Differential prognostic significance of sarcopenia in metastatic esophageal squamous and adenocarcinoma.

BACKGROUND: Sarcopenia indicates poor prognosis in various malignancies. We evaluated the association of sarcopenia with overall (OS) and progression-free survival (PFS) in metastatic esophageal cancer (MEC) patients, a population often presenting with poor nutritional status. METHODS: In newly diagnosed MEC patients managed at the Princess Margaret (PM) Cancer Centre (diagnosed 2006-2015), total muscle area, visceral adiposity (VA), and subcutaneous adiposity (SA) were quantified on abdominal computed tomography at L3. Sarcopenia was determined using published cutoffs, based on sex and height. RESULTS: Of 202 MEC patients, most were male (166/82%), < 65 years (116/57%), and had adenocarcinoma histology (141/70%); 110/54% had recurrent MEC after initial curative-intent treatment; 92/46% presented with de novo MEC. At stage IV diagnosis, 20/10% were underweight, 97/48% were normal-weight and 84/42% were overweight/obese; 103/51% were sarcopenic. Sarcopenia was associated with worse median OS (4.6 vs. 7.9 months; log-rank p = 0.03) and 1-year survival, even after adjusting for other body composition variables (e.g., BMI, VA, and SA): adjusted-HR 1.51 [95% CI 1.1-2.2, p = 0.02]. In post hoc analysis, sarcopenia was highly prognostic in adenocarcinomas (p = 0.003), but not squamous cell carcinomas (SCC). In patients receiving palliative systemic treatment (104/51%), sarcopenia was associated with shorter PFS (p = 0.004) in adenocarcinoma patients (75/72%). CONCLUSIONS: In metastatic esophageal adenocarcinomas, sarcopenia is associated with worse PFS and OS. In metastatic esophageal SCC, there was a non-significant trend for worse PFS but no association with OS. In order to offset the poor prognosis associated with sarcopenia particularly in metastatic esophageal adenocarcinoma patients, future research should focus on possible countermeasures.

Identification of type I and type II interferon-induced effectors controlling hepatitis C virus replication.

UNLABELLED: Persistent infection with hepatitis C virus (HCV) can lead to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. All current therapies of hepatitis C include interferon-alpha (IFN-α). Moreover, IFN-gamma (IFN-γ), the only type II IFN, strongly inhibits HCV replication in vitro and is the primary mediator of HCV-specific antiviral T-cell responses. However, for both cytokines the precise set of effector protein(s) responsible for replication inhibition is not known. The aim of this study was the identification of IFN-α and IFN-γ stimulated genes (ISGs) responsible for controlling HCV replication. We devised an RNA interference (RNAi)-based "gain of function" screen and identified, in addition to known ISGs earlier reported to suppress HCV replication, several new ones with proven antiviral activity. These include IFIT3 (IFN-induced protein with tetratricopeptide repeats 3), TRIM14 (tripartite motif containing 14), PLSCR1 (phospholipid scramblase 1), and NOS2 (nitric oxide synthase 2, inducible). All ISGs identified in this study were up-regulated both by IFN-α and IFN-γ, demonstrating a substantial overlap of HCV-specific effectors induced by either cytokine. Nevertheless, some ISGs were more specific for IFN-α or IFN-γ, which was most pronounced in case of PLSCR1 and NOS2 that were identified as main effectors of IFN-γ-mediated anti-HCV activity. Combinatorial knockdowns of ISGs suggest additive or synergistic effects demonstrating that with either IFN, inhibition of HCV replication is caused by the combined action of multiple ISGs. CONCLUSION: Our study identifies a number of novel ISGs contributing to the suppression of HCV replication by type I and type II IFN. We demonstrate a substantial overlap of antiviral programs triggered by either cytokine and show that suppression of HCV replication is mediated by the concerted action of multiple effectors.

Reconstructing signaling pathways from RNAi data using probabilistic Boolean threshold networks.

MOTIVATION: The reconstruction of signaling pathways from gene knockdown data is a novel research field enabled by developments in RNAi screening technology. However, while RNA interference is a powerful technique to identify genes related to a phenotype of interest, their placement in the corresponding pathways remains a challenging problem. Difficulties are aggravated if not all pathway components can be observed after each knockdown, but readouts are only available for a small subset. We are then facing the problem of reconstructing a network from incomplete data. RESULTS: We infer pathway topologies from gene knockdown data using Bayesian networks with probabilistic Boolean threshold functions. To deal with the problem of underdetermined network parameters, we employ a Bayesian learning approach, in which we can integrate arbitrary prior information on the network under consideration. Missing observations are integrated out. We compute the exact likelihood function for smaller networks, and use an approximation to evaluate the likelihood for larger networks. The posterior distribution is evaluated using mode hopping Markov chain Monte Carlo. Distributions over topologies and parameters can then be used to design additional experiments. We evaluate our approach on a small artificial dataset, and present inference results on RNAi data from the Jak/Stat pathway in a human hepatoma cell line.

Mind the sump! - diagnostic challenge of a rare complication of choledochoduodenostomy.

Sump syndrome is a rare long-term complication of side-to-side choledochoduodenostomy (CDD), a common surgical procedure in patients with biliary tract disease in the era before endoscopic retrograde cholangiopancreatography (ERCP). Frequently only pneumobilia, serving as sign for functioning biliary-enteric anastomosis, is reminiscent of the former surgery. We present the case of an 81-year-old patient with sump syndrome who presented with clinical signs of ascending cholangitis, decades after the initial CDD procedure. Finally the detailed medical history that was taken very thoroughly in combination with the presence of pneumobilia led to the suspicion of sump syndrome. Sump syndrome was diagnosed by ERCP, and after endoscopic debris extraction and antibiotic treatment the patient recovered quickly. In the ERCP era little is known about CDD and its long-term complications, especially by young colleagues and trainees. Therefore this report provides an excellent opportunity to refresh the knowledge and raise awareness for this syndrome.

Insulin stimulates the clonogenic potential of angiogenic endothelial progenitor cells by IGF-1 receptor-dependent signaling.

Endothelial progenitor cells (EPCs) have been shown to be involved in vascular regeneration and angiogenesis in experimental diabetes. Because insulin therapy mobilizes circulating progenitor cells, we studied the effects of insulin on outgrowth of EPCs from peripheral blood mononuclear cells of healthy volunteers and patients with type 2 diabetes. Insulin increased the formation of EPC colony-forming units in a dose-dependent manner, half-maximal at 1.5 nM and peaking at 15 nM. Inhibiting the insulin receptor with neutralizing antibodies or antisense oligonucleotides had no effect on EPC outgrowth.(1) In contrast, targeting the human insulin-like growth factor 1 (IGF-1) receptor with neutralizing antibodies significantly suppressed insulin-induced outgrowth of EPCs from both healthy controls and patients with type 2 diabetes. This IGF-1 receptor-mediated insulin effect on EPC growth was at least in part dependent on MAP kinases(2) and was abrogated when extracellular signal-regulated kinase 1/2 (Erk1/2) and protein kinase 38 (p38) activity was inhibited. To study the functional relevance of the observed insulin effects, we studied EPC-induced tube formation of bovine endothelial cells in vitro. Insulin-stimulated EPCs incorporated into the endothelial tubes and markedly enhanced tube formation. In conclusion, this is the first study showing an insulin-mediated activation of the IGF-1 receptor leading to an increased clonogenic and angiogenic potential of EPCs in vitro.