Abstract P5-01-01: Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer

Lymph node (LN) metastasis is a key driver of recurrence and survival in breast cancer (BC) patients. However, the mechanisms of metastatic dissemination of tumour cells from LNs to distant sites and their predictors of response to systemic therapy remain poorly understood, mainly due to a lack of non-invasive in vivo imaging models. We have recently described ezrin, a pro-metastatic crosslinker protein, as a regulator of tumour lymphangiogenesis and metastasis in BC (Breast Cancer Res. 2014; 16(5): 438). Furthermore, we demonstrated significant association of high ezrin expression with lymphovascular invasion in a cohort (n=63) of premenopausal patients with invasive BC (p =0.024). These findings prompted us to examine the role of ezrin in migration and invasion of metastatic tumour cells in LNs and their response to ezrin-targeted therapy. Using a locally accrued LN positive patient cohort (n=94), we demonstrated a significant association between high ezrin levels and reduced recurrence-free survival (univariate Log-rank test, p=0.033), suggesting that ezrin is a potential predictor of relapse in LN positive BC. To address the mechanistic role of ezrin in LN metastasis, we developed a novel intravital imaging model using a lymphatic reporter transgenic mouse (B6-prox1-mOrange2-pA-BAC) to examine the response of tumour-draining LN to anti-ezrin systemic therapy in real time. Next, we tested the effects of a small molecule ezrin inhibitor (NSC668394) in vitro and observed significant suppression of ezrin activation (p-T567) and cancer cell invasive phenotype. Intravital imaging of inguinal LN metastases, derived from subcutaneously implanted breast adenocarcinoma E0771-LMV (lung metastatic variant) cells, demonstrated significant reduction in mobility and invasiveness (Mann Whitney, p<0.0001) of metastatic cells following systemic treatment with NSC668394 (0.5 mg/kg at 24h and 8h prior to imaging). Interestingly, LN metastases engagement by host T cell (CD3+) was notably increased, whereas T cell mobility was not affected by ezrin inhibition. Our findings present a novel non-invasive imaging model to study the LN metastasis response to anti-cancer therapy in real time, and provide new insight into the role of ezrin as a potential anti-metastatic target in BC.

(Supported by CRS, CIHR, CBCF, BCAK, Queen's SRC).

Citation Format: Ghaffari A, Hoskin V, Mullins G, Greer P, Kiefer F, Madarnas Y, SenGupta S, Elliott B. Real-time imaging of lymph node metastasis in response to systemic ezrin inhibitor treatment in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-01.

Longitudinal Mapping of Gyral and Sulcal Patterns of Cortical Thickness and Brain Volume Regain during Early Alcohol Abstinence

We explored brain volume recovery in terms of cortical thickness (CTh; gyral, sulcal pattern) and surface area (SA), as well as subcortical volume recovery in the first 2 weeks of abstinence in 49 alcohol-dependent patients (ADPs). A widespread reduction of CTh in ADPs at day 1 of abstinence compared to healthy controls, with more pronounced differences in sulci relative to gyri was found. After 2 weeks of abstinence, partial recovery to varying degrees of CTh loss in ADPs was observed for several regions. The longitudinal CTh changes were greater in sulci than in gyri of affected regions. No longitudinal change in SAs and subcortical volumes was found. Alterations of CTh contribute to brain volume loss in alcoholism and recovery during early abstinence. Sulci seem to be more vulnerable to excessive alcohol consumption and to drive abstinence-induced volume recovery. During the initial 2 weeks of abstinence no subcortical volume regain was observed. Either the time span was too short or the lower subcortical volume could represent a predisposing trait marker.

The effects of single nucleotide polymorphisms in glutamatergic neurotransmission genes on neural response to alcohol cues and craving

The aim of the current study was to determine genotype effects of four single nucleotide polymorphisms (SNPs) in the genes of the N-Methyl-d-aspartate receptor (GRIN1, GRIN2A, GRIN2C) and kainate receptor (GRIK1), which have been previously associated with alcoholism, on behavior, neural cue-reactivity and drinking outcome. Eighty-six abstinent alcohol dependent patients were recruited from an in-patient setting. Neuropsychological tests, genotyping and functional magnetic resonance imaging (fMRI) were used to study genotype effects. GRIN2C risk allele carriers displayed increased alcohol cue-induced activation in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC). Neural activation in the ACC positively correlated with craving for alcohol (r = 0.201, P = 0.032), whereas activation in the dlPFC showed a negative association (r = -0.215, P = 0.023). In addition, dlPFC activation predicted time to first relapse (HR = 2.701, 95%CI 1.244-5.864, P = 0.012). GRIK1 risk allele carriers showed increased cue-induced activation in the medial prefrontal (PFC) and orbitofrontal cortex (OFC) and in the lateral PFC and OFC. Activation in both clusters positively correlated with alcohol craving (rmedOFC, medPFC  = 0.403, P = 0.001, rlatOFC, latPFC  = 0.282, P = 0.008), and activation in the cluster that encompassed the medial OFC predicted time to first relapse (HR = 1.911, 95%CI 1.030-3.545, P = 0.040). Findings indicate that SNPs in the GRIN2C and GRIK1 genes are associated with altered cue-induced brain activation that is related to craving for alcohol and relapse risk.

Increased mesolimbic cue-reactivity in carriers of the mu-opioid-receptor gene OPRM1 A118G polymorphism predicts drinking outcome: a functional imaging study in alcohol dependent subjects

The endogenous opioid system is involved in the pathophysiology of alcohol-use disorders. Genetic variants of the opioid system alter neural and behavioral responses to alcohol. In particular, a single nucleotide polymorphism rs1799971 (A118G) in the mu-opioid receptor gene (OPRM1) is suggested to modulate alcohol-related phenotypes and neural response in the mesocorticolimbic dopaminergic system. Little is known about the clinical implications of these changes. The current study investigated the relationship of genotype effects on subjective and neural responses to alcohol cues and relapse in a sample of abstinent alcohol-dependent patients. Functional magnetic resonance imaging (fMRI) was used to investigate alcohol cue-reactivity and drinking outcome of 81 abstinent alcohol-dependent patients. G-allele carriers displayed increased fMRI cue-reactivity in the left dorsal striatum and bilateral insulae. Neural responses to alcohol cues in these brain regions correlated positively with subjective craving for alcohol and positive expectations of alcohol׳s effects. Moreover, alcohol cue-reactivity in the left dorsal striatum predicted time to first severe relapse. Current results show that alcohol-dependent G-allele carriers׳ increased cue-reactivity is associated with an increased relapse risk. This suggests that genotype effects on cue-reactivity might link the OPRM1 A118G risk allele with an increased relapse risk that was reported in earlier studies. From a clinical perspective, risk-allele carriers might benefit from treatments, such as neuro-feedback or extinction-based therapy that are suggested to reduce mesolimbic reactivity.

Predicting naltrexone response in alcohol-dependent patients: the contribution of functional magnetic resonance imaging

BACKGROUND

Effect sizes of pharmacotherapy in alcoholism are modest. They might improve if subjects could be divided into more homogeneous subgroups and would then be treated targeted to their neurobiological profile. In such an effort, we tested neural cue reactivity as a potential predictor of treatment response to naltrexone. Alcohol-associated cues cause brain activations in mesocorticolimbic networks due to the positive reinforcing properties of alcohol. These activations were reported to be associated with relapse behavior. Naltrexone, an antagonist at the mu-opioid receptor, improves drinking behavior in some but not all patients probably by blocking the positive reinforcement of alcohol. Conversely, acamprosate is proposed to modulate negative reinforcement (withdrawal and cue-induced withdrawal). Identifying subjects with elevated cue reactivity and testing their response to medical treatment could thus improve our understanding of some of the mechanisms underlying pharmacotherapy response.

METHODS

A picture-perception task featuring alcohol-related and neutral stimuli was presented to 64 recently detoxified alcohol-dependent patients. Patients came from 1 center of a larger double-blind randomized multicenter clinical trial (the "PREDICT Study"). They were scanned prior to being randomized to either naltrexone or acamprosate. We examined the interaction between medication and functional magnetic resonance imaging (fMRI) cue reactivity, as measured by the percentage of voxels activated, using the time to the first severe relapse as the outcome criterion. Our a priori formulated hypothesis was that naltrexone but not acamprosate should be efficacious in subjects with high cue reactivity.

RESULTS

We observed an interaction effect between pretreatment brain activation induced by alcohol images and medication (acamprosate/naltrexone) on relapse behavior. In line with our hypothesis, this interaction was driven by treatment response to naltrexone in patients with elevated pretreatment cue reactivity in the ventral striatum.

CONCLUSIONS

fMRI has the potential for predicting treatment response to naltrexone in a subgroup of alcohol-dependent patients. However, this approach will be limited to researching the mechanisms and principles of treatment response.

How do we 'learn' addiction? Risk factors and mechanisms getting addicted to alcohol

BACKGROUND

Alcohol dependence is one of the leading contributors to the burden of disease in the world. A range of genetic and environmental risk factors has been identified to date, and preclinical and clinical studies including imaging studies have identified neuronal networks involved in the development of alcohol dependence.

METHODS

We review genetic and environmental risk factors for the development of alcohol addiction as well as structural and neuronal changes, including their transmitter systems, due to regular alcohol intake.

RESULTS

Stress as well as family background and, in juveniles, the peer group could be identified as environmental risk factors for alcohol dependence. Heritability is estimated at around 50%, and it seems to be comparable in women and men. There is ongoing research on a broad range of putative endophenotypes such as tolerance of the effects of alcohol intake or personal traits like 'impulsivity'. On the neurobiological level, chronic alcohol intake seems to render mesolimbic circuits hypersensitive to alcohol and alter the motivational reward system including dopaminergic neurotransmission.

CONCLUSION

Environmental and genetic risk factors, and especially their interaction, facilitate the development of alcohol dependence. Ongoing alcohol intake results in profound alterations of neuronal systems crucial for motivation, learning, memory and cognition control. Future studies should further combine the knowledge of neurobiological mechanisms and risk factors to develop new prevention strategies.

Effects of Cigarette Smoking on Plasma Concentration of the Appetite-Regulating Peptide Ghrelin

BACKGROUND

Weight gain is a common but only a partially understood consequence of smoking cessation. Existing data suggest modulating effects of the orexigenic peptide ghrelin on food intake. The aim of the present study was to investigate the effect of tobacco withdrawal on plasma concentration of acetylated and total ghrelin.

METHODS

Fifty four normal-weighted smokers and 30 non-smoking healthy controls were enrolled in our study. Concentrations of acetylated and total ghrelin were measured in blood plasma drawn two hours after a standardized meal and three hours after the smokers smoked their last cigarette. The severity of tobacco addiction was assessed based on cotinine plasma concentration, the Fagerström Test for Nicotine Dependence (FTND) and the number of cigarettes smoked per day.

RESULTS

The plasma concentration of acetylated ghrelin, but not total ghrelin, was significantly higher in smokers than in non-smokers. Moreover, we found significant negative correlations between acetylated ghrelin and all measures of the severity of nicotine dependence.

CONCLUSIONS

Early abstinence from tobacco smoking seems to be associated with increased plasma concentration of the orexigenic peptide acetylated ghrelin. This could be one reason for increased food craving during nicotine withdrawal and subsequent weight gain. Smokers might compensate these effects by increasing tobacco intake.

A comparison of region-of-interest measures for extracting whole brain data using survival analysis in alcoholism as an example

BACKGROUND

Aggregation of functional magnetic resonance imaging (fMRI) data in regions-of-interest (ROIs) is required for complex statistical analyses not implemented in standard fMRI software. Different data-aggregation measures assess various aspects of neural activation, including spatial extent and intensity.

NEW METHOD

In this study, conducted within the framework of the PREDICT study, we compared different aggregation measures for voxel-wise fMRI activations to be used as prognostic factors for relapse in 49 abstinent alcohol-dependent individuals in an outpatient setting using a cue-reactivity task. We compared the importance of the data-aggregation measures as prognostic factors for treatment outcomes by calculating the proportion of explained variation.

RESULTS AND COMPARISON WITH EXISTING METHOD(S)

Relapse risk was associated with cue-induced brain activation during abstinence in the ventral striatum (VS) and in the orbitofrontal cortex (OFC). While various ROI measures proved appropriate for using fMRI cue-reactivity to predict relapse, on the descriptive level the most "important" prognostic factor was a measure defined as the sum of t-values exceeding an individually defined threshold. Data collected in the VS was superior to that from other regions.

CONCLUSIONS

In conclusion, it seems that fMRI cue-reactivity, especially in the VS, can be used as prognostic factor for relapse in abstinent alcohol-dependent patients. Our findings suggest that data-aggregation measures that take both spatial extent and intensity of cue-induced brain activation into account make better biomarkers for predicting relapse than measures that consider an activation's spatial extent or intensity alone.

XRCC5 as a risk gene for alcohol dependence: evidence from a genome-wide gene-set-based analysis and follow-up studies in Drosophila and humans

Genetic factors have as large role as environmental factors in the etiology of alcohol dependence (AD). Although genome-wide association studies (GWAS) enable systematic searches for loci not hitherto implicated in the etiology of AD, many true findings may be missed owing to correction for multiple testing. The aim of the present study was to circumvent this limitation by searching for biological system-level differences, and then following up these findings in humans and animals. Gene-set-based analysis of GWAS data from 1333 cases and 2168 controls identified 19 significantly associated gene-sets, of which 5 could be replicated in an independent sample. Clustered in these gene-sets were novel and previously identified susceptibility genes. The most frequently present gene, ie in 6 out of 19 gene-sets, was X-ray repair complementing defective repair in Chinese hamster cells 5 (XRCC5). Previous human and animal studies have implicated XRCC5 in alcohol sensitivity. This phenotype is inversely correlated with the development of AD, presumably as more alcohol is required to achieve the desired effects. In the present study, the functional role of XRCC5 in AD was further validated in animals and humans. Drosophila mutants with reduced function of Ku80-the homolog of mammalian XRCC5-due to RNAi silencing showed reduced sensitivity to ethanol. In humans with free access to intravenous ethanol self-administration in the laboratory, the maximum achieved blood alcohol concentration was influenced in an allele-dose-dependent manner by genetic variation in XRCC5. In conclusion, our convergent approach identified new candidates and generated independent evidence for the involvement of XRCC5 in alcohol dependence.

Neurobiological correlates of physical self-concept and self-identification with avatars in addicted players of Massively Multiplayer Online Role-Playing Games (MMORPGs)

AIMS

MMORPG addiction has been associated with self-concept impairments and increased identification with the own avatar. Yet, the underlying neurobiological mechanisms of self-identification with avatars, especially reflected in the left angular gyrus (AG), have only been assessed in regular gamers. Therefore, the study aims to examine neurobiological processes in addicted MMORPG players while evaluating their own and their personal avatar's body image (physical self-concept).

METHODS

Sixteen addicted and seventeen non-addicted gamers underwent functional Magnetic Resonance Imaging (fMRI) while viewing images of themselves, their own avatar and unfamiliar persons. The Body Image Questionnaire (FKB-20) and Visual Analog Scales (VAS) assessing the degree of attractiveness, sympathy and gender identity of the self, of the avatar as well as of the unfamiliar persons were applied.

RESULTS

Addicts showed a significantly extended negative body image and lower gender identity levels as well as decreased bilateral brain activations in the AG and the middle occipital gyrus during self-perception. They further exhibited higher activations in the left AG during avatar-perception. Regression analyses in the overall group and in addicted gamers indicated a significant positive correlation between gender identity and brain activation in the left AG during self-perception.

CONCLUSIONS

Our results confirm addicted MMORPG players to have physical self-concept deficits which may be related to hypoactivations in the AG. The findings further indicate addicted gamers to have a tendency to identify themselves easier with their own avatar than with their real self. Lower gender identity levels might be associated with physical self-concept deficits in MMORPG addiction.

[Improvement of management of hypertension by implementation of alcohol screening and subsequent interventions in primary practice]

Hypertension and alcohol use are both part of the five most important risk factors for burden of disease in Western Europe, mainly because of their impact on non-communicable diseases (NCD). Both risk factors are prevalent with high overlap among patients in primary care. Implementation of a screening for alcohol among patients of hypertension in primary care followed by brief intervention for problem alcohol use or formal treatment for people with alcohol dependence could constitute an important step to reach the goals of the Global WHO Action Plan for Prevention and Control of NCD. In addition, such an intervention could improve the management of hypertension. In a working group of experts from clinical practice and research the rationale and potential barriers for this intervention were discussed and steps for implementation in primary care were developed.

Oleoylethanolamide and human neural responses to food stimuli in obesity

IMPORTANCE

Obesity has emerged as a leading health threat but its biological basis remains insufficiently known, hampering the search for novel treatments. Here, we study oleoylethanolamide, a naturally occurring lipid that has been clearly implicated in weight regulation in animals. However, its role for weight regulation and obesity in humans is still unclear.

OBJECTIVE

To investigate associations between plasma oleoylethanolamide levels and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) and functional magnetic resonance imaging response to food stimuli in obese patients and matched control participants.

DESIGN, SETTING, AND PARTICIPANTS

Case-control study of 21 obese patients and 24 matched control participants. Obesity was defined as having a BMI of at least 30. The mean age of participants was 40.8 years and BMIs ranged from 18.2 to 47.5.

MAIN OUTCOMES AND MEASURES

Interactions between plasma oleoylethanolamide levels and obesity on BMI and functional magnetic resonance imaging response to food stimuli.

RESULTS

Associations between oleoylethanolamide and BMI differed significantly depending on whether individuals were obese or not (P = .02). In obese individuals, oleoylethanolamide showed a trend toward a positive correlation with BMI (P = .06, ρ = 0.42), while this relationship was inverse for nonobese control participants (P = .07, ρ = -0.34). Similarly, we found significant interactions between oleoylethanolamide levels and obesity on food-related brain activation in cortical areas associated with reward processing and interoceptive signaling (P = .009). Specifically, nonobese individuals with higher oleoylethanolamide levels had higher insular brain activity (P < .001, ρ = 0.70); again, the relationship trended to be inverse for obese patients (P = .11, ρ = -0.36). These effects were not associated with plasma levels of leptin and anandamide, suggesting an independent role of oleoylethanolamide in hunger-associated interoceptive signaling. Analysis of food craving during the functional magnetic resonance imaging task suggested that the identified brain areas may be involved in suppressing food-liking reactions in nonobese individuals.

CONCLUSIONS AND RELEVANCE

This study suggests that oleoylethanolamide-mediated signaling plays an important role for hedonic regulation of food craving and obesity in humans and thus may be a valuable target for developing novel antiobesity drugs.

Two families of exocomets in the β Pictoris system

The young planetary system surrounding the star β Pictoris harbours active minor bodies. These asteroids and comets produce a large amount of dust and gas through collisions and evaporation, as happened early in the history of our Solar System. Spectroscopic observations of β Pictoris reveal a high rate of transits of small evaporating bodies, that is, exocomets. Here we report an analysis of more than 1,000 archival spectra gathered between 2003 and 2011, which provides a sample of about 6,000 variable absorption signatures arising from exocomets transiting the disk of the parent star. Statistical analysis of the observed properties of these exocomets allows us to identify two populations with different physical properties. One family consists of exocomets producing shallow absorption lines, which can be attributed to old exhausted (that is, strongly depleted in volatiles) comets trapped in a mean motion resonance with a massive planet. Another family consists of exocomets producing deep absorption lines, which may be related to the recent fragmentation of one or a few parent bodies. Our results show that the evaporating bodies observed for decades in the β Pictoris system are analogous to the comets in our own Solar System.

Genetic markers associated with abstinence length in alcohol-dependent subjects treated with acamprosate

Acamprosate supports abstinence in some alcohol-dependent subjects, yet predictors of response are unknown. To identify response biomarkers, we investigated associations of abstinence length with polymorphisms in candidate genes in glycine and glutamate neurotransmission pathways and genes previously implicated in acamprosate response. Association analyses were conducted in the discovery sample of 225 alcohol-dependent subjects treated with acamprosate for 3 months in community-based treatment programs in the United States. Data from 110 alcohol-dependent males treated with acamprosate in the study PREDICT were used for replication of the top association findings. Statistical models were adjusted for relevant covariates, including recruitment site and baseline clinical variables associated with response. In the discovery sample, shorter abstinence was associated with increased intensity of alcohol craving and lower number of days between the last drink and initiation of acamprosate treatment. After adjustment for covariates, length of abstinence was associated with the GRIN2B rs2058878 (P=4.6 × 10(-5)). In the replication sample, shorter abstinence was associated with increased craving, increased depressive mood score and higher alcohol consumption. Association of abstinence length with GRIN2B rs2058878 was marginally significant (P=0.0675); as in the discovery sample, the minor A allele was associated with longer abstinence. Furthermore, rs2300272, which is in strong linkage disequilibrium with rs2058878, was also associated with abstinence length (P=0.049). This is the first report of a replicated association of genetic markers with the length of abstinence in acamprosate-treated alcoholics. Investigation of the underlying mechanisms of this association and its usefulness for individualized treatment selection should follow.