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// Kerstin Menck 1,* , Florian Klemm 1,* , Julia Christina Gross 2 , Tobias Pukrop 1 , Dirk Wenzel 3 , Claudia Binder 1 1 Dept of Hematology/Oncology, University Medicine, Gottingen, Germany 2 Div. Signaling and Functional Genomics, German Cancer Research Center, Heidelberg, Germany 3 Max Planck Institute for Biophysical Chemistry, Gottingen, Germany * These authors contributed equally to this work. Correspondence: Claudia Binder, email: // Keywords : Breast cancer, exosomes, Evi, microvesicles, macrophages, Wnt 5a Received : August 27, 2013 Accepted : October 19, 2013 Published : October 21, 2013 Abstract Recently, we have shown that macrophage (MΦ)-induced invasion of breast cancer cells requires upregulation of Wnt 5a in MΦ leading to activation of β-Catenin-independent Wnt signaling in the tumor cells. However, it remained unclear, how malignant cells induce Wnt 5a in MΦ and how it is transferred back to the cancer cells. Here we identify two types of extracellular particles as essential for this intercellular interaction in both directions. Plasma membrane-derived microvesicles (MV) as well as exosomes from breast cancer cells, although biologically distinct populations, both induce Wnt 5a in MΦ. In contrast, the particle-free supernatant and vesicles from benign cells, such as platelets, have no such effect. Induction is antagonized by the Wnt inhibitor Dickkopf-1. Subsequently, Wnt 5a is shuttled via responding MΦ-MV and exosomes to the tumor cells enhancing their invasion. Wnt 5a export on both vesicle fractions depends at least partially on the cargo protein Evenness interrupted (Evi). Its knockdown leads to Wnt 5a depletion of both particle populations and reduced vesicle-mediated invasion. In conclusion, MV and exosomes are critical for MΦ-induced invasion of cancer cells since they are responsible for upregulation of MΦ-Wnt 5a as well as for its delivery to the recipient cells via a reciprocal loop. Although of different biogenesis, both populations share common features regarding function and Evi-dependent secretion of non-canonical Wnts.

Maintenance of tissue homeostasis and immune surveillance are important functions of the lymphatic vascular system. Lymphatic vessels are lined by lymphatic endothelial cells (LECs). By gene micro-array expression studies we recently compared human lymphangioma-derived LECs with umbilical vein endothelial cells (HUVECs). Here, we followed up on these studies. Besides well-known LEC markers, we observed regulation of molecules involved in immune regulation, acetylcholine degradation and platelet regulation. Moreover we identified differentially expressed WNT pathway components, which play important roles in the morphogenesis of various organs, including the blood vascular system. WNT signaling has not yet been addressed in lymphangiogenesis. We found high expression of FZD3, FZD5 and DKK2 mRNA in HUVECs, and WNT5A in LECs. The latter was verified in normal skin-derived LECs. With immunohistological methods we detected WNT5A in LECs, as well as ROR1, ROR2 and RYK in both LECs and HUVECs. In the human, mutations of WNT5A or its receptor ROR2 cause the Robinow syndrome. These patients show multiple developmental defects including the cardio-vascular system. We studied Wnt5a-knockout (ko) mouse embryos at day 18.5. We show that the number of dermal lymphatic capillaries is significantly lower in Wnt5a-null-mice. However, the mean size of individual lymphatics and the LEC number per vessel are greater. In sum, the total area covered by lymphatics and the total number of LECs are not significantly altered. The reduced number of lymphatic capillaries indicates a sprouting defect rather than a proliferation defect in the dermis of Wnt5a-ko-mice, and identifies Wnt5a as a regulator of lymphangiogenesis.

Liposomes are frequently used in cancer therapy to encapsulate and apply anticancer drugs. Here, we show that a systemic treatment of mice bearing skin tumors with empty phosphatidylcholine liposomes (PCL) resulted in inhibition of tumor growth, which was similar to that observed with the synthetic bacterial lipoprotein and TLR1/2 agonist Pam(3)CSK(4) (BLP). Both compounds led to a substantial decrease of macrophages in spleen and in the tumor-bearing skin. Furthermore, both treatments induced the expression of typical macrophage markers in the tumor-bearing tissue. As expected, BLP induced the expression of the M1 marker genes Cxcl10 and iNOS, whereas PCL, besides inducing iNOS, also increased the M2 marker genes Arg1 and Trem2. In vitro experiments demonstrated that neither PCL nor BLP influenced proliferation or survival of tumor cells, whereas both compounds inhibited proliferation and survival and increased the migratory capacity of bone marrow-derived macrophages (BMDM). However, in contrast to BLP, PCL did not activate cytokine secretion and induced a different BMDM phenotype. Together, the data suggest that similar to BLP, PCL induce an antitumor response by influencing the tumor microenvironment, in particular by functional alterations of macrophages, however, in a distinct manner from those induced by BLP.

Burkitt's lymphoma (BL) is a highly malignant, aggressive non-Hodgkin's lymphoma derived from germinal center B cells. Recently, global gene expression profiling of patient samples led to a molecular definition of BL with lymphocyte enhancer-binding factor 1 (LEF1) as a signature gene. Herein, we report the expression of nucleic LEF1 in 15 of 18 patients with BL and the identification of LEF1 target genes. Germinal center B cells were devoid of detectable nuclear LEF1 expression, as were mantle cell lymphoma (0 of 5), marginal zone lymphoma (0 of 6), follicular lymphoma (0 of 12), and diffuse large B-cell lymphoma (1 of 31). Whole-genome gene expression profiling after transient knockdown of LEF1 in BL cell lines identified new LEF1 target genes; these LEF1 targets are enriched with genes associated with cancers. The expression of LEF1 and LEF1-regulated genes in primary BL suggests that LEF1 is not only aberrantly expressed but also transcriptionally active. This study supports a functionally important role for LEF1 and its target genes in BLs.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and show characteristics of skeletal muscle differentiation. The two major RMS subtypes in children are alveolar (ARMS) and embryonal RMS (ERMS). We demonstrate that approximately 50% of ARMS and ERMS overexpress the LEF1/TCF transcription factor LEF1 when compared to normal skeletal muscle and that LEF1 can restrain aggressiveness especially of ARMS cells. LEF1 knockdown experiments in cell lines reveal that depending on the cellular context, LEF1 can induce pro-apoptotic signals. LEF1 can also suppress proliferation, migration and invasiveness of RMS cells both in vitro and in vivo. Furthermore, LEF1 can induce myodifferentiation of the tumor cells. This may involve regulation of other LEF1/TCF factors i.e. TCF1, whereas β-catenin activity plays a subordinate role. Together these data suggest that LEF1 rather has tumor suppressive functions and attenuates aggressiveness in a subset of RMS.

Liver metastasis development in breast cancer patients is common and confers a poor prognosis. So far, the prognostic significance of surgical resection and clinical relevance of biomarker analysis in metastatic tissue have barely been investigated. We previously demonstrated an impact of WNT signaling in breast cancer brain metastasis. This study aimed to investigate the value of established prognostic markers and WNT signaling components in liver metastases. Overall N = 34 breast cancer liver metastases (with matched primaries in 19/34 cases) were included in this retrospective study. Primaries and metastatic samples were analyzed for their expression of the estrogen (ER) and progesterone receptor, HER-2, Ki67, and various WNT signaling-components by immunohistochemistry. Furthermore, β-catenin-dependent and -independent WNT scores were generated and analyzed for their prognostic value. Additionally, the influence of the alternative WNT receptor ROR on signaling and invasiveness was analyzed in vitro. ER positivity (HR 0.09, 95 % CI 0.01–0.56) and high Ki67 (HR 3.68, 95 % CI 1.12–12.06) in the primaries had prognostic impact. However, only Ki67 remained prognostic in the metastatic tissue (HR 2.46, 95 % CI 1.11–5.44). Additionally, the β-catenin-independent WNT score correlated with reduced overall survival only in the metastasized situation (HR 2.19, 95 % CI 1.02–4.69, p = 0.0391). This is in line with the in vitro results of the alternative WNT receptors ROR1 and ROR2, which foster invasion. In breast cancer, the value of prognostic markers established in primary tumors cannot directly be translated to metastases. Our results revealed β-catenin-independent WNT signaling to be associated with poor prognosis in patients with breast cancer liver metastasis. Electronic supplementary material The online version of this article (doi:10.1007/s10585-016-9780-3) contains supplementary material, which is available to authorized users.

Malignant melanoma is the deadliest of skin cancers. Melanoma frequently metastasizes to the brain, resulting in dismal survival. Nevertheless, mechanisms that govern early metastatic growth and the interactions of disseminated metastatic cells with the brain microenvironment are largely unknown. To study the hallmarks of brain metastatic niche formation, we established a transplantable model of spontaneous melanoma brain metastasis in immunocompetent mice and developed molecular tools for quantitative detection of brain micrometastases. Here we demonstrate that micrometastases are associated with instigation of astrogliosis, neuroinflammation, and hyperpermeability of the blood–brain barrier. Furthermore, we show a functional role for astrocytes in facilitating initial growth of melanoma cells. Our findings suggest that astrogliosis, physiologically instigated as a brain tissue damage response, is hijacked by tumor cells to support metastatic growth. Studying spontaneous melanoma brain metastasis in a clinically relevant setting is the key to developing therapeutic approaches that may prevent brain metastatic relapse. Cancer Res; 76(15); 4359–71. ©2016 AACR.

BACKGROUND: Standard treatment for patients with primary CNS lymphoma remains to be defined. Active therapies are often associated with increased risk of haematological or neurological toxicity. In this trial, we addressed the tolerability and efficacy of adding rituximab with or without thiotepa to methotrexate-cytarabine combination therapy (the MATRix regimen), followed by a second randomisation comparing consolidation with whole-brain radiotherapy or autologous stem cell transplantation in patients with primary CNS lymphoma. We report the results of the first randomisation in this Article.METHODS: For the international randomised phase 2 International Extranodal Lymphoma Study Group-32 (IELSG32) trial, HIV-negative patients (aged 18-70 years) with newly diagnosed primary CNS lymphoma and measurable disease were enrolled from 53 cancer centres in five European countries (Denmark, Germany, Italy, Switzerland, and the UK) and randomly assigned (1:1:1) to receive four courses of methotrexate 3·5 g/m(2) on day 1 plus cytarabine 2 g/m(2) twice daily on days 2 and 3 (group A); or the same combination plus two doses of rituximab 375 mg/m(2) on days -5 and 0 (group B); or the same methotrexate-cytarabine-rituximab combination plus thiotepa 30 mg/m(2) on day 4 (group C), with the three groups repeating treatment every 3 weeks. Patients with responsive or stable disease after the first stage were then randomly allocated between whole-brain radiotherapy and autologous stem cell transplantation. A permuted blocks randomised design (block size four) was used for both randomisations, and a computer-generated randomisation list was used within each stratum to preserve allocation concealment. Randomisation was stratified by IELSG risk score (low vs intermediate vs high). No masking after assignment to intervention was used. The primary endpoint of the first randomisation was the complete remission rate, analysed by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT01011920.FINDINGS: Between Feb 19, 2010, and Aug 27, 2014, 227 eligible patients were recruited. 219 of these 227 enrolled patients were assessable. At median follow-up of 30 months (IQR 22-38), patients treated with rituximab and thiotepa had a complete remission rate of 49% (95% CI 38-60), compared with 23% (14-31) of those treated with methotrexate-cytarabine alone (hazard ratio 0·46, 95% CI 0·28-0·74) and 30% (21-42) of those treated with methotrexate-cytarabine plus rituximab (0·61, 0·40-0·94). Grade 4 haematological toxicity was more frequent in patients treated with methotrexate-cytarabine plus rituximab and thiotepa, but infective complications were similar in the three groups. The most common grade 3-4 adverse events in all three groups were neutropenia, thrombocytopenia, anaemia, and febrile neutropenia or infections. 13 (6%) patients died of toxicity.INTERPRETATION: With the limitations of a randomised phase 2 study design, the IELSG32 trial provides a high level of evidence supporting the use of MATRix combination as the new standard chemoimmunotherapy for patients aged up to 70 years with newly diagnosed primary CNS lymphoma and as the control group for future randomised trials.FUNDING: Associazione Italiana del Farmaco, Cancer Research UK, Oncosuisse, and Swiss National Foundation.

Background: Programme evaluation of medical education should be multi-dimensional. While structural and organisational aspects of teaching are frequently assessed, programme evaluation tools are rarely matched to specific learning objectives. Aims: This study used one medical school's catalogue of specific learning objectives to implement and critically appraise a novel programme evaluation tool based on comparative student self-assessments. Method: Medical students enrolled in the clinical phase of the undergraduate curriculum in Gottingen were invited to self-rate their knowledge, skills and attitudes before and after each course. A newly developed formula controlling for student performance levels when entering a course was used to compute a percentage gain in knowledge, skills and attitudes. Data derived from a prospective, longitudinal intervention study on the development of electrocardiogram interpretation skills including 636 students from four consecutive cohorts were used to provide validity evidence of the new approach. Results: The novel tool appeared superior to plain mean differences and effect sizes in detecting outstanding teaching as well as shortcomings of the curriculum. In addition, it adequately reflected objectively measured performance levels and was responsive to curriculum change. Conclusions: Comparative student self-assessment is a valid tool to appraise undergraduate medical curricula at the level of specific learning objectives.

Although there is increasing evidence that blood-derived macrophages support tumor progression, it is still unclear whether specialized resident macrophages, such as brain microglia, also play a prominent role in metastasis formation. Here, we show that microglia enhance invasion and colonization of brain tissue by breast cancer cells, serving both as active transporters and guiding rails. This is antagonized by inactivation of microglia as well as by the Wnt inhibitor Dickkopf-2. Proinvasive microglia demonstrate altered morphology, but neither upregulation of M2-like cytokines nor differential gene expression. Bacterial lipopolysacharide shifts tumor-educated microglia into a classical M1 phenotype, reduces their proinvasive function, and unmasks inflammatory and Wnt signaling as the most strongly regulated pathways. Histological findings in human brain metastases underline the significance of these results. In conclusion, microglia are critical for the successful colonization of the brain by epithelial cancer cells, suggesting inhibition of proinvasive microglia as a promising antimetastatic strategy. © 2010 Wiley-Liss, Inc.

Medical Education 2010: 44: 731–740 Objectives Interpretation of the electrocardiogram (ECG) is a core clinical skill that should be developed in undergraduate medical education. This study assessed whether small-group peer teaching is more effective than lectures in enhancing medical students’ ECG interpretation skills. In addition, the impact of assessment format on study outcome was analysed. Methods Two consecutive cohorts of Year 4 medical students (n = 335) were randomised to receive either traditional ECG lectures or the same amount of small-group, near-peer teaching during a 6-week cardiorespiratory course. Before and after the course, written assessments of ECG interpretation skills were undertaken. Whereas this final assessment yielded a considerable amount of credit points for students in the first cohort, it was merely formative in nature for the second cohort. An unannounced retention test was applied 8 weeks after the end of the cardiovascular course. Results A significant advantage of near-peer teaching over lectures (effect size 0.33) was noted only in the second cohort, whereas, in the setting of a summative assessment, both teaching formats appeared to be equally effective. A summative instead of a formative assessment doubled the performance increase (Cohen’s d 4.9 versus 2.4), mitigating any difference between teaching formats. Within the second cohort, the significant difference between the two teaching formats was maintained in the retention test (p = 0.017). However, in both cohorts, a significant decrease in student performance was detected during the 8 weeks following the cardiovascular course. Conclusions Assessment format appeared to be more powerful than choice of instructional method in enhancing student learning. The effect observed in the second cohort was masked by an overriding incentive generated by the summative assessment in the first cohort. This masking effect should be considered in studies assessing the effectiveness of different teaching methods.

Basal cell carcinoma (BCC) is the most common skin tumor in humans. Although BCCs rarely metastasize, they can cause significant morbidity due to local aggressiveness. Approximately 20% of BCCs show signs of spontaneous regression. The understanding of molecular events mediating spontaneous regression has the potential to reduce morbidity of BCC and, potentially, other tumors, if translated into tumor therapies. We show that BCCs induced in conditional Ptchflox/floxERT2+/− knockout mice regress with time and show a more differentiated phenotype. Differentiation is accompanied by Wnt5a expression in the tumor stroma, which is first detectable at the fully developed tumor stage. Coculture experiments revealed that Wnt5a is upregulated in tumor-adjacent macrophages by soluble signals derived from BCC cells. In turn, Wnt5a induces the expression of the differentiation marker K10 in tumor cells, which is mediated by Wnt/Ca2+ signaling in a CaMKII-dependent manner. These data support a role of stromal Wnt5a in BCC differentiation and regression, which may have important implications for development of new treatment strategies for this tumor. Taken together, our results establish BCC as an easily accessible model of tumor regression. The regression of BCC despite sustained Hedgehog signaling activity seems to be mediated by tumor-stromal interactions via Wnt5a signaling. Cancer Res; 70(7); 2739–48

Patientenversorgung, Forschung und Lehrtatigkeit im Rahmen der medizinischen Ausbildung stellen die drei Saulen universitarer Medizin dar. Uber die didaktische Ausbildung und Qualifikation der in lehrender Funktion tatigen Arztinnen und Arzte an deutschen medizinischen Hochschulen gibt es jedoch wenige, unzureichende Erhebungen. Im Januar 2009 wurden sowohl Arztinnen und Arzte als auch Studierende der Universitatsmedizin Gottingen in einer Online-Umfrage um Einschatzungen hinsichtlich der didaktischen Qualifikation der klinischen Dozenten gebeten. Zugleich wurde untersucht, ob seitens der in der Lehre tatigen Assistenten Interesse an einem hochschuldidaktischen Fortbildungsprogramm besteht. Wahrend der 12-tagigen Erhebungsperiode beteiligten sich 359 Studierende und 126 Lehrende an der Umfrage. Die in der Lehre tatigen Arztinnen und Arzte fuhlten sich insgesamt schlecht auf ihre didaktischen Aufgaben vorbereitet. Zugleich zeigten sie eine hohe Bereitschaft zur Teilnahme an einer hochschuldidaktischen Fortbildung. Die befragten Studierenden waren der Ansicht, dass Lehrende aller Unterrichtsformen von einer didaktischen Fortbildung profitieren wurden. Im Interesse einer besseren Ausbildung kunftiger Arztinnen und Arzte mussen seitens der Politik und der Verantwortlichen an den einzelnen Fakultaten unbedingt bessere Rahmenbedingungen fur die Implementierung hochschuldidaktischer Fortbildungen in der Medizin geschaffen werden, so wie sie auch in der Ausbildung von Lehrern an Schulen vorgeschrieben sind.

Bedside teaching is an important element of undergraduate medical education. However, the impact of curricular course structure on student outcome needs to be determined.This study assessed changes in fourth-year medical students' evaluations of clinical teaching sessions before and after the introduction of a new course format.The curricular structure of bedside teaching sessions in cardiology was modified without changing the amount of teaching time. Clinical teachers were instructed about the new teaching format and learning objectives. The new format implemented for adult but not paediatric cardiology sessions was piloted with 143 students in winter 2007/08. By computing effect sizes, evaluation results were compared to data obtained from 185 students before the intervention.Significant rating increases were observed for adult cardiology teaching sessions (Cohen's d = 0.66) but not paediatric cardiology sessions (d = 0.22). In addition to improving the structure and organization of the course, the intervention significantly impacted on students' perceptions of their learning outcome regarding practical skills (d = 0.69).Minimal curricular changes combined with basic faculty development measures significantly increase students' perception of learning outcome. Curricular structure needs to be considered when planning bedside teaching sessions in medical undergraduate training.

Classical Hodgkin lymphoma (cHL) has a typical clinical manifestation, with dissemination involving functionally neighboring lymph nodes. The factors involved in the spread of lymphoma cells are poorly understood. Here we show that cHL cell lines migrate with higher rates compared with non-Hodgkin lymphoma cell lines. cHL cell migration, invasion and adhesion depend on autocrine WNT signaling as revealed by the inhibition of WNT secretion with the porcupine inhibitors Wnt-C59/IWP-2, but did not affect cell proliferation. While application of recombinant WNT5A or WNT5A overexpression stimulates HL cell migration, neither WNT10A, WNT10B nor WNT16 did so. Time-lapse studies revealed an amoeboid type of cell migration modulated by WNT5A. Reduced migration distances and velocity of cHL cells, as well as altered movement patterns, were observed using porcupine inhibitor or WNT5A antagonist. Knockdown of Frizzled5 and Dishevelled3 disrupted the WNT5A-mediated RHOA activation and cell migration. Overexpression of DVL3-K435M or inhibition of ROCK (Rho-associated protein kinase) by Y-27632/H1152P disrupted cHL cell migration. In addition to these mechanistic insights into the role of WNT5A in vitro, global gene expression data revealed an increased WNT5A expression in primary HL cells in comparison with normal B-cell subsets and other lymphomas. Furthermore, the activity of both porcupine and WNT5A in cHL cells had an impact on lymphoma development in the chick chorionallantoic membrane assay. Massive bleeding of these lymphomas was significantly reduced after inhibition of WNT secretion by Wnt-C59. Therefore, a model is proposed where WNT signaling has an important role in regulating tumor-promoting processes.

Tumor cells secrete not only a variety of soluble factors, but also extracellular vesicles that are known to support the establishment of a favorable tumor niche by influencing the surrounding stroma cells. Here we show that tumor-derived microvesicles (T-MV) also directly influence the tumor cells by enhancing their invasion in a both autologous and heterologous manner. Neither the respective vesicle-free supernatant nor MV from benign mammary cells mediate invasion. Uptake of T-MV is essential for the proinvasive effect. We further identify the highly glycosylated form of the extracellular matrix metalloproteinase inducer (EMMPRIN) as a marker for proinvasive MV. EMMPRIN is also present at high levels on MV from metastatic breast cancer patients in vivo. Anti-EMMPRIN strategies, such as MV deglycosylation, gene knockdown, and specific blocking peptides, inhibit MV-induced invasion. Interestingly, the effect of EMMPRIN-bearing MV is not mediated by matrix metalloproteinases but by activation of the p38/MAPK signaling pathway in the tumor cells. In conclusion, T-MV stimulate cancer cell invasion via a direct feedback mechanism dependent on highly glycosylated EMMPRIN. peerReviewed

Interactions between neoplastic and stromal cells contribute to tumor progression. Wnt genes, involved in cell migration and often deregulated in cancers, are attractive candidates to regulate these effects. We have recently shown that coculture of breast cancer cells with macrophages enhances invasiveness via matrix metalloproteases and TNF-α. Here we demonstrate that coculture of MCF-7 cells and macrophages leads to up-regulation of Wnt 5a in the latter. This was accompanied by activation ofAP-1/c-Junin MCF-7. Recombinant Wnt 5a mimicked the coculture effect. Wnt 5a was also detectable in tumor-associated macrophages in primary breast cancers. Experiments with agonists and antagonists of Wnt signaling revealed that a functional canonical pathway in the tumor cells was a necessary prerequisite; however, noncanonical signaling via Wnt 5a and the Jun-N-terminal kinase pathway was critical for invasiveness. It was also responsible for induction of matrix metalloprotease-7, known to release TNF-α. All these effects could be antagonized by dickkopf-1. Our results indicate that Wnt 5a is essential for macrophage-induced invasiveness, because it regulates tumor cell migration as well as proteolytic activity of the macrophages. The function of Wnt 5a as either a suppressor or promoter of malignant progression seems to be modulated by intercellular interactions. Wnt 5a detection in tumor-associated macrophages in breast cancer biopsies supports the assumption that similar events play a rolein vivo.

There is increased staining of endothelins (ET-1, -2, and -3) and receptors (ET-RA and -RB) in invasive breast tumors compared to nonneoplastic tissue, and ETs stimulate MCF-7 cell invasion in vitro. We analyzed ETstimulation of benign and transformed mammary epithelial cells, and whether expression of ETs is sufficient to induce invasiveness. In breast cancer patient serum, ET-1 was increased in those patients with lymph node metastases compared to those with no lymph node involvement; ETs, however, had no mitogenic effect on breast tumor cell lines in vitro. The benign mammary epithelial cell line, hTERT-HME1, and the poorly invasive breast tumor cell line MCF-7 secreted low levels of ET-1, while the invasive cell lines SKBR3 and MDAMB231 secreted high levels. Expression of the ETs and receptors by the cell lines broadly correlated with their in vitro invasiveness; overexpression of ETs in MCF-7 cells increased basal invasion. ET-mediated invasion involved both receptors and a calcium influx to induce a pertussis toxin-sensitive MAPK pathway. MMP-14 activity was induced via ET-RA in an autocrine manner. In contrast to transformed cells, ET stimulation or overexpression did not induce an invasive phenotype in benign cells. Benign cells do not respond to ETs, and ET expression is not sufficient to induce invasion; however, the level of ET production by tumor cells correlates with their invasiveness, and increasing expression of the ET axis promotes breast tumor cell invasion via both receptors, while MMP-14 is induced via ET-RA.

Tumor-associated macrophages may influence tumor progression, angiogenesis and invasion. To investigate mechanisms by which macrophages interact with tumor cells, we developed an in vitro coculture model. Previously we reported that coculture enhanced invasiveness of the tumor cells in a TNF-α- and matrix metalloprotease-dependent manner. In this report, we studied intracellular signaling pathways and induction of inflammatory genes in malignant cells under the influence of macrophage coculture. We report that coculture of macrophages with ovarian or breast cancer cell lines led to TNF-α-dependent activation of JNK and NF-κB pathways in tumor cells, but not in benign immortalized epithelial cells. Tumor cells with increased JNK and NF-κB activity exhibited enhanced invasiveness. Inhibition of the NF-κB pathway by TNF-α neutralizing Abs, an NF-κB inhibitor, RNAi to RelA, or overexpression of IκB inhibited tumor cell invasiveness. Blockade of JNK also significantly reduced invasiveness, but blockade of p38 MAPK or p42 MAPK had no effect. Cocultured tumor cells were screened for the expression of 22 genes associated with inflammation and invasion that also contained an AP-1 and NF-κB binding site. EMMPRIN and MIF were up-regulated in cocultured tumor cells in a JNK- and NF-κB-dependent manner. Knocking down either MIF or EMMPRIN by RNAi in the tumor cells significantly reduced tumor cell invasiveness and matrix metalloprotease activity in the coculture supernatant. We conclude that TNF-α, via NF-κB, and JNK induces MIF and EMMPRIN in macrophage to tumor cell cocultures and this leads to increased invasive capacity of the tumor cells.

Progenitor cells with differentiation capacity along multiple mesengenic lineages are attractive tools for numerous purposes in regenerative medicine. Such mesengenic progenitor cells have been isolated from adult mammalian bone marrow, and we here report placental tissue as an alternative source for these cells. By means of dissection/proteinase digestion techniques, high numbers of viable mononuclear cells were harvested from human placenta at term, and a mesenchymal cell population with characteristic expression of CD9, CD29, and CD73 was obtained in culture. The in vitro growth behavior of such placenta-derived mesengenic cells was similar to that of human bone marrow mesengenic progenitor cells. After in vitro propagation for more than three passages the cells were exclusively of maternal origin. Differentiation experiments showed differentiation potential along osteogenic, chondrogenic, adipogenic, and myogenic lineages. In conclusion, we propose human term placenta as an easily accessible, ample source of multipotent mesengenic progenitor cells.

The putative protein tyrosine kinase (PTK) inhibitor tyrphostin AG126 has proven beneficial in various models of inflammatory disease. Yet molecular targets and cellular mechanisms remained enigmatic. We demonstrate here that AG126 treatment has beneficial effects in experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. AG126 alleviates the clinical symptoms, diminishes encephalitogenic Th17 differentiation, reduces inflammatory CNS infiltration as well as microglia activation and attenuates myelin damage. We show that AG126 directly inhibits Bruton's tyrosine kinase (BTK), a PTK associated with B cell receptor and Toll-like receptor (TLR) signaling. However, BTK inhibition cannot account for the entire activity spectrum. Effects on TLR-induced proinflammatory cytokine expression in microglia involve AG126 hydrolysis and conversion of its dinitrile side chain to malononitrile (MN). Notably, while liberated MN can subsequently mediate critical AG126 features, full protection in EAE still requires delivery of intact AG126. Its anti-inflammatory potential and especially interference with TLR signaling thus rely on a dual mechanism encompassing BTK and a novel MN-sensitive target. Both principles bear great potential for the therapeutic management of disturbed innate and adaptive immune functions.

Human macrophages are involved in a plethora of pathologic processes ranging from infectious diseases to cancer. Thus they pose a valuable tool to understand the underlying mechanisms of these diseases. We therefore present a straightforward protocol for the isolation of human monocytes from buffy coats, followed by a differentiation procedure which results in high macrophage yields. The technique relies mostly on commonly available lab equipment and thus provides a cost and time effective way to obtain large quantities of human macrophages. Briefly, buffy coats from healthy blood donors are subjected to a double density gradient centrifugation to harvest monocytes from the peripheral blood. These monocytes are then cultured in fluorinated ethylene propylene (FEP) Teflon-coated cell culture bags in the presence of macrophage colony-stimulating factor (M-CSF). The differentiated macrophages can be easily harvested and used for subsequent studies and functional assays. Important methods for quality control and validation of the isolation and differentiation steps will be highlighted within the protocol. In summary, the protocol described here enables scientists to routinely and reproducibly isolate human macrophages without the need for cost intensive tools. Furthermore, disease models can be studied in a syngeneic human system circumventing the use of murine macrophages.

Introduction Various studies have identified aberrantly expressed miRNAs in breast cancer and demonstrated an association between distinct miRNAs and malignant progression as well as metastasis. Even though tumor‐associated macrophages (TAM) are known mediators of these processes, little is known regarding their miRNA expression upon education by malignant cells in vivo. Methods We profiled miRNA and mRNA expression of in vitro tumor‐educated macrophages (TEM) by indirectly co‐culturing with estrogen‐receptor‐positive (ER+) MCF‐7 breast cancer cells. The prognostic power of the resulting miRNA list was investigated in primary breast cancer datasets and compared to other signatures. Furthermore, miRNA expression levels were correlated to mRNA expression of macrophage markers and the impact on prognosis was assessed. Results Through the evaluation of the group effects between differentially‐expressed miRNAs and their target mRNAs in TEM, the power of detecting regulated miRNAs was greatly increased. The resulting list of 96 miRNAs predicts disease‐free survival (DFS) in external datasets of ER+ breast cancer patients and performs well in comparison with other miRNA signatures. Clustering with the predefined miRNA list revealed a significant difference in survival between the two resulting patient groups. Furthermore, an optimized miRNA list, based on correlations with macrophages markers, proved even more capable at identifying patient clusters significantly differing in DFS. Conclusions In vitro profiling of TEM and subsequent bioinformatic verification identified miRNAs with a high prognostic power for DFS when transferred into the clinical setting of primary breast cancer. The resulting miRNAs not only verify previously established findings but also lead to new prognostic markers. Furthermore, our data suggest that TAM contribute to the total miRNA expression profile of ER + breast cancers., Highlights miRNA and mRNA were measured in macrophages exposed to ER + breast cancer cells.Regulated miRNAs were detected by analyzing group effects of mRNA targets.The resulting miRNA list has good prognostic value for DFS in ER + breast cancer.Correlation of miRNAs to macrophage markers improved identification of clusters differing in DFS.

Convergent extension movements are the main driving force of Xenopus gastrulation. A fine-tuned regulation of cadherin-mediated cell-cell adhesion is thought to be required for this process. Members of the Wnt family of extracellular glycoproteins have been shown to modulate cadherin-mediated cell-cell adhesion, convergent extension movements, and cell differentiation. Here we show that endogenous Wnt/beta-catenin signaling activity is essential for convergent extension movements due to its effect on gene expression rather than on cadherins. Our data also suggest that XLEF-1 rather than XTCF-3 is required for convergent extension movements and that XLEF-1 functions in this context in the Wnt/beta-catenin pathway to regulate Xnr-3. In contrast, activation of the Wnt/Ca2+ pathway blocks convergent extension movements, with potential regulation of the Wnt/beta-catenin pathway at two different levels. PKC, activated by the Wnt/Ca2+ pathway, blocks the Wnt/beta-catenin pathway upstream of beta-catenin and phosphorylates Dishevelled. CamKII, also activated by the Wnt/Ca2+ pathway, inhibits the Wnt/beta-catenin signaling cascade downstream of beta-catenin. Thus, an opposing cross-talk of two distinct Wnt signaling cascades regulates convergent extension movements in Xenopus.

Introduction: IELSG32 is an international randomized phase II trial with 2 key clinical questions in pts with PCNSL. The first question focused on optimal induction therapy, and results of the 1st randomization have demonstrated that MATRix combination (methotrexate (MTX), cytarabine (ARAC), thiotepa, rituximab (R)) is associated with significantly better outcome [Ferreri AJ, et al. Lancet Haematol 2016]. The second question addresses the efficacy and neurotolerability of ASCT, as an alternative to WBRT as consolidation. Herein, we report the results of the 2nd randomization (NCT01011920). Methods: HIV-neg pts 18-70 ys and ECOG PS ≤3 with new histology-proven PCNSL and measurable disease were randomly assigned to receive 4 courses of MTX-ARAC (arm A); or R-MTX-ARAC (arm B); or MATRix (arm C). ASC were collected after 2nd c. Pts with responsive or stable disease were further randomized between WBRT 36 ± 9 Gy (arm D) and BCNU-thiotepa conditioned/ASCT (arm E). Stratification parameters were induction arm and response . Primary endpoint of the 2ndrandomization was 2-year PFS. To demonstrate a 2-yr PFS improvement from 65% (P0) to 85% (P1), 52 pts/arm (one-sided; α 5%; β 95%) were required. Consolidation arm would be considered effective if ≥40 pts were progression-free survivors at 2 ys. Analyses were performed on an intention-to-treat (ITT) basis. Effects of consolidation treatments on neurocognitive functions and quality of life (QoL) were assessed with the IPCG tests panel and EORTC-QLQ at baseline, after treatment and every 6 months afterwards. Results: 227 pts were enrolled in 52 centers of 5 countries; 219 assessable pts were referred to 1st randomization (arm A 75; B 69; C 75). 167 pts had responsive or stable disease after induction: 49 pts were excluded from 2nd randomization (poor mobilization, poor condition or patients' refusal); 118 pts were thus randomized (59 pts/arm) and constitute the study population (median age 58 ys; range 18-70). 15 (13%) pts had high IELSG risk, 3 pts had ocular disease and 20 pts had meningeal disease; with the exception of a higher male prevalence in arm D, there were no differences in clinical presentation between two arms; There were 6 protocol violations: 4 pts randomly allocated to arm D were treated with ASCT and 2 pts randomly allocated to arm E were treated with WBRT; 5 pts (D 2; E 3) refused consolidation. Therefore, per-protocol (PP) groups consisted of 55 pts treated with WBRT and 58 with ASCT. Both consolidation therapies were well tolerated. Grade 4 toxicity was uncommon (≤5% of pts); as expected, hematological toxicity was more common in arm E (neutropenia 5% vs. 71%; p=0.00001 - thrombocytopenia 2% vs. 72%; p=0.00001). There were 2 toxic deaths (infections), both in arm E. Neuropsychological tests showed a significant impairment of attention/executive functions and a non-significant trend to impaired memory among pts treated with WBRT, whereas pts treated with ASCT exhibited improved functions. Both consolidation therapies were associated with significant improvement in language and QoL. Both WBRT and ASCT were active and resulted in significant improvement in CR rate: from 54% after induction to 95% (95%CI: 90-100) after consolidation in arm D, and from 53% to 93% (95%CI: 87-99) in arm E. After a median follow-up of 40 months (range 24-76), there were 20 events (16 relapses, 2 PDs, 2 off-therapy deaths) in arm D, and 25 events (18 relapses, 2 PDs, 2 toxic deaths, 3 off-therapy deaths) in arm E. Importantly, WBRT and ASCT were both effective, with a number of progression-free survivors at 2 ys equal to the pre-determined efficacy threshold: 40 among both the first 52 arm-D and 52 arm-E pts. There were no significant differences in PFS between WBRT and ASCT; on ITT basis, the 2-yr PFS was 80 ± 5% after WBRT and 70 ± 6% after ASCT; per protocol, the 2-yr PFS was 76 ± 6% and 75 ± 6%, respectively. In multivariate analysis, IELSG risk group, number of lesions and induction arm were independently associated with PFS; gender, CSF cytology status and consolidation arm were not. Forty-two pts randomized to arm D and 37 randomized to arm E are alive, with 2-year OS of 85 ± 5% and 71 ± 6% (p=0.12), respectively. Conclusions: WBRT and ASCT are both feasible, active and effective as consolidation therapies after high-dose-MTX-based chemoimmunotherapy in pts ≤70 ys with PCNSL. Potential impairment of specific neurocognitive functions after WBRT should be considered at the time of therapeutic decision. Disclosures Ferreri: Sandoz: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Research Funding, Speakers Bureau; Italfarmaco: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adienne: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees. Fox:Adienne: Honoraria, Research Funding; Takeda: Honoraria, Other: travel funding; Gilead: Honoraria, Other: travel funding; Janssen: Honoraria, Other: travel funding; AbbVie: Consultancy. Röth:Alexion Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria. Johnson:Celldex Therapeutics: Research Funding. Linton:Takeda: Research Funding. Hess:Roche: Honoraria; Novartis: Honoraria; Janssen: Honoraria; Roche, CTI, Pfizer, Celgene: Research Funding; Celgene: Honoraria; Pfizer: Honoraria. Stilgenbauer:Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Genentech: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau; Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Genzyme: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding, Speakers Bureau. Rummel:Roche Pharma AG: Other: Personal fees, Research Funding; Mundipharma GmbH: Other: Personal fees, Research Funding. Illerhaus:Riemser: Honoraria; Amgen: Honoraria.

// Eva Rietkotter 1 , Kerstin Menck 1 , Annalen Bleckmann 1,2 , Katja Farhat 3 , Meike Schaffrinski 1 , Matthias Schulz 1 , Uwe-Karsten Hanisch 4 , Claudia Binder 1 , Tobias Pukrop 1 1 Department of Hematology/Oncology, University Medical Center, 37099 Gottingen, Germany 2 Department of Medical Statistics, University Medical Center, 37099 Gottingen, Germany 3 Department of Cardiovascular Physiology, University Medical Center, 37099 Gottingen, Germany 4 Institute of Neuropathology, University Medical Center, 37099 Gottingen, Germany Correspondence: Tobias Pukrop, email: // Keywords : Zoledronic acid, macrophages, microglia, metastasis, tumor microenvironment Received : July 23, 2013 Accepted : August 17, 2013 Published : August 19, 2013 Abstract The bisphosphonate zoledronic acid (ZA) significantly reduces complications of bone metastasis by inhibiting resident macrophages, the osteoclasts. Recent clinical trials indicate additional anti-metastatic effects of ZA outside the bone. However, which step of metastasis is influenced and whether thisis due to directtoxicity on cancer cells or inhibition of the tumor promoting microenvironment, is unknown. In particular, tumor-associated and resident macrophages support each step of organ metastasis and could be a crucial target of ZA. Thus, we comparatively investigate the ZA effects on: i) different types of macrophages, ii) on breast cancer cells but also iii) on macrophage-induced invasion. We demonstrate that ZA concentrations reflecting the plasma level affected viability of human macrophages, murine bone marrow-derived macrophages as well as their resident brain equivalents, the microglia, while it did not influence the tested cancer cells. However, the effects on the macrophages subsequently reduced the macrophage/microglia-induced invasiveness of the cancer cells. In line with this, manipulation of microglia by ZA in organotypic brain slice cocultures reduced the tissue invasion by carcinoma cells. The characterization of human macrophages after ZA treatment revealed a phenotype/response shift, in particular after external stimulation. In conclusion, we show that therapeutic concentrations of ZA affect all types of macrophages but not the cancer cells. Thus, anti-metastatic effects of ZA are predominantly caused by modulating the microenvironment. Most importantly, our findings demonstrate that ZA reduced microglia-assisted invasion of cancer cells to the brain tissue, indicating a potential therapeutic role in the prevention of cerebral metastasis.

The metastatic colonization of the brain by carcinoma cells is still barely understood, in particular when considering interactions with the host tissue. The colonization comes with a substantial destruction of the surrounding host tissue. This leads to activation of damage responses by resident innate immune cells to protect, repair, and organize the wound healing, but may distract from tumoricidal actions. We recently demonstrated that microglia, innate immune cells of the CNS, assist carcinoma cell invasion. Here we report that this is a fatal side effect of a physiological damage response of the brain tissue. In a brain slice coculture model, contact with both benign and malignant epithelial cells induced a response by microglia and astrocytes comparable to that seen at the interface of human cerebral metastases. While the glial damage response intended to protect the brain from intrusion of benign epithelial cells by inducing apoptosis, it proved ineffective against various malignant cell types. They did not undergo apoptosis and actually exploited the local tissue reaction to invade instead. Gene expression and functional analyses revealed that the C-X-C chemokine receptor type 4 (CXCR4) and WNT signaling were involved in this process. Furthermore, CXCR4-regulated microglia were recruited to sites of brain injury in a zebrafish model and CXCR4 was expressed in human stroke patients, suggesting a conserved role in damage responses to various types of brain injuries. Together, our findings point to a detrimental misuse of the glial damage response program by carcinoma cells resistant to glia-induced apoptosis. peerReviewed

Learning outcome is an important measure for overall teaching quality and should be addressed by comprehensive evaluation tools. The authors evaluated the validity of a novel evaluation tool based on student self-assessments, which may help identify specific strengths and weaknesses of a particular course.In 2011, the authors asked 145 fourth-year students at Göttingen Medical School to self-assess their knowledge on 33 specific learning objectives in a pretest and posttest as part of a cardiorespiratory module. The authors compared performance gain calculated from self-assessments with performance gain derived from formative examinations that were closely matched to these 33 learning objectives.Eighty-three students (57.2%) completed the assessment. There was good agreement between performance gain derived from subjective data and performance gain derived from objective examinations (Pearson r=0.78; P.0001) on the group level. The association between the two measures was much weaker when data were analyzed on the individual level. Further analysis determined a quality cutoff for performance gain derived from aggregated student self-assessments. When using this cutoff, the evaluation tool was highly sensitive in identifying specific learning objectives with favorable or suboptimal objective performance gains.The tool is easy to implement, takes initial performance levels into account, and does not require extensive pre-post testing. By providing valid estimates of actual performance gain obtained during a teaching module, it may assist medical teachers in identifying strengths and weaknesses of a particular course on the level of specific learning objectives.

Melanoma frequently metastasizes to the brain, resulting in dismal survival. A major obstacle for characterizing mechanisms of brain metastasis is the lack of tractable pre-clinical models that mimic the multi-stage process of brain metastasis. We established a novel model of spontaneous melanoma brain metastasis in immunocompetent mice. Aggressive local tumors are formed following orthotopic injection, and 3-4 months after surgical excision of the primary tumor, 50% of the mice develop brain macrometastases. By utilizing a unique ex-vivo modeling system, we detected brain micrometastases in 50-60% of the mice and quantified the metastatic load. Moreover, we show that the detection of melanoma transcripts in cerebrospinal fluid (CSF) is correlated with brain metastases. Interestingly, preliminary findings suggest that the melanoma-derived transcripts are found in exosomes. Astrocytes are glial cells that maintain brain homeostasis, and constitute a central part of the brain microenvironment. Reactive astrogliosis is the primary response of astrocytes to brain insult. While much data have accumulated on the contribution of astrogliosis to neurodegenerative diseases, the functional role of astrogliosis in promoting melanoma brain metastases is unknown. Utilizing our model we demonstrate early changes in the microenvironment and show that micrometastases are associated with activation of astrocytes and with hyperpermeability of the blood-brain-barrier. In-vitro, paracrine signaling by melanoma cells activated astrocytes to up-regulate a ‘wound healing program’ including Cxcl10 and Serpins. Reciprocally, astrocytes facilitated the invasion of melanoma cells and were necessary for primary outgrowth in 3D co-cultures. Finally, we show that intracranial co-injection of astrocytes with melanoma cells resulted in a 9 fold increase of tumor volume, and that the same gene-signature was up-regulated in astrocytes in-vivo. Studying spontaneous melanoma brain metastasis in a clinically relevant setting enables in-depth understating of the metastatic microenviromet which is the key to developing therapeutic approaches that may prevent brain metastatic relapse. Citation Format: Hila Schwartz, Eran Blacher, Malak Amer, Nir Livneh, Anat Klein, Dikla Ben-Shushan, Shelly Soffer, Reuven Stein, Ronit Satchi-Fainaro, Viktor Umansky, Tobias Pukrop, Neta Erez. Melanoma brain metastasis is facilitated by instigation of reactive astrogliosis. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C26.

With the improvement of therapeutic options for the treatment of breast cancer, the development of brain metastases has become a major limitation to life expectancy in many patients. Loss of Phosphatase and tensin homolog (PTEN) is correlated with occurrence of breast cancer brain metastases, but its functional role in metastases formation remains unclear. Here, we first assessed the clinical role of PTEN expression in brain metastases, by performing immunohistochemical analyses on a TMA consisting of 132 breast cancer brain metastases samples. Loss of PTEN protein expression was found in 48.6% of brain metastases, and significantly associated with the triple-negative breast cancer subtype (67.5%, p = 0.01). Loss of PTEN was furthermore significantly associated with shorter overall survival (p = 0.048). We then investigated the biological role of PTEN in breast cancer brain metastasis formation by overexpressing PTEN in the triple-negative brain metastatic breast cancer cell cline MDA-MB-231 BR. Overexpression of PTEN was shown to reduce the AKT pathway activation especially by reducing the Akt1 kinase activity. Coculture experiments with glia cells (astrocytes and microglia) showed that astrocytes can inhibit cell proliferation of the tumor cells in a PTEN dependent manner. Both astrocytes and microglia promote migration of MDA-MB-231 BR cells in a PTEN-dependent manner in vitro. Using an organotypic brain slice model as a representation of the brain tumor microenvironment, the PTEN-dependent invasion of tumor cells could be confirmed. Furthermore, PTEN overexpression reduced the astrocyte activation. Coculture experiments with glia cells showed PTEN-dependent, differential cytokine expression. We could identify an endocrine and paracrine regulation between tumor cells and astrocytes, where GM-CSF, CSF2RA, EGF and PTEN play an important role. In conclusion, loss of PTEN is associated with poor prognosis and is an important mediator of a “vicious circle” mediated by the cross talk between tumor cells and glia cells. Citation Format: Harriet Wikman, Ina Hohensee, Han-Ning Chuang, Astrid Grottke, Stefan Werner, Alexander Schulte, Jakob Matschke, Markus Glatzel, Stefan Horn, Manfred Jücker, Tobias Pukrop, Klaus Pantel. PTEN is an important mediator of tumor and glia cell crosstalk in breast cancer brain metastasis. [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 1571.

The sentinel and immune functions of microglia require rapid and appropriate reactions to infection and damage. Their Toll-like receptors (TLRs) sense both as threats. However, whether activated microglia mount uniform responses or whether subsets conduct selective tasks is unknown. We demonstrate that murine microglia reorganize their responses to TLR activations postnatally and that this process comes with a maturation of TLR4-organized functions. Although induction of MHCI for antigen presentation remains as a pan-populational feature, synthesis of TNFα becomes restricted to a subset, even within adult central nervous system regions. Response heterogeneity is evident ex vivo, in situ, and in vivo, but is not limited to TNFα production or to TLR-triggered functions. Also, clearance activities for myelin under physiological and pathophysiological conditions, IFNγ-enforced upregulation of MHCII, or challenged inductions of other proinflammatory factors reveal dissimilar microglial contributions. Notably, response heterogeneity is also confirmed in human brain tissue. Our findings suggest that microglia divide by constitutive and inducible capacities. Privileged production of inflammatory mediators assigns a master control to subsets. Sequestration of clearance of endogenous material versus antigen presentation in exclusive compartments can separate potentially interfering functions. Finally, subsets rather than a uniform population of microglia may assemble the reactive phenotypes in responses during infection, injury, and rebuilding, warranting consideration in experimental manipulation and therapeutic strategies.

To assess the extent of undergraduate medical training on alcohol use disorders (AUD) and smoking, and medical students' perceived knowledge regarding consequences of, and treatment options for, these disorders compared with other chronic conditions.Cross-sectional survey assessing teaching and perceived knowledge of health consequences and treatment options for AUD and smoking compared with diabetes and hypertension.Medical schools in Germany.Twenty-five of 36 medical school offices (response rate 69.4%) and 19 526 of 39 358 students from 27 medical schools (response rate 49.6%).Medical schools were asked to provide information on curricular coverage of the four conditions. Students reported their year of study and perceived knowledge about the consequences of all four disorders and perceived knowledge of treatment options.Courses time-tabled approximately half as many teaching hours on AUD and tobacco as on diabetes or hypertension. Final-year students reported high levels of knowledge of consequences of all four conditions and how to treat diabetes and hypertension, but only 20% believed they knew how to treat alcohol use disorders or smoking.Curriculum coverage in German medical schools of alcohol use disorders and smoking is half that of diabetes and hypertension, and in the final year of their undergraduate training most students reported inadequate knowledge of how to intervene to address them.

An essential function of the transcription factors LEF1/TCF4 in cerebral metastases of lung adenocarcinomas has been described in mouse models, suggesting a WNT/β-catenin effect as potential mechanism. Their role in humans is still unclear, thus we analyzed LEF1, TCF4, β-catenin, and early stage prognostic markers in 25 adenocarcinoma brain metastases using immunohistochemistry (IHC). IHC revealed nuclear TCF4 in all adenocarcinoma samples, whereas only 36 % depicted nuclear LEF1 and nuclear β-catenin signals. Samples with nuclear LEF1 as well as high TCF4 (++++) expression were associated with a shorter survival (p = 0.01, HR = 6.68), while nuclear β-catenin had no significant impact on prognosis and did not significantly correlate with nuclear LEF1. High proliferation index Ki67 was associated with shorter survival in late-stage disease (p = 0.03, HR 3.27). Additionally, we generated a LEF1/TCF4 as well as an AXIN2 signature, the latter as representative of WNT/β-catenin activity, following a bioinformatics approach with a gene expression dataset of cerebral metastases in lung adenocarcinoma. To analyze the prognostic relevance in primary lung adenocarcinomas, we applied both signatures to a microarray dataset of 58 primary lung adenocarcinomas. Only the LEF1/TCF4 signature was able to separate clusters with impact on survival (p = 0.01, HR = 0.32). These clusters displayed diverging enrichment patterns of the cell cycle pathway. In conclusion, our data show that LEF1/TCF4, but not β-catenin, have prognostic relevance in primary and cerebrally metastasized human lung adenocarcinomas. In contrast to the previous in vivo findings, these results indicate that LEF1/TCF4 act independently of β-catenin in this setting. Electronic supplementary material The online version of this article (doi:10.1007/s10585-012-9552-7) contains supplementary material, which is available to authorized users.

A considerable percentage of rectal cancers are resistant to standard preoperative chemoradiotherapy. Because patients with a priori-resistant tumors do not benefit from multimodal treatment, understanding and overcoming this resistance remains of utmost clinical importance. We recently reported overexpression of the Wnt transcription factor TCF4, also known as TCF7L2, in rectal cancers that were resistant to 5-fluorouracil-based chemoradiotherapy. Because Wnt signaling has not been associated with treatment response, we aimed to investigate whether TCF4 mediates chemoradioresistance. RNA interference-mediated silencing of TCF4 was employed in three colorectal cancer (CRC) cell lines, and sensitivity to (chemo-) radiotherapy was assessed using a standard colony formation assay. Silencing of TCF4 caused a significant sensitization of CRC cells to clinically relevant doses of X-rays. This effect was restricted to tumor cells with high T cell factor (TCF) reporter activity, presumably in a β-catenin-independent manner. Radiosensitization was the consequence of (i) a transcriptional deregulation of Wnt/TCF4 target genes, (ii) a silencing-induced G(2)/M phase arrest, (iii) an impaired ability to adequately halt cell cycle progression after radiation and (iv) a compromised DNA double strand break repair as assessed by γH2AX staining. Taken together, our results indicate a novel mechanism through which the Wnt transcription factor TCF4 mediates chemoradioresistance. Moreover, they suggest that TCF4 is a promising molecular target to sensitize resistant tumor cells to (chemo-) radiotherapy.

A role of WNT signaling for primary breast cancers of the basal-like subtype and as a predictor of brain metastasis has been described. However, a responsible WNT ligand has not been identified. To further clarify this question, we comparatively investigated 22 human breast cancer brain metastases as well as the highly invasive human breast cancer cell line MDA-MB-231 and the weakly motile MCF-7 as models for the basal-like and the luminal A subtype. WNT5A and B were found overexpressed in MDA-MB-231 cells as compared with MCF-7. This corresponded to reduction of MDA-MB-231 invasiveness by WNT inhibitors, whereas MCF-7 invasion was enhanced by recombinant WNT5B and abolished by WNT and Jun-N-terminal kinase antagonists. Expression and subcellular distribution of β-catenin remained uninfluenced. Consistently, β-catenin was not localized in the nuclei of brain metastases while there was strong nuclear c-Jun staining. Similar to MDA-MB-231, metastases showed expression of WNT5A/B and the alternative WNT receptors ROR1 and 2. These findings were validated using external gene expression datasets (Gene Expression Omnibus) of different breast cancer subtypes and brain metastases. Hierarchical cluster analysis yielded a close relation between basal-like cancers and brain metastases. Gene set enrichment analyses confirmed WNT pathway enrichment not only in basal-like primaries but also in cerebral metastases of all subtypes. In conclusion, WNT signaling seems highly relevant for basal-like and other subtypes of breast cancers metastasizing into the brain. β-catenin-independent WNT signaling, presumably via ROR1-2, plays a major role in this context.

Although there is increasing evidence that blood-derived macrophages support tumor progression, it is still unclear whether specialized resident macrophages, such as brain microglia, also play a prominent role in metastasis formation. Here, we show that microglia enhance invasion and colonization of brain tissue by breast cancer cells, serving both as active transporters and guiding rails. This is antagonized by inactivation of microglia as well as by the Wnt inhibitor Dickkopf-2. Proinvasive microglia demonstrate altered morphology, but neither upregulation of M2-like cytokines nor differential gene expression. Bacterial lipopolysacharide shifts tumor-educated microglia into a classical M1 phenotype, reduces their proinvasive function, and unmasks inflammatory and Wnt signaling as the most strongly regulated pathways. Histological findings in human brain metastases underline the significance of these results. In conclusion, microglia are critical for the successful colonization of the brain by epithelial cancer cells, suggesting inhibition of proinvasive microglia as a promising antimetastatic strategy.

Clinical reasoning skills are essential for medical practice. Problem-based collaborative learning via the internet might prove useful in imparting these skills.This randomized study assessed whether web-based learning (WBL) is superior to face-to-face problem-based learning (PBL) in the setting of a 6-week cardio-respiratory course.During winter term 2007/08, all 148 fourth-year medical students enrolled in the 6-week course consented to be randomized in small groups to diagnose a patient complaining of dyspnoea either using a virtual collaborative online module or a traditional PBL session. Clinical reasoning skills were assessed by means of a key feature examination at the end of the course.No significant difference between the mean scores of both study groups was detected (p = 0.843). In virtual learning groups, costs for diagnostic tests were significantly correlated to the number of contributions to online group discussions (r = 0.881; p = 0.002). Evaluation data favored traditional PBL sessions over virtual collaborative learning.While virtual collaborative learning was as effective as traditional PBL regarding the acquisition of clinical reasoning skills, it was less well accepted than traditional PBL. Future research needs to determine the ideal format and time-point for computer-assisted learning in medical education.

In addition to patient care and research activity, physicians working in medical school hospitals serve as teachers in undergraduate medical education. However, teaching qualifications of German university hospital physicians have not been studied in great detail.In January 2009, medical students as well as physicians involved in medical teaching at Göttingen Medical School, Germany, were invited to complete an online survey addressing their views on clinical teachers' educational skills. In addition, physicians' motivation to engage in pedagogical training was assessed.During a 12-day period, 359 students and 126 physicians involved in undergraduate medical education completed the survey. The latter did not feel well prepared for their teaching activities. At the same time, they expressed the willingness to improve their teaching skills. Students felt that, across all instructional methods, teachers would benefit from teacher training programs.In order to improve undergraduate education for future physicians, politicians and local representatives alike must set the scene for the implementation of faculty development measures in German medical schools.

In recent years, increasing attention has been paid to web-based learning although the advantages of computer-aided instruction over traditional teaching formats still need to be confirmed. This study examined whether participation in an online module on the differential diagnosis of dyspnoea impacts on student performance in a multiple choice examination of factual knowledge in cardiology and pneumology. A virtual problem-based learning environment for medical students supervised by postgraduate teachers was created. Seventy-four out of 183 fourth-year medical students volunteered to use the online module while attending a 6-week cardio-respiratory curriculum in summer 2007. Of these, 40 were randomly selected to be included (intervention group); the remaining 34 served as an internal control group. Analysis of all written exams taken during the preceding term showed that both groups were comparable (86.4 ± 1.1 vs. 85.9 ± 1.1%; p = 0.751). Students in the intervention group scored significantly higher in the final course assessment than students allocated to the control group (84.8 ± 1.3 vs. 79.5 ± 1.4%; p = 0.006; effect size 0.67). Thus, additional problem-based learning with an online module as part of an undergraduate cardio-respiratory curriculum lead to higher students’ scores in an exam testing factual knowledge. Whether using this teaching format increases overall student motivation to engage in the learning process needs to be further investigated. peerReviewed

In contrast to the transforming members of the Wnt family, shown to be upregulated in many cancers, the role of Wnt 5a is still controversial. While it has been attributed a tumour suppressor function in some malignancies, there is increasing evidence of promigratory and proinvasive effects in others, mediated predominantly through the planar cell polarity pathway and activation of protein kinase C. Obviously, the outcome of an individual Wnt 5a signal is dependent on a multitude of variables, ranging from availability of receptors, downstream effectors, and inhibitors to external influences coming from the tumour microenvironment and the extracellular matrix.

B-cell chronic lymphocytic leukemia (B-CLL) is phenotypically characterized by cell surface co-expression of CD19, CD20, CD5, and CD23. However, the concomitant presence of other antigens distinctive of a particular leukocyte subset, e.g. T cells, is an unusual finding in B-CLL. In the present report, a case of B-CLL with aberrant expression of the T-cell-associated antigen CD8 is described. Flow cytometric analysis of the patient's cells demonstrated lack of CD38 expression, and cytogenetic analysis by FISH did not show any abnormalities of chromosomes 17p, 11q, and 12. Furthermore, the B-CLL cells expressed only low levels of the tyrosine kinase ZAP-70, which was in agreement with the mutated status of the immunoglobulin heavy-chain variable-region gene (IgVH). In summary, the determined profile of prognostic markers together with the highly stable and indolent disease in the described patient suggest a good prognosis of B-CLL with aberrant CD8 expression.

Background: The clinical response of locally advanced rectal cancers to preoperative chemoradiotherapy is very heterogeneous. We previously identified TCF4, the key downstream effector of the Wnt/β-catenin signaling pathway, as over-expressed in tumors that were resistant to chemoradiotherapy. The aim of this study was to explore the potential functional relevance of Wnt/ß-catenin signaling for mediating treatment resistance. Methods: Using RNA interference, TCF4 and β-catenin were inhibited in the colorectal cancer cell lines SW837 and SW480. Subsequently, these cell lines were irradiated with varying doses of X-rays. In addition, normal retinal epithelial cells (RPE) were stimulated with Wnt-3a for 28 hours, and also irradiated. Wnt/β-catenin activity was assessed using the TOPFLASH/FOPFLASH reporter assay, and induction of Axin2 was confirmed by Western blotting. Results: Protein levels of both TCF4 and β-catenin were considerably reduced following RNAi, accompanied by a decreased TOP/FOP reporter activity. Importantly, silencing of both proteins led to a pronounced radiosensitization in SW837 and SW480 cells. Exogenous stimulation of canonical Wnt signaling in RPE cells using Wnt-3a resulted in an increased Axin2 expression and an increased TOP/FOP reporter activity. Importantly, however, this activation of canonical Wnt signaling was associated with significant increase in resistance to radiation therapy. Conclusion: TCF4 was found to be over-expressed in resistant rectal carcinomas, and its RNAi-mediated silencing caused a significant radiosensitization. To determine whether this effect was dependent on canonical Wnt signaling, we inhibited ß-catenin, another key factor of this pathway and binding partner of TCF4, and observed a similar sensitization to radiation therapy. Follow-up experiments show that external stimulation of canonical Wnt signaling confers radiation resistance in normal cells. These data suggest that targeting canonical Wnt signaling may represent a potential therapeutic strategy for sensitizing tumor cells to radiation. In vivo studies are ongoing to validate these results. Citation Format: Georg Emons, Janneke Möller, Melanie Spitzner, Emil Kendziorra, Jochen Gaedcke, Margret Rave-Fränk, Tobias Pukrop, Michael Ghadimi, Thomas Ried, Marian Grade. Canonical Wnt signaling mediates resistance of colorectal cancer cells to radiation therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1588. doi:10.1158/1538-7445.AM2013-1588

Background: We recently demonstrated that the Wnt transcription factor TCF4 is over-expressed in rectal cancers that were resistant to preoperative chemoradiotherapy. Because the association between Wnt signaling and chemoradioresistance is a novel finding, we aimed to investigate whether this over-expression is functionally relevant. Methods: Three colorectal cancer cell lines were transfected with two shRNA-vectors targeting TCF4. Stable single-cell clone (SCC) populations were established, and selected clones were irradiated at 0, 1, 2, 4, 6 and 8 Gy. γH2AX staining was used to evaluate DNA double strand repair after irradiation, and changes in cell cycle distribution were analyzed before and after radiation. Finally, β-catenin activity was inhibited using both siRNAs and the small molecule inhibitor XAV939. Results: Silencing of TCF4 led to a significant radiosensitization in SW837 and SW480, whereas there was no effect in HT-29. Well-fitting, we observed significantly more γH2AX foci 24 hrs after radiation in SW837 SCCs compared to HT-29 SCCs, pointing to an impaired DNA damage repair in SW837. Furthermore, in SW837 SCCs, but not in HT-29 SCCs, we noticed a change in the cell cycle distribution towards radiosensitive cell cycle phases before radiation, and compromised cell cycle control after radiation. Finally, both siRNA- and small molecule-mediated inhibition of β-catenin activity did not influence the sensitivity to chemoradiotherapy. Conclusion: Our results indicate a novel mechanism through which the Wnt transcription factor TCF4 mediates chemoradioresistance in a β-catenin-independent manner. Moreover, they suggest that TCF4 is a potential molecular target to sensitize resistant tumor cells to (chemo-) radiotherapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5729. doi:1538-7445.AM2012-5729

Background: The clinical response of locally advanced rectal cancers to preoperative chemoradiotherapy is very heterogeneous. We recently profiled a series of responsive and resistant rectal carcinomas using gene expression microarrays and identified TCF7L2, the main downstream effector of the Wnt/β-catenin pathway, as over-expressed in the resistant tumors. The aim of this study was to explore the relevance of TCF7L2 for resistance to radiation and to study the underlining mechanisms. Methods: We transfected three microsatellite-stable colorectal cancer cell lines (SW837, SW480 and HT-29) with two different shRNA-vectors targeting TCF7L2 and a non-silencing. Next, we established single cell clone (SCC) populations, and after confirming the reduction of TCF7L2 protein levels by Western blotting, we irradiated the SCCs at 0, 1, 2, 4, 6 and 8 Gy and calculated survival fractions. To gain functional insight, we chose SW837 and HT-29 for further experiments. Using γH2AX staining we evaluated DNA double strand repair after irradiation at 2 Gy and analyzed cell cycle changes before and after radiation. Furthermore, we studied Wnt/β-catenin pathway activity using the TOPFLASH/FOPFLASH reporter assay. Results: RNAi-mediated silencing of TCF7L2 led to a pronounced reduction in TCF7L2 protein levels. In radiation experiments we observed a highly significant radiosensitization in SW837 and SW480 SCCs, whereas no effect was observed in HT-29 SCCs. Well-fitting, we observed significantly more γH2AX foci 24h after radiation in SW837 SCCs compared to HT-29 SCCs, pointing to impaired DNA damage repair in the SCCs from SW837. Furthermore, in SW837 SCCs but not in HT-29 SCCs we noticed a change in the cell cycle distribution towards radiosensitive cell cycle phases before radiation and compromised cell cycle control after radiation. Finally, using the TOPFLASH/FOPFLASH reporter assay we found SW837 wild-type cells to show high Wnt/β-catenin pathway activity, while HT-29 wild-type cells only showed very low activity. Conclusion: TCF7L2 was found to be over-expressed in resistant rectal carcinomas, and its RNAi-mediated silencing caused a significant radiosensitization, mediated by DNA damage repair deficiencies and impaired cell cycle control. Interestingly, radiosensitization effetcts were only observed in cell lines showing Wnt/β-catenin pathway activity. Thus, we have uncovered a novel role of Wnt/β-catenin signaling for mediating resistance to multimodal cancer therapy. Moreover, these data suggest that TCF7L2 is a potential molecular target for sensitizing Wnt/β-catenin-dependent tumor cells to radiation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2490. doi:10.1158/1538-7445.AM2011-2490

Background: The standard treatment for locally advanced rectal carcinomas consists of preoperative chemoradiotherapy (CT/RT), followed by radical surgery. However, the clinical response to this treatment strategy is very heterogeneous. To determine the molecular basis of disparate response, we recently profiled a series of responsive and resistant rectal cancers using gene expression microarrays and identified a set of differentially expressed genes. One gene that was significantly over-expressed in the resistant tumors was TCF7L2 (also known as TCF4), the main downstream effector of the Wnt signaling pathway. The aim of this study was to understand its role in treatment response by testing the hypothesis that RNAi-mediated silencing of TCF7L2 sensitizes tumor cells to radiation therapy. Methods: The colorectal cancer cell line SW480, which is relatively resistant to radiation, was transfected with two different shRNA-vectors targeting TCF7L2, and a non-silencing control. Subsequently, stable single cell clones were established, and knockdown efficiency was analyzed by Western blot analysis. For each vector, individual clones were irradiated at 2, 4, 6 and 8 Gy. Colonies were counted after 10 days to calculate the respective surviving fractions. Results: TCF7L2 protein levels were reduced to ∼ 34% for shRNA_1, and ∼ 29% for shRNA_2. This led to a ∼ 1.6-fold growth inhibition (plating efficiency) compared to the non-silencing control. Importantly, RNAi-mediated silencing of TCF7L2 significantly reduced colony-formation after radiation (dose reduction factors of ∼ 1.5 and ∼ 2.0 at 37% survival for shRNA_1 and shRNA_2, respectively). These results were validated in a second cell line (HT29). In addition, we analyzed global gene expression profiles after RNAi to analyze the global transcriptomic changes induced by silencing TCF7L2. Conclusion: TCF7L2 is over-expressed in rectal carcinomas resistant to chemoradiotherapy. RNAi-mediated silencing of this gene caused a significant growth inhibition and, importantly, radiosensitization of colorectal cancer cells. Thus, TCF7L2 might represent a potential molecular target to sensitize a priori resistant tumor cells. Additionally, these data provide first evidence that the Wnt signaling pathway might not only be central for the development of colorectal cancers, but also for the resistance to therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 487.

ETV6 is the only known transcriptional repressor which plays an important role in the malignant transformation of haematopoietic cells in different leukemias. In most cases of ETV6-AML1 + leukemias, the second ETV6 allele is knocked out by deletions. Other mechanisms of knocking out the second ETV6 allele in acute leukemias carrying ETV6 fusion genes, have not been described as of yet. Recently, we have published that the MT-ALL cell line with multilineage differentiation potential carries an ETV6-ARG fusion gene. The second ETV6 allele carries a point mutation in the highly conserved ETS-domain (G to A, bp 1220), leading to the replacement of arginine, normally directly binding to DNA, by histidine (R399H). Therefore, we investigated whether the R399H point mutation leads to a functional double knock-out and will reduce the DNA binding affinity of ETV6. For the ETV6 binding studies the single point mutated and wild type ETS-domains were amplified and the proteins were expressed. Electro mobility shift assays (EMSA) were performed with the EBS (ETS binding site) carrying the specific GGAA core motif. The wild type ETS domain (ETSwt) incubated with the EBS showed a clear shift of the protein DNA complex loaded on a gel, but not the point mutated ETS domain (ETSmt). In order to quantify the binding of the ETSwt and mt-domains to EBS we established a transient transfection reporter gene assay. For this assay we constructed vectors which contain the EBS fused to the TK promoter, firefly luciferase serves as reporter gene. After transient cotransfections of HeLa cells with plasmids which expressed the ETSwt- or ETSmt-domain together with the vector containing the EBS(wt or mt), the activities of luciferase were measured in a tube luminometer. As expected, cotransfection of ETSwt and EBSwt reduced luciferase activity up to 75% compared with control vector and EBSwt cotransfection. Cotransfection of ETSmt with EBSwt did not lead to a reduction of luciferase activity. The specificity of the reporter gene analysis was controlled by using EBSmt. These results show that the transcriptional repressor function of ETV6 is dependent on binding of ETV6-ETS domain to EBS and that the point mutation completely alters the physiological function of ETV6. Further studies would explain whether the multilineage differentiation potential of MT-ALL is dependent on ETV6 double-knock-out.