Placebo effects in mental health disorders: protocol for an umbrella review.

INTRODUCTION: Given the high prevalence of mental health disorders and their significant socioeconomic burden, there is a need to develop improved treatments, and to evaluate them through placebo-controlled trials. However, the magnitude of the placebo response in randomised controlled trials to test medications may be substantial, affecting their interpretation. Therefore, improved understanding of the patient, trial and mental disorder factors that influence placebo responses would inform clinical trial design to better detect active treatment effects. There is a growing literature exploring the placebo response within specific mental health disorders, but no overarching synthesis of this research has been produced to date. We present a protocol for an umbrella review of systematic reviews and/or meta-analyses in which we aim to understand the effect size and potential predictors of placebo response within, and across, mental health disorders. METHODS AND ANALYSIS: We will systematically search databases (Medline, PsycINFO, EMBASE+EMBASE Classic, Web of Knowledge) for systematic reviews and/or meta-analyses that report placebo effect size in clinical trials in patients with mental health disorders (initial search date 23 October 2022). Screening of abstracts and full texts will be done in pairs. We will extract data to qualitatively examine how placebo effect size varies across mental health disorders. We also plan to qualitatively summarise predictors of increased placebo response identified either quantitatively (eg, through meta-regression) or qualitatively. Risk of bias will be assessed using the AMSTAR-2 tool. We aim to not only summarise the current literature but also to identify gaps in knowledge and generate further hypotheses. ETHICS AND DISSEMINATION: We do not believe there are any specific ethical considerations relevant to this study. We will publish the results in a peer-reviewed journal.

T Lymphocytes and Their Potential Role in Dementia with Lewy Bodies.

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative cause of dementia. People with DLB have an inferior prognosis compared to Alzheimer's disease (AD), but the diseases overlap in their neuropathology and clinical syndrome. It is imperative that we enhance our understanding of the aetiology and pathogenesis of DLB. The impact of peripheral inflammation on the brain in dementia has been increasingly explored in recent years, with T lymphocyte recruitment into brain parenchyma identified in AD and Parkinson's disease. There is now a growing range of literature emerging on the potential role of innate and adaptive immune cells in DLB, including T lymphocytes. In this review, we examine the profile of T lymphocytes in DLB, focusing on studies of post-mortem brain tissue, cerebrospinal fluid, and the blood compartment. We present an integrated viewpoint on the results of these studies by proposing how changes to the T lymphocyte profile in the brain and periphery may relate to each other. Improving our understanding of T lymphocytes in DLB has the potential to guide the development of disease-modifying treatments.

Esophageal adenocarcinoma with metastasis to the prostatic urethra and bladder.

Metastatic esophageal adenocarcinoma to the urinary bladder is extremely rare and aggressive. We discuss here the case of an 83-year-old male with history of esophageal adenocarcinoma treated with chemoradiation therapy and esophagectomy who presented with gross hematuria and lower urinary tract symptoms. Pathology of the bladder tumor after transurethral resection demonstrated invasive adenocarcinoma of both the bladder and the prostatic urethra consistent with metastatic esophageal adenocarcinoma.

The Impact of Social Isolation Due to COVID-19 on Symptom Progression in People With Dementia: Findings of the SOLITUDE Study.

Background: People with dementia (PWD) are vulnerable to abrupt changes to daily routines. The lockdown enforced on the 23rd of March 2020 in the UK to contain the expansion of the COVID-19 pandemic limited opportunities for PWD to access healthcare services and socialise. The SOLITUDE study explored the potential long-term effects of lockdown on PWD's symptoms and carers' burden. Methods: Forty-five carers and 36 PWD completed a telephone-based assessment at recruitment (T0) and after 3 (T1) and 6 months (T2). PWD completed measures validated for telephonic evaluations of cognition and depression. Carers completed questionnaires on their burden and on PWD's health and answered a customised interview on symptom changes observed in the initial months of lockdown. Longitudinal changes were investigated for all outcome variables with repeated-measures models. Additional post hoc multiple regression analyses were carried out to investigate whether several objective factors (i.e., demographics and time under social restrictions) and carer-reported symptom changes observed following lockdown before T0 were associated with all outcomes at T0. Results: No significant changes were observed in any outcomes over the 6 months of observations. However, post hoc analyses showed that the length of social isolation before T0 was negatively correlated with episodic and semantic memory performance at T0. Carers reporting worsening of neuropsychiatric symptoms and faster disease progression in PWD also reported higher burden. Moreover, carer-reported worsening of cognitive symptoms was associated with poorer semantic memory at T0. Conclusion: PWD's symptoms and carers' burden remained stable over 6 months of observation. However, the amount of time spent under social restrictions before T0 appears to have had a significant detrimental impact on cognitive performance of patients. In fact, carer-reported cognitive decline during social isolation was consistent with the finding of poorer semantic memory, a domain sensitive to progression in Alzheimer's disease. Therefore, the initial stricter period of social isolation had greater detrimental impact on patients and their carers, followed then by a plateau. Future interventions may be designed to maintain an optimal level of social and cognitive engagement for PWD in challenging times, to prevent abrupt worsening of symptoms and associated detrimental consequences on patients' carers.

The impact of social isolation due to the COVID-19 pandemic on patients with dementia and caregivers.

OBJECTIVE: Social distancing to limit COVID-19 transmission has led to extensive lifestyle changes, including for people with dementia (PWD). The aim of this study, therefore, was to assess the impact of lockdown on the mental health of PWD and their carers. METHODS: Forty-five carers of PWD completed a telephone interview during the baseline assessment of the SOLITUDE study to gather information on life conditions and changes in symptoms of PWD during lockdown. Associations between changes in symptoms of PWD and carers' concerns and mental health were investigated. RESULTS: About 44% of carers experienced anxiety and irritability and reported changes in behavioural and cognitive symptoms in PWD. These changes were associated with worse carers' mental health and concerns about faster disease progression (χ2 = 13.542, p < 0.001). CONCLUSION: COVID-19-related social isolation has had a negative impact on patients' and carers' mental health. Potential long-term neurocognitive consequences require further investigation.

Inflammation in dementia with Lewy bodies.

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative cause of dementia, behind Alzheimer's disease (AD). The profile of inflammation in AD has been extensively researched in recent years, with evidence that chronic peripheral inflammation in midlife increases the risk of late-onset AD, and data supporting inflammation being associated with disease progression. In contrast, our understanding of the role of inflammation in DLB is less developed. Most research to date has examined inflammation in related disorders, such as Parkinson's disease, but there is now a growing range of literature examining inflammation in DLB itself. We present a review of the literature in this field, exploring a range of research methodologies including those quantifying markers of inflammation in cerebrospinal fluid, peripheral blood, post-mortem brain tissue, and using neuroimaging and preclinical data. Our review reveals evidence from PET imaging and peripheral blood analysis to support an increase in cerebral and peripheral inflammation in mild or prodromal DLB, that dissipates with disease progression. We present evidence from post-mortem brain tissue and pre-clinical studies that indicate α-synuclein directly promotes inflammation, but that also support the presence of AD co-pathology as an important factor in the profile of neuroinflammation in DLB. We propose that specific markers of inflammation may play a sentinel role in the mild stage of the disease, particularly when combined with AD pathology. We advocate further examination of the profile of inflammation in DLB through robust longitudinal studies, to enhance our understanding of the pathogenesis of the disease. The goal should be to utilise future results to develop a composite biomarker to aid diagnosis of DLB, and to potentially identify novel therapeutic targets.

Voiding cystourethrogram: Who gets a cyclic study and does it matter?

BACKGROUND: Voiding cystourethrogram (VCUG) images the urethra and bladder during both bladder filling and emptying, as well as the ureters and kidneys when vesicoureteral reflux (VUR) is present. Given the variation in VCUG technique and reporting, the American Academy of Pediatrics Sections on Urology and Radiology published a joint standardized VCUG protocol in 2016, which included the recommendation of at least 2 voiding cycles to identify intermittent VUR and/or ureteral ectopia. STUDY DESIGN: VCUG were assessed for adherence to performance of cyclic study. Children who underwent cyclic evaluation were compared to those who underwent a single cycle VCUG. Radiation dosage was also analyzed. Studies performed on patients >18 years of age and those obtained as part of a trauma evaluation were excluded from study. RESULTS: Two hundred and eighty-four VCUGs were analyzed, 97 (34.2%) were positive for VUR on the initial cycle. Of the remaining 187 studies, 116 (62%) had multiple filling-voiding cycles while in 71 (38%) only a single cycle was performed. One hundred and sixty-one (86.1%) were negative for vesicoureteral reflux. Twenty-six (13.9%) children were diagnosed with VUR after the initial filling-voiding cycle: 6 were diagnosed with grade I, 2 grade II, 11 grade III, 2 grade IV and 5 grade V. Of the 123 total children found to have VUR, 26 (21.2%) were diagnosed after an initial negative cycle. Younger children were significantly more likely to have a cyclic study performed; mean age of patients undergoing a cyclic study was 1.09 ± 2.16 years versus 3.86 ± 4.5 years (p ≤ 0.0001). Categorically, 74.1% of children less than 1 year of age underwent a cyclic study compared to 6.9% of children older than 5 years of age (p ≤ 0.0001). There was no difference based on sex with 49.1% of males and 50.9% of females (p = 0.667) undergoing cyclic evaluation. Children undergoing a cyclic study had lower median radiation dose 2.15 microGy m2 (range 0.09-111) compared to 4.41 (range 1.3-104) [p = 0.01]. DISCUSSION: Vesicoureteral reflux may occur intermittently and cyclic VCUG is thought to enhance the ability to detect reflux. In our cohort, 26 children (9.2%) were only diagnosed after an additional cycle - ie 21.1% of reflux would have been missed had a cyclic study not been performed. The majority of these patients (69.2%, 18 of 26) were found to have dilating, and thus perhaps more clinically significant, reflux. Our study highlights the importance of obtaining as much information as possible and adhering to the standardized VCUG protocol. CONCLUSION: Younger children are more likely to undergo cyclic VCUG. While most reflux is detected with the initial filling-voiding cycle, 26 (21.2%) patients were diagnosed after an initial negative cycle with the majority being dilating VUR.

Implementation of treatment escalation plans in an old age psychiatry inpatient hospital.

A treatment escalation plan (TEP) enables timely and appropriate decision making in the management of deteriorating patients. The COVID-19 pandemic precipitated the widespread use of TEPs in acute care settings throughout the National Health Service (NHS) to facilitate safe and effective decision making. TEP proformas have not been developed for the inpatient psychiatric setting. This is particularly concerning in old age psychiatry inpatient wards where patients often have multiple compounding comorbidities and complex decisions regarding capacity are often made. Our aim for this quality improvement project was to pilot a novel TEP proforma within a UK old age psychiatry inpatient hospital. We first adapted a TEP proforma used in our partner acute tertiary hospital and implemented it on our old age psychiatry wards. We then further refined the form and gathered data about uptake, length of time to complete a TEP and the ceiling of care documented in the TEP. We also explored staff, patient and family views on the usefulness of TEP proformas using questionaries. TEP decisions were documented in 54% of patient records at baseline. Following revision and implementation of a TEP proforma this increased to 100% on our two wards. The mean time taken to complete a TEP was reduced from 7.1 days to 3.2 days following inclusion of the TEP proforma in admission packs. Feedback from staff showed improvements in understanding about TEP and improved knowledge of where these decisions were documented. We advocate the use of TEP proformas on all old age psychiatry inpatient wards to offer clear guidance to relatives and treating clinicians about the ceilings of care for patients. There are potentially wider benefits to healthcare systems by reducing inappropriate transfers between psychiatry and acute NHS hospitals.

Refractory catatonia in old age: a case report.

BACKGROUND: Catatonia is a clinical syndrome characterized by psychomotor disruption, which often goes undiagnosed. Most reports have focused on interventions and outcomes for catatonia in younger people and those with schizophrenia. The clinical characteristics and course of catatonia in old age are poorly understood. We present a report of an older person whose catatonia was refractory to extensive treatment, and we identify important implications for the management of catatonia in old age. CASE PRESENTATION: We describe a 73-year-old white man with longstanding autistic spectrum disorder who presented with symptoms of depression. Following a period of diagnostic uncertainty and failure to improve with antidepressant medication, a lorazepam challenge yielded an abrupt improvement in presentation. The patient was treated extensively with lorazepam, zolpidem, and electroconvulsive therapy during his 16-month hospital admission, but his catatonia ultimately proved refractory to treatment. CONCLUSIONS: Catatonia should be considered promptly as a differential diagnosis in older people presenting with atypical features of functional mental illness. Although partial improvement of catatonic features was achieved using benzodiazepines and electroconvulsive therapy, these were not sustained in our patient. We identified comorbid autistic spectrum disorder, prolonged duration of catatonia, and sensitivity to benzodiazepines as important factors in prognostication in old age.

Peripheral immunophenotype in dementia with Lewy bodies and Alzheimer's disease: an observational clinical study.

BACKGROUND: Inflammation plays a key role in the aetiology and progression of Alzheimer's disease (AD). However, the immunophenotype of the second most common neurodegenerative cause of dementia, dementia with Lewy bodies (DLB), remains unclear. To date there have been no studies examining peripheral inflammation in DLB using multiplex immunoassay and flow cytometry concomitantly. We hypothesised that, using blood biomarkers, DLB would show an increased proinflammatory profile compared with controls, and that there would be a distinct profile compared with AD. METHODS: 93 participants (31 with DLB, 31 with AD and 31 healthy older controls) completed a single study visit for neuropsychiatric testing and phlebotomy. Peripheral blood mononuclear cells were quantified for T and B cell subsets using flow cytometry, and serum cytokine concentrations were measured using multiplex immunoassay. RESULTS: We detected reduced relative numbers of helper T cells and reduced activation of B cells in DLB compared with AD. Additionally, interleukin (IL)-1ß was detected more frequently in DLB and the serum concentration of IL-6 was increased compared with controls. CONCLUSIONS: Peripheral inflammation is altered in DLB compared with AD, with T cell subset analysis supporting a possible shift towards senescence of the adaptive immune system in DLB. Furthermore, there is a proinflammatory signature of serum cytokines in DLB. Identification of this unique peripheral immunophenotype in DLB could guide development of an immune-based biomarker and direct future work exploring potential immune modulation as a novel treatment.

Neuroinflammation in dementia with Lewy bodies: a human post-mortem study.

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative cause of dementia, behind Alzheimer's disease (AD). It is now established that cerebral inflammation has a key role in the aetiology and progression of AD, but this has yet to be confirmed in DLB. We aimed to determine the neuroinflammatory profile in the cerebral cortex of a large cohort of DLB cases. Thirty post-mortem confirmed DLB cases and twenty-nine matched controls were immunolabelled (Brodmann area 21) and quantified for: neuropathology-αSYN, Aß, P-tau; microglial phenotype-Iba1, HLA-DR, CD68, FcÆ´R (CD64, CD32a, CD32b, CD16); presence of T lymphocytes-CD3; and anti-inflammatory markers-IL4R, CHI3L1. Status spongiosis, as a marker of neuropil degeneration, was quantified using Haematoxylin and Eosin staining. We found no significant difference between groups in protein load for Iba1, HLA-DR, CD68, CD64, CD32b, IL4R, or CHI3L1, despite increased neuropathology in DLB. CD32a load was significantly lower, and CD16 load higher, in DLB compared with controls. There was no difference in status spongiosis between groups. Significantly more DLB cases than controls showed T-lymphocyte recruitment. Overall, we conclude that microglial activation is not a prominent feature of DLB, and that this may be associated with the relatively modest neuropil degeneration observed in DLB. Our findings, based on the largest post-mortem cohort to date exploring neuroinflammation in DLB, demonstrate a dissociation between protein deposition, neurodegeneration and microglial activation. The relative preservation of cortical structures in DLB suggests the dementia could be more amenable to potential therapies.

Psychological stress, cognitive decline and the development of dementia in amnestic mild cognitive impairment.

To determine the relationship between psychological stress with cognitive outcomes in a multi-centre longitudinal study of people with amnestic mild cognitive impairment (aMCI) we assessed three parameters of psychological stress (Recent Life Changes Questionnaire (RLCQ); the Perceived Stress Scale (PSS) and salivary cortisol) and their relationship with rates of cognitive decline over an 18 month follow up period and conversion to dementia over a 5.5 year period. In 133 aMCI and 68 cognitively intact participants the PSS score was higher in the aMCI compared with control group but neither the RLCQ scores nor salivary cortisol measures were different between groups. In the aMCI group the RLCQ and the PSS showed no significant association with cognitive function at baseline, cognitive decline or with conversion rates to dementia but high salivary cortisol levels were associated with RLCQ scores and poorer cognitive function at baseline and lower rates of cognitive decline. No relationship was found between salivary cortisol levels and conversion rate to dementia. We conclude that psychological stress as measured by the RLCQ or PSS was not associated with adverse cognitive outcomes in an aMCI population and hypothesise that this may reflect diminished cortisol production to psychological stress as the disease progresses.

Identification and Validation of Radiographic Enhancement for Reliable Differentiation of CD117(+) Benign Renal Oncocytoma and Chromophobe Renal Cell Carcinoma.

Purpose: The diagnostic differential for CD117/KIT(+) oncocytic renal tumor biopsies is limited to benign renal oncocytoma versus chromophobe renal cell carcinoma (ChRCC); however, further differentiation is often challenging and requires surgical resection. We investigated clinical variables that might improve preoperative differentiation of CD117(+) renal oncocytoma versus ChRCC to avoid the need for benign tumor resection.Experimental Design: A total of 124 nephrectomy patients from a single institute with 133 renal oncocytoma or ChRCC tumors were studied. Patients from 2003 to 2012 comprised a retrospective cohort to identify clinical/radiographic variables associated with renal oncocytoma versus ChRCC. Prospective validation was performed among consecutive renal oncocytoma/ChRCC tumors resected from 2013 to 2017.Results: Tumor size and younger age were associated with ChRCC, and multifocality with renal oncocytoma; however, the most reliable variable for ChRCC versus renal oncocytoma differentiation was the tumor:cortex peak early-phase enhancement ratio (PEER) using multiphase CT. Among 54 PEER-evaluable tumors in the retrospective cohort [19 CD117(+), 13 CD117(-), 22 CD117-untested], PEER classified each correctly as renal oncocytoma (PEER >0.50) or ChRCC (PEER ≤0.50), except for four misclassified CD117(-) ChRCC variants. Prospective study of PEER confirmed 100% accuracy of renal oncocytoma/ChRCC classification among 22/22 additional CD117(+) tumors. Prospective interobserver reproducibility was excellent for PEER scoring (intraclass correlation coefficient, ICC = 0.97) and perfect for renal oncocytoma/ChRCC assignment (ICC = 1.0).Conclusions: In the largest clinical comparison of renal oncocytoma versus ChRCC to our knowledge, we identified and prospectively validated a reproducible radiographic measure that differentiates CD117(+) renal oncocytoma from ChRCC with potentially 100% accuracy. PEER may allow reliable biopsy-based diagnosis of CD117(+) renal oncocytoma, avoiding the need for diagnostic nephrectomy. Clin Cancer Res; 24(16); 3898-907. ©2018 AACR.

What do we know about the inflammasome in humans?

The inflammasome complex is part of the innate immune system, which serves to protect the host against harm from pathogens and damaged cells. It is a term first proposed by Tschopp's group in 2002, with numerous original research articles and reviews published on the topic since. There have been many types of inflammasome identified, but all result in the common pathway of activation of caspases and interleukin 1ß along with possible cell death called pyroptosis. Despite a growing body of research investigating the structure and function of the inflammasome in animal models, there is still limited evidence identifying inflammasome components in human physiology and disease. In this review, we explore the molecular structure and mechanism of activation of the inflammasome with a particular focus on inflammasome complexes expressed in humans. Inflammasome components have been identified in several human peripheral and brain tissues using both in vivo and ex vivo work, and the inflammasome complex has been shown to be associated with several genetic and acquired inflammatory and neoplastic disorders. We discuss the strengths and weaknesses of the information available on the inflammasome with an emphasis on the importance of prioritizing work on human tissue. There is a huge demand for more effective treatments for a number of inflammatory and neurodegenerative diseases. Modulation of the inflammasome has been proposed as a novel treatment for several of these diseases and there are currently clinical trials ongoing to test this theory.

Effect of active Aß immunotherapy on neurons in human Alzheimer's disease.

Amyloid ß peptide (Aß) immunization of Alzheimer's disease (AD) patients has been reported to induce amyloid plaque removal, but with little impact on cognitive decline. We have explored the consequences of Aß immunotherapy on neurons in post mortem brain tissue. Eleven immunized (AN1792, Elan Pharmaceuticals) AD patients were compared to 28 non-immunized AD cases. Immunohistochemistry on sections of neocortex was performed for neuron-specific nuclear antigen (NeuN), neurofilament protein (NFP) and phosphorylated-(p)PKR (pro-apoptotic kinase detected in degenerating neurons). Quantification was performed for pPKR and status spongiosis (neuropil degeneration), NeuN-positive neurons/field, curvature of the neuronal processes and interneuronal distance. Data were corrected for age, gender, duration of dementia and APOE genotype and also assessed in relation to Aß42 and tau pathology and key features of AD. In non-immunized patients, the degree of neuritic curvature correlated with spongiosis and pPKR, and overall the neurodegenerative markers correlated better with tau pathology than Aß42 load. Following immunization, spongiosis increased, interneuronal distance increased, while the number of NeuN-positive neurons decreased, consistent with enhanced neuronal loss. However, neuritic curvature was reduced and pPKR was associated with Aß removal in immunized patients. In AD, associations of spongiosis status, curvature ratio and pPKR load with microglial markers Iba1, CD68 and CD32 suggest a role for microglia in neurodegeneration. After immunization, correlations were detected between the number of NeuN-positive neurons and pPKR with Iba1, CD68 and CD64, suggesting that microglia are involved in the neuronal loss. Our findings suggest that in established AD this form of active Aß immunization may predominantly accelerate loss of damaged degenerating neurons. This interpretation is consistent with in vivo imaging indicating an increased rate of cerebral atrophy in immunized AD patients.

Effect of amyloid-ß (Aß) immunization on hyperphosphorylated tau: a potential role for glycogen synthase kinase (GSK)-3ß.

AIMS: Active amyloid-ß (Aß) immunotherapy in Alzheimer's disease (AD) induces removal of Aß and phosphorylated tau (ptau). Glycogen synthase kinase (GSK)-3ß is a kinase, responsible for phosphorylation of tau, activation of which can be induced by phosphorylated double-stranded RNA-dependent protein kinase (pPKR). Using a post-mortem cohort of immunized AD cases, we investigated the effect of Aß immunization on GSK-3ß expression and pPKR. METHODS: We immunostained 11 immunized AD cases and 28 unimmunized AD cases for active, inactive and total GSK-3ß, and for pPKR. Quantification of protein load was performed in the hippocampal region including CA1, subiculum and entorhinal cortex. RESULTS: All three areas showed a significant decrease in the three forms of GSK-3ß (P < 0.05) and a nonsignificant trend towards lower pPKR load in the immunized AD cases compared with the unimmunized AD cases. CONCLUSION: The lower GSK-3ß expression generated by Aß immunotherapy shows evidence of a modification of the signalling pathway induced by GSK-3ß leading to the overall reduction of tau, supporting the contention that in humans, GSK-3ß unifies Aß and tau-related neuropathology.

Eicosanoid profiling in an orthotopic model of lung cancer progression by mass spectrometry demonstrates selective production of leukotrienes by inflammatory cells of the microenvironment.

Eicosanoids are bioactive lipid mediators derived from arachidonic acid(1) (AA), which is released by cytosolic phospholipase A2 (cPLA2). AA is metabolized through three major pathways, cyclooxygenase (COX), lipoxygenase (LO) and cytochrome P450, to produce a family of eicosanoids, which individually have been shown to have pro- or anti-tumorigenic activities in cancer. However, cancer progression likely depends on complex changes in multiple eicosanoids produced by cancer cells and by tumor microenvironment and a systematic examination of the spectrum of eicosanoids in cancer has not been performed. We used liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) to quantitate eicosanoids produced during lung tumor progression in an orthotopic immunocompetent mouse model of lung cancer, in which Lewis lung carcinoma (LLC) cells are injected into lungs of syngeneic mice. The presence of tumor increased products of both the cyclooxygenase and the lipoxygenase pathways in a time-dependent fashion. Comparing tumors grown in cPLA2 knockout vs wild-type mice, we demonstrated that prostaglandins (PGE2, PGD2 and PGF2a) were produced by both cancer cells and the tumor microenvironment (TME), but leukotriene (LTB4, LTC4, LTD4, LTE4) production required cPLA2 expression in the TME. Using flow cytometry, we recovered tumor-associated neutrophils and 2 types of tumor-associated macrophages from tumor-bearing lungs and we defined their distinct eicosanoid profiles by LC/MS/MS. The combination of flow cytometry and LC/MS/MS unravels the complexity of eicosanoid production in lung cancer and provides a rationale to develop therapeutic strategies that target select cell populations to inhibit specific classes of eicosanoids.

Activation of PPARγ in myeloid cells promotes lung cancer progression and metastasis.

Activation of peroxisome proliferator-activated receptor-γ (PPARγ) inhibits growth of cancer cells including non-small cell lung cancer (NSCLC). Clinically, use of thiazolidinediones, which are pharmacological activators of PPARγ is associated with a lower risk of developing lung cancer. However, the role of this pathway in lung cancer metastasis has not been examined well. The systemic effect of pioglitazone was examined in two models of lung cancer metastasis in immune-competent mice. In an orthotopic model, murine lung cancer cells implanted into the lungs of syngeneic mice metastasized to the liver and brain. As a second model, cancer cells injected subcutaneously metastasized to the lung. In both models systemic administration of pioglitazone increased the rate of metastasis. Examination of tissues from the orthotopic model demonstrated increased numbers of arginase I-positive macrophages in tumors from pioglitazone-treated animals. In co-culture experiments of cancer cells with bone marrow-derived macrophages, pioglitazone promoted arginase I expression in macrophages and this was dependent on the expression of PPARγ in the macrophages. To assess the contribution of PPARγ in macrophages to cancer progression, experiments were performed in bone marrow-transplanted animals receiving bone marrow from Lys-M-Cre+/PPARγ(flox/flox) mice, in which PPARγ is deleted specifically in myeloid cells (PPARγ-Mac(neg)), or control PPARγ(flox/flox) mice. In both models, mice receiving PPARγ-Mac(neg) bone marrow had a marked decrease in secondary tumors which was not significantly altered by treatment with pioglitazone. This was associated with decreased numbers of arginase I-positive cells in the lung. These data support a model in which activation of PPARγ may have opposing effects on tumor progression, with anti-tumorigenic effects on cancer cells, but pro-tumorigenic effects on cells of the microenvironment, specifically myeloid cells.

Lysyl oxidase contributes to mechanotransduction-mediated regulation of transforming growth factor-ß signaling in breast cancer cells.

Transforming growth factor-ß (TGF-ß) regulates all stages of mammary gland development, including the maintenance of tissue homeostasis and the suppression of tumorigenesis in mammary epithelial cells (MECs). Interestingly, mammary tumorigenesis converts TGF-ß from a tumor suppressor to a tumor promoter through molecular mechanisms that remain incompletely understood. Changes in integrin signaling and tissue compliance promote the acquisition of malignant phenotypes in MECs in part through the activity of lysyl oxidase (LOX), which regulates desmoplastic reactions and metastasis. TGF-ß also regulates the activities of tumor reactive stroma and MEC metastasis. We show here that TGF-ß1 stimulated the synthesis and secretion of LOX from normal and malignant MECs in vitro and in mammary tumors produced in mice. The ability of TGF-ß1 to activate Smad2/3 was unaffected by LOX inactivation in normal MECs, whereas the stimulation of p38 MAPK by TGF-ß1 was blunted by inhibiting LOX activity in malignant MECs or by inducing the degradation of hydrogen peroxide in both cell types. Inactivating LOX activity impaired TGF-ß1-mediated epithelial-mesenchymal transition and invasion in breast cancer cells. We further show that increasing extracellular matrix rigidity by the addition of type I collagen to three-dimensional organotypic cultures promoted the proliferation of malignant MECs, a cellular reaction that was abrogated by inhibiting the activities of TGF-ß1 or LOX, and by degrading hydrogen peroxide. Our findings identify LOX as a potential mediator that couples mechanotransduction to oncogenic signaling by TGF-ß1 and suggest that measures capable of inactivating LOX function may prove effective in diminishing breast cancer progression stimulated by TGF-ß1.

Depletion of cytosolic phospholipase A2 in bone marrow-derived macrophages protects against lung cancer progression and metastasis.

Cancer progression and metastasis involves interactions between tumor cells and the tumor microenvironment (TME). We reported that mice deficient for cytosolic phospholipase A(2) (cPLA(2)-KO) are protected against the development of lung tumors. The goal of this study was to examine the role of cPLA(2) in the TME. Mouse lung cancer cells (CMT167 and Lewis lung carcinoma cells) injected directly into lungs of syngeneic mice formed a primary tumor, and then metastasized to other lobes of the lung and to the mediastinal lymph nodes. Identical cells injected into cPLA(2)-KO mice showed a dramatic decrease in the numbers of secondary metastatic tumors. This was associated with decreased macrophage staining surrounding the tumor. Wild-type mice transplanted with cPLA(2)-KO bone marrow had a marked survival advantage after inoculation with tumor cells compared with mice receiving wild-type (WT) bone marrow. In vitro, coculturing CMT167 cells with bone marrow-derived macrophages from WT mice increased production of interleukin 6 (IL-6) by cancer cells. This increase was blocked in cocultures using cPLA(2)-KO macrophages. Correspondingly, IL-6 staining was decreased in tumors grown in cPLA(2)-KO mice. These data suggest that stromal cPLA(2) plays a critical role in tumor progression by altering tumor-macrophage interactions and cytokine production.