Perineural Inflammation as a Novel Feature in Lichen Sclerosus: A Case Series of Histologic and Clinical Features.

ABSTRACT: Lichen sclerosus (LS) is a frequently encountered inflammatory skin disorder characterized by whitened, atrophic patches that can cause pain and pruritus. The underlying cause of this condition remains unknown. Primarily affecting the genital area, this condition carries an increased risk of developing cutaneous cancers and frequently co-occurs with autoimmune disorders. Our retrospective study aimed to explore histologic features of LS, with a particular focus on a newly established finding and its potential implications. We examined 53 histologic cases of LS collected over 2 years. Experienced pathologists evaluated and reached a consensus on the assignment of histologic features. Patient charts were manually reviewed to gather relevant demographic and clinical data. Statistical analysis was performed using IBM SPSS Statistics (2021). Of the 53 total patients identified as meeting criteria for inclusion in this study, only 8 (15%) were male. Eight cases (15%) demonstrated perineural inflammatory infiltrate. Notably, half of all samples from male patients exhibited perineural inflammatory infiltrate. A statistically significant increase ( P < 0.01) in the presence of dermal plasma cells was identified in cases with perineural inflammation versus cases without this feature. The findings of our study highlight the recurrent nature of perineural inflammation in LS, providing valuable insights into this condition. Furthermore, we observed a notable correlation between perineural inflammation, male patients, and the presence of dermal plasma cells. These discoveries contribute to a better understanding of the underlying mechanisms of LS and suggest avenues for future research into the condition.

CYFRA 21-1, CA 125 and CEA provide additional prognostic value in NSCLC patients with stable disease at first CT scan.

BACKGROUND: Serum tumor markers (STM) may complement imaging and provide additional clinical information for patients with non-small cell lung cancer (NSCLC). OBJECTIVE: To determine whether STMs can predict outcomes in patients with stable disease (SD) after initial treatment. METHODS: This single-center, prospective, observational trial enrolled 395 patients with stage III/IV treatment-naïve NSCLC; of which 263 patients were included in this analysis. Computed Tomography (CT) scans were performed and STMs measured before and after initial treatment (two cycles of chemotherapy and/or an immune checkpoint inhibitor or tyrosine kinase inhibitor); analyses were based on CT and STM measurements obtained at first CT performed after cycle 2 only PFS and OS were analyzed by Kaplan-Meier curves and Cox-proportional hazard models. RESULTS: When patients with SD (n = 100) were split into high- and low-risk groups based on CYFRA 21-1, CEA and CA 125 measurements using an optimized cut-off, a 4-fold increase risk of progression or death was estimated for high- vs low-risk SD patients (PFS, HR 4.17; OS, 3.99; both p < 0.0001). Outcomes were similar between patients with high-risk SD or progressive disease (n = 35) (OS, HR 1.17) and between patients with low-risk SD or partial response (n = 128) (PFS, HR 0.98; OS, 1.14). CONCLUSIONS: STMs can provide further guidance in patients with indeterminate CT responses by separating them into high- and low-risk groups for future PFS and OS events.

A Novel Brain PET Radiotracer for Imaging Alpha Synuclein Fibrils in Multiple System Atrophy.

Abnormal α-synuclein (α-syn) aggregation characterizes α-synucleinopathies, including Parkinson's disease (PD) and multiple system atrophy (MSA). However, no suitable positron emission tomography (PET) radiotracer for imaging α-syn in PD and MSA exists currently. Our structure-activity relationship studies identified 4-methoxy-N-(4-(3-(pyridin-2-yl)-3,8-diazabicyclo[3.2.1]octan-8-yl)phenyl)benzamide (4i) as a PET radiotracer candidate for imaging α-syn. In vitro assays revealed high binding of 4i to recombinant α-syn fibrils (inhibition constant (Ki) = 6.1 nM) and low affinity for amyloid beta (Aß) fibrils in Alzheimer's disease (AD) homogenates. However, [3H]4i also exhibited high specific binding to AD, progressive supranuclear palsy, and corticobasal degeneration tissues as well as PD and MSA tissues, suggesting notable affinity to tau. Nevertheless, the specific binding to pathologic α-syn aggregates in MSA post-mortem brain tissues was significantly higher than in PD tissues. This finding demonstrated the potential use of [11C]4i as a PET tracer for imaging α-syn in MSA patients. Nonhuman primate PET studies confirmed good brain uptake and rapid washout for [11C]4i.

Subjective beliefs and economic preferences during the COVID-19 pandemic.

The COVID-19 pandemic presents a remarkable opportunity to put to work all of the research that has been undertaken in past decades on the elicitation and structural estimation of subjective belief distributions as well as preferences over atemporal risk, patience, and intertemporal risk. As contributors to elements of that research in laboratories and the field, we drew together those methods and applied them to an online, incentivized experiment in the United States. We have two major findings. First, the atemporal risk premium during the COVID-19 pandemic appeared to change significantly compared to before the pandemic, consistent with theoretical results of the effect of increased background risk on foreground risk attitudes. Second, subjective beliefs about the cumulative level of deaths evolved dramatically over the period between May and November 2020, a volatile one in terms of the background evolution of the pandemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s10683-021-09738-3.

Literacy and the quality of index insurance decisions.

There is widespread concern in developing countries with the expansion of formal insurance products to help manage significant risks. These concerns arise primarily from a lack of understanding of insurance products, general failures of financial literacy and the need to use relatively exotic products in order to keep costs down for poor households. We investigate the importance of incentivized measures for general understanding, as well as domain-specific knowledge of the decision context on the purchase and the quality of index insurance decisions. We evaluate the quality of financial decisions by comparing the individual expected welfare outcomes of a number of decisions each individual makes to purchase index insurance or not. We find that excess purchase is an important driver of welfare losses, and that our incentivized measure of domain-specific literacy plays a critical role in bringing about better quality index insurance decisions. Supplementary Information: The online version contains supplementary material available at 10.1057/s10713-020-00060-1.

Poly (ADP-ribose) Interacts With Phosphorylated α-Synuclein in Post Mortem PD Samples.

Poly (ADP-ribose) (PAR) is a negatively charged polymer that is biosynthesized by Poly (ADP-ribose) Polymerase-1 (PARP-1) and regulates various cellular processes. Alpha-synuclein (αSyn) is an intrinsically disordered protein (IDP) that has been directly implicated with driving the onset and progression of Parkinson's disease (PD). The mechanisms by which α-synuclein (αSyn) elicits its neurotoxic effects remain unclear, though it is well established that the main components of Lewy bodies (LBs) and Lewy neurites (LNs) in PD patients are aggregated hyperphosphorylated (S129) forms of αSyn (pαSyn). In the present study, we used immunofluorescence-based assays to explore if PARP-1 enzymatic product (PAR) promotes the aberrant cytoplasmic accumulation of pαSyn. We also performed quantitative measurements using in situ proximity ligation assays (PLA) on a transgenic murine model of α-synucleinopathy (M83-SNCA∗A53T) and post mortem PD/PDD patient samples to characterize PAR-pαSyn interactions. Additionally, we used bioinformatic approaches and site-directed mutagenesis to identify PAR-binding regions on αSyn. In summary, our studies show that PAR-pαSyn interactions are predominantly observed in PD-relevant transgenic murine models of αSyn pathology and post mortem PD/PDD patient samples. Moreover, we confirm that the interactions between PAR and αSyn involve electrostatic forces between negatively charged PAR and lysine residues on the N-terminal region of αSyn.

Eliciting Beliefs about COVID-19 Prevalence and Mortality: Epidemiological Models Compared with The Street.

Subjective belief elicitation about uncertain events has a long lineage in the economics and statistics literatures. Recent developments in the experimental elicitation and statistical estimation of subjective belief distributions allow inferences about whether these beliefs are biased relative to expert opinion, and the confidence with which they are held. Beliefs about COVID-19 prevalence and mortality interact with risk management efforts, so it is important to understand relationships between these beliefs and publicly disseminated statistics, particularly those based on evolving epidemiological models. The pandemic provides a unique setting over which to bracket the range of possible COVID-19 prevalence and mortality outcomes given the proliferation of estimates from epidemiological models. We rely on the epidemiological model produced by the Institute for Health Metrics and Evaluation together with the set of epidemiological models summarised by FiveThirtyEight to bound prevalence and mortality outcomes for one-month, and December 1, 2020 time horizons. We develop a new method to partition these bounds into intervals, and ask subjects to place bets on these intervals, thereby revealing their beliefs. The intervals are constructed such that if beliefs are consistent with epidemiological models, subjects are best off betting the same amount on every interval. We use an incentivised experiment to elicit beliefs about COVID-19 prevalence and mortality from 598 students at Georgia State University, using six temporally-spaced waves between May and November 2020. We find that beliefs differ markedly from epidemiological models, which has implications for public health communication about the risks posed by the virus.

A Mechanism for Stroke Complicating Coronary Thrombus Aspiration.

Coronary thrombus aspiration was developed to remove thrombus, prevent distal embolization, and prepare the vessel for definitive intervention. However, its use is now limited by the risk of stroke. We describe a case where appropriate aspiration technique likely prevented central embolization of a coronary thrombus. (Level of Difficulty: Beginner.).

Thinking Machines and Risk Assessment: On the Path to Precision Medicine.

See Article by Al'Aref et al.

TMEM97 and PGRMC1 do not mediate sigma-2 ligand-induced cell death.

Sigma-2 receptors have been implicated in both tumor proliferation and neurodegenerative diseases. Recently the sigma-2 receptor was identified as transmembrane protein 97 (TMEM97). Progesterone receptor membrane component 1 (PGRMC1) was also recently reported to form a complex with TMEM97 and the low density lipoprotein (LDL) receptor, and this trimeric complex is responsible for the rapid internalization of LDL. Sigma-2 receptor ligands with various structures have been shown to induce cell death in cancer cells. In the current study, we examined the role of TMEM97 and PGRMC1 in mediating sigma-2 ligand-induced cell death. Cell viability and caspase-3 assays were performed in control, TMEM97 knockout (KO), PGRMC1 KO, and TMEM97/PGRMC1 double KO cell lines treated with several sigma-2 ligands. The data showed that knockout of TMEM97, PGRMC1, or both did not affect the concentrations of sigma-2 ligands that induced 50% of cell death (EC50), suggesting that cytotoxic effects of these compounds are not mediated by TMEM97 or PGRMC1. Sigma-1 receptor ligands, (+)-pentazocine and NE-100, did not block sigma-2 ligand cytotoxicity, suggesting that sigma-1 receptor was not responsible for sigma-2 ligand cytotoxicity. We also examined whether the alternative, residual binding site (RBS) of 1,3-Di-o-tolylguanidine (DTG) could be responsible for sigma-2 ligand cytotoxicity. Our data showed that the binding affinities (K i) of sigma-2 ligands on the DTG RBS did not correlate with the cytotoxicity potency (EC50) of these ligands, suggesting that the DTG RBS was not fully responsible for sigma-2 ligand cytotoxicity. In addition, we showed that knocking out TMEM97, PGRMC1, or both reduced the initial internalization rate of a sigma-2 fluorescent ligand, SW120. However, concentrations of internalized SW120 became identical later in the control and knockout cells. These data suggest that the initial internalization process of sigma-2 ligands does not appear to mediate the cell-killing effect of sigma-2 ligands. In summary, we have provided evidence that sigma-2 receptor/TMEM97 and PGRMC1 do not mediate sigma-2 ligand cytotoxicity. Our work will facilitate elucidating mechanisms of sigma-2 ligand cytotoxicity.

Volatile fingerprinting of human respiratory viruses from cell culture.

Volatile metabolites are currently under investigation as potential biomarkers for the detection and identification of pathogenic microorganisms, including bacteria, fungi, and viruses. Unlike bacteria and fungi, which produce distinct volatile metabolic signatures associated with innate differences in both primary and secondary metabolic processes, viruses are wholly reliant on the metabolic machinery of infected cells for replication and propagation. In the present study, the ability of volatile metabolites to discriminate between respiratory cells infected and uninfected with virus, in vitro, was investigated. Two important respiratory viruses, namely respiratory syncytial virus (RSV) and influenza A virus (IAV), were evaluated. Data were analyzed using three different machine learning algorithms (random forest (RF), linear support vector machines (linear SVM), and partial least squares-discriminant analysis (PLS-DA)), with volatile metabolites identified from a training set used to predict sample classifications in a validation set. The discriminatory performances of RF, linear SVM, and PLS-DA were comparable for the comparison of IAV-infected versus uninfected cells, with area under the receiver operating characteristic curves (AUROCs) between 0.78 and 0.82, while RF and linear SVM demonstrated superior performance in the classification of RSV-infected versus uninfected cells (AUROCs between 0.80 and 0.84) relative to PLS-DA (0.61). A subset of discriminatory features were assigned putative compound identifications, with an overabundance of hydrocarbons observed in both RSV- and IAV-infected cell cultures relative to uninfected controls. This finding is consistent with increased oxidative stress, a process associated with viral infection of respiratory cells.

Effects of Dosimetrically Guided I-131 Therapy on Hematopoiesis in Patients With Differentiated Thyroid Cancer.

OBJECTIVE: The objective of the study was to evaluate the effects of dosimetrically guided I-131 prescribed activities on hematopoiesis reflected by changes in complete blood counts (CBCs). DESIGN: This was a retrospective analysis. SETTING: The study was conducted at an academic center. PATIENTS: A total of 152 patients with differentiated thyroid cancer who had 185 dosimetrically guided I-131 treatments. INTERVENTIONS: There were no interventions. MAIN OUTCOME MEASURES: Repeated-measure ANOVA was used for the analysis of the differences in the averages of CBCs that were documented at baseline and 1, 6, 12, 24­36, and 48­60 months after I-131 treatment. RESULTS: All parameters decreased to their respective nadir at 1 month and then gradually returned toward baseline values. White blood cells (WBCs) and platelets (PLTs) were the most significantly affected cells. At 1 month, the decrease was 29.6% (P < .0001) for WBCs and 25% (P < .0001) for PLTs, whereas at 12 months, the decrease was 15.5% (P < .0001) and 13% (P < .0001), respectively. Lymphocytes appeared to be more susceptible to I-131 than neutrophils (ANCs). The decreases were small in absolute numbers for red blood cells, hematocrit and hemoglobin not surpassing 10%. Multivariate analysis demonstrated that the ratio of administered prescribed activity-to-maximum tolerated activity was associated with the decreases in WBCs (P = .0038), ANCs (P = .0063), and red blood cells (P = .029), with borderline significance for PLTs (P = .057) and hemoglobin (P = .057). CONCLUSIONS: Dosimetrically guided I-131 resulted in statistically significant decreases in CBC parameters, which were more prominent in WBCs and PLTs. Lymphocytes were more severely affected than ANCs, whereas all parameters reached a nadir at 1 month and then gradually returned toward baseline values over the 5-year follow-up of our study.

Neutralizing Antibodies Against Adeno-Associated Viral Capsids in Patients with mut Methylmalonic Acidemia.

Isolated methylmalonic acidemia (MMA), a group of autosomal recessive inborn errors of metabolism, is most commonly caused by complete (mut(0)) or partial (mut(-)) deficiency of the enzyme methylmalonyl-CoA mutase (MUT). The severe metabolic instability and increased mortality experienced by many affected individuals, especially those with mut(0) MMA, has led centers to use elective liver transplantation as a treatment for these patients. We have previously demonstrated the efficacy of systemic adeno-associated viral (AAV) gene delivery as a treatment for MMA in a murine model and therefore sought to survey AAV antibody titers against serotypes 2, 8, and 9 in a group of well-characterized MMA patients, accrued via a dedicated natural history study ( clinicaltrials.gov ID: NCT00078078). Plasma samples provided by 42 patients (8 mut(-) and 34 mut(0); 10 had received organ transplantation), who ranged in age between 2 and 31 years, were analyzed to examine AAV2 (n = 35), AAV8 (n = 41), and AAV9 (n = 42) antibody titers. In total, the seroprevalence of antibodies against AAV2, AAV8, or AAV9 was 20%, 22%, and 24%, respectively. We observed a lower-than-expected seropositivity rate (titers ≥1:20) in the pediatric MMA patients (2-18 years) for both AAV2 (p < 0.05) and AAV8 (p < 0.01) neutralizing antibodies (NAbs) compared with historical controls. Those with positive NAb titers were typically older than 18 years (p < 0.05 all serotypes) or had received solid organ transplantation (p < 0.01 AAV8, AAV9). The mut(0) patients who had not been transplanted (n = 24)-that is, the subset with the greatest need for improved treatments-represented the seronegative majority, with 21 out of 24 patients lacking Abs against all AAV capsids tested. The unexpected lack of NAbs against AAV in this patient population has encouraging implications for systemic gene delivery as a treatment for mut MMA.

Sarcopenia, obesity and sarcopenic obesity: effects on liver function and volume in patients scheduled for major liver resection.

BACKGROUND: Sarcopenia, obesity and sarcopenic obesity have been linked to impaired outcome after liver surgery. Preoperative liver function of sarcopenic, obese and sarcopenic-obese patients might be reduced, possibly leading to more post-operative morbidity. The aim of this study was to explore whether liver function and volume were influenced by body composition in patients undergoing liver resection. METHODS: In 2011 and 2012, all consecutive patients undergoing the methacetin breath liver function test were included. Liver volumetry and muscle mass analysis were performed using preoperative CT scans and Osirix(®) software. Muscle mass and body-fat% were calculated. Predefined cut-off values for sarcopenia and the top two body-fat% quintiles were used to identify sarcopenia and obesity, respectively. Histologic assessment of the resected liver gave insight in background liver disease. RESULTS: A total number of 80 patients were included. Liver function and volume were comparable in sarcopenic(-obese) and non-sarcopenic(-obese) patients. Obese patients showed significantly reduced liver function [295 (95-508) vs. 358 (96-684) µg/kg/h, P = 0.018] and a trend towards larger liver size [1694 (1116-2685) vs. 1533 (869-2852) mL, P = 0.079] compared with non-obese patients. Weight (r = -0.40), body surface area (r = -0.32), estimated body-fat% (r = -0.43) and body mass index (r = -0.47) showed a weak but significant negative (all P < 0.05) correlation with liver function. Moreover, body-fat% was identified as an independent factor negatively affecting the liver function. CONCLUSION: Sarcopenia and sarcopenic obesity did not seem to influence liver size and function negatively. However, obese patients had larger, although less functional, livers, indicating dissociation of liver function and volume in these patients.

Opposing roles for mammary epithelial-specific PPARγ signaling and activation during breast tumour progression.

BACKGROUND: Among women worldwide, breast cancer is the most commonly diagnosed cancer, and the second leading cause of cancer-related deaths. Improved understanding of breast tumourigenesis may facilitate the development of more effective therapies. Peroxisome proliferator-activated receptor (PPAR)γ is a transcription factor that regulates genes involved in insulin sensitivity and adipogenesis. Previously, we showed, using 7,12-dimethylbenz [a] anthracene (DMBA)-treated haploinsufficient PPARγ mice, that PPARγ suppresses breast tumour progression; however, the PPARγ expressing cell types and mechanisms involved remain to be clarified. Here, the role of PPARγ expression and activation in mammary epithelial cells (MG) with respect to DMBA-mediated breast tumourigenesis was investigated. METHODS: PPARγ MG knockout (PPARγ-MG KO) mice and their congenic, wild-type controls (PPARγ-WT) were treated once a week for six weeks by oral gavage with 1 mg DMBA dissolved in corn oil and maintained on a normal chow diet. At week 7, mice were randomly divided into those maintained on a normal chow diet (DMBA Only; PPARγ-WT: n = 25 and PPARγ-MG KO: n = 39) or those receiving a diet supplemented with the PPARγ ligand, rosiglitazone (ROSI, 4 mg/kg/day) (DMBA + ROSI; PPARγ-WT: n = 34 and PPARγ-MG KO: n = 17) for the duration of the 25-week study. RESULTS: Compared to DMBA Only-treated PPARγ-WTs, both breast tumour susceptibility and serum levels of proinflammatory and chemotactic cytokines, namely IL-4, eotaxin, GM-CSF, IFN-γ, and MIP-1α, were decreased among PPARγ-MG KOs. Cotreatment with ROSI significantly reduced breast tumour progression among PPARγ-WTs, correlating with increased BRCA1 and decreased VEGF and COX-2 protein expression levels in breast tumours; whereas, surprisingly DMBA + ROSI-treated PPARγ-MG KOs showed increased breast tumourigenesis, correlating with activation of COX-2. CONCLUSION: These novel data suggest MG-specific PPARγ expression and signaling is critical during breast tumourigenesis, and may serve as a strong candidate predictive biomarker for response of breast cancer patients to the use of therapeutic strategies that include PPARγ ligands.

Endophilin A2 Promotes TNBC Cell Invasion and Tumor Metastasis.

UNLABELLED: Triple-negative breast cancers (TNBCs) are highly aggressive cancers that lack targeted therapies. However, EGFR is frequently activated in a subset of TNBCs and represents a viable clinical target. Because the endocytic adaptor protein Endophilin A2 (SH3GL1/Endo II) has been implicated in EGFR internalization, we investigated Endo II expression and function in human TNBCs. Endo II expression was high in several TNBC cells compared with normal breast epithelial cells. Stable knockdown (KD) of Endo II was achieved in two TNBC cell lines, and although cell viability was unaffected, defects in receptor-mediated endocytosis were observed. EGFR signaling to Erk and Akt kinases was impaired in Endo II KD cells, and this correlated with reduced rates of EGFR internalization and cell motility. Endo II KD cells also displayed defects in three dimensional (3D) cell invasion, and this correlated with impaired extracellular matrix degradation and internalization of MT1-MMP. Endo II silencing also caused a significant reduction in TNBC tumor growth and lung metastasis in mammary orthotopic tumor xenograft assays. In human breast tumor specimens, Endo II expression was highest in TNBC tumors compared with other subtypes, and at the level of gene expression, high Endo II was associated with reduced relapse-free survival in patients with basal-like breast cancers. Together, these results identify a positive role for Endo II in TNBC tumor metastasis and a potential link with poor prognosis. IMPLICATIONS: Endophilin A2 and related adaptor proteins represent important signaling hubs to target in metastatic cancers.

Tissue-protective effects of NKG2A in immune-mediated clearance of virus infection.

Virus infection triggers a CD8(+) T cell response that aids in virus clearance, but also expresses effector functions that may result in tissue injury. CD8(+) T cells express a variety of activating and inhibiting ligands, though regulation of the expression of inhibitory receptors is not well understood. The ligand for the inhibitory receptor, NKG2A, is the non-classical MHC-I molecule Qa1(b), which may also serve as a putative restricting element for the T cell receptors of purported regulatory CD8(+) T cells. We have previously shown that Qa1(b)-null mice suffer considerably enhanced immunopathologic lung injury in the context of CD8(+) T cell-mediated clearance of influenza infection, as well as evidence in a non-viral system that failure to ligate NKG2A on CD8(+) effector T cells may represent an important component of this process. In this report, we examine the requirements for induction of NKG2A expression, and show that NKG2A expression by CD8(+) T cells occurs as a result of migration from the MLN to the inflammatory lung environment, irrespective of peripheral antigen recognition. Further, we confirmed that NKG2A is a mediator in limiting immunopathology in virus infection using mice with a targeted deletion of NKG2A, and infecting the mutants with two different viruses, influenza and adenovirus. In neither infection is virus clearance altered. In influenza infection, the enhanced lung injury was associated with increased chemoattractant production, increased infiltration of inflammatory cells, and significantly enhanced alveolar hemorrhage. The primary mechanism of enhanced injury was the loss of negative regulation of CD8(+) T cell effector function. A similar effect was observed in the livers of mutant mice infected intravenously with adenovirus. These results demonstrate the immunoregulatory role of CD8(+) NKG2A expression in virus infection, which negatively regulates T cell effector functions and contributes to protection of tissue integrity during virus clearance.

Loss of PPARγ expression in mammary secretory epithelial cells creates a pro-breast tumorigenic environment.

Breast cancer is the leading cause of new cancer diagnoses among women. Using peroxisome proliferator-activated receptor (PPAR)γ((+/-)) mice, we showed normal expression of PPARγ was critical to stop 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast tumorigenesis. PPARγ is expressed in many breast cell types including mammary secretory epithelial (MSE) cells. MSEs proliferate as required during pregnancy, and undergo apoptosis or reversible transdifferentiation during involution once lactation is complete. Thus, MSE-specific loss of PPARγ was hypothesized to enhance DMBA-mediated breast tumorigenesis. To test this, MSE cell-specific PPARγ knockout (PPARγ-MSE KO) and control (PPARγ-WT) mice were generated, mated and allowed to nurse for three days. One week after involution, dams were treated with DMBA to initiate breast tumors, and randomized on week 7 to continue receiving a normal chow diet (DMBA Only: PPARγ-WT, n = 15; PPARγ-MSE KO, n = 25) or one supplemented with a PPARγ activating drug (DMBA + ROSI: PPARγ-WT, n = 17; PPARγ-MSE KO, n = 24), and monitored for changes in breast tumor outcomes. PPARγ-MSE KOs had significantly lower overall survival and decreased mammary tumor latency as compared to PPARγ-WT controls. PPARγ activation significantly reduced DMBA-mediated malignant mammary tumor volumes irrespective of genotype. MSE-specific PPARγ loss resulted in decreased mammary gland expression of PTEN and Bax, increased superoxide anion production, and elevated serum eotaxin and RANTES, creating a protumorigenic environment. Moreover, PPARγ activation in MSEs delayed mammary tumor growth in part by down-regulating Cox-1, Cox-2 and cyclin D1. Collectively, these studies highlight a protective role of MSE-specific PPARγ during breast tumorigenesis, and support a novel chemotherapeutic role of PPARγ activation in breast cancer.

Stromal adipocyte PPARγ protects against breast tumorigenesis.

Peroxisome proliferator-activated receptor (PPAR)γ regulates the expression of genes essential for fat storage, primarily through its activity in adipocytes. It also has a role in carcinogenesis. PPARγ normally stops the in vivo progression of 7,12-dimethylbenz[a]anthracene (DMBA)-mediated breast tumours as revealed with PPARγ haploinsufficient mice. Since many cell types associated with the mammary gland express PPARγ, each with unique signal patterns, this study aimed to define which tissues are required for PPARγ-dependent antitumour effects. Accordingly, adipocyte-specific PPARγ knockout (PPARγ-A KO) mice and their wild-type (PPARγ-WT) controls were generated, and treated with DMBA for 6 weeks to initiate breast tumorigenesis. On week 7, mice were randomized to continue on normal chow diet or one supplemented with rosiglitazone (ROSI), and followed for 25 weeks for tumour outcomes. In PPARγ-A KO versus PPARγ-WT mice, malignant mammary tumour incidence was significantly higher and mammary tumour latency was decreased. DMBA + ROSI treatment reduced average mammary tumour volumes by 50%. Gene expression analyses of mammary glands by quantitative real-time polymerase chain reaction and immunofluorescence indicated that untreated PPARγ-A KOs had significantly decreased BRCA1 expression in mammary stromal adipocytes. Compared with PPARγ-WT mice, serum leptin levels in PPARγ-A KOs were also significantly higher throughout the study. Together, these data are the first to suggest that in vivo PPARγ expression in mammary stromal adipocytes attenuates breast tumorigenesis through BRCA1 upregulation and decreased leptin secretion. This study supports a protective effect of activating PPARγ as a novel chemopreventive therapy for breast cancer.

Avoiding bandwidth collapse in long chains of coupled optical microresonators.

Coupled photonic oscillators and resonators are sensitive to unavoidable nanoscale disorder, and localization in periodic structures induced by disorder leads eventually to a complete collapse of the bandwidth, which is generally considered problematic for device applications. Here, we investigate the dependence of bandwidth collapse on the interresonator coupling coefficient, a parameter controllable by lithography or device operation.