[Seeing others is believing-analgesic placebo effects through observational learning?]

Hintergrund

Es gibt viele Studien zur Placeboanalgesie und deren zugrundliegenden Wirkmechanismen, die eine Behandlung von Patient:innen mit chronischen Schmerzen signifikant verbessern können. Beobachtungslernen als ein Wirkmechanismus wurde hingegen noch wenig untersucht.

Fragestellung

Das Ziel der Arbeit ist es, einen Überblick über die aktuelle Forschungslage zu Placeboanalgesie durch Beobachtungslernen zu geben. Dabei soll geklärt werden, ob Beobachtungslernen überhaupt einen signifikanten Placeboeffekt auslösen kann und durch welche Faktoren dieses Lernen beeinflusst wird.

Material und Methoden

Dafür wurden die Forschungsdatenbanken nach Studien zur Placeboanalgesie durch Beobachtungslernen durchsucht.

Ergebnisse

Nach der Anwendung der Ein- und Ausschlusskriterien verblieben 12 Studien. Es gab nur eine Studie, die an Patient:innen mit chronischen Schmerzen durchgeführt wurde. Die geringe Anzahl an Studien lässt noch keine allgemeingültigen Aussagen zu, aber es gibt erste Hinweise für die folgenden Aussagen: Beobachtungslernen von Placeboeffekten ist unter Laborbedingungen möglich und eine Aufmerksamkeitslenkung ist wichtig. Die Effektstärken reichen von klein bis groß. Die Effekte von klassischer Konditionierung und Beobachtungslernen sind vergleichbar. Live-Modelle, Videoaufnahmen und Bilder lösen ähnliche Effekte aus. Beobachtungslernen führt zu einer Erwartungsänderung.

Diskussion

Die vorliegende Evidenz liefert die Grundlage dafür, dass theoretisch und auch praktisch klinisch signifikante Effekte möglich sind. Weitere Studien sind nötig, um diese Aussagen verlässlich auch auf chronische Schmerzpatient:innen zu beziehen.

Analgetische Placeboeffekte und Implikationen für die Behandlung chronischer Schmerzen

Die Behandlung von chronischen Schmerzen kann langwierig sein. Erste Ansätze zur Nutzung von Placeboeffekten bei der Behandlung von chronischen Schmerzen zeigen erfolgversprechende Ergebnisse und können dazu beitragen, die z. T. frustranen Therapieoptionen zu verbessern. Daher sollten Placeboeffekte zur verbesserten Behandlung genutzt werden. Im derzeitigen Modell zur Entstehung von Placeboeffekten spielt die Erwartung eine zentrale Rolle. Eine positive oder negative Erwartung wird durch psychologische und biologische „State“- und „Trait“-Faktoren der Patient:innen sowie die früheren Lernerfahrungen, die der:die Patient:in mitbringt, beeinflusst. Aus diesem Modell ergeben sich Implikationen für die klinische Praxis: Positive Erwartungen sollten unterstützt werden, wobei unrealistische Erwartungen wiederum den Placeboeffekt reduzieren. Negative Erwartungen sollten kritisch diskutiert werden. Es sollte im interdisziplinären Team eine gemeinsame Botschaft an die Patient:innen vermittelt werden. Open-Label-Placebos können als Intervention genutzt werden, um die Selbstwirksamkeit zu steigern.

[Placebo effects in pain therapy]

In the past few decades, research on pain and placebo analgesia has gained importance both scientifically and clinically. In this article, the current findings and focus of research as well as the significance of placebo research for assessing the effectiveness of pain medication are illustrated. The underlying mechanisms of placebo analgesia not only have implications for theoretical models but also offer clinically relevant guidelines for everyday interventions in pain treatment. However, many placebo phenomena are not fully understood and have to be investigated further in order to exploit the full potential of placebo effects. Interindividual differences and their inclusion in treatment will play a major role in this aspect.

Combination of variations in inflammation- and endoplasmic reticulum-associated genes as putative biomarker for bevacizumab response in KRAS wild-type colorectal cancer

Chemotherapy combined with the angiogenesis inhibitor bevacizumab (BVZ) is approved as a first-line treatment in metastatic colorectal cancer (mCRC). Limited clinical benefit underpins the need for improved understanding of resistance mechanisms and the elucidation of novel predictive biomarkers. We assessed germline single-nucleotide polymorphisms (SNPs) in 180 mCRC patients (Angiopredict [APD] cohort) treated with combined BVZ + chemotherapy and investigated previously reported predictive SNPs. We further employed a machine learning approach to identify novel associations. In the APD cohort IL8 rs4073 any A carriers, compared to TT carriers, were associated with worse progression-free survival (PFS) (HR = 1.51, 95% CI:1.03-2.22, p-value = 0.037) and TBK1 rs7486100 TT carriers, compared to any A carriers, were associated with worse PFS in KRAS wild-type (wt) patients (HR = 1.94, 95% CI:1.04-3.61, p-value = 0.037), replicating previous findings. Machine learning identified novel associations in genes encoding the inflammasome protein NLRP1 and the ER protein Sarcalumenin (SRL). A negative association between PFS and carriers of any A at NLRP1 rs12150220 and AA for SRL rs13334970 in APD KRAS wild-type patients (HR = 4.44, 95% CI:1.23-16.13, p-value = 0.005), which validated in two independent clinical cohorts involving BVZ, MAVERICC and TRIBE. Our findings highlight a key role for inflammation and ER signalling underpinning BVZ + chemotherapy responsiveness.

Abstract 5033: The role of the epigenetic regulator SATB2 in colon cancer progression

SATB2 is a nuclear matrix-associated transcription factor that orchestrates gene expression by regulating higher-order chromatin structure. Using antibody-based screening of 48 normal human tissues and 20 cancer types, we identified SATB2 as a protein almost exclusively expressed in gastrointestinal tissue. We confirmed this observation at the mRNA level in 10,533 human tissue samples. Differential expression of SATB2 was observed in colorectal cancer, with loss of expression occurring along the adenoma-carcinoma sequence. Additionally, SATB2 expression was markedly decreased in metastatic SW620 colon cancer cells and siRNA knockdown of SATB2 expression in parental SW480 cells increased their growth and migratory capacity. Ectopic expression of SATB2 in the metastatic variant reversed the observed phenotype. Using tissue microarray and automated image analysis of SATB2 expression in colorectal cancers (n=309), SATB2 was demonstrated by multivariate Cox regression analysis to be an independent predictor of disease-specific survival (HR=0.52, 95% CI 0.32-0.83, p=0.006). SATB2 mRNA levels were examined in a second cohort (n=290) and again, SATB2 was demonstrated to be an independent predictor of disease-specific survival (HR=0.40, 95% CI 0.18-0.92, p=0.031). Interestingly, in colorectal cancer patients, SATB2 levels significantly correlated with CD3+ T-cell infiltrates in the tumours (p=0.006) and inversely correlated with COX2 expression (p=0.019). In two independent colorectal cancer cohorts (n=467), SATB2-low tumours were found to be significantly enriched in the CMS1 (immune-related) subtype (p<0.001). Gene set enrichment analysis revealed that SATB2 low tumours demonstrated altered immune signalling with significant increases in IFNγ (p=0.001), IL6 (p=0.001), IL8 (p<0.001) TFGβ (p<0.001), which was mirrored by in vitro manipulation of SATB2 expression in colon cancer cells. Furthermore, in a longitudinal cohort of patients with ulcerative colitis, we observed a significant correlation between loss of SATB2 expression and occurrence of future cancers (p=0.013). We therefore postulate that SATB2 acts as a master regulator of the inflammatory response in the gut and loss of expression is significantly associated with the progression of colorectal cancer.

Citation Format: Donal J. Brennan, Kirsha Naicker, Sudipto Das, Bruce Moran, Rut Klinger, Fredrik Ponten, Stephen Hewitt, Karin Jirström, Annette T. Byrne, Jacintha O'Sullivan, William M. Gallagher, Darran P. O'Connor. The role of the epigenetic regulator SATB2 in colon cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5033.

Abstract P5-05-07: Expression of the cocaine- and amphetamine-regulated transcript (CART) recruits SWI/SNF chromatin remodelling complexes to the estrogen receptor

Introduction

Cocaine- and amphetamine-regulated transcript (CART) peptides are neuropeptides involved in regulating physiological processes, such as feeding and drug reward. Recent studies have associated high CART expression with worse overall survival in patients with small-bowel carcinoid tumours and estrogen receptor-positive (ER+), lymph node-negative breast cancer. CART was also shown to be associated with poor patient response to tamoxifen, suggesting CART may play a role in conferring tamoxifen resistance.

Materials and methods

We have previously demonstrated that CART can impact the transcriptional activity of ERα through the use of western blotting and qPCR for specific ERα gene targets. RNA sequencing was carried out using a stable CART-inducible cell line model to identify genes which are upregulated/downregulated in cells expressing CART. Further, using our stable CART-inducible cell line model, we preformed ERα-Immunoprecipitation followed by in-solution mass spectrometry to identify differentially recruited protein complexes +/- CART expression.

Results and discussion

RNA sequencing revealed 156 significantly downregulated, and 100 significantly upregulated, genes in cells expressing CART (p<0.05). Through mining of publicly available ERα ChIP-seq data sets, both upregulated and downregulated gene sets were found to contain genes which have previously been shown to contain ERα binding events within their promotor regions. Mass spectrometry analysis revealed that the majority of proteins recruited to ERα in the presence of CART were members of the SWI/SNF (BAF) chromatin remodelling complex. The identification of SMARCD1 within this complex was of particular interest to this study, as this protein has previously been reported to be a critical mediator of nuclear receptor function. Further in silico analysis demonstrated high expression of SMARCD1 correlates with poor overall survival (OS) (p<0.00001) and distant metastasis free survival (DMFS) (p=0.00708) in a cohort of ER+ breast cancer patients. Intriguingly, SMARCD1 expression did not correlate with poor OS or DMFS in a cohort of ER- breast cancer patients, suggesting that this negative impact on survival is dependent on ER status.

Conclusion

In conclusion, we suggest that CART expression results in the recruitment of chromatin remodelling complexes to ERα in order to facilitate the regulation of receptor function and this impacts on patient outcome.

Citation Format: O'Connor DP, Mooney B, Das S, Klinger R, Moran B, Ni Chonghaile T, Cagney G, Bracken A, Gallagher WM. Expression of the cocaine- and amphetamine-regulated transcript (CART) recruits SWI/SNF chromatin remodelling complexes to the estrogen receptor [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-07.

Suitability of Wild Boar (Sus scrofa) as a Bioindicator for Environmental Pollution with Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS)

Wildlife species, such as roe deer, moose, brown hare, wild boar, etc., are known to accumulate persistent environmental contaminants and thus are useful as bioindicators for environmental pollution. Wild boars become exposed to perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from flora, fauna, water, and soil. The main exposure pathway to PFOA and PFOS is assumed to be the oral intake. From studies in domestic pigs (belonging to the same species Sus scrofa), it has been established that the oral exposure results in the liver accumulation of PFOA and PFOS. Thus, we posit that wild boars can be quantitatively used as suitable bioindicators for the presence of these substances in the environment. After the environmental pollution case in the Hessian region Sauerland in 2006, monitoring programs of individual Federal States from 2007 to 2013 showed that almost all wild boar liver samples contained PFOA and PFOS. In 2014, the analyses of PFOA and PFOS in liver of wild boars hunted in the south, north, and west of Germany showed liver concentrations at the same level among regions. Overall, an average ratio of PFOS:PFOA concentration in liver of 20.5:1 was found. To estimate the actual ratio of PFOS:PFOA in the wild boars' dietary exposure, we performed toxicokinetic modeling. According to the model, the PFOS exposure is only 2.2 times that of PFOA (because PFOS has slower elimination kinetics and higher affinity for the liver than PFOA). Overall, the determination of PFOA and PFOS in liver of wild boars indicates that both substances are ubiquitously distributed in the environment. At the same time, higher exposures were found for animals living in closer proximity to dense human populations.

Copy number load predicts outcome of metastatic colorectal cancer patients receiving bevacizumab combination therapy

Increased copy number alterations (CNAs) indicative of chromosomal instability (CIN) have been associated with poor cancer outcome. Here, we study CNAs as potential biomarkers of bevacizumab (BVZ) response in metastatic colorectal cancer (mCRC). We cluster 409 mCRCs in three subclusters characterized by different degrees of CIN. Tumors belonging to intermediate-to-high instability clusters have improved outcome following chemotherapy plus BVZ versus chemotherapy alone. In contrast, low instability tumors, which amongst others consist of POLE-mutated and microsatellite-instable tumors, derive no further benefit from BVZ. This is confirmed in 81 mCRC tumors from the phase 2 MoMa study involving BVZ. CNA clusters overlap with CRC consensus molecular subtypes (CMS); CMS2/4 xenografts correspond to intermediate-to-high instability clusters and respond to FOLFOX chemotherapy plus mouse avastin (B20), while CMS1/3 xenografts match with low instability clusters and fail to respond. Overall, we identify copy number load as a novel potential predictive biomarker of BVZ combination therapy.

Increased copy number alterations, indicative of chromosomal instability, is associated with poor cancer outcome. Here, metastatic colorectal cancer patients displaying intermediate-high CIN associate with improved outcome following chemotherapy and bevacizumab treatment, suggesting CIN as a predictive biomarker.

Abstract 698: The loss of SATB2 promotes ulcerative colitis-related colon cancer progression through altered localized inflammatory response

SATB2 is a member of a family of special AT-rich binding proteins and a novel transcription factor that orchestrates gene expression in a tissue-specific manner by regulating higher-order chromatin structure. Here, we assess the precise functional role of SATB2 in the development and progression of colorectal cancer, initiating from the proinflammatory phenotype. Differential expression of SATB2 was observed in colorectal cancer, with loss of expression occurring sequentially along the adenoma-carcinoma sequence, with the early preneoplastic tissue demonstrating highest SATB2 levels, which diminishes within adenomas followed by complete loss of SATB2 expression in metastatic disease. Functionally, we demonstrate that siRNA-mediated knockdown of SATB2 in SW480 cells was associated with the acquisition of an aggressive phenotype. Consistent with these findings, loss of SATB2 protein and mRNA expression was determined as an independent predictor of poor prognosis in 3 independent CRC cohorts (n=776). Furthermore, gene set enrichment analysis in two of these independent colorectal cancer cohorts revealed that loss of SATB2 mRNA expression was associated with a TH2 cytokine response and checkpoint genes like CTLA4 and PD1 and modulation of SATB2 expression in CRC cell lines led to altered expression of proinflammatory cytokines. Within this context, following classification of the patient samples within these cohorts into the recently published consensus molecular subtypes (CMS) revealed that SATB2 levels were significantly lower in the CMS1 subtype that effectively represents the immune subtype of colorectal cancer. In addition, tissue microarray (TMA) analysis of a sigmoidal colorectal cancer TMA representing 350 colorectal cancer patients demonstrated that lower SATB2 levels with poor outcome and inversely correlated with CD68+ infiltrates. Intriguingly, SATB2 expression was associated with chromosomal stability as knockdown of SATB2 resulted in an increase of anaphase bridging, which was independent of telomere length and directly related to the spindle assembly complex. Given the relationship between SATB2, chromosomal instability and local inflammatory response, SATB2 protein expression was assessed in a large cohort of patients with ulcerative colitis (UC), some of whom developed UC-related carcinoma. SATB2 protein expression decreased across the disease spectrum from normal to UC to dysplasia to carcinoma, suggesting that SATB2 expression can be used to monitor UC patients at risk of developing CRC. The findings from this study for the first time demonstrate the role of SATB2 as potential master immune-regulator in colon cancer and its pivotal role in regulating key inflammatory factors facilitating the progression of colorectal cancer initiating from a proinflammatory phenotype.

Citation Format: Sudipto Das, Kirsha Naicker, Rut Klinger, Yue Fan, Girish Mallya, Fredrick Ponten, Karin Jirström, Jacintha O'Sullivan, William M. Gallagher, Donal J. Brenan, Darran P. O'Connor. The loss of SATB2 promotes ulcerative colitis-related colon cancer progression through altered localized inflammatory response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 698.

Abstract 2579: Loss of chromosome 18q11.2-18q12.1 is predictive for progression-free survival in metastatic colorectal cancer patients treated with bevacizumab

Introduction: Most patients with metastatic colorectal cancer (mCRC) have a limited benefit from the addition of bevacizumab to standard combination chemotherapy. However, a subset of patients benefits substantially, highlighting an unmet clinical need for a predictive biomarker of response to bevacizumab. Previously, we demonstrated that losses in chromosome 5q34, 17q12 and 18q12.1-21.1 have a significant correlation with progression free survival (PFS) in patients treated with, but not without bevacizumab. These data warrant extensive validation. Patients: For validation, two cohorts of patients that received bevacizumab were analysed, one of 121 mCRC patient samples of the European multicenter study Angiopredict and one of 81 mCRC patient samples from the Italian multicenter study MoMA. A third cohort was included of 90 mCRC samples from patients that did not receive bevacizumab. Genome wide copy number aberrations were correlated with PFS, Results: Loss of chromosome 18q11.2-18q21.1 most significantly associated with PFS in both cohorts that received bevacizumab (Angiopredict: HR=0.61, p=0.016; MoMa: HR=0.55, p=0.019). No significant association with PFS was observed in the cohort that did not receive bevacizumab (HR=0.85, p=0.67). Patients of all three cohorts without an 18q11.2-21.1 loss had similar PFS regardless of treatment (Angiopredict, median PFS 211 days; MoMa, median PFS 232 days; no bevacizumab, median PFS 189 days). No significant associations with PFS were found for chromosome 5q34 and 17q for any of the cohorts. Conclusion: We conclude that loss of chromosomal region 18q11.2-18q21.1 is consistently predictive for PFS in patients receiving bevacizumab. 18q11.2 loss provides an increase in median PFS of 83 days, compared to patients without this loss. No significant increase was found for patients that did not received bevacizumab.

Citation Format: Erik van Dijk, Hedde Biesma, Martijn Cordes, Dominiek Smeets, Maarten Neerincx, Sudipto Das, Verena Murphy, Anna Barat, Orna Bacon, Jochen H.M. Prehn, Johannes Betge, Gaiser Timo, Bozena Fender, Gerrit A. Meijer, Deborah A. McNamara, Rut Klinger, Miriam Koopman, Matthias P.A. Ebert, Elaina W. Kay, Bryan T. Hennessey, Henk M.W. Verheul, William M. Gallagher, Darran P. O'Connor, Cornelis J.A. Punt, Fotios Loupakis, Diether Lambrechts, Annette Byrne, Nicole C.T. van Grieken, Bauke Ylstra. Loss of chromosome 18q11.2-18q12.1 is predictive for progression-free survival in metastatic colorectal cancer patients treated with bevacizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2579.

Loss of Chromosome 18q11.2-q12.1 Is Predictive for Survival in Patients With Metastatic Colorectal Cancer Treated With Bevacizumab

Purpose Patients with metastatic colorectal cancer (mCRC) have limited benefit from the addition of bevacizumab to standard chemotherapy. However, a subset probably benefits substantially, highlighting an unmet clinical need for a biomarker of response to bevacizumab. Previously, we demonstrated that losses of chromosomes 5q34, 17q12, and 18q11.2-q12.1 had a significant correlation with progression-free survival (PFS) in patients with mCRC treated with bevacizumab in the CAIRO2 clinical trial but not in patients who did not receive bevacizumab in the CAIRO trial. This study was designed to validate these findings. Materials and Methods Primary mCRC samples were analyzed from two cohorts of patients who received bevacizumab as first-line treatment; 96 samples from the European multicenter study Angiopredict (APD) and 81 samples from the Italian multicenter study, MOMA. A third cohort of 90 samples from patients with mCRC who did not receive bevacizumab was analyzed. Copy number aberrations of tumor biopsy specimens were measured by shallow whole-genome sequencing and were correlated with PFS, overall survival (OS), and response. Results Loss of chromosome 18q11.2-q12.1 was associated with prolonged PFS most significantly in both the cohorts that received bevacizumab (APD: hazard ratio, 0.54; P = .01; PFS difference, 65 days; MOMA: hazard ratio, 0.55; P = .019; PFS difference, 49 days). A similar association was found for OS and overall response rate in these two cohorts, which became significant when combined with the CAIRO2 cohort. Median PFS in the cohort of patients with mCRC who did not receive bevacizumab and in the CAIRO cohort was similar to that of the APD, MOMA, and CAIRO2 patients without an 18q11.2-q12.1 loss. Conclusion We conclude that the loss of chromosome 18q11.2-q12.1 is consistently predictive for prolonged PFS in patients receiving bevacizumab. The predictive value of this loss is substantiated by a significant gain in OS and overall response rate.

Dysregulated mitogen-activated protein kinase signalling as an oncogenic basis for clear cell sarcoma of the kidney

The oncogenic mechanisms and tumour biology underpinning clear cell sarcoma of the kidney (CCSK), the second commonest paediatric renal malignancy, are poorly understood and currently, therapy depends heavily on doxorubicin with cardiotoxic side-effects. Previously, we characterized the balanced t(10;17)(q22;p13) chromosomal translocation, identified at that time as the only recurrent genetic aberration in CCSK. This translocation results in an in-frame fusion of the genes YWHAE (encoding 14-3-3ϵ) and NUTM2, with a somatic incidence of 12%. Clinico-pathological features of that cohort suggested that this aberration might be associated with higher stage and grade disease. Since no primary CCSK cell line exists, we generated various stably transfected cell lines containing doxycycline-inducible HA-tagged YWHAE-NUTM2, in order to study the effect of expressing this transcript. 14-3-3ϵ-NUTM2-expressing cells exhibited significantly greater cell migration compared to isogenic controls. Gene and protein expression studies were indicative of dysregulated MAPK/PI3K-AKT signalling, and by blocking these pathways using neutralizing antibodies, the migratory advantage conferred by the transcript was abrogated. Importantly, CCSK tumour samples similarly show up-regulation/activation of these pathways. These results support the oncogenic role of 14-3-3ϵ-NUTM2 in CCSK and provide avenues for the exploration of novel therapeutic approaches. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mutant p53 as a therapeutic target for the treatment of triple-negative breast cancer: Preclinical investigation with the anti-p53 drug, PK11007

The identification of a targeted therapy for patients with triple-negative breast cancer (TNBC) is one of the most urgent needs in breast cancer therapeutics. The p53 gene is mutated in approximately 80% of patients with TNBC, and is a potential therapeutic target for patients with this form of breast cancer. The 2-sulfonylpyrimidine compound, PK11007, preferentially decreases viability in p53-compromised cancer cell lines. We investigated PK11007 as a potential new treatment for TNBC. IC₅₀ values for inhibition of proliferation in a panel of 17 breast cell lines by PK11007 ranged from 2.3 to 42.2 μM. There were significantly lower IC₅₀ values for TNBC than for non-TNBC cell lines (p = 0.03) and for p53-mutated cell lines compared with p53 WT cells (p = 0.003). Response to PK11007 however, was independent of the estrogen receptor (ER) or HER2 status of the cell lines. In addition to inhibiting cell proliferation, PK11007 induced apoptosis in p53 mutant cell lines. Using RNAseq and gene ontology analysis, we found that PK11007 altered the expression of genes enriched in pathways involved in regulated cell death, regulation of apoptosis, signal transduction, protein refolding and locomotion. The observations that PK11007 inhibited cell proliferation, induced apoptosis and altered genes involved in cell death are all consistent with the ability of PK11007 to reactivate mutant p53. Based on our data, we conclude that targeting mutant p53 with PK11007 is a potential approach for treating p53-mutated breast cancer, including the subgroup with TN disease.

Therapeutic Rationale to Target Highly Expressed CDK7 Conferring Poor Outcomes in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) patients commonly exhibit poor prognosis and high relapse after treatment, but there remains a lack of biomarkers and effective targeted therapies for this disease. Here, we report evidence highlighting the cell-cycle-related kinase CDK7 as a driver and candidate therapeutic target in TNBC. Using publicly available transcriptomic data from a collated set of TNBC patients (n = 383) and the METABRIC TNBC dataset (n = 217), we found CDK7 mRNA levels to be correlated with patient prognosis. High CDK7 protein expression was associated with poor prognosis within the RATHER TNBC cohort (n = 109) and the METABRIC TNBC cohort (n = 203). The highly specific CDK7 kinase inhibitors, BS-181 and THZ1, each downregulated CDK7-mediated phosphorylation of RNA polymerase II, indicative of transcriptional inhibition, with THZ1 exhibiting 500-fold greater potency than BS-181. Mechanistic investigations revealed that the survival of MDA-MB-231 TNBC cells relied heavily on the BCL-2/BCL-XL signaling axes in cells. Accordingly, we found that combining the BCL-2/BCL-XL inhibitors ABT-263/ABT199 with the CDK7 inhibitor THZ1 synergized in producing growth inhibition and apoptosis of human TNBC cells. Collectively, our results highlight elevated CDK7 expression as a candidate biomarker of poor prognosis in TNBC, and they offer a preclinical proof of concept for combining CDK7 and BCL-2/BCL-XL inhibitors as a mechanism-based therapeutic strategy to improve TNBC treatment. Cancer Res; 77(14); 3834-45. ©2017 AACR.

Targeting mutant p53 with PK11007: A new approach for the treatment of patients with triple-negative breast cancer?

e14099

Background:The identification of a targeted therapy for patients with triple-negative breast cancer (TNBC) is one of the most urgent needs in breast cancer therapeutics. Since the p53 gene is mutated in approximately 80% of TNBC patients, it is a potential therapeutic target for this form of breast cancer. PK11007 is a 2-sulfonypyrimidine that stabilizes and reactivates mutant p53 (Bauer et al, PNAS 2016). The compound recently was reported to preferentially decrease viability in p53-compromised cancer cells. The aim of this investigation was to evaluate PK11007 as a potential new treatment for TNBC. Methods: Cell viability was determined using the MTT assay. Apoptosis was detected using Annexin V Apoptosis Detection Kit. Migration was determined by Transwell migration assay. Knockdowns of p53 protein were carried out using predesigned Flexitube sequences (Qiagen). Results: IC50 values for inhibition of proliferation by PK11007 in the panel of 17 breast cell lines ranged from 2.3 to 42.2 μM. There were significantly lower IC50values for TNBC than for non-TNBC cell lines (p = 0.03) and for p53-mutated cell lines compared with p53 WT cells (p = 0.003). Response to PK11007 however, was independent of ER or HER2 status of the cells. In addition, PK11007 induced apoptosis and inhibited migration in p53 mutant cell lines. Using RNAseq and gene ontogeny analysis, we found that PK11007 altered the expression of genes enriched in pathways involved in regulated cell death, regulation of apoptosis, signal transduction, protein refolding and locomotion. To establish if PK11007 acts by targeting mutant p53, we used siRNA to knockdown p53 in 3 p53-mutated TNBC cell lines. Reduction in p53 protein levels resulted in a significant decrease in the growth inhibitory effects of PK11007, in all 3 cell lines investigated, suggesting that PK11007 mediates growth inhibition via p53. The observations that PK11007 inhibited cell growth, induced apoptosis, blocked cell migration and altered genes involved in cell death, are all consistent with the ability of PK11007 to activate mutant p53. Conclusions: Based on our data, we conclude that targeting mutant p53 with PK11007 is a potential approach for treating p53-mutated TNBC.

Identification of a novel predictive genomic biomarker for response to combination bevacizumab in metastatic colorectal cancer (mCRC)

3580

Background: Somatic copy number alterations (SCNA) are genomic alterations evident in cancers including mCRC. These alterations support biomarker discovery, allowing identification of variants that can be used to predict response to therapy. Herein, we studied the impact of SCNAs on mCRC patient response to bevacizumab (BVZ). Methods: SCNA data was assembled from mCRC tumors in the TCGA cohort (n = 676), from the CAIRO 2 study [n = 143] and from the ANGIOPREDICT cohort (n = 258) [Betge et al. Digestion 2016 94(3):129-137]. GISTIC v2.0 was used to identify the most frequent and overrepresented chromosomal aberrations. A region was considered deleted if the logR value was < 0.1 and amplified when the logR was > 0.1. A cutoff q-value of 0.25 was used to select significantly overrepresented SCNAs. To further explore the impact of new ANGIOPREDICT clusters and consensus molecular subtypes (CMS), [Guinney J et al Nat Med. 2015 21(11):1350-6], a panel of seven xenografts representing each CMS subtype was treated with FOLFOX (40mg/kg 5-FU, 13.4mg/kg folinic acid & 2.4mg/kg oxaliplatin) + B20 antibody (mouse avastin, 10mg/kg) for 4 weeks. Results: Unsupervised hierarchical clustering classified all 1077 tumors into 3 consensus SCNA subgroups termed ‘ANGIOPREDICT’ clusters 1-3. Concordance between CMS and ANGIOPREDICT clusters was evident: CMS1 - Cluster 1 78%, CMS3 - Cluster 1 50%. CMS2 - Cluster 2/3 92% and CMS4 - Cluster 2/3 84%. Tumors with intermediate or high copy number instability (ANGIOPREDICT cluster 2 & 3) showed improved progression free survival (PFS): 369d vs. 227d p = 1.36e-7) whereas tumors with low copy number alterations displayed a poor response to BVZ therapy (PFS: 147d vs 152d p = 0.906). Xenografts corresponding to CMS 2&4/ ANGIOPREDICT cluster 2-3 showed improved response to FOLFOX + B20 therapy and increased PFS (p < 0.001) vs. CMS1&3/ ANGIOPREDICT cluster 1. Conclusions: For the first time, in a large test and validation cohort including retrospectively collected and randomized controlled trial patient samples, we have identified a predictive genomic biomarker for BVZ therapy in mCRC. We have further demonstrated the utility of CMS subtyping to stratify patients to BVZ .

Vitamin D receptor as a target for breast cancer therapy

Considerable epidemiological evidence suggests that high levels of circulating vitamin D (VD) are associated with a decreased incidence and increased survival from cancer, i.e., VD may possess anti-cancer properties. The aim of this investigation was therefore to investigate the anti-cancer potential of a low calcaemic vitamin D analogue, i.e., inecalcitol and compare it with the active form of vitamin D, i.e., calcitriol, in a panel of breast cancer cell lines (n = 15). Using the MTT assay, IC₅₀ concentrations for response to calcitriol varied from 0.12 µM to >20 µM, whereas those for inecalcitol were significantly lower, ranging from 2.5 nM to 63 nM (P = 0.001). Sensitivity to calcitriol and inecalcitol was higher in VD receptor (VDR)-positive compared to VDR-negative cell lines (P = 0.0007 and 0.0080, respectively) and in ER-positive compared to ER-negative cell lines (P = 0.043 and 0.005, respectively). Using RNA-seq analysis, substantial but not complete overlap was found between genes differentially regulated by calcitriol and inecalcitol. In particular, significantly enriched gene ontology terms such as cell surface signalling and cell communication were found after treatment with inecalcitol but not with calcitriol. In contrast, ossification and bone morphogenesis were found significantly enriched after treatment with calcitriol but not with inecalcitol. Our preclinical results suggest that calcitriol and inecalcitol can inhibit breast cancer cell line growth, especially in cells expressing ER and VDR. As inecalcitol is significantly more potent than calcitriol and has low calcaemic potential, it should be further investigated for the treatment of breast cancer.

Abstract 4529: Tailoring approaches for global epigenome analysis from archival formalin-fixed paraffin-embedded tissue samples

Novel DNA extraction methodologies allow the use of archival material from formalin fixed paraffin embedded (FFPE) tissue samples in genomic studies. A major limitation of this source of DNA is the fragmented nature and low overall yield generally obtained from clinical materials, making downstream applications such as epigenetic analysis challenging. Previous published attempts have focussed on smaller regions of CpG islands, such as the use of Illumina's 450k arrays (which measure methylation at approximately 485,000 sites). The objective of this study was to optimize experimental and analytical workflows that allow effective interrogation of global DNA methylation profiles from FFPE samples.

Methylation capture was conducted on DNA from matched FFPE and fresh frozen samples from the same metastatic colorectal cancer patient as well as two colorectal cancer cell lines, using the SeqCap Epi (Roche) methyl capture system. The custom capture designed includes 5.5 million CpG sites across the genome, a greater than 10-fold increase compared to previously published studies. The wet-lab protocol was robustly optimized for several parameters, such as overall yield and bisulphite conversion efficiency (measured by shallow-read next generation sequencing). A data analysis pipeline composed of the bisulfite-converted DNA aligner BWA-meth, as well as in-house Perl and R scripts, was used to generate detailed methylation maps for individual sample types in order to identify differentially methylated regions (DMRs), which were further validated using targeted bisulphite sequencing for selected loci.

Preliminary analysis of the data revealed 98% bisulphite conversion efficiency and low PCR duplicate rate (4-5%) across both sample types. Intriguingly, we observe an 80% concordance between the overall DNA methylation profiles between FFPE and fresh frozen samples, with a 60% overlap between the FFPE and fresh frozen samples in terms of direction of methylation i.e. hyper or hypomethylation. Mapping overall methylation levels to CpG ‘resorts’ (+/- 4kb of CpG islands) indicated ∼10% of methylation occurred in these regions totalling 245MB. Known genomic features, including exons, promoters of coding/non-coding genes and enhancers, contained ∼30% (1.5 million) of the methylated positions. In addition, this methodology also allowed us to identify C to T transitions across all samples, a common artefact of formalin fixed samples. The analysis revealed that a significantly low proportion of C to T transitions were detected across all samples, the levels of the transitions being consistent between the two sample types. Taken together, these results demonstrate a robust and novel approach to generate DNA methylation profiles from difficult-to-handle, but frequently available material, thus establishing a suitable platform for a whole methylome profiling from archival samples.

Citation Format: Sudipto Das, Bruce Moran, Dominiek Smeets, Gillian Peuteman, Rut Klinger, Bozena Fender, Kate Connor, Matthias Ebert, Timo Gaiser, JHM Prehn, Orna Bacon, Elaine Kay, Bryan Hennessy, Verena Murphy, William Gallagher, Annette Byrne, Diether Lambrechts, Darran O’Connor. Tailoring approaches for global epigenome analysis from archival formalin-fixed paraffin-embedded tissue samples. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4529.

Abstract 4561: Dissecting mechanisms of CART signalling through the estrogen receptor in ER+ breast cancer

The cocaine- and amphetamine-regulated transcript (CART) was first discovered as a peptide up-regulated by the administration of cocaine and amphetamine to rats. CART peptides are involved in regulating physiological processes, such as feeding, reward and neuro-protection. However, recent studies have associated high CART expression with worse overall survival in patients with small-bowel carcinoid tumours [1] and estrogen receptor-positive (ER+), lymph node-negative breast cancer [2]. Interestingly, in ER+ breast cancer, CART was also shown to be associated with poor patient response to tamoxifen, suggesting CART may play a role in conferring tamoxifen resistance [2].

The aim of this study was to elucidate the mechanism(s) by which CART signals in ER+ breast cancer. In order to test whether CART could mediate the ligand-independent activation of ER-alpha, MAP-Kinase pathway activation and levels of downstream gene-targets of ER-alpha were assessed post CART stimulation. Additionally, the ability of CART to activate ER-alpha using three LXD motifs (nuclear receptor co-activator recognition motifs) present within the CART sequence was also assessed. This was achieved through selectively mutating these motifs and testing whether CART still possessed the ability to activate ER-alpha using an ERE-Dual luciferase reporter assay.

Treatment of cells with CART demonstrated an increase in MAP-Kinase activity through the detection of increasing phosphorylated ERK levels. An increase in the phosphorylation of ER-alpha at serine 118 (a phosphorylation site thought to be involved in tamoxifen resistance) was also evident following CART stimulation. CART stimulation also resulted in an increase in levels of the progesterone receptor, a known ER-alpha gene target. Mutagenesis of each LXD motif within CART resulted in significant decreases in ER-alpha activity, suggesting a potential structure-function relationship between CART and ER-alpha.

In conclusion, we suggest that CART can activate ER-alpha in a ligand-independent manner through the MAP-Kinase pathway, and also potentially through specific LXD motifs within its sequence. Further investigation into the relationship between CART and ER-alpha will help us gain a better understanding of, not only the potential structure-function relationship between CART and ER-alpha, but also the role CART plays with regards to tamoxifen resistance in ER+ breast cancer.

[1] Landerholm K et al., Expression of cocaine- and amphetamine-regulated transcript is associated with worse survival in small bowel carcinoid tumors. Clin Cancer Res. 2012 Jul 1;18(13):3668-76

[2] DJ Brennan, DP O’Connor et al., The cocaine- and amphetamine-regulated transcript mediates ligand-independent activation of ERα, and is an independent prognostic factor in node-negative breast cancer. Oncogene 2011 Dec 5. Doi: 10.1038/onc.2011.519

Citation Format: Brian Mooney, Sudipto Das, Rut Klinger, William Gallagher, Darran O’Connor. Dissecting mechanisms of CART signalling through the estrogen receptor in ER+ breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4561.

Treatment history and placebo responses to experimental and clinical pain in chronic pain patients

BACKGROUND

Placebo analgesia refers to the reduction in pain due to the administration of an inert treatment. It is induced by expectations of pain relief which are enhanced by learning mechanisms. In healthy humans, prior positive experiences enhance the placebo response. However, the effects of patients' prior experiences with treatment on placebo responses have not yet been examined. This study investigated how verbal information, learning and treatment history influence the magnitude of placebo analgesia in chronic pain.

METHODS

We administered a pharmacological placebo intervention in a sample of chronic pain patients (n = 49) who were seeking treatment in an outpatient pain clinic. Analyses were based on placebo responders.

RESULTS

We found that verbal information about a potent pain-relieving effect of the intervention induced a large placebo analgesic response to both acute experimental (F(1,44) = 43.35, p < 0.001) and chronic pain (F(1,44) = 37.72, p < 0.001). However, the placebo responses to experimental and chronic pain were not significantly related (r = 0.012, p = 0.95). An additional conditioning procedure did not significantly enhance placebo analgesia. Treatment history modulated the magnitude of the placebo response: patients with a more negative pain-related treatment history reported significantly larger placebo responses to their own chronic pain (τ = 0.271, p = 0.044).

CONCLUSIONS

We could show that placebo responses to both acute and chronic pain are high in pain treatment settings and that treatment history modulates this effect. Different mechanisms might underlie placebo responses to acute and chronic pain. Our findings highlight the necessity of considering placebo responses and treatment history in the treatment of chronic pain. WHAT DOES THIS STUDY ADD?: Placebo analgesia following verbal information of potent pain relief is high in chronic pain patients in a clinical setting. It is modulated by treatment history. Different mechanisms might underlie placebo analgesia to acute and chronic pain.

Abstract PD3-01: CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is defined by absent expression of estrogen receptor (ER), progesterone receptor (PR) and non-overexpression of human epidermal growth factor receptor 2 (HER2), representing a heterogeneous subgroup of breast cancer with substantial genotypic and phenotypic diversity. TNBC patients commonly exhibit poor prognosis and high relapse rates at early stages after conventional treatments. Currently, there is a lack of biomarkers and targeted therapies for the management of TNBC. During tumour development and progression, alterations in cellular behaviour are frequently linked with kinase expression and activity. Here, we aimed to identify novel kinase targets that may play a pivotal role in the progression of TNBC and, thus, offer new therapeutic vantage points.

We initially focused on identifying kinases correlated with differential outcome. Using publicly available transcriptomic data from a collated set of TNBC patients (n = 483), we identified 9 kinases that were significantly associated with survival at the mRNA level. From this in silico screen, CDK7 (cyclin-dependent kinase 7) was found to be correlated with poor recurrence-free survival. CDK7's trait as a marker of poor prognosis was further validated within another TNBC cohort (n=109) via assessment of a tissue microarray generated as part of the RATHER Consortium (www.ratherproject.com). At the protein level, high CDK7 expression was associated with poor breast cancer-specific, recurrence-free and distant recurrence-free survival.

To evaluate CDK7 as a therapeutic target in TNBC, two TNBC cell lines (BT-549 and MDA-MB-231) were selected to evaluate phenotypic alterations post shRNA-mediated CDK7 knockdown. CDK7 silencing led to decreased cell proliferation, colony formation and migration in vitro. CDK7 down-regulation also increased TNBC cell sensitivity to doxorubicin. BS-181 and THZ1, two highly specific CDK7 inhibitors, attenuated TNBC tumour growth by inducing G2/M phase cell cycle arrest and apoptosis, as well as down-regulation of RNAPII phosphorylation, an indication of global RNA transcription inhibition. Moreover, the covalent CDK7 inhibitor THZ1 demonstrated 1000-fold higher potency than BS-181. Inhibition of global RNA transcription preferentially affects proteins with short half-lives. Accordingly, we detected a reduction in the expression of the anti-apoptotic protein MCL-1 in both cell lines.

Next, we assessed anti-apoptotic dependence in MDA-MB-231 cells following treatment with THZ1 via BH3 profiling technology, and observed an increased response to the BAD and HRK peptides, inferring an elevated survival dependence on BCL-2/BCL-XL. We subsequently evaluated the combination of the BCL-2/BCL-XL inhibitor ABT-263 with THZ1 and discovered a synergistic inhibition of cell growth and apoptosis. Resulting combination index (CI) values demonstrated that synergistic cell death occurred following combined treatment with THZ1 and ABT-263/ABT-199 at various doses in both TNBC cell lines tested.

Our data implicate high CDK7 expression as a promising biomarker of poor prognosis in TNBC. Moreover, these findings suggest that targeting CDK7, combined with the BCL-2/BCL-XL inhibitor ABT-263, may be a useful therapeutic strategy for TNBC.

Citation Format: Gallagher WM, Li B, Ni Chonghaile T, Fan Y, Klinger R, O'Connor AE, Conroy E, Tarrant F, O'Hurley G, Mallya Udupi G, Gaber A, Chin S-F, Schouten PC, Dubois T, Linn S, Jirstrom K, Caldas C, Bernards R, O'Connor DP. CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative 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 PD3-01.

Abstract B06: CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative breast cancer

Triple-negative breast cancer (TNBC) represents a heterogeneous subgroup of breast cancer with substantial genotypic and phenotypic diversity. TNBC patients commonly exhibit poor prognosis and high relapse rates at early stages after conventional treatments. Currently, there is a lack of biomarkers and targeted therapies for the management of TNBC. During tumor development and progression, alterations in cellular behavior are frequently linked with kinase expression and activity. Here, we aimed to identify novel kinase targets that may play a pivotal role in the progression of TNBC and, thus, offer new therapeutic vantage points.

We initially focused on identifying kinases linked to differential outcome. Using publicly available transcriptomic data from a collated set of TNBC patients (n = 483), we identified 9 kinases that were associated with survival at the mRNA level. From this screen, CDK7 (cyclin-dependent kinase 7) was found to be correlated with poor relapse-free survival. CDK7's trait as a marker of poor prognosis was further validated within another TNBC cohort (n=109) via assessment of a tissue microarray generated as part of the RATHER Consortium (www.ratherproject.com). At the protein level, high CDK7 expression was associated with poor breast cancer-specific survival, recurrence-free survival and distance recurrence-free survival.

To evaluate CDK7 as a therapeutic target in TNBC, two TNBC breast cancer cell lines (BT-549 and MDA-MB-231) were selected to evaluate phenotypic alterations post shRNA-mediated CDK7 knockdown. CDK7 silencing led to decreased cell proliferation, colony formation and migration in vitro. CDK7 down-regulation also increased TNBC cell sensitivity to the chemotherapeutic agent doxorubicin. BS-181 and THZ1, two highly specific CDK7 inhibitors, attenuated TNBC tumor growth by inducing G2/M cell cycle arrest and global RNA transcription. Moreover, the covalent CDK7 inhibitor THZ1 demonstrated 1000-fold higher potency than BS-181. Inhibition of global RNA transcription preferentially affects proteins with short half-lives. Accordingly, we detected a reduction in the expression of the anti-apoptotic protein MCL-1 in both cell lines. Next, we assessed anti-apoptotic dependence in MDA-MB-231 cells following treatment with THZ1 via the BH3 profiling technology, and observed an increased response to the BAD and HRK peptides, inferring an elevated survival dependence on BCL-2/BCL-XL.

We subsequently evaluated the combination of the BCL-2/BCL-XL inhibitor ABT-263 with THZ1 and discovered synergistic responses in cell growth inhibition and apoptosis. In vivo testing of the efficacy of the CDK7 inhibitor, THZ1, in a xenograft model of TNBC was also carried out. Preliminary data revealed that tumor growth was suppressed following daily treatment with 10mg/kg of THZ1.

Our data implicate that high CDK7 expression is a promising biomarker of poor prognosis in TNBC. Moreover, these findings suggest that targeting CDK7, combined with BCL-2/BCL-XL inhibitor ABT-263, may be a useful therapeutic strategy for TNBC.

Citation Format: Bo Li, Triona Ni Chonghaile, Yue Fan, Rut Klinger, Aisling E. O'Connor, Emer Conroy, Finbarr Tarrant, Gillian O'Hurley, Girish Mallya Udupi, Alexander Gaber, Suet-Feung Chin, Helen A. Bardwell, Philip C. Schouten, Thierry Dubois, Sabine Linn, Karin Jirstrom, Carlos Caldas, Rene Bernards, Darran P. O'Connor, William M. Gallagher. CDK7: A marker of poor prognosis and tractable therapeutic target in triple-negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B06.

Monounsaturated fatty acid-enriched high-fat diets impede adipose NLRP3 inflammasome-mediated IL-1β secretion and insulin resistance despite obesity

Saturated fatty acid (SFA) high-fat diets (HFDs) enhance interleukin (IL)-1β-mediated adipose inflammation and insulin resistance. However, the mechanisms by which different fatty acids regulate IL-1β and the subsequent effects on adipose tissue biology and insulin sensitivity in vivo remain elusive. We hypothesized that the replacement of SFA for monounsaturated fatty acid (MUFA) in HFDs would reduce pro-IL-1β priming in adipose tissue and attenuate insulin resistance via MUFA-driven AMPK activation. MUFA-HFD-fed mice displayed improved insulin sensitivity coincident with reduced pro-IL-1β priming, attenuated adipose IL-1β secretion, and sustained adipose AMPK activation compared with SFA-HFD-fed mice. Furthermore, MUFA-HFD-fed mice displayed hyperplastic adipose tissue, with enhanced adipogenic potential of the stromal vascular fraction and improved insulin sensitivity. In vitro, we demonstrated that the MUFA oleic acid can impede ATP-induced IL-1β secretion from lipopolysaccharide- and SFA-primed cells in an AMPK-dependent manner. Conversely, in a regression study, switching from SFA- to MUFA-HFD failed to reverse insulin resistance but improved fasting plasma insulin levels. In humans, high-SFA consumers, but not high-MUFA consumers, displayed reduced insulin sensitivity with elevated pycard-1 and caspase-1 expression in adipose tissue. These novel findings suggest that dietary MUFA can attenuate IL-1β-mediated insulin resistance and adipose dysfunction despite obesity via the preservation of AMPK activity.

microRNAs: a new class of breast cancer biomarkers

MicroRNAs (miRNAs) are regulatory molecules known to be aberrantly expressed in cancer and contribute to numerous aspects of tumor biology including the initiation, growth and spread of the tumor. With such diverse roles, it is becoming apparent that some may also provide valuable information which may be of use in a clinical setting, demonstrating the potential to act as both screening tools for the stratification of high-risk patients, while informing the treatment decision-making process. There is mounting evidence to suggest that some miRNAs may even provide assistance in the diagnosis of patients with breast cancer. In addition, miRNAs may themselves be considered therapeutic targets, with inhibition or reintroduction of a particular miRNA capable of inducing a response in vivo. This review focuses on miRNAs that have prognostic, diagnostic or predictive potential in breast cancer as well as the possible challenges in the translation of such observations to the clinic.

Dynamic and influential interaction of cancer cells with normal epithelial cells in 3D culture

Background

The cancer microenvironment has a strong impact on the growth and dynamics of cancer cells. Conventional 2D culture systems, however, do not reflect in vivo conditions, impeding detailed studies of cancer cell dynamics. This work aims to establish a method to reveal the interaction of cancer and normal epithelial cells using 3D time-lapse.

Methods

GFP-labelled breast cancer cells, MDA-MB-231, were co-cultured with mCherry-labelled non-cancerous epithelial cells, MDCK, in a gel matrix. In the 3D culture, the epithelial cells establish a spherical morphology (epithelial sphere) thus providing cancer cells with accessibility to the basal surface of epithelia, similar to the in vivo condition. Cell movement was monitored using time-lapse analyses. Ultrastructural, immunocytochemical and protein expression analyses were also performed following the time-lapse study.

Results

In contrast to the 2D culture system, whereby most MDA-MB-231 cells exhibit spindle-shaped morphology as single cells, in the 3D culture the MDA-MB-231 cells were found to be single cells or else formed aggregates, both of which were motile. The single MDA-MB-231 cells exhibited both round and spindle shapes, with dynamic changes from one shape to the other, visible within a matter of hours. When co-cultured with epithelial cells, the MDA-MB-231 cells displayed a strong attraction to the epithelial spheres, and proceeded to surround and engulf the epithelial cell mass. The surrounded epithelial cells were eventually destroyed, becoming debris, and were taken into the MDA-MB-231 cells. However, when there was a relatively large population of normal epithelial cells, the MDA-MB-231 cells did not engulf the epithelial spheres effectively, despite repeated contacts. MDA-MB-231 cells co-cultured with a large number of normal epithelial cells showed reduced expression of monocarboxylate transporter-1, suggesting a change in the cell metabolism. A decreased level of gelatin-digesting ability as well as reduced production of matrix metaroproteinase-2 was also observed.

Conclusions

This culture method is a powerful technique to investigate cancer cell dynamics and cellular changes in response to the microenvironment. The method can be useful for various aspects such as; different combinations of cancer and non-cancer cell types, addressing the organ-specific affinity of cancer cells to host cells, and monitoring the cellular response to anti-cancer drugs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-014-0108-6) contains supplementary material, which is available to authorized users.

[Quality assurance in therapy of chronic pain. Results obtained by a taskforce of the German Section of the Association for the Study of Pain on psychological assessment of chronic pain. V. Instruments for the assessment of pain-related cognitions and coping with pain.]

The present paper is one of a series of publications, reviewing German instruments for psychological assessment of pain. Their main focus is on the results of a task force on quality testing for each subject. This paper describes and comments on methods regarding self-reporting of pain cognitions and both cognitive and behavioral strategies for coping with pain. Concerning pain cognitions one focus is on patients' attributions of causes of pain and the modes of controlling pain (subjective pain model). The other focus is on instruments recording "pain beliefs" in the sense of dysfunctional congitions associated with the experience of pain. Each instrument was examined with reference to approved psychometric criteria, empirical foundation and clinical relevance. It was noted that several instruments are deficient in their psychometric criteria and their empirical foundations. We used these data as a basis to elaborate a specific and differential recommendation. A similar procedure was followed with instruments for the assessment of pain-related coping strategies. According to our research there are two subgroups of coping instruments, one more specifically for cognitive coping with pain, and the other combined with behavioral coping strategies. Once again, we elaborated a specific and differential recommendation, giving priority to instruments taking account of both cognitive and behavioral dimensions of coping with pain.

[Comparative psychological aspects of itching and pain]

Itching is a major symptom of chronic skin diseases such as atopic dermatitis and leads to considerable psychological strain. Chronic itching lowers patient's quality of life similar to chronic pain and influences the medical treatment. The frequently resulting scratching behavior (short-term avoidance of itch) leads to continuation and exacerbation of the disease, just as with specific pain behavior. For the development of itching and pain psychosocial factors have been identified in addition to somatic ones. However, recent data suggest that there is a complex interaction between pain and itching and comparable mechanisms of neuronal sensitization. In contrast to traditional biomedical one-dimensional models which focus mainly on physical and not psychological factors of a disease, recent data support a biopsychosocial model of development and maintenance for itching and pain. Biopsychosocial understanding of a disease should consequently be taken as the basis for treatment and the importance of interdisciplinary treatment is emphasized. This article will focus on chronic itching and pain with particular consideration of psychological factors.

[Can failed back surgery be prevented? Psychological risk factors for postoperative pain after back surgery]

Aside from the surgical technique used, the development of peri- and postoperative pain and impairments in patients following intervertebral disk surgery is also determined to a crucial extent by psychological factors. Based on a systematic literature review, we checked whether evidence-based recommendations could be deduced on how to take into account psychological risk factors in back surgery in order to avoid postoperative complications, such as failed back surgery syndrome. The current state of research suggests three groups of risk factors: (1) negative psychological factors, (2) preexisting pain chronification, and (3) psychological disorders. In the case of elective intervertebral disk surgery, these factors should therefore be determined and identified preoperatively and taken into account in the indication for surgery. Multimodal treatments could conceivably prove to be more effective, or else psychological pain management therapy might be considered prior to surgery so as to avoid postoperative complications. If surgery is medically unavoidable despite existing risk factors, postoperative treatment should incorporate psychological pain management therapy at an early stage in the context of a multidisciplinary approach.

The interaction of disturbances and small mammal community dynamics in a lowland forest in Belize

1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species.

The interaction of disturbances and small mammal community dynamics in a lowland forest in Belize

1. Three floods (July 2000, August 2002, September 2003) and a hurricane (October 2001) that occurred in a lowland forest in the southern Maya Mountains of Belize presented an opportunity to evaluate the influence of these disturbances on the structure of a small mammal assemblage. 2. Four terrestrial and four primarily scansorial/arboreal species were trapped July 2000-March 2005 in six grids over 14 irregularly spaced trapping periods. 3. Community dynamics were characterized more by changes in species composition than changes in diversity. The dynamics were driven by species-specific variation in abundance, with changes in composition generally, but not exclusively, due to the occurrence or disappearance of species at low abundance. Despite the disturbances, species richness remained relatively constant. Evenness within the assemblage was consistently low, primarily as a result of dominance by one species, Heteromys desmarestianus. 4. Effects of flooding on community structure were direct but relatively brief (< 1 year), and varied with the duration and intensity of flooding. Effects from the hurricane were indirect but long-lasting and strongly related to severely reduced food resources. 5. This study suggests that long-term dynamics in the structure of many animal communities in the tropics often results from interactions between direct and indirect effects of disturbance. It also suggests that community resistance will depend on variation in disturbance type and regime, but resilience will be determined by the life-history characteristics of each species.

Impact of low back pain on functional limitations, depressed mood and quality of life in patients with rheumatoid arthritis

Low back pain (LBP) and rheumatoid arthritis (RA) are common orthopedic problems, but there is little information on the importance of LBP in RA patients. The aim of this study was to investigate how LBP affects functional limitations, depressed mood, and quality of life in patients with RA. A complex questionnaire was answered by 281 RA patients, including questions about their RA and their experience of LBP. Functional limitations were assessed using the Hannover Activities of Daily Living questionnaire (ADL), depressed mood using the Center for Epidemiological Studies Depression Scale (CES-D) and health-related quality of life using the Short Form 12 health questionnaire (SF-12). The prevalence of LBP in RA patients was 53.4%. RA patients with LBP displayed a significantly higher degree of disability and depression than RA patients without LBP. There were no differences between the two groups with regard to the duration of RA, the number of operations or medication. LBP is an important factor for the physical and psychological behavior of RA patients. Therefore, the onset of LBP should not be overlooked or underestimated.