Effect of inulin on breath hydrogen, postprandial glycemia, gut hormone release, and appetite perception in RYGB patients: a prospective, randomized, cross-over pilot study

BACKGROUND AND OBJECTIVE

Large intestinal fermentation of dietary fiber may control meal-related glycemia and appetite via the production of short-chain fatty acids (SCFA) and the secretion of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). We investigated whether this mechanism contributes to the efficacy of the Roux-en-Y gastric bypass (RYGB) by assessing the effect of oligofructose-enriched inulin (inulin) vs. maltodextrin (MDX) on breath hydrogen (a marker of intestinal fermentation), plasma SCFAs, gut hormones, insulin and blood glucose concentrations as well as appetite in RYGB patients.

METHOD

Eight RYGB patients were studied on two occasions before and ~8 months after surgery using a cross-over design. Each patient received 300 ml orange juice containing 25 g inulin or an equicaloric load of 15.5 g MDX after an overnight fast followed by a fixed portion snack served 3 h postprandially. Blood samples were collected over 5 h and breath hydrogen measured as well as appetite assessed using visual analog scales.

RESULTS

Surgery increased postprandial secretion of GLP-1 and PYY (P ≤ 0.05); lowered blood glucose and plasma insulin increments (P ≤ 0.05) and reduced appetite ratings in response to both inulin and MDX. The effect of inulin on breath hydrogen was accelerated after surgery with an increase that was earlier in onset (2.5 h vs. 3 h, P ≤ 0.05), but less pronounced in magnitude. There was, however, no effect of inulin on plasma SCFAs or plasma GLP-1 and PYY after the snack at 3 h, neither before nor after surgery. Interestingly, inulin appeared to further potentiate the early-phase glucose-lowering and second-meal (3-5 h) appetite-suppressive effect of surgery with the latter showing a strong correlation with early-phase breath hydrogen concentrations.

CONCLUSION

RYGB surgery accelerates large intestinal fermentation of inulin, however, without measurable effects on plasma SCFAs or plasma GLP-1 and PYY. The glucose-lowering and appetite-suppressive effects of surgery appear to be potentiated with inulin.

Evidence-Based Tools for Dietary Assessments in Nutrition Epidemiology Studies for Dementia Prevention

Increasing evidence proposes diet as a notable modifiable factor and viable target for the reduction of Alzheimer's Disease risk and age-related cognitive decline. However, assessment of dietary exposures is challenged by dietary capture methods that are prone to misreporting and measurement errors. The utility of -omics technologies for the evaluation of dietary exposures has the potential to improve reliability and offer new insights to pre-disease indicators and preventive targets in cognitive aging and dementia. In this review, we present a focused overview of metabolomics as a validation tool and framework for investigating the immediate or cumulative effects of diet on cognitive health.

Investigating the Role of Diet and Exercise in Gut Microbe-Host Cometabolism

We investigated the individual and combined effects of diet and physical exercise on metabolism and the gut microbiome to establish how these lifestyle factors influence host-microbiome cometabolism. Urinary and fecal samples were collected from athletes and less active controls. Individuals were further classified according to an objective dietary assessment score of adherence to healthy dietary habits according to WHO guidelines, calculated from their proton nuclear magnetic resonance (1H-NMR) urinary profiles. Subsequent models were generated comparing extremes of dietary habits, exercise, and the combined effect of both. Differences in metabolic phenotypes and gut microbiome profiles between the two groups were assessed. Each of the models pertaining to diet healthiness, physical exercise, or a combination of both displayed a metabolic and functional microbial signature, with a significant proportion of the metabolites identified as discriminating between the various pairwise comparisons resulting from gut microbe-host cometabolism. Microbial diversity was associated with a combination of high adherence to healthy dietary habits and exercise and was correlated with a distinct array of microbially derived metabolites, including markers of proteolytic activity. Improved control of dietary confounders, through the use of an objective dietary assessment score, has uncovered further insights into the complex, multifactorial relationship between diet, exercise, the gut microbiome, and metabolism. Furthermore, the observation of higher proteolytic activity associated with higher microbial diversity indicates that increased microbial diversity may confer deleterious as well as beneficial effects on the host.IMPORTANCE Improved control of dietary confounders, through the use of an objective dietary assessment score, has uncovered further insights into the complex, multifactorial relationship between diet, exercise, the gut microbiome, and metabolism. Each of the models pertaining to diet healthiness, physical exercise, or a combination of both, displayed a distinct metabolic and functional microbial signature. A significant proportion of the metabolites identified as discriminating between the various pairwise comparisons result from gut microbe-host cometabolism, and the identified interactions have expanded current knowledge in this area. Furthermore, although increased microbial diversity has previously been linked with health, our observation of higher microbial diversity being associated with increased proteolytic activity indicates that it may confer deleterious as well as beneficial effects on the host.

Acute dietary saturated fat intake suppresses human monocyte subset inflammatory and chemokine responses

Background

Dietary saturated fat (SF) intake is implicated in increasing cardiovascular risk. Studies suggest SF may incite an inflammatory immune response yet the mechanisms for this remain unclear. Circulating blood monocyte subsets (classical “CD16low” and non-classical/intermediate “CD16high”) are thought to differentially contribute to the macrophage foam cell burden in atherosclerotic plaque, yet they are heterogenous and much is still unknown about their response to dietary lipid.

Purpose

This dietary intervention study hypothesised that a subset-specific monocyte response occurs following acute SF intake in healthy individuals.Top of Form

Methods

10 healthy participants were fed a coconut oil, lauric acid-rich meal. Monocyte subsets were purified from fasting and 4h postprandial blood by fluorescence activated cytometry (FACS) into CD16low and CD16high subsets. Surface marker expression was recorded by FACS, gene expression by qPCR, lipid loading by fluorescence microscopy, cytokine responses by ELISA and mass spectrometry was utilised to trace dietary fat into circulating monocytes. Triglyceride rich lipoprotein (TGRL) was obtained through ultracentrifugation of postprandial blood. TLR agonists LPS (TLR4) and R848 (TLR7/8) were used to replicate infectious stimuli to provoke a cytokine response.

Results

SF meal intake resulted in a 4h postprandial rise in serum triglycerides (TG). Other than a small rise in HLA-DR in postprandial CD16low monocytes, no changes in CD14, CD16 or CD11c levels were noted. Inflammatory gene expression was downregulated although a rise in lipid handling gene ABCA1 was noted in both subsets. Postprandial monocytes accumulated cytoplasmic neutral lipid droplets (larger and more numerate droplets in CD16low). Mass-spectrometry confirmed entry of dietary lipid into circulating monocytes. Postprandial monocyte functional responses were impaired; lipid-loaded postprandial monocytes were less able to migrate towards a chemokine gradient. Following TLR challenge, the inflammatory response was abrogated in postprandial monocytes, further suppressed by in vitro postprandial TGRL addition. Lipidomic analyses confirmed postprandial monocyte lauric acid accumulation in the form of free fatty acid and TG trilaurin, and 9(S)-, 13(S)-HODE and 17(S)-HDoHE, that are metabolites of docosahexanoic acid (DHA) and possess anti-inflammatory properties. The attached graphical abstract summarises the pertinent findings.

Conclusions

Acute dietary SF intake of a lauric acid-rich meal results in postprandial monocyte suppression of inflammatory TLR responses, a reduction in the ability to migrate towards a chemokine gradient whilst accumulating cytoplasmic neutral lipid droplets. The immunosuppression may be caused by accumulation of anti-inflammatory metabolites of DHA.

Graphical Abstract

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation, UK

Success of reformulation and health education in reducing sodium intakes across socioeconomic groups

Background

The UK salt reduction programme started in 2005, consisting of education campaigns and a reformulation strategy. This programme is often cited as an example of a successful public health programme, and used as a model for other programmes. This study aims at assessing how the programme succeeded in reducing sodium intakes, and whether success was even across socioeconomic (SES) groups.

Methods

Food intakes for the UK adult population were derived from food diaries in the UK National Diet and Nutrition Survey for 2008/09 (Y1) and 2016/17 (Y9). Year-specific sodium densities of foods were used to calculate the quantity-weighted average sodium density of all food and beverage consumed by the population. Using a decomposition approach (Griffith et al., Economica, 2017), changes in sodium density were attributed to either changes in food composition (change in sodium density), or changes in behaviour (type and quantity of food products consumed), stratifying by SES.

Results

The programme was linked to a 16% decrease in sodium intakes between Y1 and Y9, while sodium density decreased by 15%. This decrease was largely driven by reformulation (-12mg/100g), while changes in food choices had a smaller impact (-2mg/100g). This finding was consistent across SES groups, whether stratified by education or income, with no significant differences between SES groups in behavioural responses to the programme (changes in food choices).

Conclusions

Changing people's food environment, through reformulation to reduce the sodium density of foods, had a larger impact on sodium intakes in the UK population than efforts to change food choices, and produced consistent impacts across SES groups.

Key messages

Reformulation led to a consistent reduction of the sodium density of food consumed across SES. There was no evidence of adverse equity impact from changes in behaviour.

Short chain fatty acids in human gut and metabolic health

Evidence is accumulating that short chain fatty acids (SCFA) play an important role in the maintenance of gut and metabolic health. The SCFA acetate, propionate and butyrate are produced from the microbial fermentation of indigestible carbohydrates and appear to be key mediators of the beneficial effects elicited by the gut microbiome. Microbial SCFA production is essential for gut integrity by regulating the luminal pH, mucus production, providing fuel for epithelial cells and effects on mucosal immune function. SCFA also directly modulate host metabolic health through a range of tissue-specific mechanisms related to appetite regulation, energy expenditure, glucose homeostasis and immunomodulation. Therefore, an increased microbial SCFA production can be considered as a health benefit, but data are mainly based on animal studies, whereas well-controlled human studies are limited. In this review an expert group by ILSI Europe’s Prebiotics Task Force discussed the current scientific knowledge on SCFA to consider the relationship between SCFA and gut and metabolic health with a particular focus on human evidence. Overall, the available mechanistic data and limited human data on the metabolic consequences of elevated gut-derived SCFA production strongly suggest that increasing SCFA production could be a valuable strategy in the preventing gastro-intestinal dysfunction, obesity and type 2 diabetes mellitus. Nevertheless, there is an urgent need for well controlled longer term human SCFA intervention studies, including measurement of SCFA fluxes and kinetics, the heterogeneity in response based on metabolic phenotype, the type of dietary fibre and fermentation site in fibre intervention studies and the control for factors that could shape the microbiome like diet, physical activity and use of medication.

Understanding the interplay between food structure, intestinal bacterial fermentation and appetite control

Epidemiological and clinical evidence highlight the benefit of dietary fibre consumption on body weight. This benefit is partly attributed to the interaction of dietary fibre with the gut microbiota. Dietary fibre possesses a complex food structure which resists digestion in the upper gut and therefore reaches the distal gut where it becomes available for bacterial fermentation. This process yields SCFA which stimulate the release of appetite-suppressing hormones glucagon-like peptide-1 and peptide YY. Food structures can further enhance the delivery of fermentable substrates to the distal gut by protecting the intracellular nutrients during upper gastrointestinal digestion. Domestic and industrial processing can disturb these food structures that act like barriers towards digestive enzymes. This leads to more digestible products that are better absorbed in the upper gut. As a result, less resistant material (fibre) and intracellular nutrients may reach the distal gut, thus reducing substrates for bacterial fermentation and its subsequent benefits on the host metabolism including appetite suppression. Understanding this link is essential for the design of diets and food products that can promote appetite suppression and act as a successful strategy towards obesity management. This article reviews the current evidence in the interplay between food structure, bacterial fermentation and appetite control.

A national Health and Work Strategy: a search for evidence

BACKGROUND

The Health and Safety Executive's new Health and Work Strategy is based on an up-to-date assessment of workplace health priorities. Rather than replicating traditional prioritization approaches, a broader assessment of health and work priorities was carried out using a range of stakeholders.

AIMS

To develop a set of health priorities for further research and intervention activity.

METHODS

Four exercises were carried out, including internal prioritization, two external web-hosted questionnaire studies of younger workers and occupational health professionals, focus groups and tele-depth interviews with workplace health and safety professionals.

RESULTS

The highest rated internal priorities (weighted priority scores) were identified as mesothelioma (70), lung cancer (69.25), chronic obstructive pulmonary disease (COPD; 69), musculoskeletal disorders (MSDs; 66.25), hearing loss (65.75), stress (65.5), asthma (64.5) and hand-arm vibration syndrome (61.5). Using the three highest ranked criteria developed by occupational health professionals ((i) the preventability of the condition, (ii) the impact of the condition and (iii) the number of workers affected), mesothelioma, lung cancer, COPD, MSDs, hearing loss, stress and asthma were identified as the top seven priorities. Generic issues identified included ageing and work, obesity, newer technologies, and ethnicity and cultures of workforces. Apprentices identified stress, depression, anxiety, musculoskeletal and respiratory disorders, fatigue and workload as important workplace health considerations.

CONCLUSIONS

This process identified a number of expected and new areas of health research interest. We believe the findings reflect the real world requirements of work as assessed by occupational health and safety practitioners and workers.

Sensory perception testing by monofilaments in the digits of controls and workers with HAVS

Objective

To determine if heavy manual work affects sensory perception in the digits and whether Semmes–Weinstein monofilaments (SWM) can be used as a screening tool to detect sensory neuropathy in the digits of workers exposed to hand-transmitted vibration (HTV).

Methods

A cross-sectional study of office workers, heavy manual workers not exposed to HTV and workers with hand-arm vibration syndrome (HAVS). Sensory perception was measured in the digits by SWM using a forced-choice method to determine variability by sex, age, hand and digit. Frequency distributions were used to determine limit values and linear weighted kappa for intra-digit variability. Poisson regression was used to explore the relationship between sensory perception by SWM and abnormalities of thermal and vibration perception in the hands of workers with HAVS.

Results

The sensory perception threshold of office workers did not vary by hand or digit. It was significantly lower in women < 30 than women aged ≥ 30 years. The 95th percentile for heavy manual workers was 1.00 (95% CI 0.60–1.00) and significantly higher than for office workers at 0.16 (95% CI 0.16–0.16). Heavy manual workers > 50 years had the highest threshold at 1.40 (95% CI 1.00–2.00). Weighted kappa for reliability was 0.63 (95% CI 0.53–0.70). A mean SWM threshold of ≥ 1.0 gram-force had a 79% sensitivity and 64% specificity for detecting abnormalities of thermal and vibration perception in the ipsilateral index and little fingers of workers with HAVS.

Conclusions

SWM are a useful screening tool for detecting sensory loss in the digits of workers exposed to HTV.

Developing a questionnaire to assess the health effects of bioaerosols

Background

Bioaerosol exposure occurs in several industries including green waste recycling, poultry farming, grain, animal feed and cotton production. Whilst several studies have investigated exposure and health effects in compost workers, the best questions to ask about health are uncertain.

Aims

This study aimed to develop a questionnaire to assess health symptoms in compost workers.

Methods

A 46-item questionnaire to ascertain possible symptoms of occupational illness related to bioaerosol exposure in a cohort of UK industrial compost workers and delivery in an interviewer-led format. The reliability of the questionnaire was assessed using Cronbach's α. A principal component analysis (PCA) was conducted to condense the questionnaire for practical purposes.

Results

One hundred and eleven (89%) workers completed the questionnaire. All items showed very good reliability (Cronbach's α = 0.83). After removing perfectly correlated questions from the data set, the PCA was conducted on a reduced data set of 28 items to explore underlying themes. Nine components were identified that explained 77% of the total variation. Nine of the questions removed prior to PCA due to perfect correlation were reintroduced because they added clinical value. The final questionnaire therefore consisted of 37 items and retained very adequate reliability (Cronbach's α = 0.76).

Conclusions

Our health questionnaire has demonstrated adequate reliability when used within this industrial composting workforce. Further applications may include health surveillance, investigating outbreaks of occupational disease or research. Future work should examine the predictive validity of the questionnaire in these settings.

Reflecting on progress since the 2005 NARSTO emissions inventory report

Emission inventories are the foundation for cost-effective air quality management activities. In 2005, a report by the public/private partnership North American Research Strategy for Tropospheric Ozone (NARSTO) evaluated the strengths and weaknesses of North American emissions inventories and made recommendations for improving their effectiveness. This paper reviews the recommendation areas and briefly discusses what has been addressed, what remains unchanged, and new questions that have arisen. The findings reveal that all emissions inventory improvement areas identified by the 2005 NARSTO publication have been explored and implemented to some degree. The U.S. National Emissions Inventory has become more detailed and has incorporated new research into previously under-characterized sources such as fine particles and biomass burning. Additionally, it is now easier to access the emissions inventory and the documentation of the inventory via the internet. However, many emissions-related research needs exist, on topics such as emission estimation methods, speciation, scalable emission factor development, incorporation of new emission measurement techniques, estimation of uncertainty, top-down verification, and analysis of uncharacterized sources. A common theme throughout this retrospective summary is the need for increased coordination among stakeholders. Researchers and inventory developers must work together to ensure that planned emissions research and new findings can be used to update the emissions inventory. To continue to address emissions inventory challenges, industry, the scientific community, and government agencies need to continue to leverage resources and collaborate as often as possible. As evidenced by the progress noted, continued investment in and coordination of emissions inventory activities will provide dividends to air quality management programs across the country, continent, and world. Implications: In 2005, a report by the public/private partnership North American Research Strategy for Tropospheric Ozone (NARSTO) evaluated the strengths and weaknesses of North American air pollution emissions inventories. This paper reviews the eight recommendation areas and briefly discusses what has been addressed, what remains unchanged, and new questions that have arisen. Although progress has been made, many opportunities exist for the scientific agencies, industry, and government agencies to leverage resources and collaborate to continue improving emissions inventories.

Abstract 2327: Same day transduction and in vivo expansion of chimeric antigen receptors and synthetic driver constructs for adoptive cellular therapy

Adoptive cellular therapy (ACT) using ex vivo expanded chimeric antigen receptor (CAR) modified T cells to target cancer cells expressing CD19 has been very successful in the treatment of hematologic malignancies and the clinical application of this technology for solid tumor malignancies is a major focus of several research and development programs. Despite the clinical success of these products, there are several obstacles that currently limit widespread deployment of CAR-T. Current autologous CAR-T manufacturing approaches are complex, requiring centralized manufacturing facilities and extensive logistical control over the receipt and delivery of individually patient matched products. Several weeks are required to prepare and release CAR-T cells using current manufacturing processes from apheresis to genetic modification and expansion before the cell product is reinfused into the patient. However, recent studies suggest that limiting the ex vivo expansion time results in less differentiated CAR-T products with enhanced effector function. Successful engraftment and persistence for current autologous CAR-T cell products require the depletion of normal lymphocytes in patients with cytotoxic drugs (primarily cyclophosphamide, fludarabine or combinations) prior to administration of CAR-T cells. Although the use of non-myeloablative lymphodepleting regimens prior to CAR-T infusion significantly enhances the successful in vivo homeostatic expansion and persistence of administered CAR-T cells, non-myeloablative chemotherapy also requires significant supportive care. The development of a point of care approach to ACT has the potential to reduce the complexity of CAR T-cell immunotherapy and broaden access to a substantially greater number of cancer patients and address many of the limitations discussed above. The most ideal system would allow for rapid genetic modification of patient’s cells next to the patient, thereby eliminating chain of custody risks, combined with successful in vivo expansion and engraftment of cells in the patient to achieve therapeutic cellular levels without preconditioning through lymphodepletion. Here we describe and provide data demonstrating initial proof of concept for a novel point of care approach for CAR-T using engineered lentivirus vectors and resting human PBMC. Resting human PBMC were isolated from blood and successfully transduced within a four hour exposure to engineered lentivirus particles encoding a synthetic lymphoproliferative element. These modified cells expanded in vivo upon administration in mice. The entire process of PBMC isolation, genetic modification and dosing was completed within twelve hours vein to vein and represents a significant step forward in advancing the development of CAR-T therapies with point of care potential expanding upon patient accessibility and deployment.

Citation Format: Frederic Vigant, Jianfang Hu, Laurence Jadin, Benjamin Lopez, Tiffany Lam, Hiba Shaban, Anirban Kundu, Timothy Mayall, Gregory Schreiber, Farzad Haerizadeh, James Onuffer, Gregory Frost. Same day transduction and in vivo expansion of chimeric antigen receptors and synthetic driver constructs for adoptive cellular therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2327.

Abstract 3189: CAB-CAR-T: A novel conditionally active biologics approach to minimize on-target off-tumor effects in adoptive immunotherapy

Adoptive cellular therapy (ACT) using chimeric antigen receptor (CAR) modified T cells has demonstrated promising antitumor effects in hematologic malignancies leading to the recent approval of two CAR-T products targeting the B cell receptor associated protein CD19, however the safe development of CAR-T therapies for solid tumor malignancies remains less advanced in part due to the lack of precision in targeting solid tumor antigens. Identification of clinically viable tumor restricted target antigens while avoiding on-target off-tumor toxicities in normal tissue presents a significant challenge in the solid tumor CAR-T therapeutic scenario. The altered glycolytic pathway of the Warburg effect within the tumor microenvironment (TME) drives lactic acid production leading to an opportunity to develop novel CARs with functional TME dependent switching ability. The resulting acidic extracellular pH is a major feature of the TME and this unique property represents one novel mechanism by which target specificity may be achieved. Here we describe a novel Conditionally Active Biologics approach in adoptive immunotherapy termed CAB-CAR-T. By genetically engineering combinations of amino acid mutations into the antibody variable antigen recognition domains (scFv) of CAR constructs, we demonstrate that TME restricted target antigen engagement can be engineered into chimeric antigen receptors. The described CAB-CARs display minimal antigen dependent activity at the physiological pH of normal tissue. Under TME conditions (low pH) the affinity of CAB-CAR scFv domains against their antigen increases, such that tumor target recognition and CAR-T activity become pH dependent. Thus CAB-CAR-T cells display reversible “AND logic gate” properties, requiring both antigen presence and TME conditions for activity. Comparisons of target cell killing under TME permissive and physiologic pH conditions in a cellular impedance based kinetic killing assay demonstrate that CAB-CAR-T cells efficiently lyse antigen positive target cells at pH 6.7 (TME) with minimal activity at pH 7.4 (normal tissue). pH profiles of CAB-CAR-T were examined through buffering the culture medium down from physiologic pH in 0.1 pH increments, and the data demonstrated that the cytolytic activity of CAB-CAR-T incrementally increased as extracellular pH was decreased compared to control T cells. Similar pH dependence was observed for other measures of CAB-CAR-T activation including the early T cell surface activation marker CD69, the degranulation marker CD107a and cytokine release (IL-2 and IFNγ). Conditionally active chimeric antigen receptor T cells (CAB-CAR-T) harness unique properties of the tumor microenvironment to provide an opportunity to develop safer CAR-T therapeutics for tumor antigen targets also expressed on healthy tissues by minimizing on-target off-tumor activity.

Citation Format: Jianfang Hu, Benjamin Lopez, Tiffany Lam, Anirban Kundu, Timothy Mayall, Gregory Schreiber, Farzad Haerizadeh, James Onuffer, Gregory Frost. CAB-CAR-T: A novel conditionally active biologics approach to minimize on-target off-tumor effects in adoptive immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3189.

Abstract 3523: A high-throughput screening strategy for the identification of novel lymphoproliferative elements

Introduction - Chimeric Antigen Receptor (CAR) T-cell therapy is effective against certain leukemias and lymphomas and shows promise for other incurable malignancies. Considerable challenges remain however to expand this platform technology beyond transplant-oriented hospital care. Centralized manufacturing of genetically modified T cells, lymphodepleting chemotherapy and patient management of current CAR-T therapies are associated with significant costs and treatment complexity. As a first step to reduce this treatment complexity, the present study describes a high throughput combinatorial domain library screening method to identify synthetic lymphoproliferative elements capable of driving in vivo expansion and survival of CAR-T cells in a lymphoreplete host without the homeostatic proliferation signals generated by lymphodepleting chemotherapy.

Methods - High-diversity semi-rationally-designed combinatorial libraries of putative lymphoproliferative protein subdomains were DNA barcoded and assembled into a lentiviral vector co-expressing a ROR2-targeted CAR. Human PBMC were transduced with the library and cultured in vitro for several days. Purified cells were injected into mice bearing xenograft tumors modified to express the ROR2 antigen and compared to unmodified xenograft controls. The expansion rate of integrated cells was monitored weekly by quantitative PCR and, after 21 days of exposure, genomic DNA was isolated from blood, spleen and xenograft tumor tissues. Enriched barcodes were amplified using PCR and amplicons were subjected to HiSeq Next-Generation Sequencing. Barcode decoding was achieved using PacBio long read sequencing analysis to align full-length construct sequences with barcode quantitation.

Results - Using this approach, putative CAR-T cell driver candidates and common key protein subdomains were identified that support selective in vivo expansion and survival of human lymphocytes in a tumor-bearing mouse model.

Conclusion - Taken together, these results demonstrate that a high throughput combinatorial screening strategy with quantitative bioinformatics is a viable method for identifying protein domain combinations capable of selectively driving human CAR-T cells in vivo. These small synthetic combinatorial protein domains may facilitate lymphodepleting chemotherapy-free regimens and lower CAR-T cell doses in the future.

Citation Format: Laurence Jadin, Hiba Shaban, Anirban Kundu, Gregory Schreiber, Scooter Willis, Farzad Haerizadeh, James Onuffer, Gregory Frost. A high-throughput screening strategy for the identification of novel lymphoproliferative elements [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3523.

Abstract 5101: CAB-CAR-T: The prioritization of cell surface protein targets for conditionally active biologics to treat all solid tumors

Introduction

Proteins on the surface of cancer cells represent viable targets for conditionally active biologic (CAB) CAR-T therapy that only work in the tumor microenvironment. By modeling properties of cell surface proteins from TCGA datasets we seek to identify optimal targets across all TCGA cancer cohorts that when used in CAB-CAR-T therapies will provide the greatest number of treatment options for patients across all cancer malignancies.

Method

Cell surface proteins(n=1086) were identified and meta data specific to each gene was organized from a variety of public databases for data modeling. Various approaches based on ideal CAB-CAR-T properties are used to rank the cell surface proteins as therapeutic targets. The 31 TCGA cohorts representing the most comprehensive collection of genomic profiled tumor samples and outcomes of all cancers is used to rank cell surface proteins for the percentage of patients in each cohort who would be eligible for treatment based on predetermined mRNA cutoffs.

Various approaches were used to filter the ranked list based on ideal CAB-CAR-T properties: known antibodies that can be used for initial CAB-CAR-T development, non-receptor as a static protein structure, highly expressed in CCLE indicating mRNA expression is a feature of cancer cell lines and low expression in critical tissues like Heart, Lung, Liver, Muscle etc. Different ranked lists of cell surface proteins were used to determine the number of CAB-CAR-T products required to treat 90% of patients in TCGA cohorts. A patient with the highest mRNA expression above the mean plus one standard deviation as determine across all TCGA samples is assigned to that specific protein biomarker as eligible for treatment and removed from the list of patients still to be treated. A bootstrap p-value for the ranked lists was determined by calculating the minimum number of randomly selected cell surface proteins that would give 90% coverage of the TCGA cohort.

Results

It was shown that it is reasonable to find ranked list of genes with high mRNA expression in TCGA and minimum expression in off-target critical tissue that 5-7 CAB-CAR-T products could be used to treat 90% of TCGA patients. To achieve 100% treatment coverage each additional CAB-CAR-T product added to the list had minimum inclusion of additional patients for treatment.

Conclusions

By modeling various properties of cell surface proteins to establish future development of CAB-CAR-T products it is reasonable to expect 90% patient coverage with 10 distinct therapies. Further modeling will be performed to exam combination therapies where tumor heterogeneity is an important criteria for the ranked list to have efficacy, with a goal of maximizing complete responses (CRs) and minimize the chance of relapse in the future.

Citation Format: Hiba A. Shaban, Laurence Jadin, James Onuffer, Farzad Haerizadeh, Alissa Kerner, Gregory Schreiber, Gregory Frost, Scooter Willis. CAB-CAR-T: The prioritization of cell surface protein targets for conditionally active biologics to treat all solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5101.

Phase 1 trials of PEGylated recombinant human hyaluronidase PH20 in patients with advanced solid tumours

Background:

Hyaluronan accumulation in tumour stroma is associated with reduced survival in preclinical cancer models. PEGPH20 degrades hyaluronan to facilitate tumour access for cancer therapies. Our objective was to assess safety and antitumour activity of PEGPH20 in patients with advanced solid tumours.

Methods:

In HALO-109-101 (N=14), PEGPH20 was administered intravenously once or twice weekly (0.5 or 50 μg kg⁻¹) or once every 3 weeks (0.5–1.5 μg kg⁻¹). In HALO-109-102 (N=27), PEGPH20 was administered once or twice weekly (0.5–5.0 μg kg⁻¹), with dexamethasone predose and postdose.

Results:

Dose-limiting toxicities included grade ⩾3 myalgia, arthralgia, and muscle spasms; the maximum tolerated dose was 3.0 μg kg⁻¹ twice weekly. Plasma hyaluronan increased in a dose-dependent manner, achieving steady state by Day 8 in multidose studies. A decrease in tumour hyaluronan level was observed in 5 of the 6 patients with pretreatment and posttreatment tumour biopsies. Exploratory imaging showed changes in tumour perfusion and decreased tumour metabolic activity, consistent with observations in animal models.

Conclusions:

The tumour stroma has emerging importance in the development of cancer therapeutics. PEGPH20 3.0 μg kg⁻¹ administered twice weekly is feasible in patients with advanced cancers; exploratory analyses indicate antitumour activity supporting further evaluation of PEGPH20 in solid tumours.

Abstract B32: A tumor microenvironment specific EGFR targeting antibody-drug conjugate promotes regression in KRAS or BRAF mutant tumors

The epidermal growth factor (EGF) signaling pathway relies on recognition by its receptor, EGFR, and subsequent downstream signaling by the KRAS and BRAF proteins to relay proper proliferative, migratory, and angiogenic functions. Cancers with activating KRAS or BRAF mutations are resistant to EGFR targeting agents and correspond to a significant unmet medical need. We hypothesized that an anti-EGFR antibody-drug conjugate (ADC) could be active against KRAS or BRAF mutated tumors, due to the cytotoxic mechanism of the ADC warhead. In an effort to eliminate the known dermal toxicity associated with anti-EGFR therapy, and to mitigate potential toxicities associated with treatment by an anti-EGFR ADC, we wished to engineer an antibody with enhanced specificity towards EGFR in the tumor microenvironment (TME) and attenuated binding to EGFR in normal tissue. This was achieved by screening a library of antibody variants (based on cetuximab) in a spatially addressed manner for binding to a recombinant version of the EGFR extracellular domain (EGFRECD) in two separate ELISA reaction conditions. High affinity binding to the EGFRECD was desired in the first condition, which approximated the physicochemical properties of the TME (acidic pH, high lactic acid concentration, 25% human serum). In the second assay condition, which approximated mAb binding to EGFRECD in normal tissue (neutral pH, low lactic acid concentration, 25% human serum), attenuated binding affinity was desired. We identified a lead mAb variant, cMab-1501, which possessed several fold reduced binding to EGFRECD in the neutral pH, low lactic acid condition, when compared to EGFRECD binding in the low-pH, high lactic acid, assay condition. To evaluate enhanced specificity for binding to EGFR in vivo, cMab-1501 was compared to cetuximab for binding to both human donor foreskin xenografts and human A431 tumor xenografts, using a DyLight 755 conjugated version of each antibody, and subsequent fluorescence detection with a Caliper IVIS system. cMab-1501 and cetuximab demonstrated relatively comparable binding towards human A431 tumor xenografts in vivo. In addition, cetuximab bound relatively equally between human tumor xenografts and human skin grafts. However, no binding to EGFR in the human skin graft was detected for cMab-1501 over all days measured; suggesting that cMab-1501 was highly specific for binding to EGFR in the TME. We next generated an cMab-1501 based ADC (antibody-drug conjugate), via maleimide chemistry carrying a protease cleavable valine-citrulline-p-aminobenzyloxycarbonyl monomethylauristatin E (vcPAB-MMAE) cytotoxic moiety, forming a cMab-1501-vcPAB-MMAE conjugate. Both the conjugated and un-conjugated versions of cMab-1501 were rapidly internalized by EGFR positive MDA-MB-231M tumor cells over several hours. In tumor xenograft models, the TME-specific anti-EGFR ADC demonstrated complete tumor regressions against two human EGFR overexpressing tumor types, MDA-MB-231M (TNBC, KRAS G13D) and HT-29 (CRC, BRAF V600E). In both in vivo models, tumors were resistant to treatment by cetuximab. These data suggest that it is possible to engineer a monoclonal antibody with enhanced specificity for its target within the TME and that an ADC-based approach could be utilized as potential treatment of EGFR overexpressing tumors with KRAS or BRAF mutations.

Citation Format: Bob Veneziale, Lei Huang, Xiaoming Li, Qiping Zhao, Chunmei Zhao, Ryan Osgood, Jessica Cowell, Sanna Rosengren, Jason Parise, Ge Wei, Kim Phan, Robert Connor, Steve Rowe, Gilbert Keller, Gregory Frost, Dan Maneval, Curtis Thompson, Michael Shepard, Christopher Thanos. A tumor microenvironment specific EGFR targeting antibody-drug conjugate promotes regression in KRAS or BRAF mutant tumors. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr B32.

Systematic review: Body composition in children with inflammatory bowel disease

BACKGROUND

Paediatric inflammatory bowel disease (IBD) is associated with weight loss, growth restriction and malnutrition. Bone mass deficits are well described, little is known about other body composition compartments.

AIMS

To define the alterations in non-bone tissue compartments in children with IBD, and explore the effects of demographic and disease parameters.

METHODS

A systematic search was carried out in the PubMed (www.ncbi.nlm.nih.gov/pubmed) and Web of Science databases in May 2014 (limitations age <17 years, and composition measurements compared with a defined control population).

RESULTS

Twenty-one studies were included in this systematic review, reporting on a total of 1479 children with IBD [1123 Crohn's disease, 243 ulcerative colitis], pooled mean age 13.1 ± 3.2 years, and 34.9% female. Data were highly heterogeneous, in terms of methodology and patients. Deficits in protein-related compartments were reported. Lean mass deficits were documented in 93.6% of Crohn's disease and 47.7% of ulcerative colitis patients when compared with healthy control populations. Lower lean mass was common to both sexes in Crohn's disease and ulcerative colitis, deficits in females with persisted for longer. Fat-related compartment findings were inconsistent, some studies report reductions in body fat in new diagnosis/active Crohn's disease.

CONCLUSIONS

It is clear that almost all children with Crohn's disease and half with ulcerative colitis have reduced lean mass, however, body fat alterations are not well defined. To understand what impact this may have on health and disease in children with IBD, further studies are needed to identify in which tissues these deficits lie, and to quantify body fat and its distribution.

Abstract P5-04-02: Hyaluronan (HA) depletion sensitizes HAhigh tumors to antibody-dependent cell-mediated cytotoxicity

Therapeutic efficacy of monoclonal antibodies (MAbs) against solid tumor targets, like trastuzumab (anti-HER2) and cetuximab (anti-EGFR), have been used successfully to treat cancer, despite the many physical barriers impeding their access to the malignant cell surface1. For example, only about 50% of HER23+ patients have a durable response to therapy with trastuzumab2. Extracellular matrix (ECM)-mediated inhibition may be among the mechanisms of resistance to MAb therapy of solid tumors. Aberrant accumulation of hyaluronan (HA), a major component of the ECM in many tumors, is associated with poor prognosis and treatment-resistance in multiple malignancies3-5. We investigated HA-dependent pericellular matrix-mediated inhibition to ADCC in HAhigh human cancer cells in vitro and in vivo. We observed high levels of tumor associated HA (HA3+) in &gt;50% of HER23+ breast adenocarcinoma and ∼40% of EGFR+ head and neck squamous cell carcinoma (HNSCC) primary tumors. Human hyaluronan synthase 2 (HAS2)-overexpressing breast cancer cells formed an HAhigh pericellular matrix, which inhibited both natural killer (NK) cell access to tumor cells and ADCC in vitro. Hyaluronan depletion by PEGPH20, a pegylated recombinant human PH20 hyaluronidase currently in clinical study for pancreatic cancer, increased NK cell access to HAS2-overexpressing breast cancer cells and greatly enhanced trastuzumab- or cetuximab-dependent ADCC. Trastuzumab and NK cell accessibility to HAS2-overexpressing tumors was enhanced following HA-depletion by PEGPH20. In an in vivo ADCC-based efficacy study, PEGPH20 treatment in combination with trastuzumab and NK cells enhanced tumor growth inhibition. This work describes a novel tumor microenvironment (TME)-dependent mechanism of inherent resistance to therapeutic antibody-mediated ADCC in vitro and in vivo, and furthermore shows that ADCC can be enhanced by hyaluronan depletion. These results may help to explain as to why tumors with high levels of HA are more aggressive, and suggest potential benefits of PEGPH20-mediated HA depletion in combination with therapeutic antibodies like trastuzumab or cetuximab in the treatment of HAhigh solid tumors.

References:

1. J. Christiansen, A. K. Rajasekaran, Biological impediments to monoclonal antibody–based cancer immunotherapy. Mol Cancer Ther. 3, 1493-1501 (2004).

2. H. M. Shepard, C. M. Brdlik, H. Schreiber, Signal integration: a framework for understanding the efficacy of therapeutics targeting the human EGFR family. J. Clin. Invest. 118, 3574-3581 (2008).

3. A. Kultti, X. Li, P. Jiang, C. B. Thompson, G. I Frost, H. M. Shepard Therapeutic Targeting of Hyaluronan in the Tumor Stroma. Cancers 4, 873-903 (2012).

4. R.K. Jain, Normalizing tumor microenvironment to treat cancer: bench to bedside to biomarkers. J Clin Oncol. 31, 2205-18 (2013).

5. R. K. Boregowda, H. N. Appaiah, M. Siddaiah, S. B. Kumarswamy, S. Sunila, K. N. Thimmaiah, K. Mortha, B. Toole, S. D. Banerjee, Expression of hyaluronan in human tumor progression. J. Carcinog. 5, 2 (2006).

Citation Format: Netai C Singha, Tara Nekoroski, Chunmei Zhao, Rebecca Symons, Ping Jiang, Gregory Frost, Zhongdong Huang, H Michael Shepard. Hyaluronan (HA) depletion sensitizes HAhigh tumors to antibody-dependent cell-mediated cytotoxicity [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 P5-04-02.

Plasma free fatty acids do not provide the link between obesity and insulin resistance or β-cell dysfunction: results of the Reading, Imperial, Surrey, Cambridge, Kings (RISCK) study

AIMS

To investigate the relationship between adiposity and plasma free fatty acid levels and the influence of total plasma free fatty acid level on insulin sensitivity and β-cell function.

METHODS

An insulin sensitivity index, acute insulin response to glucose and a disposition index, derived from i.v. glucose tolerance minimal model analysis and total fasting plasma free fatty acid levels were available for 533 participants in the Reading, Imperial, Surrey, Cambridge, Kings study. Bivariate correlations were made between insulin sensitivity index, acute insulin response to glucose and disposition index and both adiposity measures (BMI, waist circumference and body fat mass) and total plasma free fatty acid levels. Multivariate linear regression analysis was performed, controlling for age, sex, ethnicity and adiposity.

RESULTS

After adjustment, all adiposity measures were inversely associated with insulin sensitivity index (BMI: β = -0.357; waist circumference: β = -0.380; body fat mass: β = -0.375) and disposition index (BMI: β = -0.215; waist circumference: β = -0.248; body fat mass: β = -0.221) and positively associated with acute insulin response to glucose [BMI: β = 0.200; waist circumference: β = 0.195; body fat mass β = 0.209 (P values <0.001)]. Adiposity explained 13, 4 and 5% of the variation in insulin sensitivity index, acute insulin response to glucose and disposition index, respectively. After adjustment, no adiposity measure was associated with free fatty acid level, but total plasma free fatty acid level was inversely associated with insulin sensitivity index (β = -0.133), acute insulin response to glucose (β = -0.148) and disposition index [β = -0.218 (P values <0.01)]. Plasma free fatty acid concentration accounted for 1.5, 2 and 4% of the variation in insulin sensitivity index, acute insulin response to glucose and disposition index, respectively.

CONCLUSIONS

Plasma free fatty acid levels have a modest negative association with insulin sensitivity, β-cell secretion and disposition index but no association with adiposity measures. It is unlikely that plasma free fatty acids are the primary mediators of obesity-related insulin resistance or β-cell dysfunction.

The short chain fatty acid propionate stimulates GLP-1 and PYY secretion via free fatty acid receptor 2 in rodents

Background and Objectives:

The gut hormones peptide YY (PYY) and glucagon-like peptide 1 (GLP-1) acutely suppress appetite. The short chain fatty acid (SCFA) receptor, free fatty acid receptor 2 (FFA2) is present on colonic enteroendocrine L cells, and a role has been suggested for SCFAs in appetite regulation. Here, we characterise the in vitro and in vivo effects of colonic propionate on PYY and GLP-1 release in rodents, and investigate the role of FFA2 in mediating these effects using FFA2 knockout mice.

Methods:

We used Wistar rats, C57BL6 mice and free fatty acid receptor 2 knockout (FFA^−/−) mice on a C57BL6 background to explore the impact of the SCFA propionate on PYY and GLP-1 release. Isolated colonic crypt cultures were used to assess the effects of propionate on gut hormone release in vitro. We subsequently developed an in vivo technique to assess gut hormone release into the portal vein following colonic infusion of propionate.

Results:

Propionate stimulated the secretion of both PYY and GLP-1 from wild-type primary murine colonic crypt cultures. This effect was significantly attenuated in cultures from FFA2^−/− mice. Intra-colonic infusion of propionate elevated PYY and GLP-1 levels in jugular vein plasma in rats and in portal vein plasma in both rats and mice. However, propionate did not significantly stimulate gut hormone release in FFA2^−/− mice.

Conclusions:

Intra-colonic administration of propionate stimulates the concurrent release of both GLP-1 and PYY in rats and mice. These data demonstrate that FFA2 deficiency impairs SCFA-induced gut hormone secretion both in vitro and in vivo.

Effect of short chain fatty acids on the expression of free fatty acid receptor 2 (Ffar2), Ffar3 and early-stage adipogenesis

Adipose tissue has a major influence on insulin sensitivity. Stimulation of free fatty acid receptor 2 (FFAR2) has been proposed to influence adipocyte differentiation. We hypothesised that exposing preadipocytes to short chain fatty acids would induce earlier expression of nuclear receptors that co-ordinate adipogenesis, triglyceride accumulation and leptin secretion. 3T3-L1 preadipocytes were differentiated in the presence of 1 μM acetate, 0.1-10 μM propionate or vehicle control. In experiment 1, expression of Ffar2 and nuclear receptor mRNA was measured by quantitative PCR over 48 h following onset of differentiation. In experiment 2, extracellular leptin concentration and intracellular triglyceride content were measured at days 0, 2, 4, 6, 8 and 10 following the onset of differentiation. Control cells exhibited similar temporal dynamics of gene expression, triglyceride accumulation and leptin secretion as reported previously. We were unable to detect expression of Ffar3 mRNA at any stage of differentiation. Consistent with a lack of Ffar2 expression in the first 24 h of differentiation, acetate and propionate had no significant effect on nuclear receptor expression. Furthermore, acetate or propionate treatment did not alter leptin concentration or triglyceride content. In conclusion, we observed no significant effect of propionate or acetate on adipogenesis in 3T3-L1 cells using validated quantitative techniques.

Hepcidin levels in diabetes mellitus and polycystic ovary syndrome

AIM

Increased body iron is associated with insulin resistance. Hepcidin is the key hormone that negatively regulates iron homeostasis. We hypothesized that individuals with insulin resistance have inadequate hepcidin levels for their iron load.

METHODS

Serum concentrations of the active form of hepcidin (hepcidin-25) and hepcidin:ferritin ratio were evaluated in participants with Type 2 diabetes (n = 33, control subjects matched for age, gender and BMI, n = 33) and participants with polycystic ovary syndrome (n = 27, control subjects matched for age and BMI, n = 16). To investigate whether any changes observed were associated with insulin resistance rather than insulin deficiency or hyperglycaemia per se, the same measurements were made in participants with Type 1 diabetes (n = 28, control subjects matched for age, gender and BMI, n = 30). Finally, the relationship between homeostasis model assessment of insulin resistance and serum hepcidin:ferritin ratio was explored in overweight or obese participants without diabetes (n = 16).

RESULTS

Participants with Type 2 diabetes had significantly lower hepcidin and hepcidin:ferritin ratio than control subjects (P < 0.05 and P < 0.01, respectively). Participants with polycystic ovary syndrome had a significantly lower hepcidin:ferritin ratio than control subjects (P < 0.05). There was no significant difference in hepcidin or hepcidin:ferritin ratio between participants with Type 1 diabetes and control subjects (P = 0.88 and P = 0.94). Serum hepcidin:ferritin ratio inversely correlated with homeostasis model assessment of insulin resistance (r = -0.59, P < 0.05).

CONCLUSION

Insulin resistance, but not insulin deficiency or hyperglycaemia per se, is associated with inadequate hepcidin levels. Reduced hepcidin concentrations may cause increased body iron stores in insulin-resistant states.

Review: efficacy of alginate supplementation in relation to appetite regulation and metabolic risk factors: evidence from animal and human studies

This review provides a critical update on human and animal studies investigating the effect of alginate supplementation on appetite regulation, glycaemic and insulinemic responses, and lipid metabolism with discussion of the evidence on potential mechanisms, efficacy and tolerability. Dependent on vehicle applied for alginate supplementation, the majority of animal and human studies suggest that alginate consumption does suppress satiety and to some extent energy intake. Only one long-term intervention trial found effects on weight loss. In addition, alginates seem to exhibit beneficial influence on postprandial glucose absorption and insulin response in animals and humans. However, alginate supplementation was only found to have cholesterol-lowering properties in animals. Several mechanisms have been suggested for the positive effect observed, which involve delayed gastric emptying, increased viscosity of digesta and slowed nutrient absorption in the small intestine upon alginate gel formation. Despite reasonable efficacy and tolerability from the acute or short-term studies, we still realize there is a critical need for development of optimal alginate types and vehicles as well as studies on further long-term investigation on alginate supplementation in humans before inferring that it could be useful in the management of obesity and the metabolic syndrome.

Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes

This article summarizes the Diabetes UK evidence-based guidelines for the prevention of Type 2 diabetes and nutritional management of diabetes. It describes the development of the recommendations and highlights the key changes from previous guidelines. The nutrition guidelines include a series of recommendations for the prevention of Type 2 diabetes, nutritional management of Type 1 and Type 2 diabetes, weight management, management of microvascular and macrovascular disease, hypoglycaemia management, and additional considerations such as nutrition support, end-of-life care, disorders of the pancreas, care of the older person with diabetes, nutrition provided by external agencies and fasting. The evidence-based recommendations were graded using the Scottish Intercollegiate Guidelines Network methodology and, in a small number of topic areas, where strong evidence was lacking, the recommendations were reached by consensus. The Diabetes UK 2011 guidelines place an emphasis on carbohydrate management and a more flexible approach to weight loss, unlike previous guidelines which were expressed in terms of recommendations for individual nutrient intakes. Additionally, the guidelines for alcohol have been aligned to national recommendations. The full evidence-based nutrition guidelines for the prevention and management of diabetes are available from: http://www.diabetes.org.uk/nutrition-guidelines.

Mortality and cancer incidence among British agricultural pesticide users

BACKGROUND

Although the acute effects of pesticides in humans are well known, uncertainty still exists about the health effects of chronic low-level exposure to pesticides.

AIMS

To compare mortality and cancer incidence experienced by a cohort of British pesticide users to that of the Great Britain (GB) population.

METHODS

The Pesticide Users Health Study (PUHS) comprises users of agricultural pesticides who have Certificates of Competence under the Control of Pesticides Regulations 1986. Participants were followed up between 1987 and 2004 (cancer incidence) or 2005 (mortality). Standardized mortality ratios (SMRs) and Standardized incidence ratios (SIRs) were estimated for outcomes of interest identified from the literature.

RESULTS

Altogether, 62,960 pesticide users were followed up for 829,709 person-years (to 31 December 2005). Most participants were male (94%) and based in England (86%). All-cause mortality was lower for both men [SMR 0.58, 95% confidence interval (CI) 0.55-0.60] and women (SMR 0.71, 95% CI 0.52-0.98) compared to the GB population. Mortality and incidence were below those expected for all cancers combined among men (SMR 0.71, 95% CI 0.66-0.77; SIR 0.85, 95% CI 0.81-0.90), particularly for cancers of the lip, oral cavity and pharynx, digestive organs and respiratory system. The incidence of testicular cancer, non-melanoma skin cancer and multiple myeloma were above expected. Mortality from injury by machinery was significantly above expected for men (SMR 4.21, 95% CI 2.11-8.42).

CONCLUSIONS

This study suggests that pesticide users in the PUHS are generally healthier than the national population but may have excesses of non-melanoma skin cancer, testicular cancer and multiple myeloma.

Pragmatic study of orlistat 60 mg on abdominal obesity

BACKGROUND/OBJECTIVES

It is well established that combining a reduced calorie, low-fat diet with the lipase inhibitor orlistat results in significantly greater weight loss than placebo plus diet. This weight loss is accompanied by changes in adipose tissue (AT) distribution. As 60 mg orlistat is now available as an over-the-counter medication, the primary objective of this study was to determine whether 60 mg orlistat is effective as a weight loss option in a free-living community population with minimal professional input.

METHODS

AT and ectopic lipid content were measured using magnetic resonance imaging and (1)H MR spectroscopy, respectively, in 27 subjects following 3 months treatment with orlistat 60 mg and a reduced calorie, low-fat diet.

RESULTS

Significant reductions in intra-abdominal AT (-10.6%, P=0.023), subcutaneous (-11.7% P<0.0001) and pericardial fat (-9.8%, P=0.034) volumes and intrahepatocellular lipids (-43.3%, P=0.0003) were observed. These changes in body fat content and distribution were accompanied by improvements in plasma lipids and decreases in blood pressure and heart rate.

CONCLUSION

These findings suggest that over-the-counter 60 mg orlistat, in combination with the type of advice a subject could expect to be given when obtaining 60 mg orlistat in a community setting, does indeed result in potentially clinically beneficial changes in body composition and risk factors for metabolic diseases.

Abstract LB-307: Hyaluronan deposition correlates with poor survival in pancreatic cancer

Hyaluronan (HA) is an extracellular matrix component that plays an important role in a diverse range of cellular processes including proliferation, tissue hydration, cell motility, inflammation, angiogenesis, and malignancy. Increased HA deposition is a characteristic of many desmoplastic tumors. High HA levels have been correlated with poor prognosis in some cancer types, including gastric, colorectal, breast, ovarian, and bladder cancers. Considering the high desmoplastic stromal content of pancreatic tumors, we hypothesized that high HA levels may contribute to poor prognosis or survival in pancreatic cancer. Utilizing a biotinylated HA binding protein-based staining method in a tissue microarray constructed from resected pancreatic tumor tissues, we assessed HA-specific staining in 43 pancreatic ductal adenocarcinoma samples for which patient survival had been followed for more than eight years. We observed HA staining primarily in the peritumoral, or stromal, compartment of the tumor tissue samples. 100% of the patient tumors stained positive in at least some fraction of the tissue area (stroma) for HA. The staining was scored according to the percentage area of HA-positivity, relative to total tissue area. We observed low (&lt;40%) and high (≥40%) levels of stromal HA in 11 and 32 patient samples, respectively. We tested our hypothesis with the log-rank test and found that the survival rate was significantly lower among patients with high HA (P&lt;0.05). The median survival among those patients with high HA was 299 days, and 738 days for those with low HA (the difference in median survival between the two patient groups is 439 days). These results suggest that HA levels in pancreatic adenocarcinoma patients may be predictive of survival. Because HA functions in maintaining high tumoral interstitial fluid pressure, resulting in vascular compression and limited tumor-drug access, our results also suggest that HA may serve as a potential therapeutic target in pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-307. doi:10.1158/1538-7445.AM2011-LB-307

Abstract 2265: Expression of hyaluronan in human cancer tissue: A predictive biomarker for PEGPH20-mediated therapy

Background: Hyaluronan (HA), a ubiquitous, high-molecular-mass polysaccharide in the precellular and extracellular matrix, is frequently elevated in malignancy, and associated with aggressive disease. Interaction of HA and tumor cells may activate receptor tyrosine kinases, enhance drug resistance, and facilitate tumor progression. A pegylated recombinant human PH20 hyaluronidase (PEGPH20) has been developed to systemically target tumors that accumulated with HA. Systemic PEGPH20 administration in mice bearing PC3 tumors induced a decrease in tumor interstitial fluid pressure (IFP), a decrease in tumor water content, and an increase in tumor vascular volume by enzymatically depleting the HA from the extracellular tumor microenvironment and resulted in significant tumor growth inhibition. PEGPH20 therefore represents an innovative potential treatment approach that may provide improved therapeutic outcomes for cancer patients.

Methods: The present study investigated the expression of HA in paraffin embedded human tissue from 9 tumor types as well as corresponding normal tissue by immunohistochemical staining of BioMax tissue arrays with biotinylated HA binding protein (HABP) as a probe. Staining intensity was quantified using Aperio Spectrum plus software. The correlation between HA expression and PEGPH20 response has also been explored using established preclinical models.

Results: Strong HA expression was found in 87% of pancreatic, 64% of breast, 50% of multiple myeloma, 46% of NSCLC, 39% of gastric, and 22% of prostate cancer tissues, when compared with corresponding normal tissue (p&lt;0.05). BxPc3 (HA high), MIA PaCa-2 (HA low) and AsPC-1 (HAlow) pancreatic tumor xenografts were evaluated for tumor growth inhibition (TGI) after systemic PEGPH20 treatment and TGI's of 25%, 9% and 15% were observed respectively. In addition, 3 prostate cancers, PC3 (HA high), MatLylu (HA high) and Du145 (HA low) were also evaluated in xenografts with significant growth inhibition shown for PC3 (72%) and MatLylu (34%). Systemic PEGPH20 treatment also induced tumor growth inhibition (60%) for 4T1 (HA high) breast cancer.

Conclusion: Accumulation of HA compared to normal tissue was commonly observed and most frequent in pancreatic adenocarcinomas (87%). Furthermore, accumulation of HA was shown to predict response to PEGPH20 therapy in xenograft models (R2=0.805, p&lt;0.01). This work provides strong rationale for exploring efficacy of PEGPH20 in clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2265.

Adipose tissue, adipocytes and the circadian timing system

Circadian clocks time the daily occurrence of multiple aspects of behaviour and physiology. Through studies of chronic misalignment between our internal clocks and the environment (e.g. during shift work), it has long been postulated that disruption of circadian rhythms is detrimental to human health. Recent advances in understanding of the cellular and molecular basis of mammalian circadian timing mechanisms have identified many key genes involved in circadian rhythm generation and demonstrated the presence of clocks throughout the body. Furthermore, clear links between sleep, circadian rhythms and metabolic function have been revealed, and much current research is studying these links in more detail. Here, we review the evidence linking circadian rhythms, clock genes and adipose biology. We also highlight gaps in our understanding and finally suggest avenues for future research.

Evaluation of attendance and weight loss in an intensive weight management clinic compared to standard dietetic care

BACKGROUND

With increasing rates of obesity, the effectiveness of weight reduction programmes come under increasing scrutiny. This nonrandomized study aimed to review the effectiveness of two weight loss clinics in terms of percent and rate of weight loss, and attendance.

METHODS

Data were collected on consecutive obese patients, attending either an intensive weight management clinic (IWMC) or a general dietetic outpatient clinic. The IWMC had a structured approach with six once-a-month appointments, a signed agreement to attend, an initial screening of readiness to change and consistent advice from one dietitian. The general clinic was less structured, had more ad hoc follow up and did not guarantee one dietitian.

RESULTS

Seventy percent of patients referred were female [mean (SD) age 48 (14.2) years]. Thirty-three percent (103/313) of all patients referred did not book an appointment. Of those attending with a body mass index > or = 32 kg m(-2), 55% were seen in the general and 45% in the intensive clinic, but only 19% and 53%, respectively, completed the programmes. The total amount and rate of weight loss did not differ significantly between clinics. However, analysis using the last recorded weight revealed a median weight reduction of 1.8% (interquartile range = -5.6-0) at the median rate of -0.4 kg month(-1) (-1-0) in the intensive clinic, compared to no overall weight loss in the general clinic (P < or = 0.001).

CONCLUSIONS

A more structured approach and initial screening of readiness to change is likely to achieve better weight loss results and therefore will comprise a better use of dietetic time than including obese patients in general clinics.

Clinical trial: normal diet vs. partial replacement with oral E028 formula for the prevention of gastrointestinal toxicity in cancer patients undergoing pelvic radiotherapy

BACKGROUND

Acute gastrointestinal symptoms affect 90% of patients during pelvic radiotherapy. Elemental diet is protective in animal models. A nonrandomized study suggested benefit from a partial elemental diet. A pilot study suggested that radiotherapy patients only tolerate oral elemental diet comprising one-third of total calories for 3 weeks.

AIM

To assess the feasibility and efficacy of replacing one-third of normal diet with elemental diet during the first 3 weeks of pelvic radiotherapy in reducing acute gastrointestinal toxicity.

METHODS

Patients were randomized to elemental diet or no intervention. Toxicity was assessed using the Inflammatory Bowel Disease Questionnaire, Vaizey Incontinence scale and Radiation Therapy Oncology Group tool. Faecal calprotectin measured intestinal mucosal inflammation.

RESULTS

Twenty-nine women and 21 men, median age 61.5 years were randomized. Patients taking elemental diet did not have lower gastrointestinal toxicity ratings or inflammatory markers (P > 0.2). The mean dose taken was 21% (2-36%) of total caloric requirements.

CONCLUSIONS

Patients cannot tolerate large volumes of oral elemental diet. The quantities consumed in this study produced no therapeutic benefit. Future studies should aim to replace a higher proportion of nutritional intake for a longer duration of radiotherapy treatment.

A new method of energy prescription to improve weight loss

Clinical outcome audit was carried out on two groups of obese out-patients for a 3-month follow-up period. In the first audit group of 35 patients (A1), energy intake was prescribed by diet history, whereas in the second audit group of 27 patients (A2) energy intake was prescribed from an estimate of individual energy requirements based on age, sex, and activity. There was no significant difference in age or initial BMI between the two groups and the failure-to-attend rate was the same in each group. Patients in Group A2 received a significantly higher energy prescription (P<0.001) than Group A1, but this was still significantly more restricted than the recommended 500 kcal energy deficit from energy expenditure (P<0.05). Weight loss was significant in both groups, but was greater in Group A2 than in Group A1. There was no significant correlation between weight loss and energy deficit. In a selected group of patients from Group A2 who were prescribed energy intake close to the recommended deficit of 500 kcal, weight loss was found to be significantly greater (P<0.05) when compared to the weight loss in Group A1. Results suggest that a diet prescription with an energy deficit below the estimated energy requirements does not lead to greater weight loss and probably reduces compliance. Estimating individual energy requirements rather than using dietary assessment may improve weight loss.