ABSTRACT
BACKGROUND: When massive necrosis occurs in acute liver failure (ALF), rapid expansion of HSCs called liver progenitor cells (LPCs) in a process called ductular reaction is required for survival. The underlying mechanisms governing this process are not entirely known to date. In ALF, high levels of retinoic acid (RA), a molecule known for its pleiotropic roles in embryonic development, are secreted by activated HSCs. We hypothesized that RA plays a key role in ductular reaction during ALF. METHODS: RNAseq was performed to identify molecular signaling pathways affected by all-trans retinoid acid (atRA) treatment in HepaRG LPCs. Functional assays were performed in HepaRG cells treated with atRA or cocultured with LX-2 cells and in the liver tissue of patients suffering from ALF. RESULTS: Under ALF conditions, activated HSCs secreted RA, inducing RARα nuclear translocation in LPCs. RNAseq data and investigations in HepaRG cells revealed that atRA treatment activated the WNT-ß-Catenin pathway, enhanced stemness genes (SOX9, AFP, and others), increased energy storage, and elevated the expression of ATP-binding cassette transporters in a RARα nuclear translocation-dependent manner. Further, atRA treatment-induced pathways were confirmed in a coculture system of HepaRG with LX-2 cells. Patients suffering from ALF who displayed RARα nuclear translocation in the LPCs had significantly better MELD scores than those without. CONCLUSIONS: During ALF, RA secreted by activated HSCs promotes LPC activation, a prerequisite for subsequent LPC-mediated liver regeneration.
Subject(s)
Liver Failure, Acute , Stem Cells , Tretinoin , Humans , Tretinoin/pharmacology , Stem Cells/drug effects , Wnt Signaling Pathway/drug effects , Liver/drug effects , Retinoic Acid Receptor alpha/genetics , Retinoic Acid Receptor alpha/metabolism , Coculture Techniques , Hepatic Stellate Cells/drug effects , Hepatic Stellate Cells/metabolismABSTRACT
OBJECTIVE: This systematic review aims to elucidate the diagnostic capabilities of imaging techniques in identifying Non-Occlusive Hepatic Artery Hypoperfusion Syndrome (NOHAH) and to evaluate the efficacy and outcomes of splenic artery embolization (SAE), including the choice and placement of embolic agents. MATERIALS AND METHODS: A comprehensive literature search was conducted using PubMed, CINAHL, and Scopus databases, adhering to PRISMA guidelines. Fifteen studies encompassing 240 patients treated with embolization (using coils or Amplatzer Vascular Plugs (AVP)) were analyzed. Key metrics assessed included patient demographics, embolization techniques, embolic agents, technical success, radiologic findings pre- and post-embolization, and complication rates. RESULTS: Among the 240 patients studied, 177 (73.8%) were reported by gender, with a majority being male (127/177, 71.7%). Doppler ultrasonography (DUS) emerged as the primary initial screening tool in 80% of studies. The hepatic arterial resistive index (RI) was a critical parameter, with mean values significantly decreasing from 0.84 pre-embolization to 0.70 post-embolization (p < 0.001). All cases confirmed technical success via digital subtraction angiography, revealing delayed hepatic arterial filling without stenosis or thrombosis. Coils were the predominant embolic agent, used in 80.8% of patients, followed by AVP in 16.3%. The overall mortality rate was 4.58%, with 29 major and 3 minor complications noted. Notably, proximal placement of coils in the splenic artery was associated with lower mortality rates compared to distal placement and showed comparable complication rates to AVPs. CONCLUSION: DUS is a reliable screening modality for NOHAH, with post-SAE assessments showing significant improvements. The choice and location of embolization significantly impact patient outcomes, with proximal placement of coils emerging as a preferable strategy due to lower mortality rates and comparable complication profiles to alternative methods.
Subject(s)
Embolization, Therapeutic , Hepatic Artery , Humans , Hepatic Artery/diagnostic imaging , Embolization, Therapeutic/methods , Syndrome , Splenic Artery/diagnostic imagingABSTRACT
Inhibition of K-RAS effectors like B-RAF or MEK1/2 is accompanied by treatment resistance in cancer patients via re-activation of PI3K and Wnt signaling. We hypothesized that myotubularin-related-protein-7 (MTMR7), which inhibits PI3K and ERK1/2 signaling downstream of RAS, directly targets RAS and thereby prevents resistance. Using cell and structural biology combined with animal studies, we show that MTMR7 binds and inhibits RAS at cellular membranes. Overexpression of MTMR7 reduced RAS GTPase activities and protein levels, ERK1/2 phosphorylation, c-FOS transcription and cancer cell proliferation in vitro. We located the RAS-inhibitory activity of MTMR7 to its charged coiled coil (CC) region and demonstrate direct interaction with the gastrointestinal cancer-relevant K-RASG12V mutant, favouring its GDP-bound state. In mouse models of gastric and intestinal cancer, a cell-permeable MTMR7-CC mimicry peptide decreased tumour growth, Ki67 proliferation index and ERK1/2 nuclear positivity. Thus, MTMR7 mimicry peptide(s) could provide a novel strategy for targeting mutant K-RAS in cancers.
Subject(s)
Neoplasms , Protein Tyrosine Phosphatases, Non-Receptor , Animals , Humans , Mice , Peptides , Phosphatidylinositol 3-Kinases/metabolism , Protein Tyrosine Phosphatases, Non-Receptor/genetics , Protein Tyrosine Phosphatases, Non-Receptor/metabolism , Signal TransductionABSTRACT
In the context of the COVID-19 pandemic, there has been a scarcity of resources with various effects on the care of cancer patients. This paper provides an English summary of a German guideline on prioritization and resource allocation for colorectal and pancreatic cancer in the context of the pandemic. Based on a selective literature review as well as empirical and ethical analyses, the research team of the CancerCOVID Consortium drafted recommendations for prioritizing diagnostic and treatment measures for both entities. The final version of the guideline received consent from the executive boards of nine societies of the Association of Scientific Medical Societies in Germany (AWMF), 20 further professional organizations and 22 other experts from various disciplines as well as patient representatives. The guiding principle for the prioritization of decisions is the minimization of harm. Prioritization decisions to fulfill this overall goal should be guided by (1) the urgency relevant to avoid or reduce harm, (2) the likelihood of success of the diagnostic or therapeutic measure advised, and (3) the availability of alternative treatment options. In the event of a relevant risk of harm as a result of prioritization, these decisions should be made by means of a team approach. Gender, age, disability, ethnicity, origin, and other social characteristics, such as social or insurance status, as well as the vehemence of a patient's treatment request and SARS-CoV-2 vaccination status should not be used as prioritization criteria. The guideline provides concrete recommendations for (1) diagnostic procedures, (2) surgical procedures for cancer, and (3) systemic treatment and radiotherapy in patients with colorectal or pancreatic cancer within the context of the German healthcare system.
Subject(s)
COVID-19 , Colorectal Neoplasms , Pancreatic Neoplasms , Resource Allocation , SARS-CoV-2 , Humans , Colorectal Neoplasms/therapy , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/diagnosis , COVID-19/epidemiology , Germany , Health Care Rationing/organization & administration , Health Priorities , Pancreatic Neoplasms/therapy , Pancreatic Neoplasms/epidemiology , Pandemics , Practice Guidelines as TopicABSTRACT
Diagnosis and therapy of esophageal carcinoma is challenging and requires a multidisciplinary approach. The purpose of the updated German guideline "Diagnosis and Treatment of Squamous Cell Carcinoma and Adenocarcinoma of the Esophagus-version 3.1" is to provide practical and evidence-based advice for the management of patients with esophageal cancer. Recommendations were developed by a multidisciplinary expert panel based on an extensive and systematic evaluation of the published medical literature and the application of well-established methodologies (e.g. Oxford evidence grading scheme, grading of recommendations). Accurate diagnostic evaluation of the primary tumor as well as lymph node and distant metastases is required in order to guide patients to a stage-appropriate therapy after the initial diagnosis of esophageal cancer. In high-grade intraepithelial neoplasia or mucosal carcinoma endoscopic resection shall be performed. Whether endoscopic resection is the definitive therapeutic measure depends on the histopathological evaluation of the resection specimen. Esophagectomy should be performed minimally invasive or in combination with open procedures (hybrid technique). Because the prognosis in locally advanced esophageal carcinoma is poor with surgery alone, multimodality therapy is recommended. In locally advanced adenocarcinomas of the esophagus or esophagogastric junction, perioperative chemotherapy or preoperative radiochemotherapy should be administered. In locally advanced squamous cell carcinomas of the esophagus, preoperative radiochemotherapy followed by complete resection or definitive radiochemotherapy without surgery should be performed. In the case of residual tumor in the resection specimen after neoadjuvant radiochemotherapy and R0 resection of squamous cell carcinoma or adenocarcinoma, adjuvant immunotherapy with nivolumab should be given. Systemic palliative treatment options (chemotherapy, chemotherapy plus immunotherapy, immunotherapy alone) in unresectable or metastastic esophageal cancer depend on histology and are stratified according to PD-L1 and/or Her2 expression.
Subject(s)
Adenocarcinoma , Carcinoma, Squamous Cell , Esophageal Neoplasms , Humans , Adenocarcinoma/diagnosis , Adenocarcinoma/therapy , Adenocarcinoma/pathology , Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/therapy , Carcinoma, Squamous Cell/pathology , Esophageal Neoplasms/diagnosis , Esophageal Neoplasms/therapy , Esophageal Neoplasms/pathology , Combined Modality TherapyABSTRACT
Manipulation of the subcellular localization of transcription factors by preventing their shuttling via the nuclear pore complex (NPC) emerges as a novel therapeutic strategy against cancer. One transmembrane component of the NPC is POM121, encoded by a tandem gene locus POM121A/C on chromosome 7. Overexpression of POM121 is associated with metabolic diseases (e.g., diabetes) and unfavorable clinical outcome in patients with colorectal cancer (CRC). Peroxisome proliferator-activated receptor-gamma (PPARγ) is a transcription factor with anti-diabetic and anti-tumoral efficacy. It is inhibited by export from the nucleus to the cytosol via the RAS-RAF-MEK1/2-ERK1/2 signaling pathway, a major oncogenic driver of CRC. We therefore hypothesized that POM121 participates in the transport of PPARγ across the NPC to regulate its transcriptional activity on genes involved in metabolic and tumor control. We found that POM121A/C mRNA was enriched and POM121 protein co-expressed with PPARγ in tissues from CRC patients conferring poor prognosis. Its interactome was predicted to include proteins responsible for tumor metabolism and immunity, and in-silico modeling provided insights into potential 3D structures of POM121. A peptide region downstream of the nuclear localization sequence (NLS) of POM121 was identified as a cytoplasmic interactor of PPARγ. POM121 positivity correlated with the cytoplasmic localization of PPARγ in patients with KRAS mutant CRC. In contrast, POM121A/C silencing by CRISPR/Cas9 sgRNA or siRNA enforced nuclear accumulation of PPARγ and activated PPARγ target genes promoting lipid metabolism and cell cycle arrest resulting in reduced proliferation of human CRC cells. Our data suggest the POM121-PPARγ axis as a potential drugable target in CRC.
Subject(s)
Neoplasms , Nuclear Pore , Humans , Nuclear Pore/metabolism , PPAR gamma/genetics , PPAR gamma/metabolism , RNA, Guide, CRISPR-Cas Systems , Nuclear Pore Complex Proteins/metabolism , Transcription Factors/metabolism , Neoplasms/metabolism , Membrane Glycoproteins/metabolismABSTRACT
BACKGROUND & AIMS: Transforming growth factor-ß1 (TGF-ß1) plays important roles in chronic liver diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD involves various biological processes including dysfunctional cholesterol metabolism and contributes to progression to metabolic dysfunction-associated steatohepatitis and hepatocellular carcinoma. However, the reciprocal regulation of TGF-ß1 signaling and cholesterol metabolism in MASLD is yet unknown. METHODS: Changes in transcription of genes associated with cholesterol metabolism were assessed by RNA sequencing of murine hepatocyte cell line (alpha mouse liver 12/AML12) and mouse primary hepatocytes treated with TGF-ß1. Functional assays were performed on AML12 cells (untreated, TGF-ß1 treated, or subjected to cholesterol enrichment [CE] or cholesterol depletion [CD]), and on mice injected with adenovirus-associated virus 8-control/TGF-ß1. RESULTS: TGF-ß1 inhibited messenger RNA expression of several cholesterol metabolism regulatory genes, including rate-limiting enzymes of cholesterol biosynthesis in AML12 cells, mouse primary hepatocytes, and adenovirus-associated virus-TGF-ß1-treated mice. Total cholesterol levels and lipid droplet accumulation in AML12 cells and liver tissue also were reduced upon TGF-ß1 treatment. Smad2/3 phosphorylation after 2 hours of TGF-ß1 treatment persisted after CE or CD and was mildly increased after CD, whereas TGF-ß1-mediated AKT phosphorylation (30 min) was inhibited by CE. Furthermore, CE protected AML12 cells from several effects mediated by 72 hours of incubation with TGF-ß1, including epithelial-mesenchymal transition, actin polymerization, and apoptosis. CD mimicked the outcome of long-term TGF-ß1 administration, an effect that was blocked by an inhibitor of the type I TGF-ß receptor. In addition, the supernatant of CE- or CD-treated AML12 cells inhibited or promoted, respectively, the activation of LX-2 hepatic stellate cells. CONCLUSIONS: TGF-ß1 inhibits cholesterol metabolism whereas cholesterol attenuates TGF-ß1 downstream effects in hepatocytes.
Subject(s)
Fatty Liver , Transforming Growth Factor beta1 , Mice , Animals , Transforming Growth Factor beta1/metabolism , Hepatocytes/metabolism , Hepatic Stellate Cells/pathology , Cell Line , Fatty Liver/metabolismABSTRACT
Bone morphogenetic protein (BMP)-9, a member of the TGFß-family of cytokines, is believed to be mainly produced in the liver. The serum levels of BMP-9 were reported to be reduced in newly diagnosed diabetic patients and BMP-9 overexpression ameliorated steatosis in the high fat diet-induced obesity mouse model. Furthermore, injection of BMP-9 in mice enhanced expression of fibroblast growth factor (FGF)21. However, whether BMP-9 also regulates the expression of the related FGF19 is not clear. Because both FGF21 and 19 were described to protect the liver from steatosis, we have further investigated the role of BMP-9 in this context. We first analyzed BMP-9 levels in the serum of streptozotocin (STZ)-induced diabetic rats (a model of type I diabetes) and confirmed that BMP-9 serum levels decrease during diabetes. Microarray analyses of RNA samples from hepatic and intestinal tissue from BMP-9 KO- and wild-type mice (C57/Bl6 background) pointed to basal expression of BMP-9 in both organs and revealed a down-regulation of hepatic Fgf21 and intestinal Fgf19 in the KO mice. Next, we analyzed BMP-9 levels in a cohort of obese patients with or without diabetes. Serum BMP-9 levels did not correlate with diabetes, but hepatic BMP-9 mRNA expression negatively correlated with steatosis in those patients that did not yet develop diabetes. Likewise, hepatic BMP-9 expression also negatively correlated with serum LPS levels. In situ hybridization analyses confirmed intestinal BMP-9 expression. Intestinal (but not hepatic) BMP-9 mRNA levels were decreased with diabetes and positively correlated with intestinal E-Cadherin expression. In vitro studies using organoids demonstrated that BMP-9 directly induces FGF19 in gut but not hepatocyte organoids, whereas no evidence of a direct induction of hepatic FGF21 by BMP-9 was found. Consistent with the in vitro data, a correlation between intestinal BMP-9 and FGF19 mRNA expression was seen in the patients' samples. In summary, our data confirm that BMP-9 is involved in diabetes development in humans and in the control of the FGF-axis. More importantly, our data imply that not only hepatic but also intestinal BMP-9 associates with diabetes and steatosis development and controls FGF19 expression. The data support the conclusion that increased levels of BMP-9 would most likely be beneficial under pre-steatotic conditions, making supplementation of BMP-9 an interesting new approach for future therapies aiming at prevention of the development of a metabolic syndrome and liver steatosis.
Subject(s)
Diabetes Mellitus, Experimental , Fatty Liver , Humans , Rats , Mice , Animals , Growth Differentiation Factor 2/metabolism , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/metabolism , Obesity/complications , Obesity/metabolism , Liver/metabolism , Fatty Liver/metabolism , Fibroblast Growth Factors/genetics , Fibroblast Growth Factors/metabolism , RNA, Messenger/metabolismABSTRACT
BACKGROUND AND AIMS: In patients with acute liver failure (ALF) who suffer from massive hepatocyte loss, liver progenitor cells (LPCs) take over key hepatocyte functions, which ultimately determines survival. This study investigated how the expression of hepatocyte nuclear factor 4α (HNF4α), its regulators, and targets in LPCs determines clinical outcome of patients with ALF. APPROACH AND RESULTS: Clinicopathological associations were scrutinized in 19 patients with ALF (9 recovered and 10 receiving liver transplantation). Regulatory mechanisms between follistatin, activin, HNF4α, and coagulation factor expression in LPC were investigated in vitro and in metronidazole-treated zebrafish. A prospective clinical study followed up 186 patients with cirrhosis for 80 months to observe the relevance of follistatin levels in prevalence and mortality of acute-on-chronic liver failure. Recovered patients with ALF robustly express HNF4α in either LPCs or remaining hepatocytes. As in hepatocytes, HNF4α controls the expression of coagulation factors by binding to their promoters in LPC. HNF4α expression in LPCs requires the forkhead box protein H1-Sma and Mad homolog 2/3/4 transcription factor complex, which is promoted by the TGF-ß superfamily member activin. Activin signaling in LPCs is negatively regulated by follistatin, a hepatocyte-derived hormone controlled by insulin and glucagon. In contrast to patients requiring liver transplantation, recovered patients demonstrate a normal activin/follistatin ratio, robust abundance of the activin effectors phosphorylated Sma and Mad homolog 2 and HNF4α in LPCs, leading to significantly improved coagulation function. A follow-up study indicated that serum follistatin levels could predict the incidence and mortality of acute-on-chronic liver failure. CONCLUSIONS: These results highlight a crucial role of the follistatin-controlled activin-HNF4α-coagulation axis in determining the clinical outcome of massive hepatocyte loss-induced ALF. The effects of insulin and glucagon on follistatin suggest a key role of the systemic metabolic state in ALF.
Subject(s)
Activins/genetics , Follistatin/metabolism , Hepatocyte Nuclear Factor 4/metabolism , Liver Failure, Acute/metabolism , Activins/metabolism , Acute-On-Chronic Liver Failure/blood , Adult , Aged , Animals , Blood Coagulation , Cell Line , Factor V/genetics , Female , Follistatin/blood , Follow-Up Studies , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression , Hepatocyte Nuclear Factor 4/genetics , Hepatocytes/metabolism , Humans , Liver Failure, Acute/chemically induced , Liver Failure, Acute/pathology , Liver Failure, Acute/surgery , Liver Regeneration , Liver Transplantation , Male , Metronidazole , Mice , Middle Aged , Prognosis , Promoter Regions, Genetic , Prospective Studies , Prothrombin/genetics , Signal Transduction , Smad2 Protein/genetics , Smad2 Protein/metabolism , Smad3 Protein/genetics , Smad3 Protein/metabolism , Smad4 Protein/genetics , Stem Cells/metabolism , Transforming Growth Factor beta1/genetics , ZebrafishABSTRACT
PURPOSE: Regorafenib (REG) is approved for the treatment of metastatic colorectal cancer, but has modest survival benefit and associated toxicities. Robust predictive/early response biomarkers to aid patient stratification are outstanding. We have exploited biological pathway analyses in a patient-derived xenograft (PDX) trial to study REG response mechanisms and elucidate putative biomarkers. EXPERIMENTAL DESIGN: Molecularly subtyped PDXs were annotated for REG response. Subtyping was based on gene expression (CMS, consensus molecular subtype) and copy-number alteration (CNA). Baseline tumor vascularization, apoptosis, and proliferation signatures were studied to identify predictive biomarkers within subtypes. Phospho-proteomic analysis was used to identify novel classifiers. Supervised RNA sequencing analysis was performed on PDXs that progressed, or did not progress, following REG treatment. RESULTS: Improved REG response was observed in CMS4, although intra-subtype response was variable. Tumor vascularity did not correlate with outcome. In CMS4 tumors, reduced proliferation and higher sensitivity to apoptosis at baseline correlated with response. Reverse phase protein array (RPPA) analysis revealed 4 phospho-proteomic clusters, one of which was enriched with non-progressor models. A classification decision tree trained on RPPA- and CMS-based assignments discriminated non-progressors from progressors with 92% overall accuracy (97% sensitivity, 67% specificity). Supervised RNA sequencing revealed that higher basal EPHA2 expression is associated with REG resistance. CONCLUSIONS: Subtype classification systems represent canonical "termini a quo" (starting points) to support REG biomarker identification, and provide a platform to identify resistance mechanisms and novel contexts of vulnerability. Incorporating functional characterization of biological systems may optimize the biomarker identification process for multitargeted kinase inhibitors.
Subject(s)
Colorectal Neoplasms/drug therapy , Phenylurea Compounds/therapeutic use , Pyridines/therapeutic use , Xenograft Model Antitumor Assays , Animals , Biomarkers, Tumor , Colorectal Neoplasms/classification , Colorectal Neoplasms/genetics , Disease Models, Animal , Mice , Treatment OutcomeABSTRACT
Only a small subset of colorectal cancer (CRC) patients benefits from immunotherapies, comprising blocking antibodies (Abs) against checkpoint receptor "programmed-cell-death-1" (PD1) and its ligand (PD-L1), because most cases lack the required mutational burden and neo-antigen load caused by microsatellite instability (MSI) and/or an inflamed, immune cell-infiltrated PD-L1+ tumor microenvironment. Peroxisome proliferator-activated-receptor-gamma (PPARγ), a metabolic transcription factor stimulated by anti-diabetic drugs, has been previously implicated in pre/clinical responses to immunotherapy. We therefore raised the hypothesis that PPARγ induces PD-L1 on microsatellite stable (MSS) tumor cells to enhance Ab-target engagement and responsiveness to PD-L1 blockage. We found that PPARγ-agonists upregulate PD-L1 mRNA/protein expression in human gastrointestinal cancer cell lines and MSS+ patient-derived tumor organoids (PDOs). Mechanistically, PPARγ bound to and activated DNA-motifs similar to cognate PPARγ-responsive-elements (PPREs) in the proximal -2 kb promoter of the human PD-L1 gene. PPARγ-agonist reduced proliferation and viability of tumor cells in co-cultures with PD-L1 blocking Ab and lymphokine-activated killer cells (LAK) derived from the peripheral blood of CRC patients or healthy donors. Thus, metabolic modifiers improved the antitumoral response of immune checkpoint Ab, proposing novel therapeutic strategies for CRC.
Subject(s)
Colorectal Neoplasms , PPAR gamma , B7-H1 Antigen/genetics , Colorectal Neoplasms/drug therapy , Humans , Microsatellite Instability , PPAR gamma/genetics , Tumor MicroenvironmentABSTRACT
Preventive transhepatic tract embolisation (PTTE) after percutaneous biliary intervention (PBI) may reduce adverse events. The aim of this systematic review was to analyse feasibility, safety, and efficacy of PTTE with different embolic agents. A systematic literature research was performed according to the PRISMA guidelines. The identified studies were analysed concerning study quality, number of cases, indication, embolic agent, embolisation technique, success, and embolisation-related adverse events. Out of 62 identified records, 7 studies of mainly moderate study quality published through 2019 were included for further analysis. Cyanoacrylate (n = 4), gelatin sponge (n = 2), and coils (n = 1) were used as embolic agents in a total number of 314 patients. Technical success was 96-100%. Embolisation-related adverse events (glue migration, pain) occurred in 10/314 (3.2%) patients. Reduction of PBI-related pain was approved by one controlled study; haemorrhage events were reduced but not clearly significant. Overall, biliary leak, transhepatic bleeding, and PBI-related pain occurred in 7/201 (3.5%), 1/293 (0.3%), and 17/46 (36.9%) documented patients after PTTE. Adverse events which likely could not have been prevented by PTTE occurred in 23/180 (12.8%) patients. Embolic agents were not compared. In conclusion, PTTE is feasible and safe. It is effective concerning the prevention of PBI-related pain, and it may be effective concerning haemorrhage. Prevention of biliary leak is not proven. It remains unclear which embolic agent should be preferred. A prospective randomised trial including all preventable adverse events is lacking.
Subject(s)
Embolization, Therapeutic , Cyanoacrylates , Humans , Prospective Studies , Randomized Controlled Trials as TopicABSTRACT
Peroxisome proliferator-activated receptor-gamma (PPARγ) is a transcription factor drugable by agonists approved for treatment of type 2 diabetes, but also inhibits carcinogenesis and cell proliferation in vivo. Activating mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene mitigate these beneficial effects by promoting a negative feedback-loop comprising extracellular signal-regulated kinase 1/2 (ERK1/2) and mitogen-activated kinase kinase 1/2 (MEK1/2)-dependent inactivation of PPARγ. To overcome this inhibitory mechanism, we searched for novel post-translational regulators of PPARγ. Phosphoinositide phosphatase Myotubularin-Related-Protein-7 (MTMR7) was identified as cytosolic interaction partner of PPARγ. Synthetic peptides were designed resembling the regulatory coiled-coil (CC) domain of MTMR7, and their activities studied in human cancer cell lines and C57BL6/J mice. MTMR7 formed a complex with PPARγ and increased its transcriptional activity by inhibiting ERK1/2-dependent phosphorylation of PPARγ. MTMR7-CC peptides mimicked PPARγ-activation in vitro and in vivo due to LXXLL motifs in the CC domain. Molecular dynamics simulations and docking predicted that peptides interact with the steroid receptor coactivator 1 (SRC1)-binding site of PPARγ. Thus, MTMR7 is a positive regulator of PPARγ, and its mimicry by synthetic peptides overcomes inhibitory mechanisms active in cancer cells possibly contributing to the failure of clinical studies targeting PPARγ.
ABSTRACT
It was previously shown that Bone Morphogenetic Protein (BMP)-9 is constitutively produced and secreted by hepatic stellate cells (HSC). Upon acute liver damage, BMP-9 expression is transiently down-regulated and blocking BMP-9 under conditions of chronic damage ameliorated liver fibrogenesis in C57BL/6 mice. Thereby, BMP-9 acted as a pro-fibrogenic cytokine in the liver but without directly activating isolated HSC in vitro. Lipopolysaccharide (LPS), an endotoxin derived from the membrane of Gram-negative bacteria in the gut, is known to be essential in the pathogenesis of diverse kinds of liver diseases. The aim of the present project was therefore to investigate how high levels of BMP-9 in the context of LPS signalling might result in enhanced liver damage. For this purpose, we stimulated human liver sinusoidal endothelial cells (LSEC) with LPS and incubated primary human liver myofibroblasts (MF) with the conditioned medium of these cells. We found that LPS led to the secretion of factors from LSEC that upregulate BMP-9 expression in MF. At least one of these BMP-9 enhancing factors was defined to be IL-6. High BMP-9 in turn, especially in combination with LPS stimulation, induced the expression of certain capillarization markers in LSEC and enhanced the LPS-mediated induction of pro-inflammatory cytokines in primary human macrophages. In LSEC, pre-treatment with BMP-9 reduced the LPS-mediated activation of the NfkB pathway, whereas in macrophages, LPS partially inhibited the BMP-9/Smad-1 signaling cascade. In vivo, in mice, BMP-9 led to the enhanced presence of F4/80-positive cells in the liver and it modulated the LPS-mediated regulation of inflammatory mediators. In summary, our data point to BMP-9 being a complex and highly dynamic modulator of hepatic responses to LPS: Initial effects of LPS on LSEC led to the upregulation of BMP-9 in MF but sustained high levels of BMP-9 in turn promote pro-inflammatory reactions of macrophages. Thereby, the spatial and timely fine-tuned presence (or absence) of BMP-9 is needed for efficient wound-healing responses in the liver.
Subject(s)
Endothelial Cells/drug effects , Growth Differentiation Factor 2/pharmacology , Lipopolysaccharides/pharmacology , Liver/drug effects , Animals , Cells, Cultured , Cytokines/metabolism , Down-Regulation/drug effects , Endothelial Cells/metabolism , Growth Differentiation Factor 2/metabolism , Hepatocytes/drug effects , Hepatocytes/metabolism , Inflammation/drug therapy , Inflammation/pathology , Inflammation Mediators/metabolism , Mice, Inbred C57BLABSTRACT
BACKGROUND: Sex-determining region Y-box (SRY-box) containing gene 9 (SOX9) expression confers cancer stem cell features. However, SOX9 function in intrahepatic cholangiocarcinoma (iCCA) is unknown. This study investigated the effects and underlying mechanisms of SOX9 in iCCA. METHODS: SOX9 expression in 59 iCCA patients was examined by immunohistochemistry. The association between SOX9 expression and clinical outcome was evaluated. Gene signature and biological functions of SOX9 in iCCA were examined in vitro. RESULTS: iCCA patients with high SOX9 expression had shorter survival time than those with low SOX9. In patients receiving chemotherapy, median survival time in patients with low and high levels of SOX9 were 62 and 22 months, respectively. In vitro, gemcitabine increased SOX9 expression in iCCA cells. When SOX9 was knocked down, gemcitabine-induced apoptosis was markedly increased. Silencing SOX9 significantly inhibited gemcitabine-induced phosphorylation of checkpoint kinase 1, a key cell cycle checkpoint protein that coordinates the DNA damage response and inhibited the expression of multidrug resistance genes. Microarray analyses showed that SOX9 knockdown in CCA cells altered gene signatures associated with multidrug resistance and p53 signalling. CONCLUSIONS: SOX9 governs the response of CCA cells to chemotherapy. SOX9 is a biomarker to select iCCA patients eligible for efficient chemotherapy.
Subject(s)
Antineoplastic Agents/therapeutic use , Bile Duct Neoplasms/drug therapy , Cholangiocarcinoma/drug therapy , Drug Resistance, Neoplasm/genetics , SOX9 Transcription Factor/metabolism , Biomarkers, Tumor/metabolism , Cell Proliferation/drug effects , Cell Proliferation/genetics , Chronic Disease , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Humans , Liver Diseases/metabolism , SOX9 Transcription Factor/genetics , Survival Analysis , Treatment Outcome , GemcitabineABSTRACT
Increased copy number alterations (CNAs) indicative of chromosomal instability (CIN) have been associated with poor cancer outcome. Here, we study CNAs as potential biomarkers of bevacizumab (BVZ) response in metastatic colorectal cancer (mCRC). We cluster 409 mCRCs in three subclusters characterized by different degrees of CIN. Tumors belonging to intermediate-to-high instability clusters have improved outcome following chemotherapy plus BVZ versus chemotherapy alone. In contrast, low instability tumors, which amongst others consist of POLE-mutated and microsatellite-instable tumors, derive no further benefit from BVZ. This is confirmed in 81 mCRC tumors from the phase 2 MoMa study involving BVZ. CNA clusters overlap with CRC consensus molecular subtypes (CMS); CMS2/4 xenografts correspond to intermediate-to-high instability clusters and respond to FOLFOX chemotherapy plus mouse avastin (B20), while CMS1/3 xenografts match with low instability clusters and fail to respond. Overall, we identify copy number load as a novel potential predictive biomarker of BVZ combination therapy.
Subject(s)
Adenocarcinoma/genetics , Antineoplastic Agents, Immunological/therapeutic use , Bevacizumab/therapeutic use , Colorectal Neoplasms/genetics , DNA Copy Number Variations , Adenocarcinoma/drug therapy , Aged , Animals , Chromosomal Instability , Colorectal Neoplasms/drug therapy , Female , Humans , Male , Mice , Middle Aged , Retrospective Studies , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND AND AIM: With the development of direct acting antiviral agents (DAA) chronic hepatitis C virus (HCV) infection has become curable in most patients. Since HCV infection is known to have direct and/or indirect effects on glucose metabolism, successful HCV treatment may have an impact in reducing glucose level, pre-diabetes, the need of treatment for diabetes, and ultimately diabetes-associated morbidity. We investigated the association of DAA treatment and glucose metabolism in the context of development or resolution of hepatic fibrosis in a large cohort of HCV- infected patients. METHODS: In this retrospective single-center observational study, we investigated 281 patients receiving all-oral DAA therapy for fasting plasma glucose, HbA1c, liver enzymes and general clinical chemistry, measured during a 52-week follow-up. In addition, elastography, FIB-4- and APRI-calculation were used to assess hepatic fibrosis non-invasively. RESULTS: Successful elimination of HCV through DAA treatment was associated with a significant drop in fasting glucose level and a reduced rate of impaired fasting plasma glucose (FPG). Interestingly, this metabolic change was BMI-independent. In addition, long-term glucose levels also decreased after successful DAA treatment. A significant APRI-score reduction was associated with a persistent improvement of FPG. However, DAA did not have an impact on glucose metabolism in patients suffering from liver cirrhosis. CONCLUSION: This study highlights the beneficial impact of successful HCV therapy on glucose metabolism and identifies patients with liver cirrhosis as a collective in need of intensified surveillance with regard to diabetes progression despite HCV eradication.
Subject(s)
Antiviral Agents/therapeutic use , Blood Glucose/drug effects , Hepatitis C, Chronic/drug therapy , Liver/drug effects , Prediabetic State/drug therapy , Antiviral Agents/adverse effects , Biomarkers/blood , Blood Glucose/metabolism , Drug Therapy, Combination , Female , Germany , Glycated Hemoglobin/metabolism , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/diagnosis , Hepatitis C, Chronic/virology , Humans , Liver/metabolism , Liver/virology , Liver Cirrhosis/blood , Liver Cirrhosis/drug therapy , Liver Cirrhosis/virology , Male , Middle Aged , Prediabetic State/blood , Prediabetic State/diagnosis , Retrospective Studies , Risk Factors , Time Factors , Treatment OutcomeABSTRACT
To identify novel hubs for cancer immunotherapy, we generated C57BL/6J mice with concomitant deletion of the drugable transcription factor PPARγ and transgenic overexpression of the mutant KRASG12V oncogene in enterocytes. Animals developed epithelial hyperplasia, transmural inflammation and serrated adenomas in the small intestine with infiltration of CD3+ FOXP3+ T-cells and macrophages into the lamina propria of the non-malignant mucosa. Within serrated polyps, CD3+ CD8+ T-cells and phosphorylated ERK1/2 were reduced and the senescence marker P21 and macrophage counts up-regulated, indicative of an immunosuppressive tissue microenvironment. Treatment of mutant KRASG12V mice with the PPARγ-agonist rosiglitazone augmented M1 macrophage numbers, reduced IL4 expression and diminished polyp load in mice. Rosiglitazone also promoted M1 polarisation of human THP1-derived macrophages and decreased Il4 mRNA in isolated murine lymphocytes. Thus, inhibition of the oncogenic driver mutant RAS by PPARγ in epithelial and immune cell compartments may be a future target for the prevention or treatment of human malignancies associated with intestinal inflammation.