLUSION

A third of samples were suitable as OLO donors; however, there were insufficient 'universal' donors within smaller subgroups (<10). In this situation, we recommend the careful use of both group O and group A donors or the use of a buddy-buddy blood group matrix.

The Goal Posts Keep Moving

“New Definition

Since the links that bind a shareholder to a company are generally more tenuous than those affecting employees (it is easier to sell shares than to find another job), one may question whether the framework is entirely appropriate to the present climate of opinion. But there remains the difficulty of defining precisely what employee participation should mean and how the broader national interest should be taken into account. If this is to involve a fundamental shift in the way directors are meant to interpret their respective responsibilities to shareholders, employees and also to consumers, this will require the creation of a new legislative framework.”

Extract: Financial Times editorial “The Human Face” 9th November 1973

Functional assessment of the NMDA receptor variant GluN2A R586K

Background: The N-methyl-D-aspartate receptor (NMDAR) is an ionotropic glutamate receptor that has important roles in synaptogenesis, synaptic transmission, and synaptic plasticity. Recently, a large number of rare genetic variants have been found in NMDAR subunits in people with neurodevelopmental disorders, and also in healthy individuals. One such is the GluN2AR586K variant, found in a person with intellectual disability. Identifying the functional consequences, if any, of such variants allows their potential contribution to pathogenesis to be assessed. Here, we assessed the effect of the GluN2AR586K variant on NMDAR pore properties. Methods: We expressed recombinant NMDARs with and without the GluN2AR586K variant in Xenopus laevis oocytes and in primary cultured mouse neurons, and made electrophysiological recordings assessing Mg2+ block, single-channel conductance, mean open time and current density. Results: The GluN2AR586K variant was not found to influence any of the properties assessed. Conclusions: Our findings suggest it is unlikely that the GluN2AR586K variant contributes to the pathogenesis of neurodevelopmental disorder.

Functional assessment of the NMDA receptor variant GluN2AR586K

Background: The N-methyl-D-aspartate receptor (NMDAR) is an ionotropic glutamate receptor that has important roles in synaptogenesis, synaptic transmission, and synaptic plasticity. Recently, a large number of rare genetic variants have been found in NMDAR subunits in people with neurodevelopmental disorders, and also in healthy individuals. One such is the GluN2AR586K variant, found in a person with intellectual disability. Identifying the functional consequences, if any, of such variants allows their potential contribution to pathogenesis to be assessed. Here, we assessed the effect of the GluN2AR586K variant on NMDAR pore properties. Methods: We expressed recombinant NMDARs with and without the GluN2AR586K variant in Xenopus laevis oocytes and in primary cultured mouse neurons, and made electrophysiological recordings assessing Mg2+ block, single-channel conductance, mean open time and current density. Results: The GluN2AR586K variant was not found to influence any of the properties assessed. Conclusions: Our findings suggest it is unlikely that the GluN2AR586K variant contributes to the pathogenesis of neurodevelopmental disorder.

MET-EGFR dimerization in lung adenocarcinoma is dependent on EGFR mtations and altered by MET kinase inhibition

Advanced lung cancer has poor survival with few therapies. EGFR tyrosine kinase inhibitors (TKIs) have high response rates in patients with activating EGFR mutations, but acquired resistance is inevitable. Acquisition of the EGFR T790M mutation causes over 50% of resistance; MET amplification is also common. Preclinical data suggest synergy between MET and EGFR inhibitors. We hypothesized that EGFR-MET dimerization determines response to MET inhibition, depending on EGFR mutation status, independently of MET copy number. We tested this hypothesis by generating isogenic cell lines from NCI-H1975 cells, which co-express L858R and T790M EGFR mutations, namely H1975L858R/T790M (EGFR TKI resistant); H1975L858R (sensitized) and H1975WT (wild-type). We assessed cell proliferation in vitro and tumor growth/stroma formation in derived xenograft models in response to a MET TKI (SGX523) and correlated with EGFR-MET dimerization assessed by Förster Resonance Energy Transfer (FRET). SGX523 significantly reduced H1975L858R/T790M cell proliferation, xenograft tumor growth and decreased ERK phosphorylation. The same was not seen in H1975L858R or H1975WT cells. SGX523 only reduced stroma formation in H1975L858R. SGX523 reduced EGFR-MET dimerization in H1975L858R/T790M but induced dimer formation in H1975L858R with no effect in H1975WT. Our data suggests that MET inhibition by SGX523 and EGFR-MET heterodimerisation are determined by EGFR genotype. As tumor behaviour is modulated by this interaction, this could determine treatment efficacy.

Demystifying damage control in musculoskeletal trauma

Trauma care has evolved rapidly over the past decade. The benefits of operative fracture management in major trauma patients are well recognised. Concerns over early total care arose when applied broadly. The burden of additional surgical trauma could constitute a second hit, fuelling the inflammatory response and precipitating a decline into acute respiratory distress syndrome, sepsis and multiple organ dysfunction syndrome. Temporary external fixation aimed to deliver the benefits of fracture stabilisation without the risk of major surgery. This damage control orthopaedics approach was advocated for those in extremis and a poorly defined borderline group. An increasing understanding of the physiological response to major trauma means there is now a need to refine our treatment options. A number of large scale retrospective reviews indicate that early definitive fracture fixation is beneficial in the majority of major trauma patients. It is recommended that patients are selected appropriately on the basis of their response to resuscitation. The hope is that this approach (dubbed 'safe definitive fracture surgery' or 'early appropriate care') will herald an era when care is individualised for each patient and their circumstances. The novel Damage Control in Orthopaedic Trauma Surgery course at The Royal College of Surgeons of England aims to equip senior surgeons with the insights and mindset necessary to contribute to this key decision making process as well as also the technical skills to provide damage control interventions when needed, relying on the improved techniques of damage control resuscitation and advances in the understanding of early appropriate care.

Phase II Randomized Preoperative Window-of-Opportunity Study of the PI3K Inhibitor Pictilisib Plus Anastrozole Compared With Anastrozole Alone in Patients With Estrogen Receptor-Positive Breast Cancer

PURPOSE

Preclinical data support a key role for the PI3K pathway in estrogen receptor-positive breast cancer and suggest that combining PI3K inhibitors with endocrine therapy may overcome resistance. This preoperative window study assessed whether adding the PI3K inhibitor pictilisib (GDC-0941) can increase the antitumor effects of anastrozole in primary breast cancer and aimed to identify the most appropriate patient population for combination therapy.

PATIENTS AND METHODS

In this randomized, open-label phase II trial, postmenopausal women with newly diagnosed operable estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers were recruited. Participants were randomly allocated (2:1, favoring the combination) to 2 weeks of preoperative treatment with anastrozole 1 mg once per day (n = 26) or the combination of anastrozole 1 mg with pictilisib 260 mg once per day (n = 49). The primary end point was inhibition of tumor cell proliferation as measured by change in Ki-67 protein expression between tumor samples taken before and at the end of treatment.

RESULTS

There was significantly greater geometric mean Ki-67 suppression of 83.8% (one-sided 95% CI, ≥ 79.0%) for the combination and 66.0% (95% CI, ≤ 75.4%) for anastrozole (geometric mean ratio [combination:anastrozole], 0.48; 95% CI, ≤ 0.72; P = .004). PIK3CA mutations were not predictive of response to pictilisib, but there was significant interaction between response to treatment and molecular subtype (P = .03); for patients with luminal B tumors, the combination:anastrozole geometric mean ratio of Ki-67 suppression was 0.37 (95% CI, ≤ 0.67; P = .008), whereas no significant Ki-67 response was observed for pictilisib in luminal A tumors (1.01; P = .98). Multivariable analysis confirmed Ki-67 response to the combination treatment of patients with luminal B tumors irrespective of progesterone receptor status or baseline Ki-67 expression.

CONCLUSION

Adding pictilisib to anastrozole significantly increases suppression of tumor cell proliferation in luminal B primary breast cancer.

Abstract P5-13-01: Transcript analysis of PI3K and immune-related genes and gene signatures in the pre- and post-treatment samples from the window of opportunity study of anastrozole and anastrozole with pictilisib (GDC-0941) in patients with HR-positive early breast cancer (OPPORTUNE study)

Background: The OPPORTUNE Study randomized postmenopausal patients (pts) to receive 2-week preoperative treatment with anastrozole (ANA) plus pictilisib ("ANA+PIC" arm) or ANA alone. Patients had newly diagnosed, operable, ER+, HER2- invasive breast cancer of ≥1 cm size. The primary outcome at interim analysis (n=70) revealed that the addition of PIC significantly increased the anti-proliferative response to ANA as measured by reduction in Ki67 immunohistochemistry (IHC). Multivariate analyses suggested benefit of PIC for patients with luminal B disease (Schmid et al. SABCS 2014).

Methods: RNA expression analysis of ∼800 breast cancer-related genes was performed on patients analyzed at the interim analysis, including 14 (ANA) and 20 (ANA+PIC) patients with matched pre- and post- treatment paired tumour samples using the nCounter platform (NanoString). Differential expression of individual genes by arm was assessed using paired and moderated t-tests and statistical significance assessed through false discovery rate (FDR). Ingenuity Pathway Analysis (IPA) of differentially expressed transcripts identified pathways of relevance. Protein expression was analyzed by reverse protein array ( RPPA) in pre- and post-treatment samples.

Results: In an unsupervised analysis, down-regulation of genes associated with ER signaling was observed in patients who received single-agent ANA and ANA+PIC, which included genes that regulate the cell cycle, cell death, survival, growth and proliferation and known ER target genes (e.g., PGR, GREB1). In addition, transcripts related to growth factor signaling pathway appeared to be specifically modulated in the ANA+PIC arm, possibly via the upregulation of the expression of RTK ligands. There were no clear changes in PI3K-related phosphoproteins (e.g., AKT, S6, 4E-BP1) in the post-treatment samples by RPPA. However, known PI3K-regulated genes, IRS2 and PIK3IP1, were upregulated in the post-treatment samples and a composite PI3K gene expression signature score (O'Brien et al. 2010) was reduced in both study arms following treatment. This PI3K signature was associated with pre-treatment luminal B status (n=27) and, consistent with this finding, the baseline PI3K gene signature score in the ANA arm, but not the ANA+PIC arm, was inversely associated with the decrease in post treatment Ki67. The tumor immune microenvironment was analyzed though the use of composite gene sets. In our initial observations, analysis of pre- and post-treatment samples showed that 2-week treatment with ANA resulted in a modest increase in transcripts associated with multiple immune signatures, which was further enhanced by the addition of PIC.

Conclusions: Gene expression analysis of pre- and post-treatment samples in the OPPORTUNE study demonstrates on-target inhibition of ER and PI3K signaling networks. The analysis of additional paired samples is in progress to further assess if 2-weeks of treatment with a regimen containing an AI in patients with early breast cancer impacts the tumor immune microenvironment.

Citation Format: Schmid P, Pinder SE, Bundred N, Wheatley D, Macaskill J, Zammit C, Hu J, Price R, Shia A, Lim L, Parker P, Molinero L, Yu J, O'Brien C, Wilson T, Savage H, Derynck M, Lackner MR, Amler L, Purushotham A, Thompson A, Gendreau S. Transcript analysis of PI3K and immune-related genes and gene signatures in the pre- and post-treatment samples from the window of opportunity study of anastrozole and anastrozole with pictilisib (GDC-0941) in patients with HR-positive early breast cancer (OPPORTUNE study). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-13-01.

Abstract B43: APOBEC3B upregulation by the PKC-NFκB pathway in breast cancer

Overexpression of the antiviral DNA cytosine deaminase APOBEC3B has been linked to somatic mutagenesis in breast and other cancer. Human papillomavirus (HPV) infection accounts for APOBEC3B upregulation in cervical and head/neck cancers. However, the responsible mechanisms are unclear for non-viral malignancies such as breast cancer. Here, we demonstrate APOBEC3B upregulation through the PKC-NFκB pathway. PKC activation by the diacylglycerol mimic PMA causes specific and dose-responsive increases in APOBEC3B mRNA, protein, and activity levels, which are strongly suppressed by PKC and NFκB inhibition. Induction correlates with RELB (but not RELA) recruitment to the endogenous APOBEC3B gene implicating non-canonical NFκB signaling. Relevance to tumors is supported by PKC inhibitor-mediated APOBEC3B downregulation in multiple breast cancer cell lines. These data establish the first mechanistic link between APOBEC3B and a common signal transduction pathway, suggesting that existing PKC-NFκB inhibitors could be repurposed to suppress cancer mutagenesis, dampen tumor evolution, and decrease the probability of adverse outcomes such as drug resistance and metastases.

Citation Format: Brandon Leonard, Jennifer McCann, Gabriel Starrett, Leah Kosyakovsky, Molan Amy, Michael Burns, Rebecca McDougle, Peter Parker, William Brown, Reuben Harris. APOBEC3B upregulation by the PKC-NFκB pathway in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B43.

Contrast sonovenography - Is this the answer to complex deep vein thrombosis imaging?

BACKGROUND

Deep vein thrombosis (DVT) is a potentially fatal condition causing significant morbidity and mortality in the patient population. Ultrasound (USS) is the mainstay for detecting DVT. This can sometimes be difficult in hostile limbs due to factors such as large body habitus and oedema. This pilot study investigated contrast-enhanced ultrasound (CEUS) as a viable method to improve visualisation of the venous system of the lower limb.

METHODS

Patients at high risk for DVT were selected after an initial negative USS. A follow-up scan was performed 1 week later utilising standard B-mode imaging with a curvilinear 3-5 MHz transducer array. After the fundamental scan, intravenous Sonovue™ contrast was administered and visualisation of the proximal limb veins and visualisation gains in distance were mapped onto a proforma.

RESULTS

Twelve patients were selected. Visualisation was not improved in the common femoral vein (CFV) but increases in full visualisation were demonstrated in the femoral vein (FV) and popliteal vein (Pop V) from (n = 8) 67% and (n = 10) 83-100% in both veins, respectively. Significant gains in visualisation distance were observed in the posterior tibial vein (PTV) (p = 0.0005) and peroneal vein (Per V) (p = 0.02) with increased full visualisation of the Per V from (n = 3) 25% to (n = 7) 58%.

CONCLUSION

CEUS is a viable and clinically safe method for increasing visualisation of the deep venous system. It has the potential to improve visualisation of the lower limb venous system, reducing follow-up costs and diagnostic uncertainty for patients and the clinician.

Transfusion support by a UK Role 1 medical team: a 2-year experience from Afghanistan

INTRODUCTION

This paper describes the clinical governance, training, equipment and infrastructure developed to enable a UK Role 1 medical team to deliver forward transfusion in Southern Afghanistan. The aim was to explore the utility and feasibility of forward blood transfusion by a Role 1 medical team in an austere military environment.

METHODS

An audit of prospectively collected transfusion regulatory and cold chain data using standard-issue equipment and governance systems. TempIT tags were read before and after each mission to record blood storage temperature. Two years' data were analysed to review the use of blood products, cold chain compliance and equipment issues.

RESULTS

Over 24 months, blood products were carried on over 1000 mission hours. Two clinical cases required transfusion and were successfully resuscitated. The team was able to correctly transport, store and deploy red cells and plasma on missions using standard Ministry of Defence (MOD) issue equipment. There were seven cold chain failures, all of which were addressed locally. Current cold chain and diagnostic equipment would require further optimisation for use at Role 1.

CONCLUSIONS

An isolated Role 1 medical team can safely deliver blood transfusion on vehicle, helicopter or foot patrols. The transport and storage of blood created a large logistical burden for a relatively small clinical output. However, with further developments, this capability may have utility in contingency operations especially for isolated teams.

Abstract LB-052: Kinase identification of proximal substrates (KIPS): A novel chemical genetics approach for kinase substrate identification

Protein kinases are attractive targets for pharmacological intervention through their frequent disease associated aberration of cellular signalling networks. In this context an understanding of the myriad of substrates on which a protein kinase operates can help to reveal potential pharmacodynamic and patient stratification biomarkers. Kinase Identification of Proximal Substrates (KIPS) utilises an innovative chemical genetics approach to identify novel proximal biomarkers of kinase target response. This approach relies on the generation of a desensitized mutant protein that retains its kinase function, but loses sensitivity to small-molecule mediated inhibition. Comparative phospho-proteomics is performed on immuno-complexes of tagged wild type and mutant protein kinases in the presence and absence of inhibitor to isolate specific phospho-proteomic changes in proximal substrates. To exemplify the KIPS approach we have focused on the identification of novel substrates of the atypical protein kinase C isoform, PKCι. Through structure based design we identified two acidic amino acid residues in the PKCι nucleotide binding site that are crucial for efficacy of a previously characterized PKCι inhibitor, CRT0066854. Upon mutation to non-acidic alanine residues the PKCι protein is rendered insensitive to compound-mediated inhibition, allowing a comparison of wild type and mutant responses to PKCι inhibition to be made. Using HCT116 cells, we identified Myosin X as a putative substrate for PKCι, and demonstrated its specificity to the PKCι signalling axis through alanine-scanning peptide arrays and generation of phospho-specific antibodies. We show that the key acidic amino acids utilised in KIPS are highly conserved across the AGC and CAMK kinase super families. Furthermore, extensive compound SAR, diverse kinome profiling and structural biology have identified a tool box of inhibitor compounds with a broad range of activities across these kinase families leading to broader applicability of KIPS to enable the identification of individual kinase specific substrates and response across approximately 20% of the human kinome.

Citation Format: jon roffey, Andrew Turnbull, Christian Dillon, Susan Boyd, Philippe Riou, Mark Linch, Peter Parker, Sven Kjaer, Neil McDonald. Kinase identification of proximal substrates (KIPS): A novel chemical genetics approach for kinase substrate identification. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-052. doi:10.1158/1538-7445.AM2015-LB-052

The sorting protein PACS-2 promotes ErbB signalling by regulating recycling of the metalloproteinase ADAM17

The metalloproteinase ADAM17 activates ErbB signalling by releasing ligands from the cell surface, a key step underlying epithelial development, growth and tumour progression. However, mechanisms acutely controlling ADAM17 cell-surface availability to modulate the extent of ErbB ligand release are poorly understood. Here, through a functional genome-wide siRNA screen, we identify the sorting protein PACS-2 as a regulator of ADAM17 trafficking and ErbB signalling. PACS-2 loss reduces ADAM17 cell-surface levels and ADAM17-dependent ErbB ligand shedding, without apparent effects on related proteases. PACS-2 co-localizes with ADAM17 on early endosomes and PACS-2 knockdown decreases the recycling and stability of internalized ADAM17. Hence, PACS-2 sustains ADAM17 cell-surface activity by diverting ADAM17 away from degradative pathways. Interestingly, Pacs2-deficient mice display significantly reduced levels of phosphorylated EGFR and intestinal proliferation. We suggest that this mechanism controlling ADAM17 cell-surface availability and EGFR signalling may play a role in intestinal homeostasis, with potential implications for cancer biology.

Abstract S2-03: Preoperative window of opportunity study of the PI3K inhibitor pictilisib (GDC-0941) plus anastrozole vs anastrozole alone in patients with ER+, HER2-negative operable breast cancer (OPPORTUNE study)

Background: Preclinical and clinical data support a key role for the PI3K pathway in resistance to endocrine therapy in patients with ER+ breast cancer and suggest that combining PI3K inhibitors with endocrine therapy may overcome resistance. Short-term preoperative window of opportunity (WOO) studies are a validated strategy for novel treatments to provide proof-of-concept and define the most appropriate patient population by directly assessing treatment effects in tumour tissue before and after treatment. This is the first WOO study with the PI3K inhibitor pictilisib (GDC-0941) in combination with anastrozole (ANA).

Methods: 73 postmenopausal patients (pts) have been randomized (2:1 in favour of the combination) to receive 2-week preoperative treatment with ANA plus pictilisib (n=50, "ANA+PIC" arm) or ANA alone (n=23, "ANA" arm). Pts had newly diagnosed, operable, ER+, HER2-negative breast cancer of ≥1 cm size. Pts receiving HRT were excluded. Treatment effects and correlative studies were assessed using FFPE and frozen tumour biopsies taken before and after 14 days of study treatment.

The primary endpoint was inhibition of tumour-cell proliferation, as measured by change in Ki67 expression, determined centrally by 2 investigators. Secondary endpoints include induction of apoptosis (Caspase3) and safety. Comprehensive biomarkers analyses include targeted NGS of a comprehensive cancer panel of &gt;400 genes, copy number analyses, and pre- and post-treatment reverse-phase protein arrays (RPPA) and RNA profiling.

Results: Baseline (BL) disease characteristics were similar between both study arms. PAM50 analysis showed that 53% and 47% of tumors were Luminal (Lum) A and B, respectively. 65% of tumors had &gt;14% Ki67-positive cells. Observed treatment-emergent AEs were consistent with those previously described for single-agent pictilisib and anastrozole.

Mean post-treatment percentage reduction of Ki67 was 84% (95% CI, 75%-89%) for ANA+PIC and 72% (54%-87%) for ANA. Ki67-response (≥50% drop in % of Ki67+ cells) was 86% for ANA+PIC and 60% for ANA. By using the definition that pts with a natural logarithm of %Ki67+ cells of ≤1 or 1-2 have a day 15 anti-proliferative response, 93% [ln(ki67): &lt;1, 46%; 1-2, 46%] of ANA+PIC were responders compared with 60% [&lt;1, 47%; 1-2, 13%] of ANA-treated pts (p = 0.01).

Preplanned subgroup analyses showed a significant interaction of response to ANA+PIC with molecular subtype and Ki67 levels. Patients with LumB tumors or high BL Ki67 (&gt;14%) had a higher Ki67 response with ANA+PIC compared to ANA (LumB, 83% vs 38%; Ki67&gt;14%, 94% vs 55%), whereas Ki67 response was similar for both treatments for LumA tumors (ANA, 75%; ANA+PIC, 73%) or tumors with low BL Ki67. Mean post-treatment % reduction of Ki67 in LumB tumors was 87% (95% CI, 49%-96%) for ANA+PIC and 56% (16%-77%) for ANA (p=0.03).

Additional data on apoptosis and comprehensive pre- and post-treatment biomarkers analyses will be presented.

Conclusions: This first report of a preoperative WOO study evaluating a PI3K inhibitor in early breast cancer demonstrated addition of pictilisib to ANA was associated with increased anti-proliferative response over single-agent ANA.

Citation Format: Peter Schmid, Sarah E Pinder, Duncan Wheatley, Jane Macaskill, Charles Zammit, Jennifer Hu, Robert Price, Nigel Bundred, Sirwan Hadad, Alice Shia, Louise Lim, Shah-Jalal Sarker, Patrycja Gazinska, Natalie Woodman, Darren Korbie, Matt Trau, Paul Mainwaring, Peter Parker, Arnie Purushotham, Alastair M Thompson. Preoperative window of opportunity study of the PI3K inhibitor pictilisib (GDC-0941) plus anastrozole vs anastrozole alone in patients with ER+, HER2-negative operable breast cancer (OPPORTUNE study) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr S2-03.

Regulation of the cytokinesis cleavage furrow by PKCε

Cytokinesis is the final act of the cell cycle where the replicated DNA and cellular contents are finally split into two daughter cells. This process is very tightly controlled as DNA segregation errors and cytokinesis failure is commonly associated with aneuploidy and aggressive tumours. Protein kinase Cε (PKCε) is a lipid-activated serine/threonine kinase that is part of the PKC superfamily. PKCε plays a complex role in the regulation of migration, adhesion and cytokinesis and in the present article we discuss the interplay between these processes. Integrin-mediated interaction with the actin cytoskeleton is a known regulator of cell adhesion and migration and there is emerging evidence that this pathway may also be essential for cytokinesis. We discuss evidence that a known actin-binding region in PKCε is involved in PKCε-mediated regulation of cytokinesis, providing a link between integrin-mediated stabilization of the cytokinesis furrow and PKCε recruitment.

The ErbB4 CYT2 variant protects EGFR from ligand-induced degradation to enhance cancer cell motility

The epidermal growth factor receptor (EGFR) is a member of the ErbB family that can promote the migration and proliferation of breast cancer cells. Therapies that target EGFR can promote the dimerization of EGFR with other ErbB receptors, which is associated with the development of drug resistance. Understanding how interactions among ErbB receptors alter EGFR biology could provide avenues for improving cancer therapy. We found that EGFR interacted directly with the CYT1 and CYT2 variants of ErbB4 and the membrane-anchored intracellular domain (mICD). The CYT2 variant, but not the CYT1 variant, protected EGFR from ligand-induced degradation by competing with EGFR for binding to a complex containing the E3 ubiquitin ligase c-Cbl and the adaptor Grb2. Cultured breast cancer cells overexpressing both EGFR and ErbB4 CYT2 mICD exhibited increased migration. With molecular modeling, we identified residues involved in stabilizing the EGFR dimer. Mutation of these residues in the dimer interface destabilized the complex in cells and abrogated growth factor-stimulated cell migration. An exon array analysis of 155 breast tumors revealed that the relative mRNA abundance of the ErbB4 CYT2 variant was increased in ER+ HER2- breast cancer patients, suggesting that our findings could be clinically relevant. We propose a mechanism whereby competition for binding to c-Cbl in an ErbB signaling heterodimer promotes migration in response to a growth factor gradient.

TSPO interacts with VDAC1 and triggers a ROS-mediated inhibition of mitochondrial quality control

The 18-kDa TSPO (translocator protein) localizes on the outer mitochondrial membrane (OMM) and participates in cholesterol transport. Here, we report that TSPO inhibits mitochondrial autophagy downstream of the PINK1-PARK2 pathway, preventing essential ubiquitination of proteins. TSPO abolishes mitochondrial relocation of SQSTM1/p62 (sequestosome 1), and consequently that of the autophagic marker LC3 (microtubule-associated protein 1 light chain 3), thus leading to an accumulation of dysfunctional mitochondria, altering the appearance of the network. Independent of cholesterol regulation, the modulation of mitophagy by TSPO is instead dependent on VDAC1 (voltage-dependent anion channel 1), to which TSPO binds, reducing mitochondrial coupling and promoting an overproduction of reactive oxygen species (ROS) that counteracts PARK2-mediated ubiquitination of proteins. These data identify TSPO as a novel element in the regulation of mitochondrial quality control by autophagy, and demonstrate the importance for cell homeostasis of its expression ratio with VDAC1.

Abstract A280: Small molecule inhibition of atypical protein kinase C iota reveals a functional basis for oncogenesis

Background: Atypical protein kinase C iota (PKCι) is a serine/threonine kinase that has been implicated in a variety of cellular processes including polarity, migration, proliferation and survival. PKCι is amplified in many cancers correlating with poor prognosis, however the upstream activating inputs and downstream effectors are not well defined.

Experimental Procedures: 3D MDCK epithelial cell spheroids were grown in Matrigel and used to assess polarized morphogenesis and growth. PKCι was manipulated by inhibition with CRT0066854, or transfection with siRNA or cDNA variants. A PKCι binding interface was identified by X-ray crystallography and interrogated by mass spectrometry of wildtype or binding mutant immunocomplexes.

Results: To identify potential inputs into PKCι we assessed a panel of transformed MDCK cells; p110α, Src, Ras, ErbB2 and Raf. Parental MDCK cells form polarized cysts in Matrigel, however Ras, ErbB2 and p110α MDCK cells formed dysplastic spheroids. In the case of Ras and ErbB2, but not p110α MDCK spheroids, normal polarized morphogenesis could be rescued by siRNA-PKCι or partial PKCι inhibition with decreased spheroid size seen for all transformed cells lines. An effector binding site (PKCι RIPR motif) identified from the crystal structure of the kinase and characterized as a recruitment site for select targets including LLGL2 and Myosin X, was found to be critical for PKCι to confer polarized morphogenesis. Interestingly this binding motif shows a low frequency of mutation in a subset of human tumors.

Conclusions: Downstream of Ras and ErbB2, PKCι activity is enhanced with a resulting dysplasia and loss of polarization, that can be rescued by PKCι inhibition. Mutation of the PKCι-RIPR effector binding motif that is found in cancer, prevents interaction with LLGL2 and its expression also elicits growth as non-polarized, dysplastic epithelial spheroids. This indicates that PKCι may promote cancer, not only by amplification, but by upstream oncogenic inputs and somatic mutation. The oncogene dependent PKCι hyperactivation is pro-proliferative in 3D culture, providing compelling evidence that PKCι is a good target for Ras mutant tumors.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A280.

Citation Format: Mark Linch, Marta Sanz-Garcia, Svend Kjaer, Erika Soriano, Philippe Riou, Philip Knowles, Christian Dillon, Jon Roffey, Neil McDonald, Peter Parker. Small molecule inhibition of atypical protein kinase C iota reveals a functional basis for oncogenesis. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A280.