0000000000303527
AUTHOR
Jürgen Siebler
showing 15 related works from this author
Review article: in vivo imaging by endocytoscopy
2011
Aliment Pharmacol Ther 2011; 33: 1183–1193 Summary Background Endocytoscopy (EC) enables in vivo microscopic imaging at 1400-fold magnification, thereby allowing the analysis of mucosal structures at the cellular level. In contrast to fluorescence imaging with confocal laser endomicroscopy which allows analysis of mucosal structures up to 250 μm in depth, EC is based on the principle of contact light microscopy and only allows visualisation of the very superficial mucosal layer. Aim To systematically review the feasibility and diagnostic yield of EC for in vivo diagnosis of diseases. Methods A systematic search of the literature on diagnostic interventions in the gastrointestinal tract u…
Histone deacetylase inhibition by valproic acid down-regulates c-FLIP/CASH and sensitizes hepatoma cells towards CD95-and TRAIL receptor-mediated apo…
2005
Hepatocellular carcinoma (HCC) is highly resistant to chemotherapy, leading to a poor prognosis of advanced disease. Inhibitors of histone deacetylase (HDACi) induce re-differentiation in tumor cells and thereby re-establish sensitivity towards apoptotic stimuli. HDACi are entering the clinical stage of tumor treatment, and several substances are currently being tested in clinical trials to prove their efficacy in the treatment of leukemias and solid tumors. In this study, we investigated the impact of the HDACi valproic acid (VA) on TRAIL- and CD95-mediated apoptosis in hepatoma cells, as well as its sensitizing effect on a chemotherapeutic agent. Treatment of HepG2 cells with VA increased…
Failure on voxilaprevir, velpatasvir, sofosbuvir and efficacy of rescue therapy
2021
Background & Aims There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients. Methods Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients. Results Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis …
Real Life Study of Lenvatinib Therapy for Hepatocellular Carcinoma: RELEVANT Study
2021
<b><i>Introduction:</i></b> In the REFLECT trial, lenvatinib was found to be noninferior compared to sorafenib in terms of overall survival. Here, we analyze the effects of lenvatinib in the real-life experience of several centers across the world and identify clinical factors that could be significantly associated with survival outcomes. <b><i>Methods:</i></b> The study population was derived from retrospectively collected data of HCC patients treated with lenvatinib. The overall cohort included western and eastern populations from 23 center in five countries. <b><i>Results:</i></b> We included 1,325 patients with HCC …
Ablation of c-FLIP in hepatocytes enhances death-receptor mediated apoptosis and toxic liver injury in vivo
2010
Background & Aims Apoptosis is crucially involved in acute and chronic liver injury, including viral, cholestatic, toxic, and metabolic liver disease. Additionally, dysregulation of apoptosis signaling pathways has been implicated in hepatocarcinogenesis. The most prominent members of the apoptosis-mediating tumor necrosis factor receptor superfamily are the TNF-R1 (CD120a) and the CD95 (Apo-1/Fas) receptor. Although extensively studied, the intracellular signaling events in hepatocytes are only incompletely understood. Methods To examine the role of the caspase-8 homolog cellular FLICE-inhibitory protein (c-FLIP) in liver injury, we generated mice with hepatocyte specific deletion of c-FLI…
Randomised phase II evaluation of irinotecan plus high-dose 5-fluorouracil and leucovorin (ILF) vs 5-fluorouracil, leucovorin, and etoposide (ELF) in…
2005
An open-label randomised comparison of efficacy and tolerability of irinotecan plus high-dose 5-fluorouracil (5-FU) and leucovorin (LV) (ILF) with etoposide plus 5-FU/LV (ELF) in patients with untreated metastatic or locally advanced gastric cancer. One cycle of ILF comprised six once-weekly infusions of irinotecan 80 mg m(-2), LV 500 mg m(-2), 24-h 5-FU 2000 mg m(-2), and ELF comprised three once-daily doses of etoposide 120 mg m(-2), LV 300 mg m(-2), 5-FU 500 mg m(-2). In all, 56 patients received ILF and 58 ELF. Median age was 62 years, Karnofsky performance 90%, and disease status was comparable for both arms. The objective clinical response rates after 14 weeks treatment (primary end p…
The gut–liver-axis: Endotoxemia, inflammation, insulin resistance and NASH
2008
Metabolic endotoxemia initiates obesity and insulin resistance. Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, Neyrinck AM, Fava F, Tuohy KM, Chabo C, Waget A, Delmee E, Cousin B, Sulpice T, Chamontin B, Ferrieres J, Tanti JF, Gibson GR, Casteilla L, Delzenne NM, Alessi MC, Burcelin R. Diabetes and obesity are two metabolic diseases characterized by insulin resistance and a low-grade inflammation. Seeking an inflammatory factor causative of the onset of insulin resistance, obesity, and diabetes, we have identified bacterial lipopolysaccharide (LPS) as a triggering factor. We found that normal endotoxemia increased or decreased during the fed or fasted state, respectively, on a…
Efficacy and safety of irinotecan-based chemotherapy for advanced colorectal cancer outside clinical trials: an observational study.
2010
Background: This prospective observational study in typical community-based outpatient clinics evaluated the efficacy and toxicity of weekly and biweekly irinotecan-based chemotherapies and their compatibility depending on age. Methods: 601 patients with advanced or metastatic colorectal cancer receiving first-, second-, or third-line irinotecanbased therapy were regularly analyzed for response and toxicity until the end of therapy. Results: The median age was 65 (28–87) years, approximately one-third of the patients were ≥70 years old. Of all patients, 405 were treated weekly and 68 biweekly. Median overall survival (OS) for first-line therapy was 26.5 months for the <70-year-old patients …
Overexpression of STAT-1 by adenoviral gene transfer does not inhibit hepatitis B virus replication.
2006
Objectives Interferons are known to inhibit the replication of hepatitis B viruses (HBV) in several animal models in vitro and in vivo as well in humans. The STAT-1 protein plays a central role in the biological activity of both type I and type II interferons. The lack of functional STAT-1 renders cells and organisms susceptible to bacterial and viral infectious agents. We analysed whether the overexpression of STAT-1 protein enhances the biological interferon response and whether it elicits antiviral acitivity against HBV in vitro. Methods To achieve an efficient STAT-1 overexpression in primary liver cells and hepatoma cells, we generated a recombinant, replication-deficient adenovirus ex…
Novel ways to sensitise gastrointestinal cancer to apoptosis.
2009
Gastrointestinal (GI) cancers are major health problems, being the most common cancers worldwide. Resistance to apoptosis is closely linked to carcinogenesis and enables malignant cells to evade therapy-induced cell death. In the recent past, the increasing understanding of molecular pathways of apoptosis has provided novel targets in cancer therapy. Several drugs, either inhibiting antiapoptotic signalling or actively inducing apoptosis in cancer cells, have already entered clinical trials. Until now, agents targeting apoptosis pathways are primarily being tested alone or in combination with chemotherapy. In the near future, personalized combination therapies will probably be beneficial fo…
MORT1/FADD is involved in liver regeneration
2006
AIM: To explore the role of the adaptor molecule in liver regeneration after partial hepatectomy (PH). METHODS: We used transgenic mice expressing an N-terminal truncated form of MORT1/FADD under the control of the albumin promoter. As previously shown, this transgenic protein abrogated CD95- and CD120a-mediated apoptosis in the liver. Cyclin A expression was detected using Western blotting. ELISA and RT-PCR were used to detect IL-6 and IL-6 mRNA, respectively. DNA synthesis in liver tissue was measured by BrdU staining. RESULTS: Resection of 70% of the liver was followed by a reduced early regenerative response in the transgenic group at 36 h. Accordingly, 36 h after hepatectomy, cyclin A …
A key pathogenic role for the STAT1/T-bet signaling pathway in T-cell-mediated liver inflammation.
2003
TH1 cytokines have been suggested to contribute to the pathogenesis of T-cell-mediated liver injury and inflammation. However, the molecular signaling pathways involved in such injury are still poorly understood. In the present study, we investigated the role of the STAT1/T-bet signaling pathway in a murine model of T-cell-mediated liver inflammation induced by the application of concanavalin A (Con A) using newly created STAT1 transgenic mice as well as STAT1- and T-bet-deficient mice. Liver injury induced by Con A was associated with an increase of both pSTAT1 and T-bet levels in the liver. Furthermore, functional studies suggested a pathogenic role for STAT1 in Con A-induced liver injury…
A variant of Smurf2 protects mice against colitis-associated colon cancer by inducing transforming growth factor β signaling.
2011
Background & Aims Transforming growth factor (TGF)-β signaling, which is down-regulated by the E3 ubiquitin ligase Smad ubiquitin regulating factor 2 (Smurf2), promotes development of cancer. We identified a splice variant of Smurf2 (ΔE2Smurf2) and investigated its role in colon carcinogenesis in mice. Methods Colitis-associated colon cancer was induced in mice by administration of azoxymethane, followed by 3 cycles of oral administration of dextran sodium sulfate. Messenger RNA levels of Smurf2 in colon tumors and control tissue were measured by quantitative polymerase chain reaction; lymphocyte and cytokine levels were measured in tumor and tissue samples. Results Tumor-infiltrating CD4 +…
Phase I/II trial of capecitabine and oxaliplatin in combination with bevacizumab and imatinib in patients with metastatic colorectal cancer: AIO KRK …
2013
Background: Combined inhibition of platelet-derived growth factor receptor beta signalling and vascular endothelial growth factor promotes vascular normalisation in preclinical models and may lead to increased delivery of chemotherapy to tumour tissue. This phase I/II trial assessed the safety and efficacy of capecitabine plus oxaliplatin (XELOX) plus bevacizumab and imatinib in the first-line treatment of patients with metastatic colorectal cancer. Methods: Two dose levels (I/II) were defined: capecitabine 850/1000 mg m−2 twice daily on days 1–14; oxaliplatin 100/130 mg m−2 on day 1; bevacizumab 7.5 mg kg−1 on day 1; imatinib 300 mg day−1 on days 1–21 every 21 days. The primary study endpo…
A phase 2 study of galunisertib (TGF-Β R1 inhibitor) and sorafenib in patients with advanced hepatocellular carcinoma (HCC).
2017
4097 Background: TGFβ signaling is associated with HCC progression. Inhibition of TGFβ R1 potentiates activity of sorafenib in in-vitro and in-vivo models. Here we report the clinical activity of galunisertib (G) plus sorafenib (S) in pts with incurable HCC and no prior systemic therapy. Methods: Eligibility criteria included incurable HCC with measurable disease per RECIST 1.1, no prior systemic therapy, Child Pugh A, ECOG PS ≤1.G was administered as 80 mg PO BID (lead-in Cohort 1) or 150 mg PO BID (lead-in Cohort 2 and expansion cohort), as intermittent dosing of 14 days on/off (28 days = 1 cycle). S was administered continuously as a 400 mg PO BID. Primary objective was to characterize …