Diagnostic validation of vertebral heart score machine learning algorithm for canine lateral chest radiographs

OBJECTIVES

The vertebral heart score is a measurement used to index heart size relative to thoracic vertebra. Vertebral heart score can be a useful tool for identifying and staging heart disease and providing prognostic information. The purpose of this study is to validate the use of a vertebral heart score algorithm compared to manual vertebral heart scoring by three board-certified veterinary cardiologists.

MATERIALS AND METHODS

A convolutional neural network centred around semantic segmentation of relevant anatomical features was developed to predict heart size and vertebral bodies. These predictions were used to calculate the vertebral heart score. An external validation study consisting of 1200 canine lateral radiographs was randomly selected to match the underlying distribution of vertebral heart scores. Three American College of Veterinary Internal Medicine board-certified cardiologists were enrolled to manually score 400 images each using the traditional Buchanan method. Post-scoring, the cardiologists evaluated the algorithm for misaligned anatomic landmarks and overall image quality.

RESULTS

The 95th percentile absolute difference between the cardiologist vertebral heart score and the algorithm vertebral heart score was 1.05 vertebrae (95% confidence interval: 0.97 to 1.20 vertebrae) with a mean bias of -0.09 vertebrae (95% confidence interval: -0.12 to -0.05 vertebrae). In addition, the model was observed to be well calibrated across the predictive range.

CLINICAL SIGNIFICANCE

We have found the performance of the vertebral heart score algorithm comparable to three board-certified cardiologists. While validation of this vertebral heart score algorithm has shown strong performance compared to veterinarians, further external validation in other clinical settings is warranted before use in those settings.

Automated antigen assays display a high heterogeneity for the detection of SARS-CoV-2 variants of concern, including several Omicron sublineages

Diagnostic tests for direct pathogen detection have been instrumental to contain the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic. Automated, quantitative, laboratory-based nucleocapsid antigen (Ag) tests for SARS-CoV-2 have been launched alongside nucleic acid-based test systems and point-of-care (POC) lateral-flow Ag tests. Here, we evaluated four commercial Ag tests on automated platforms for the detection of different sublineages of the SARS-CoV-2 Omicron variant of concern (VoC) (B.1.1.529) in comparison with "non-Omicron" VoCs. A total of 203 Omicron PCR-positive respiratory swabs (53 BA.1, 48 BA.2, 23 BQ.1, 39 XBB.1.5 and 40 other subvariants) from the period February to March 2022 and from March 2023 were examined. In addition, tissue culture-expanded clinical isolates of Delta (B.1.617.2), Omicron-BA.1, -BF.7, -BN.1 and -BQ.1 were studied. These results were compared to previously reported data from 107 clinical "non-Omicron" samples from the end of the second pandemic wave (February to March 2021) as well as cell culture-derived samples of wildtype (wt) EU-1 (B.1.177), Alpha VoC (B.1.1.7) and Beta VoC (B.1.351)). All four commercial Ag tests were able to detect at least 90.9% of Omicron-containing samples with high viral loads (Ct < 25). The rates of true-positive test results for BA.1/BA.2-positive samples with intermediate viral loads (Ct 25-30) ranged between 6.7% and 100.0%, while they dropped to 0 to 15.4% for samples with low Ct values (> 30). This heterogeneity was reflected also by the tests' 50%-limit of detection (LoD50) values ranging from 44,444 to 1,866,900 Geq/ml. Respiratory samples containing Omicron-BQ.1/XBB.1.5 or other Omicron subvariants that emerged in 2023 were detected with enormous heterogeneity (0 to 100%) for the intermediate and low viral load ranges with LoD50 values between 23,019 and 1,152,048 Geq/ml. In contrast, detection of "non-Omicron" samples was more sensitive, scoring positive in 35 to 100% for the intermediate and 1.3 to 32.9% of cases for the low viral loads, respectively, corresponding to LoD50 values ranging from 6181 to 749,792 Geq/ml. All four assays detected cell culture-expanded VoCs Alpha, Beta, Delta and Omicron subvariants carrying up to six amino acid mutations in the nucleocapsid protein with sensitivities comparable to the non-VoC EU-1. Overall, automated quantitative SARS-CoV-2 Ag assays are not more sensitive than standard rapid antigen tests used in POC settings and show a high heterogeneity in performance for VoC recognition. The best of these automated Ag tests may have the potential to complement nucleic acid-based assays for SARS-CoV-2 diagnostics in settings not primarily focused on the protection of vulnerable groups. In light of the constant emergence of new Omicron subvariants and recombinants, most recently the XBB lineage, these tests' performance must be regularly re-evaluated, especially when new VoCs carry mutations in the nucleocapsid protein or immunological and clinical parameters change.

Rapid and sensitive identification of omicron by variant-specific PCR and nanopore sequencing: paradigm for diagnostics of emerging SARS-CoV-2 variants

On November 26, 2021, the World Health Organization classified B.1.1.529 as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VoC), named omicron. Spike-gene dropouts in conventional SARS-CoV-2 PCR systems have been reported over the last weeks as indirect diagnostic evidence for the identification of omicron. Here, we report the combination of PCRs specific for heavily mutated sites in the spike gene and nanopore-based full-length genome sequencing for the rapid and sensitive identification of the first four COVID-19 patients diagnosed in Germany to be infected with omicron on November 28, 2021. This study will assist the unambiguous laboratory-based diagnosis and global surveillance for this highly contagious VoC with an unprecedented degree of humoral immune escape. Moreover, we propose that specialized diagnostic laboratories should continuously update their assays for variant-specific PCRs in the spike gene of SARS-CoV-2 to readily detect and diagnose emerging variants of interest and VoCs. The combination with established nanopore sequencing procedures allows both the rapid confirmation by whole genome sequencing as well as the sensitive identification of newly emerging variants of this pandemic β-coronavirus in years to come.

The ADAM17-directed Inhibitory Antibody MEDI3622 Antagonizes Radiotherapy-induced VEGF Release and Sensitizes Non-Small Cell Lung Cancer for Radiotherapy

The cellular response to ionizing radiation (IR) depends on tumor cell and microenvironmental factors. Here, we investigated the role of IR-induced ADAM17 matrix metalloproteinase activity for the intercellular communication between tumor cells and the tumor vasculature in non-small cell lung cancer (NSCLC) tumor models. Factors shed by ADAM17 from NSCLC tumor cells (A549, H358) and relevant for endothelial cell migration were investigated using transwell migration assays, ELISA, and flow cytometry. Tumor angiogenesis-related endpoints were analyzed with the chorio-allantoic membrane assay and in murine NSCLC tumor models. Efficacy-oriented experiments were performed in a murine orthotopic NSCLC tumor model using irradiation with an image-guided small-animal radiotherapy platform alone and in combination with the novel ADAM17-directed antibody MEDI3622. In vitro, VEGF was identified as the major factor responsible for IR-induced and ADAM17-dependent endothelial cell migration toward attracting tumor cells. IR strongly enhanced tumor cell-associated ADAM17 activity, released VEGF in an ADAM17-dependent manner, and thereby coordinated the communication between tumor and endothelial cells. In vivo, tumor growth and microvessel size and density were strongly decreased in response to the combined treatment modality of IR and MEDI3622 but not by either treatment modality alone and thus suggest that the supra-additive effect of the combined treatment modality is in part due to abrogation of the ADAM17-mediated IR-induced protective effect on the tumor vasculature. Furthermore, we demonstrate that the novel ADAM17-inhibitory antibody MEDI3622 potently improves the radiotherapy response of NSCLC.

Significance

The tumor response to radiotherapy is influenced by several factors of the tumor microenvironment. We demonstrate that inhibition of the sheddase ADAM17 by the novel antibody MEDI3622 reduces IR-induced VEGF release from tumor cells relevant for endothelial cell migration and vasculature protection, thereby enhancing radiotherapy treatment outcome of NSCLC.

Genomic epidemiology reveals multiple introductions of SARS-CoV-2 followed by community and nosocomial spread, Germany, February to May 2020

Background

In the SARS-CoV-2 pandemic, viral genomes are available at unprecedented speed, but spatio-temporal bias in genome sequence sampling precludes phylogeographical inference without additional contextual data.

Aim

We applied genomic epidemiology to trace SARS-CoV-2 spread on an international, national and local level, to illustrate how transmission chains can be resolved to the level of a single event and single person using integrated sequence data and spatio-temporal metadata.

Methods

We investigated 289 COVID-19 cases at a university hospital in Munich, Germany, between 29 February and 27 May 2020. Using the ARTIC protocol, we obtained near full-length viral genomes from 174 SARS-CoV-2-positive respiratory samples. Phylogenetic analyses using the Auspice software were employed in combination with anamnestic reporting of travel history, interpersonal interactions and perceived high-risk exposures among patients and healthcare workers to characterise cluster outbreaks and establish likely scenarios and timelines of transmission.

Results

We identified multiple independent introductions in the Munich Metropolitan Region during the first weeks of the first pandemic wave, mainly by travellers returning from popular skiing areas in the Alps. In these early weeks, the rate of presumable hospital-acquired infections among patients and in particular healthcare workers was high (9.6% and 54%, respectively) and we illustrated how transmission chains can be dissected at high resolution combining virus sequences and spatio-temporal networks of human interactions.

Conclusions

Early spread of SARS-CoV-2 in Europe was catalysed by superspreading events and regional hotspots during the winter holiday season. Genomic epidemiology can be employed to trace viral spread and inform effective containment strategies.

Fenretinide Acts as Potent Radiosensitizer for Treatment of Rhabdomyosarcoma Cells

Fusion-positive rhabdomyosarcoma (FP-RMS) is a highly aggressive childhood malignancy which is mainly treated by conventional chemotherapy, surgery and radiation therapy. Since radiotherapy is associated with a high burden of late side effects in pediatric patients, addition of radiosensitizers would be beneficial. Here, we thought to assess the role of fenretinide, a potential agent for FP-RMS treatment, as radiosensitizer. Survival of human FP-RMS cells was assessed after combination therapy with fenretinide and ionizing radiation (IR) by cell viability and clonogenicity assays. Indeed, this was found to significantly reduce cell viability compared to single treatments. Mechanistically, this was accompanied by enhanced production of reactive oxygen species, initiation of cell cycle arrest and induction of apoptosis. Interestingly, the combination treatment also triggered a new form of dynamin-dependent macropinocytosis, which was previously described in fenretinide-only treated cells. Our data suggest that fenretinide acts in combination with IR to induce cell death in FP-RMS cells and therefore might represent a novel radiosensitizer for the treatment of this disease.

Visual search in ADHD, ASD and ASD + ADHD: overlapping or dissociating disorders?

Recent debates in the literature discuss commonalities between Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) at multiple levels of putative causal networks. This debate requires systematic comparisons between these disorders that have been studied in isolation in the past, employing potential markers of each disorder to be investigated in tandem. The present study, choose superior local processing, typical to ASD, and increased Intra-Subject Variability (ISV), typical to ADHD, for a head-to-head comparison of the two disorders, while also considering the comorbid cases. It directly examined groups of participants aged 10-13 years with ADHD, ASD with (ASD+) or without (ASD-) comorbid ADHD and a typically developing (TD) group (total N = 85). A visual search task consisting of an array of paired words was designed. The participants needed to find the specific pair of words, where the first word in the pair was the cue word. This visual search task was selected to compare these groups on overall search performance and trial-to-trial variability of search performance (i.e., ISV). Additionally, scanpath analysis was also carried out using Recurrence Quantification Analysis (RQA) and the Multi-Match Model. Results show that only the ASD- group exhibited superior search performance; whereas, only the groups with ADHD symptoms showed increased ISV. These findings point towards a double dissociation between ASD and ADHD, and argue against an overlap between ASD and ADHD.

Examining the Overlap Between ADHD and Autism Spectrum Disorder (ASD) Using Candidate Endophenotypes of ADHD

Objective: Recent discussions of aetiological overlap between ADHD and Autism Spectrum Disorder (ASD) require comparative studying of these disorders.

METHOD

We examined performance of ASD patients with (ASD+) and without (ASD-) comorbid ADHD, ADHD patients, and controls for selected putative endophenotypes of ADHD: Intrasubject Variability (ISV) of reaction times, working memory (WM), inhibition, and temporal processing.

RESULTS

We found that patients with ADHD or ASD+, but not ASD-, had elevated ISV across the entire task battery and temporal processing deficits, and that none of the groups were impaired in WM or inhibition. High levels of ISV and generally poor performance in ASD+ patients were only partially due to additive effects of the pure disorders.

CONCLUSION

Overall, we conclude that, within our limited but heterogeneous task battery, ISV and temporal processing deficits are most sensitive to ADHD symptomatology and that controlling for ADHD comorbidity is mandatory when assessing ISV in autism.

Consolidation cetuximab after concurrent triplet radiochemotherapy+cetuximab in patients with advanced head and neck cancer: A randomized phase II study

BACKGROUND AND PURPOSE

Preclinical data suggest that cetuximab should be continued after end of concurrent radiotherapy+cetuximab due to its efficacy against residual tumor cells in the irradiated tumor bed. Based on this concept the phase II add-on cetuximab (AOC) study was designed.

MATERIALS AND METHODS

Altogether 63 patients with advanced head and neck cancer were treated with radiochemotherapy (70 Gy, cisplatin 40 mg/m² weekly) in combination with concurrent cetuximab (loading dose 400 mg/m², then 250 mg/m² weekly). Thereafter patients were randomized to cetuximab consolidation (500 mg/m² biweekly × 6) or no further treatment. The primary endpoint was the 2-year locoregional control (LRC) rate. As translational research endpoints serum markers were analyzed before and during treatment and CT-based quantitative image analysis (radiomics) was performed.

RESULTS

Median follow-up was 24 months. The 2-year LRC rates were 67.9% and 67.7% in the treatment arms with and without consolidation cetuximab, respectively. Higher than median levels of three serum markers were negatively associated with the 2-year LRC rate in the overall patient cohort: Osteopontin, IL8 and FasL2 (p ≤ 0.05). A radiomics model consisting of two radiomics features could be built showing that higher entropy and higher complexity of tumor Hounsfield unit distribution indicates worse LRC (concordance index 0.66). No correlation was found between biological and imaging markers.

CONCLUSIONS

There was no evidence that consolidation cetuximab would improve the 2-year LRC rate. Prognostic biological and imaging markers could be identified for the overall patient cohort. Studies with larger patient numbers are needed to correlate biological and imaging markers.

Studying global processing in autism and attention-deficit/hyperactivity disorder with gaze movements: The example of a copying task

Recent discussions in the literature, along with the revision of the Diagnostic and Statistical Manual (DSM) (American Psychiatric Association 2013), suggest aetiological commonalities between the highly comorbid Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). Addressing this discussion requires studying these disorders together by comparing constructs typical to each of them. In the present study, we investigate global processing, known to be difficult for participants with ASD, and Intra-Subject Variability (ISV), known to be consistently increased in participants with ADHD, in groups, aged 10–13 years, with ADHD (n = 25), ASD without comorbid ADHD (ASD-) (n = 13) and ASD with ADHD (ASD+) (n = 18) in comparison with a typically developing group (n = 22). A Copying task, typically requiring global processing and in this case particularly designed using equally complex stimuli to also measure ISV across trials, was selected. Oculomotor measures in this task proved to be particularly sensitive to group differences. While increased ISV was not observed in the present task in participants with ADHD, both ASD groups looked longer on the figure to be drawn, indicating that global processing takes longer in ASD. However, the ASD+ group fixated on the figure only between drawing movements, whereas the ASD- group did this throughout the drawing process. The present study provides evidence towards ASD and ADHD being separate, not-overlapping, disorders. Since the pure ASD- group was affected more by central coherence problems than the ASD+ group, it may suggest that neuropsychological constructs interact differently in different clinical groups and sub-groups.

Assessing physical activity in people with mental illness: 23-country reliability and validity of the simple physical activity questionnaire (SIMPAQ)

BACKGROUND

Physical inactivity is a key contributor to the global burden of disease and disproportionately impacts the wellbeing of people experiencing mental illness. Increases in physical activity are associated with improvements in symptoms of mental illness and reduction in cardiometabolic risk. Reliable and valid clinical tools that assess physical activity would improve evaluation of intervention studies that aim to increase physical activity and reduce sedentary behaviour in people living with mental illness.

METHODS

The five-item Simple Physical Activity Questionnaire (SIMPAQ) was developed by a multidisciplinary, international working group as a clinical tool to assess physical activity and sedentary behaviour in people living with mental illness. Patients with a DSM or ICD mental illness diagnoses were recruited and completed the SIMPAQ on two occasions, one week apart. Participants wore an Actigraph accelerometer and completed brief cognitive and clinical assessments.

RESULTS

Evidence of SIMPAQ validity was assessed against accelerometer-derived measures of physical activity. Data were obtained from 1010 participants. The SIMPAQ had good test-retest reliability. Correlations for moderate-vigorous physical activity was comparable to studies conducted in general population samples. Evidence of validity for the sedentary behaviour item was poor. An alternative method to calculate sedentary behaviour had stronger evidence of validity. This alternative method is recommended for use in future studies employing the SIMPAQ.

CONCLUSIONS

The SIMPAQ is a brief measure of physical activity and sedentary behaviour that can be reliably and validly administered by health professionals.

Assessing forest availability for wood supply in Europe

The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The provision of harmonized forest statistics is necessary for the development of forest associated policies and to support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood supply (FNAWS) according to national and reference definitions by determining the restrictions and associated thresholds considered at country level to classify forests as FAWS or FNAWS. FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to 5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the European countries studied, thereby facilitating a consistent approach to assess forests available for supply for the purpose of international reporting.

The impact of the COMT genotype and cognitive demands on facets of intra-subject variability

Intra-Subject Variability (ISV), a potential index of catecholaminergic regulation, is elevated in several disorders linked with altered dopamine function. ISV has typically been defined as reaction time standard deviation. However, the ex-Gaussian and spectral measures capture different aspects and may delineate different underlying sources of ISV; thus reflecting different facets of the construct. We examined the impact of factors associated with dopamine metabolism, namely, Catechol-O-Methyltransferase Val158Met (COMT) genotype and Working Memory (WM) and response-switching on ISV facets in young healthy adults. The Met allele was associated with overall increased variability. The rather exclusive sensitivity of ex-Gaussian tau to frequencies below 0.025 Hz and the quasi-periodic structure of particularly slow responses support the interpretation of tau as low frequency fluctuations of neuronal networks. Sigma, by contrast, may reflect neural noise. Regarding cognitive demands, a WM load-related increase in variability was present for all genotypes and all ISV facets. Contrastingly, ISV facets reacted differently to variations in response-switching as, across genotypes, sigma was elevated for rare target trials whereas tau was elevated for frequent standard trials, particularly for Met homozygotes. Our findings support the significant role of COMT in regulating behavioural ISV with its facetted structure and presumed underlying neural processes.

Einsatz der Harnuntersuchung zur Beurteilung des Säure-Basen-Haushalts in der Bestandsbetreuung von Milchkuhherden

Bei Hochleistungskühen haben subklinische Störungen des Säure-Basen-Haushalts große Bedeutung. Eine Möglichkeit zur Beurteilung des Säure-Basen-Haushalts bietet die Harnuntersuchung. Im Rahmen von monatlichen Untersuchungen in neun Betrieben in Brandenburg, Mecklenburg-Vorpommern und Sachsen-Anhalt wurden bei Kühen aus je fünf unterschiedlichen Laktationsgruppen (frühe Trockensteher, Vorbereitungskühe, Kühe in Woche 0-1, 3-5, 15-18 post partum) Harnproben entnommen und die Poolproben untersucht. Der Harn-pH reagiert signifikant auf die Zufütterung saurer Salze und NaHCO3, die Veränderungen sind aber nur gering. Mit dem Einsatz saurer Salze sinken die Netto-Säure-Basen-Ausscheidung (NSBA) und die Natriumausscheidung signifikant, die Kalziumausscheidung steigt signifikant an. Mit der Zufütterung von NaHCO3 fällt die Chloridausscheidung ab, NSBA und pH-Wert steigen in alkalische Bereiche. NaHCO3 bedingt eine alkalische Harnreaktion, die es unmöglich macht, eventuelle azidotische Belastungen zu entdecken.

The hypoxia-activated prodrug evofosfamide in combination with multiple regimens of radiotherapy

The promising treatment combination of ionizing radiation (IR) with a hypoxia-activated prodrug (HAP) is based on biological cooperation. Here we investigated the hypoxia-activated prodrug evofosfamide in combination with different treatment regimens of IR against lung A549- and head&neck UT-SCC-14-derived tumor xenografts. DNA damage-related endpoints and clonogenic cell survival of A549 and UT-SCC-14 carcinoma cells were probed under normoxia and hypoxia.Evofosfamide (TH-302) induced DNA-damage and a dose-dependent antiproliferative response in A549 cells on cellular pretreatment under hypoxia, and supra-additively reduced clonogenic survival in combination with IR. Concomitant treatment of A549-derived tumor xenografts with evofosfamide and fractionated irradiation induced the strongest treatment response in comparison to the corresponding neoadjuvant and adjuvant regimens. Adjuvant evofosfamide was more potent than concomitant and neoadjuvant evofosfamide when combined with a single high dose of IR. Hypoxic UT-SCC-14 cells and tumor xenografts thereof were resistant to evofosfamide alone and in combination with IR, most probably due to reduced P450 oxidoreductase expression, which might act as major predictive determinant of sensitivity to HAPs.In conclusion, evofosfamide with IR is a potent combined treatment modality against hypoxic tumors. However, the efficacy and the therapeutic outcome of this combined treatment modality is, as indicated here in preclinical tumor models, dependent on scheduling parameters and tumor type, which is most probably related to the status of respective HAP-activating oxidoreductases. Further biomarker development is necessary for the launch of successful clinical trials.

[Specialist Training in Psychiatry and Psychotherapy : Evaluation of the East Westphalia-Lippe Academy curriculum]

BACKGROUND

Despite of the undisputed impact of education quality on becoming a specialist in psychiatry and psychotherapist, systematic studies in this field do not exist in Germany, apart from the evaluation of practical education by the medical councils.

MATERIALS AND METHODS

The Akademie-OWL, an education union of psychiatric clinics in the East Westphalia region of Germany, has provided 12-item questionnaire-based routine evaluations of theoretical education seminars since 2009. Seminars are held by consultants of psychiatry and psychotherapy within six separate weeks over a period of four years. All lecturers receive feedback from the evaluation. The results of this ongoing evaluation are presented using a typical example and in an aggregated format as a time series on the basis of one global item.

RESULTS

The data show that (1) the full range of a five-point Likert scale is used by the candidates, (2) psychiatric competences of the lecturers are more positively evaluated than their didactic competences, (3) neither within the four-years period of psychiatric education nor between different generations of candidates are systematic changes of evaluation results observed, and (4) minor to moderate differences of evaluation were observed between the different thematic fields of psychiatry and psychotherapy.

DISCUSSION

These results indicate the need of more systematic education research on establishing valid and reliable specific instruments as well as the need of systematic training of didactic competences of teaching consultants.

Secretome Signature Identifies ADAM17 as Novel Target for Radiosensitization of Non-Small Cell Lung Cancer

PURPOSE

Ionizing radiation (IR) induces intracellular signaling processes as part of a treatment-induced stress response. Here we investigate IR-induced ADAM17 activation and the role of ADAM17-shed factors for radiation resistance in non-small cell lung cancer.

EXPERIMENTAL DESIGN

Large-scale secretome profiling was performed using antibody arrays. Secretion kinetics of ADAM17 substrates was determined using ELISA across multiple in vitro and in vivo models of non-small cell lung cancer. Clonogenic survival and tumor xenograft assays were performed to determine radiosensitization by ADAM17 inhibition.

RESULTS

On the basis of a large-scale secretome screening, we investigated secretion of auto- or paracrine factors in non-small cell lung cancer in response to irradiation and discovered the ADAM17 network as a crucial mediator of resistance to IR. Irradiation induced a dose-dependent increase of furin-mediated cleavage of the ADAM17 proform to active ADAM17, which resulted in enhanced ADAM17 activity in vitro and in vivo Genetic or pharmacologic targeting of ADAM17 suppressed IR-induced shedding of secreted factors, downregulated ErbB signaling in otherwise cetuximab-resistant target cells, and enhanced IR-induced cytotoxicity. The combined treatment modality of IR with the ADAM17 inhibitor TMI-005 resulted in a supra-additive antitumor response in vivo demonstrating the potential of ADAM17 targeting in combination with radiotherapy.

CONCLUSIONS

Radiotherapy activates ADAM17 in non-small cell lung cancer, which results in shedding of multiple survival factors, growth factor pathway activation, and IR-induced treatment resistance. We provide a sound rationale for repositioning ADAM17 inhibitors as short-term adjuvants to improve the radiotherapy outcome of non-small cell lung cancer. Clin Cancer Res; 22(17); 4428-39. ©2016 AACR.

Abstract A185: Combined treatment strategies for microtubule interfering agent-resistant tumors

Treatment resistances to specific anticancer agents and radiotherapy are often linked to the mutated genetic background of tumor cells. Their activities towards co-targeted tumor microenvironment-related cells are thereby also abrogated but could be reestablished as part of rationally-designed combined treatment modalities. Here we mechanistically investigate in two clinically relevant microtubule-interfering agent (MIA)-refractory tumor models the potency of combined treatment modalities of MIAs, inhibitors of angiogenesis and ionizing radiation to overcome MIA-resistance.

Single and combined treatment regimens of ionizing radiation, microtubule stabilizing and de-stabilizing agents and anti-angiogenic compounds (everolimus, bevacizumab) were investigated in genetically defined MIA-sensitive and tubulin-mutated or P-glycoprotein/MDR1-overexpressing MIA-resistant lung and colon adenocarcinoma carcinoma cell systems (A549, SW480) and in the corresponding tumor xenografts. MIAs potently inhibited A549wt and endothelial cell proliferation, while no anti-proliferative effect was observed in the corresponding MIA-resistant tumor cells. More important, MIAs did not downregulate anymore HIF-1α transcriptional activity and subsequent secretion of HIF-1α-mediated growth factors and cytokines from these MIA-resistant tumor cells. Continuous pro-survival auto- and paracrine signaling from these resistant tumor cells resulted in an additional level of treatment resistance towards MIAs and ionizing radiation as determined in tumor xenografts derived from MIA-resistant tumor cells. However rationally-designed combined treatment of MIAs with mTOR-signaling- or VEGF-antagonists strongly re-sensitized treatment-resistant tumors to the corresponding MIA.

These data demonstrate that the interaction between the tumor cell compartment and the tumor microenvironment strongly determines the treatment response to different anticancer treatment modalities.A combined treatment modality of MIAs with antiangiogenic agents is potent to overcome tumor cell-linked MIA-resistance and should be considered as clinical strategy for MIA-refractory tumor entities.

Citation Format: Angela Broggini-Tenzer, Ashish Sharma, Sabine Bender, Katarzyna Nytko-Karouzakis, Martin Pruschy. Combined treatment strategies for microtubule interfering agent-resistant tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A185.

Abstract 4045: MRAS and SHOC2 interact with SCRIB and coordinate ERK pathway activation with polarity and tumorigenic growth

SHOC2 is mutated in Noonan syndrome and plays a key role in the activation of the ERK-MAPK pathway, which is upregulated in the majority of human cancers. SHOC2 functions as a PP1-regulatory protein and as an effector of MRAS. Here we show that SHOC2 and MRAS form a complex with SCRIB, a polarity protein with tumor suppressor properties. SCRIB functions as a PP1-regulatory protein and antagonizes SHOC2-mediated RAF dephosphorylation through a mechanism involving competition for PP1 molecules within the same macromolecular complex. SHOC2 function is selectively required for the malignant properties of tumor cells with mutant RAS, and both MRAS and SHOC2 play a key role in polarized migration. We propose that MRAS, through its ability to recruit a complex with paradoxical components, coordinates ERK pathway spatiotemporal dynamics with polarity and that this complex plays a key role during tumorigenic growth.

Citation Format: Lucy C. Young, Nicole Hartig, Marta Munoz-Alegre, Juan A. Oses-Prieto, Sevi Durdu, Sabine Bender, Vineetha Vijakumar, Matteo Vietri Rudan, Christina Gewinner, Amit P. Jathoul, Rupinder Ghatrora, Mark L. Lythgoe, Alma L. Burlingame, Pablo Rodriguez-Viciana. MRAS and SHOC2 interact with SCRIB and coordinate ERK pathway activation with polarity and tumorigenic growth. [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 4045. doi:10.1158/1538-7445.AM2015-4045

Combined treatment strategies for microtubule stabilizing agent-resistant tumors

BACKGROUND

Resistance to microtubule-stabilizing agents is a major hurdle for successful cancer therapy. We investigated combined treatment of microtubule-stabilizing agents (MSAs) with inhibitors of angiogenesis to overcome MSA resistance.

METHODS

Treatment regimens of clinically relevant MSAs (patupilone and paclitaxel) and antiangiogenic agents (everolimus and bevacizumab) were investigated in genetically defined MSA-resistant lung (A549EpoB40) and colon adenocarcinoma (SW480) tumor xenografts in nude mice (CD1-Foxn1<nu>, ICRnu; 5-14 per group). Tumor growth delays were calculated by Kaplan-Meier analysis with Holm-Sidak tests. All statistical tests were two-sided.

RESULTS

Inhibition of mTOR-kinase by everolimus only minimally reduced the proliferative activity of β tubulin-mutated lung adenocarcinoma cells alone and in combination with the MSA patupilone, but everolimus inhibited expression and secretion of vascular endothelial growth factor (VEGF) from these cells. mTOR-kinase inhibition strongly sensitized tumor xenografts derived from these otherwise MSA-resistant tumor cells to patupilone. Tumors treated with the combined modality of everolimus and patupilone had statistically significantly reduced tumor volume and stronger tumor growth delay (16.2 ± 1.01 days) than control- (7.7 ± 0.3 days, P = .004), patupilone- (10 ± 0.97 days, P = .009), and everolimus-treated (10.6 ± 1.4 days, P = .014) tumors. A combined treatment modality with bevacizumab also resensitized this MSA-refractory tumor model to patupilone. Treatment combination also strongly reduced microvessel density, corroborating the relevance of VEGF targeting for the known antivasculature-directed potency of MSA alone in MSA-sensitive tumor models. Resensitization to MSAs was also probed in P glycoprotein-overexpressing SW480-derived tumor xenografts. Different bevacizumab regimens also sensitized this otherwise-resistant tumor model to clinically relevant MSA paclitaxel.

CONCLUSIONS

A treatment combination of MSAs with antiangiogenic agents is potent to overcome tumor cell-linked MSA resistance and should be considered as strategy for MSA-refractory tumor entities.

Abstract A22: An MRAS, SHOC2, and SCRIB complex coordinates ERK pathway activation with polarity and tumorigenic growth

SHOC2 is mutated in Noonan syndrome and plays a key role in the activation of the ERK-MAPK pathway, which is upregulated in the majority of human cancers. SHOC2 functions as a PP1-regulatory protein and as an effector of MRAS. SHOC2 and MRAS form a complex with SCRIB, a polarity protein with tumor suppressor properties. SCRIB functions as a PP1-regulatory protein and antagonizes SHOC2-mediated RAF dephosphorylation through a mechanism involving competition for PP1 molecules within the same macromolecular complex. SHOC2 function is selectively required for the malignant properties of tumor cells with mutant RAS, and both MRAS and SHOC2 play a key role in polarized migration. We propose that MRAS, through its ability to recruit a complex with paradoxical components, coordinates ERK pathway spatiotemporal dynamics with polarity and that this complex plays a key role during tumorigenic growth.

Citation Format: Lucy C. Young, Nicole Hartig, Marta Munoz-Alegre, Juan A. Oses-Prieto, Sevi Durdu, Sabine Bender, Vineetha Vijayakumar, Matteo Vietri Rudan, Christina Gewinner, Stephen Henderson, Amit P. Jathoul, Rupinder Ghatrora, Mark F. Lythgoe, Alma L. Burlingame, Pablo Rodriguez-Viciana. An MRAS, SHOC2, and SCRIB complex coordinates ERK pathway activation with polarity and tumorigenic growth. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr A22. doi: 10.1158/1557-3125.RASONC14-A22

Elucidating the neurophysiological underpinnings of autism spectrum disorder: new developments

The study of neurophysiological approaches together with rare and common risk factors for Autism Spectrum Disorder (ASD) allows elucidating the specific underlying neurobiology of ASD. Whereas most neurophysiologically based research in ASD to date has focussed on case-control differences based on the DSM- or ICD-based categorical ASD diagnosis, more recent studies have aimed at studying genetically and/or neurophysiologically defined homogeneous ASD subgroups for specific neuronal biomarkers. This review addresses the neurophysiological investigation of ASD by evoked and event-related potentials, by EEG/MEG connectivity measures such as coherence, and transcranial magnetic stimulation. As an example of classical neurophysiological studies in ASD, we report event-related potential studies which have illustrated which brain areas and processing stages are affected in the visual perception of socially relevant stimuli. However, a paradigm shift has taken place in recent years focussing on how these findings can be tracked down to basic neuronal functions such as deficits in cortico-cortical connectivity and the interaction between brain areas. Disconnectivity, for example, can again be related to genetically induced shifts in the excitation/inhibition balance. Genetic causes of ASD may be grouped by their effects on the brain's system level to identify ASD subgroups which respond differentially to therapeutic interventions.