97 research outputs found

    Capillary (Gel) Electrophoresis-Based Methods for Immunoglobulin (G) Glycosylation Analysis

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    Circulating metastasis associated in colon cancer 1 transcripts in gastric cancer patient plasma as diagnostic and prognostic biomarker

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    Aim: To evaluate the diagnostic and prognostic value of circulating Metastasis Associated in Colon Cancer 1 (MACC1) transcripts in plasma of gastric cancer patients. Methods: We provide for the first time a blood-based assay for transcript quantification of the metastasis inducer MACC1 in a prospective study of gastric cancer patient plasma. MACC1 is a strong prognostic biomarker for tumor progression and metastasis in a variety of solid cancers. We conducted a study to define the diagnostic and prognostic power of MACC1 transcripts using 76 plasma samples from gastric cancer patients, either newly diagnosed with gastric cancer, newly diagnosed with metachronous metastasis of gastric cancer, as well as follow-up patients. Findings were controlled by using plasma samples from 54 tumor-free volunteers. Plasma was separated, RNA was isolated, and levels of MACC1 as well as S100A4 transcripts were determined by quantitative RT-PCR. Results: Based on the levels of circulating MACC1 transcripts in plasma we significantly discriminated tumor-free volunteers and gastric cancer patients (P < 0.001). Levels of circulating MACC1 transcripts were increased in gastric cancer patients of each disease stage, compared to tumor-free volunteers: patients with tumors without metastasis (P = 0.005), with synchronous metastasis (P = 0.002), with metachronous metastasis (P = 0.005), and patients during follow-up (P = 0.021). Sensitivity was 0.68 (95%CI: 0.45-0.85) and specificity was 0.89 (95%CI: 0.77-0.95), respectively. Importantly, gastric cancer patients with high circulating MACC1 transcript levels in plasma demonstrated significantly shorter survival when compared with patients demonstrating low MACC1 levels (P = 0.0015). Furthermore, gastric cancer patients with high circulating transcript levels of MACC1 as well as of S100A4 in plasma demonstrated significantly shorter survival when compared with patients demonstrating low levels of both biomarkers or with only one biomarker elevated (P = 0.001). Conclusion: Levels of circulating MACC1 transcripts in plasma of gastric cancer patients are of diagnostic value and are prognostic for patient survival in a prospective study

    Circulating MACC1 transcripts in colorectal cancer patient plasma predict metastasis and prognosis

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    BACKGROUND: Metastasis is the most frequent cause of treatment failure and death in colorectal cancer. Early detection of tumors and metastases is crucial for improving treatment strategies and patient outcome. Development of reliable biomarkers and simple tests routinely applicable in the clinic for detection, prognostication, and therapy monitoring is of special interest. We recently identified the novel gene Metastasis-Associated in Colon Cancer 1 (MACC1), a key regulator of the HGF/Met-pathway. MACC1 is a strong prognostic biomarker for colon cancer metastasis and allows identification of high-risk subjects in early stages, when determined in patients' primary tumors. To overcome the limitation of a restricted number of molecular analyses in tumor tissue, the establishment of a non-invasive blood test for early identification of high-risk cancer patients, for monitoring disease course and therapy response is strongly needed. METHODOLOGY/PRINCIPAL FINDINGS: For the first time, we describe a non-invasive assay for quantification of circulating MACC1 transcripts in blood of more than 300 colorectal cancer patients. MACC1 transcript levels are increased in all disease stages of the cancer patients compared to tumor-free volunteers. Highest MACC1 levels were determined in individuals with metastases (all P<0.05). Importantly, high MACC1 levels correlate with unfavorable survival (P<.0001). Combining MACC1 with circulating transcripts of the metastasis gene S100A4, a transcriptional target of the Wnt/beta-catenin-pathway, improves survival prediction for newly diagnosed cancer patients. CONCLUSION/SIGNIFICANCE: This blood-based assay for circulating MACC1 transcripts, which can be quantitated on a routine basis, is clinically applicable for diagnosis, prognosis, and therapeutic monitoring of cancer patients. Here we demonstrate the diagnostic and prognostic value of circulating MACC1 transcripts in patient plasma for metastasis and survival. Since MACC1 represents a promising target for anti-metastatic therapies, circulating MACC1 transcripts may prove to be an ideal read-out for monitoring therapeutic response of future interventions targeting MACC1-induced metastasis in cancer patients

    Calcium-binding protein S100P is a new target gene of MACC1, drives colorectal cancer metastasis and serves as a prognostic biomarker

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    BACKGROUND: The metastasis inducing gene MACC1 is a prognostic and predictive biomarker for metastasis in several cancers. Its mechanism of inducing metastasis includes the transcriptional control of other cancer-related target genes. Here, we investigate the interplay with the metastasis driver S100P in CRC progression. METHODS: MACC1-dependent S100P expression was analysed by qRT-PCR. The binding of MACC1 to the S100P promoter was determined by ChIP. Alterations in cell proliferation and motility were determined by functional in vitro assays. In vivo metastasis after intrasplenic transplantation was assessed by bioluminescence imaging and evaluation of tumour growth and liver metastasis. The prognostic value of S100P was determined in CRC patients by ROC-based Kaplan-Meier analyses. RESULTS: Expression of S100P and MACC1 correlated positively in CRC cells and colorectal tumours. MACC1 was found binding to the S100P promoter and induces its expression. The overexpression of S100P increased proliferation, migration and invasion in vitro and significantly induced liver metastasis in vivo. S100P expression was significantly elevated in metachronously metastasising CRC and was associated with shorter metastasis-free survival. CONCLUSIONS: We identified S100P as a transcriptional target gene of MACC1. Expression of S100P increases the metastatic potential of CRC cells in vitro and in vivo, and serves as a prognostic biomarker for metastasis-free survival of CRC patients, emphasising novel therapeutic interventions targeting S100P

    Reduced haemodynamic response in the ageing visual cortex measured by absolute fNIRS

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    The effect of healthy ageing on visual cortical activation is still to be fully explored. This study aimed to elucidate whether the haemodynamic response (HDR) of the visual cortex altered as a result of ageing. Visually normal (healthy) participants were presented with a simple visual stimulus (reversing checkerboard). Full optometric screening was implemented to identify two age groups: younger adults (n = 12, mean age 21) and older adults (n = 13, mean age 71). Frequency-domain Multi-distance (FD-MD) functional Near-Infrared Spectroscopy (fNIRS) was used to measure absolute changes in oxygenated [HbO] and deoxygenated [HbR] haemoglobin concentrations in the occipital cortices. Utilising a slow event-related design, subjects viewed a full field reversing checkerboard with contrast and check size manipulations (15 and 30 minutes of arc, 50% and 100% contrast). Both groups showed the characteristic response of increased [HbO] and decreased [HbR] during stimulus presentation. However, older adults produced a more varied HDR and often had comparable levels of [HbO] and [HbR] during both stimulus presentation and baseline resting state. Younger adults had significantly greater concentrations of both [HbO] and [HbR] in every investigation regardless of the type of stimulus displayed (p<0.05). The average variance associated with this age-related effect for [HbO] was 88% and [HbR] 91%. Passive viewing of a visual stimulus, without any cognitive input, showed a marked age-related decline in the cortical HDR. Moreover, regardless of stimulus parameters such as check size, the HDR was characterised by age. In concurrence with present neuroimaging literature, we conclude that the visual HDR decreases as healthy ageing proceeds

    Elevated MACC1 expression in colorectal cancer is driven by chromosomal instability and is associated with molecular subtype and worse patient survival

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    Metastasis-Associated in Colon Cancer 1 (MACC1) is a strong prognostic biomarker inducing proliferation, migration, invasiveness, and metastasis of cancer cells. The context of MACC1 dysregulation in cancers is, however, still poorly understood. Here, we investigated whether chromosomal instability and somatic copy number alterations (SCNA) frequently occurring in CRC contribute to MACC1 dysregulation, with prognostic and predictive impacts. Using the Oncotrack and Charité CRC cohorts of CRC patients, we showed that elevated MACC1 mRNA expression was tightly dependent on increased MACC1 gene SCNA and was associated with metastasis and shorter metastasis free survival. Deep analysis of the COAD-READ TCGA cohort revealed elevated MACC1 expression due to SCNA for advanced tumors exhibiting high chromosomal instability (CIN), and predominantly classified as CMS2 and CMS4 transcriptomic subtypes. For that cohort, we validated that elevated MACC1 mRNA expression correlated with reduced disease-free and overall survival. In conclusion, this study gives insights into the context of MACC1 expression in CRC. Increased MACC1 expression is largely driven by CIN, SCNA gains, and molecular subtypes, potentially determining the molecular risk for metastasis that might serve as a basis for patient-tailored treatment decisions

    Combinatorial treatment with statins and niclosamide prevents CRC dissemination by unhinging the MACC1-β-catenin-S100A4 axis of metastasis

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    Colorectal cancer (CRC) is the second-most common malignant disease worldwide, and metastasis is the main culprit of CRC-related death. Metachronous metastases remain to be an unpredictable, unpreventable, and fatal complication, and tracing the molecular chain of events that lead to metastasis would provide mechanistically linked biomarkers for the maintenance of remission in CRC patients after curative treatment. We hypothesized, that Metastasis-associated in colorectal cancer-1 (MACC1) induces a secretory phenotype to enforce metastasis in a paracrine manner, and found, that the cell-free culture medium of MACC1-expressing CRC cells induces migration. Stable isotope labeling by amino acids in cell culture mass spectrometry (SILAC-MS) of the medium revealed, that S100A4 is significantly enriched in the MACC1-specific secretome. Remarkably, both biomarkers correlate in expression data of independent cohorts as well as within CRC tumor sections. Furthermore, combined elevated transcript levels of the metastasis genes MACC1 and S100A4 in primary tumors and in blood plasma robustly identifies CRC patients at high risk for poor metastasis-free (MFS) and overall survival (OS). Mechanistically, MACC1 strengthens the interaction of β-catenin with TCF4, thus inducing S100A4 synthesis transcriptionally, resulting in elevated secretion to enforce cell motility and metastasis. In cell motility assays, S100A4 was indispensable for MACC1-induced migration, as shown via knock-out and pharmacological inhibition of S100A4. The direct transcriptional and functional relationship of MACC1 and S100A4 was probed by combined targeting with repositioned drugs. In fact, the MACC1-β-catenin-S100A4 axis by statins (MACC1) and niclosamide (S100A4) synergized in inhibiting cancer cell motility in vitro and metastasis in vivo. The MACC1-β-catenin-S100A4 signaling axis is causal for CRC metastasis. Selectively repositioned drugs synergize in restricting MACC1/S100A4-driven metastasis with cross-entity potential

    Combination of Wnt/β-catenin targets S100A4 and DKK1 improves prognosis of human colorectal cancer

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    Metastasis is directly linked to colorectal cancer (CRC) patient survival. Wnt signaling through β-catenin plays a key role. Metastasis-inducing S100A4 is a Wnt/β-catenin target gene and a prognostic biomarker for CRC and other cancer types. We aimed to identify S100A4-dependent expression alterations to better understand CRC progression and metastasis for improved patient survival. S100A4-induced transcriptome arrays, confirmatory studies in isogenic CRC cell lines with defined β-catenin genotypes, and functional metastasis studies were performed. S100A4-regulated transcriptome examination revealed the transcriptional cross-regulation of metastasis-inducing S100A4 with Wnt pathway antagonist Dickkopf-1 (DKK1). S100A4 overexpression down-regulated DKK1, S100A4 knock-down increased DKK1. Recombinant DKK1 reduced S100A4 expression and S100A4-mediated cell migration. In xenografted mice, systemic S100A4-shRNA application increased intratumoral DKK1. The inverse correlation of S100A4 and DKK1 was confirmed in five independent publicly available CRC expression datasets. Combinatorial analysis of S100A4 and DKK1 in two additional independent CRC patient cohorts improved prognosis of overall and metastasis-free survival. The newly discovered transcriptional cross-regulation of Wnt target S100A4 and Wnt antagonist DKK1 is predominated by an S100A4-induced Wnt signaling feedback loop, increasing cell motility and metastasis risk. S100A4 and DKK1 combination improves the identification of CRC patients at high risk

    Distribution of Attention Modulates Salience Signals in Early Visual Cortex

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    Previous research has shown that the extent to which people spread attention across the visual field plays a crucial role in visual selection and the occurrence of bottom-up driven attentional capture. Consistent with previous findings, we show that when attention was diffusely distributed across the visual field while searching for a shape singleton, an irrelevant salient color singleton captured attention. However, while using the very same displays and task, no capture was observed when observers initially focused their attention at the center of the display. Using event-related fMRI, we examined the modulation of retinotopic activity related to attentional capture in early visual areas. Because the sensory display characteristics were identical in both conditions, we were able to isolate the brain activity associated with exogenous attentional capture. The results show that spreading of attention leads to increased bottom-up exogenous capture and increased activity in visual area V3 but not in V2 and V1

    Intermodal attention affects the processing of the temporal alignment of audiovisual stimuli

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    The temporal asynchrony between inputs to different sensory modalities has been shown to be a critical factor influencing the interaction between such inputs. We used scalp-recorded event-related potentials (ERPs) to investigate the effects of attention on the processing of audiovisual multisensory stimuli as the temporal asynchrony between the auditory and visual inputs varied across the audiovisual integration window (i.e., up to 125 ms). Randomized streams of unisensory auditory stimuli, unisensory visual stimuli, and audiovisual stimuli (consisting of the temporally proximal presentation of the visual and auditory stimulus components) were presented centrally while participants attended to either the auditory or the visual modality to detect occasional target stimuli in that modality. ERPs elicited by each of the contributing sensory modalities were extracted by signal processing techniques from the combined ERP waveforms elicited by the multisensory stimuli. This was done for each of the five different 50-ms subranges of stimulus onset asynchrony (SOA: e.g., V precedes A by 125–75 ms, by 75–25 ms, etc.). The extracted ERPs for the visual inputs of the multisensory stimuli were compared among each other and with the ERPs to the unisensory visual control stimuli, separately when attention was directed to the visual or to the auditory modality. The results showed that the attention effects on the right-hemisphere visual P1 was largest when auditory and visual stimuli were temporally aligned. In contrast, the N1 attention effect was smallest at this latency, suggesting that attention may play a role in the processing of the relative temporal alignment of the constituent parts of multisensory stimuli. At longer latencies an occipital selection negativity for the attended versus unattended visual stimuli was also observed, but this effect did not vary as a function of SOA, suggesting that by that latency a stable representation of the auditory and visual stimulus components has been established
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