Inflammasome-dependent IL-1ß release depends upon membrane permeabilisation.

Interleukin-1ß (IL-1ß) is a critical regulator of the inflammatory response. IL-1ß is not secreted through the conventional ER-Golgi route of protein secretion, and to date its mechanism of release has been unknown. Crucially, its secretion depends upon the processing of a precursor form following the activation of the multimolecular inflammasome complex. Using a novel and reversible pharmacological inhibitor of the IL-1ß release process, in combination with biochemical, biophysical, and real-time single-cell confocal microscopy with macrophage cells expressing Venus-labelled IL-1ß, we have discovered that the secretion of IL-1ß after inflammasome activation requires membrane permeabilisation, and occurs in parallel with the death of the secreting cell. Thus, in macrophages the release of IL-1ß in response to inflammasome activation appears to be a secretory process independent of nonspecific leakage of proteins during cell death. The mechanism of membrane permeabilisation leading to IL-1ß release is distinct from the unconventional secretory mechanism employed by its structural homologues fibroblast growth factor 2 (FGF2) or IL-1α, a process that involves the formation of membrane pores but does not result in cell death. These discoveries reveal key processes at the initiation of an inflammatory response and deliver new insights into the mechanisms of protein release.

Oncological Evaluation by Positron-emission Tomography, Circulating Tumor Cells and Alpha Fetoprotein in Patients With Hepatocellular Carcinoma on the Waiting List for Liver Transplantation.

INTRODUCTION: The objectives of this study are the determination of the number of circulating tumor cells (CTCs), by means of the IsoFlux enrichment system (Fluxion Biosciences Inc, San Francisco, California, United States) in patients with hepatocellular carcinoma (HCC) in compliance with the Milan criteria and on the waiting list for hepatic transplantation, as well as the study of its relation with the of α-fetoprotein levels (AFP) and positron-emission tomography-computed tomography (PET-CT) findings. PATIENTS AND METHODS: An oncologycal evaluation with PET-CT, CTCs, and AFP was conducted in 24 consecutive patients with HCC eligible for orthotopic liver transplantation according to the Milan criteria. The diagnosis of HCC was made according to clinical, biological, and radiological findings. RESULTS: We detected CTCs in peripheral blood in 21 of 24 patients (87.5%) before liver transplantation, with a mean number CTCs of 156 ± 370 (range, 2 to 1768) with statistically significant association between number of CTCs detected in peripheral blood and the time within the waiting list (P < .05), but not betwen AFP levels and standard uptake value and time to orthotopic liver transplantation (P > .05). CONCLUSIONS: PET-TC, CTCs, and AFP levels could be an essential key for the correct management of the patients with HCC on the waiting list for liver transplantation.

Comparison of Two Types of Liquid Biopsies in Patients With Hepatocellular Carcinoma Awaiting Orthotopic Liver Transplantation.

INTRODUCTION: Orthotopic liver transplantation (OLT) is considered one of the few curative treatments available for early stages of hepatocellular carcinoma (HCC). It has been shown that more than 10% of transplanted individuals suffer relapse during the first year after surgery and most of them die because of the tumor. The circulating tumor cells (CTCs) are the main source of recurrences as they disseminate from a primary or metastatic tumor lesion through peripheral blood. We aimed to determine the concentration of CTCs in peripheral blood in these patients by 2 different approaches: the CellSearch and the IsoFlux systems to assess their applicability to this disease monitoring. PATIENTS AND METHODS: A comparative study was conducted in 21 patients with HCC eligible for liver transplantation according to the Milan criteria, whose peripheral blood was processed by the CellSearch and the IsoFlux systems. RESULTS: CTCs were isolated in 1 of the 21 patients (4.7%) by the CellSearch system and in 19 of the 21 patients (90.5%) by the IsoFlux method. The comparison of both methods using Bland-Altman plot shows that there is not consistency in the determination of CTCs in our patients, finding a proportional bias between them. CONCLUSION: The results obtained by both CTCs isolation systems are not interchangeable nor transferable. The CellSearch system does not seem to be the ideal approach for studying CTCs in patients with HCC. The IsoFlux system displays greater sensitivity in the identification of CTCs and might become an important tool in patient management.

What do we know about the clinical impact of complete withdrawal of immunosuppression in liver transplantation?

The liver is a privileged organ with a lower incidence of rejection than other organs. However, immunosuppressive regimens are still required to control the alloreactive T-lymphocyte response after transplantation. These treatments may lead to severe complications, such as infectious diseases, cancers, cardiovascular diseases, and chronic renal insufficiency. In clinical transplantation, there is increasing evidence that some liver transplant recipients who cease taking immunosuppressive drugs maintain allograft function, suggesting that tolerance is already present. This strategy is feasible in 25% to 33% of liver transplant recipients. Few of the studies performed so far have provided a detailed analysis of the impact of immunosuppression (IS) withdrawal on pre-existing complications derived from the long-term administration of immunosuppressive drugs and the side effects associated with it. In preliminary studies, IS withdrawal was safely achieved in selected liver transplant patients, and improved not only kidney function, but also other IS-associated side-effects such as hypercholesterolemia, hyperuricemia, hypertension, and diabetes control. However, longer follow-up periods are needed to confirm the benefits of IS withdrawal in liver transplant patients.

P2X(7) receptor activation enhances SK3 channels- and cystein cathepsin-dependent cancer cells invasiveness.

ATP-gated P2X(7) receptors (P2X(7)R) are unusual plasma membrane ion channels that have been extensively studied in immune cells. More recently, P2X(7)R have been described as potential cancer cell biomarkers. However, mechanistic links between P2X(7)R and cancer cell processes are unknown. Here, we show, in the highly aggressive human breast cancer cell line MDA-MB-435s, that P2X(7) receptor is highly expressed and fully functional. Its activation is responsible for the extension of neurite-like cellular prolongations, of the increase in cell migration by 35% and in cell invasion through extracellular matrix by 150%. The change in cancer cell morphology and the increased migration appeared to be due to the activation of Ca(2+)-activated SK3 potassium channels. The enhanced invasion through the extracellular matrix was related to the increase of mature forms of cysteine cathepsins in the extracellular medium, which was independent of SK3 channel activity and not associated with cell death. Pharmacological targeting of P2X(7)R in vivo was crucial for cell invasiveness in a zebrafish model of metastases. Our results demonstrate a novel mechanistic link between P2X(7)R functionality in cancer cells and invasiveness, a key parameter in tumour growth and in the development of metastases. They also suggest a potential therapeutic role for the newly developed P2X(7)R antagonists.

Impact of a CAD system in a screen-film mammography screening program: a prospective study.

OBJECTIVE: The purpose of our study was to perform a prospective assessment of the impact of a CAD system in a screen-film mammography screening program during a period of 3 years. MATERIALS AND METHODS: Our study was carried out on a population of 21,855 asymptomatic women (45-65 years). Mammograms were processed in a CAD system and independently interpreted by one of six radiologists. We analyzed the following parameters: sensitivity of radiologist's interpretation (without and with CAD), detection increase, recall rate and positive predictive value of biopsy, CAD's marks, radiologist's false negatives and comparative analysis of carcinomas detected and non-detected by CAD. RESULTS: Detection rate was 4.3‰. CAD supposed an increase of 0.1‰ in detection rate and 1% in the total number of cases (p<0.005). The impact on recall rate was not significant (0.4%) and PPV of percutaneous biopsy was unchanged by CAD (20.23%). CAD's marks were 2.7 per case and 0.7 per view. Radiologist's false negatives were 13 lesions which were initially considered as CAD's false positives. CONCLUSIONS: CAD supposed a significant increase in detection, without modifications in recall rates and PPV of biopsy. However, better results could have been achieved if radiologists had considered actionable those cases marked by CAD but initially misinterpreted.

Loss of poly(ADP-ribose) polymerase-2 leads to rapid development of spontaneous T-cell lymphomas in p53-deficient mice.

Poly(ADP-ribose) polymerase-2 (Parp-2) belongs to a family of enzymes that catalyse poly(ADP-ribosyl)ation of proteins. Parp-2 deficiency in mice (Parp-2(-/-)) results in reduced thymic cellularity associated with increased apoptosis in thymocytes, defining Parp-2 as an important mediator of T-cell survival during thymopoiesis. To determine whether there is a link between Parp-2 and the p53 DNA-damage-dependent apoptotic response, we have generated Parp-2/p53-double-null mutant mice. We found that p53(-/-) backgrounds completely restored the survival and development of Parp-2(-/-) thymocytes. However, Parp-2-deficient thymocytes accumulated high levels of DNA double-strand breaks (DSB), independently of the p53 status, in line with a function of Parp-2 as a caretaker promoting genomic stability during thymocytes development. Although Parp-2(-/-) mice do not have spontaneous tumours, Parp-2 deficiency accelerated spontaneous tumour development in p53-null mice, mainly T-cell lymphomas. These data suggest a synergistic interaction between Parp-2 and p53 in tumour suppression through the role of Parp-2 in DNA-damage response and genome integrity surveillance, and point to the potential importance of examining human tumours for the status of both genes.