The effects of rTMS on impulsivity in normal adults: a systematic review and meta-analysis

Background: Impulsivity is a multi-dimensional construct that is regarded as a symptom of many psychiatric disorders. Harm resulting from impulsive behaviour can be substantial for the individuals concerned, people around them and the society they live in. Therefore, the importance of developing therapeutic interventions to target impulsivity is paramount. Aims and methods: We conducted a systematic review and meta-analysis of the literature from AMED, Embase, Medline, and PsycINFO databases on the use of repetitive transcranial magnetic stimulation (rTMS) in healthy adults to modulate different subdomains (motor, temporal and reflection) of impulsivity. Results: The results indicated that rTMS has distinct effects on different impulsivity subdomains. It has a significant, albeit small, effect on modulating motor impulsivity (g = 0.30, 95% CI, 0.17 to 0.43, p < .001) and a moderate effect on temporal impulsivity (g = 0.59, 95% CI, 0.32 to 0.86, p < .001). Subgroup analyses (e.g., excitatory vs. inhibitory rTMS, conventional rTMS vs. theta burst stimulation, analyses by stimulation sites, and type of outcome measure used) identified key parameters associated with the effects of rTMS on motor and temporal impulsivity. Age, sex, stimulation intensity and the number of pulses were not significant moderators for effects of rTMS on motor impulsivity. Due to lack of sufficient data to inform a meta-analysis, it has not been possible to assess the effects of rTMS on reflection impulsivity. Conclusions: The present findings provide preliminary evidence that rTMS can be used to modulate motor and temporal impulsivity in healthy individuals. Further studies are required to extend the use of rTMS to modulate impulsivity in those at most risk of engaging in harmful behaviour as a result of impulsivity, such as patients with offending histories and those with a history of self-harming behaviour

MET as resistance factor for afatinib therapy and motility driver in gastric cancer cells.

The therapeutic options for advanced gastric cancer are still limited. Several drugs targeting the epidermal growth factor receptor family have been developed. So far, the HER2 antibody trastuzumab is the only drug targeting the HER-family that is available to gastric cancer patients. The pan-HER inhibitor afatinib is currently investigated in clinical trials and shows promising results in cell culture experiments and patient-derived xenograft (PDX) models. However, some cell lines do not respond to afatinib treatment. The determination of resistance factors in these cell lines can help to find the best treatment option for gastric cancer patients. In this study, we analyzed the role of MET as a resistance factor for afatinib therapy in a gastric cancer cell line. MET expression in afatinib-resistant MET-amplified Hs746T cells was reduced by means of siRNA transfection. The effects of MET knockdown on signal transduction, cell proliferation and motility were examined. In addition to the manual assessment of cell motility, a computational motility analysis involving parameters such as (approximate) average speed, displacement entropy or radial effectiveness was realized. Moreover, the impact of afatinib was compared between MET knockdown cells and control cells. MET knockdown in Hs746T cells resulted in impaired signal transduction and reduced cell proliferation and motility. Moreover, the afatinib resistance of Hs746T cells was reversed after MET knockdown. Therefore, the amplification of MET is confirmed as a resistance factor in gastric cancer cells. Whether MET is a useful resistance marker for afatinib therapy or other HER-targeting drugs in patients should be investigated in clinical trials

Abstract 1058: E-cadherin mutations contribute to gastric carcinogenesis by modulating multiple EGFR-dependent downstream signaling pathways

Abstract Mutations in the gene encoding the cell adhesion molecule E-cadherin and overexpression of the epidermal growth factor receptor (EGFR) represent fundamental genetic alterations associated with diffuse-type gastric cancer. Mutations, e.g. in frame deletion of exon 8 (del 8), lead to loss of putative extracellular Ca2+-binding sites of E-cadherin, thereby impairing its functionality. Several studies have shown a bidirectional crosstalk between E-cadherin and EGFR. Functional wild-type (wt) E-cadherin inhibits ligand-induced EGFR activation, but mutations lead to a loss of its suppressive function, resulting in increased EGFR activation and recruitment of downstream signalling components. The phenotype of cells harboring such mutations is characterized by increased proliferation and elevated migratory and invasive potential. Our project aims at studying the impact of somatic mutations of E-cadherin on EGFR-mediated signalling pathways, in order to identify signalling molecules of these pathways as molecular targets for selective therapies in gastric cancer. Cell lines expressing wt or mutant E-cadherin (del 8) were EGF-stimulated and cellular lysates were analyzed by commercial proteome profiler antibody array (R&amp;D Systems). The array allowed detection of the phosphorylation status of 48 signalling molecules and facilitated identification of differential activation. We found differential response to EGF stimulation of proteins involved in DNA damage and repair, such as p53 and CHK2, in both cell lines. As both proteins are tumorsuppressors, their dysfunction could contribute to tumor progression. Furthermore, Src-family kinases (SFKs) like Src, Yes, Fgr, Lck and Lyn exhibited different activation profiles in response to EGF-stimulation in both cell lines. As SFKs are key players in multiple cellular processes like cell growth, differentiation, cellular adhesion, migration and invasion, the impact of their differential activation on the cellular phenotype is subject of ongoing experiments. To determine the role of the identified targets in gastric carcinogenesis and the mechanisms of crosstalk between E-cadherin and EGFR a protein microarray platform was established, allowing analysis of multiple samples under the same experimental conditions. This approach will reveal new insights in EGFR-mediated signalling pathways contributing to gastric carcinogenesis and complete our data describing how tumor associated mutations of E-cadherin affect cellular signalling. 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 1058.</jats:p

Multimodal analysis of formalin-fixed and paraffin-embedded tissue by MALDI imaging and fluorescence in situ hybridization for combined genetic and metabolic analysis.

Multimodal tissue analyses that combine two or more detection technologies provide synergistic value compared to single methods and are employed increasingly in the field of tissue-based diagnostics and research. Here, we report a technical pipeline that describes a combined approach of HER2/CEP17 fluorescence in situ hybridization (FISH) analysis with MALDI imaging on the very same section of formalin-fixed and paraffin-embedded (FFPE) tissue. FFPE biopsies and a tissue microarray of human gastroesophageal adenocarcinoma were analyzed by MALDI imaging. Subsequently, the very same section was hybridized by HER2/CEP17 FISH. We found that tissue morphology of both, the biopsies and the tissue microarray, was unaffected by MALDI imaging and the HER2 and CEP17 FISH signals were analyzable. In comparison with FISH analysis of samples without MALDI imaging, we observed no difference in terms of fluorescence signal intensity and gene copy number. Our combined approach revealed adenosine monophosphate, measured by MALDI imaging, as a prognostic marker. HER2 amplification, which was detected by FISH, is a stratifier between good and poor patient prognosis. By integrating both stratification parameters on the basis of our combined approach, we were able to strikingly improve the prognostic effect. Combining molecules detected by MALDI imaging with the gene copy number detected by HER2/CEP17 FISH, we found a synergistic effect, which enhances patient prognosis. This study shows that our combined approach allows the detection of genetic and metabolic properties from one very same FFPE tissue section, which are specific for HER2 and hence suitable for prognosis. Furthermore, this synergism might be useful for response prediction in tumors

Image analysis of immunohistochemistry is superior to visual scoring as shown for patient outcome of esophageal adenocarcinoma.

Quantification of protein expression based on immunohistochemistry (IHC) is an important step in clinical diagnoses and translational tissue-based research. Manual scoring systems are used in order to evaluate protein expression based on staining intensities and distribution patterns. However, visual scoring remains an inherently subjective approach. The aim of our study was to explore whether digital image analysis proves to be an alternative or even superior tool to quantify expression of membrane-bound proteins. We analyzed five membrane-binding biomarkers (HER2, EGFR, pEGFR, β-catenin, and E-cadherin) and performed IHC on tumor tissue microarrays from 153 esophageal adenocarcinomas patients from a single center study. The tissue cores were scored visually applying an established routine scoring system as well as by using digital image analysis obtaining a continuous spectrum of average staining intensity. Subsequently, we compared both assessments by survival analysis as an end point. There were no significant correlations with patient survival using visual scoring of β-catenin, E-cadherin, pEGFR, or HER2. In contrast, the results for digital image analysis approach indicated that there were significant associations with disease-free survival for β-catenin, E-cadherin, pEGFR, and HER2 (P = 0.0125, P = 0.0014, P = 0.0299, and P = 0.0096, respectively). For EGFR, there was a greater association with patient survival when digital image analysis was used compared to when visual scoring was (visual: P = 0.0045, image analysis: P < 0.0001). The results of this study indicated that digital image analysis was superior to visual scoring. Digital image analysis is more sensitive and, therefore, better able to detect biological differences within the tissues with greater accuracy. This increased sensitivity improves the quality of quantification

Afatinib reduces cell proliferation after MET knockdown.

Hs746T cells were transfected with MET siRNA (MET KD) or control siRNA (Ctr). Non-transfected cells (NT) were analyzed in parallel. Cells were harvested and re-plated one day after transfection. The following day, cells were treated with 0.5 μM afatinib or 0.05% DMSO for 72 hours. The mean of three biological experiments with standard deviation is shown. Data are shown as percent of NT untreated cells (a) or as percent of untreated cells of each group (NT, Ctr, MET KD) (b). T-test was used to compare the untreated cells between the groups and to compare afatinib-treated, DMSO-treated and untreated cells within each group (NT, Ctr, MET KD). Statistically significant differences are indicated by **p<0.01.</p