Hemorrhagic Cholecystitis in a Patient Under Anticoagulant and Antiplatelet Therapy: A Case Report.

Hemorrhagic cholecystitis is an uncommon presentation of acute cholecystitis. Due to its etiology and unspecific clinical data, it is an entity that represents a diagnostic challenge. We present a case of a 70-year-old male with diabetes type 2, hypertension, and chronic kidney disease with hemodialysis, who attended the emergency department with sudden-onset abdominal pain in the epigastrium. The patient presented no additional symptoms, a normal electrocardiogram, but due to the characteristics of the pain and elevated troponin I, emergency medicine specialists considered an acute coronary syndrome and initiated antiplatelet and anticoagulant therapy. Due to persistent abdominal pain, a decrease in hemoglobin, and the onset of arterial hypotension, a computed tomography (CT) scan was performed, which revealed perforation of the gallbladder, apparent hemorrhagic cholecystitis, and hemoperitoneum. The patient underwent emergent surgery, where CT findings were confirmed. In our case, the suspicion of hemorrhagic cholecystitis arose until the clinical case was advanced, after receiving anticoagulant and antiplatelet therapy, and it was confirmed during surgery and with histopathology. This concludes that hemorrhagic cholecystitis is a rare disease and difficult to diagnose. Therefore, studies should focus on clinical presentation and risk factors (e.g., trauma, malignancy, renal failure, cirrhosis, and anticoagulation therapy) to promote early diagnosis and avoid complications.

Myocardial revascularization failure among patients requiring cardiac catheterization and secondary revascularization in contemporary clinical practice: Results of the REVASEC multicenter registry.

BACKGROUND: Myocardial revascularization failure (MRF) and Secondary revascularization (SR) are contemporary interventional cardiology challenges. AIM: To investigate the characteristics, management, and prognosis of patients with myocardial revascularization failure (MRF) and need for secondary revascularization (SR) in contemporary practice. METHODS: The REVASEC study is a prospective registry (NCT03349385), which recruited patients with prior revascularization referred for coronary angiography at 19 centers. The primary endpoint is a patient-oriented composite (POCE) at 1 year, including death, myocardial infarction, or repeat revascularization. RESULTS: A total of 869 patients previously revascularized by percutaneous intervention (83%) or surgery (17%) were recruited. MRF was found in 83.7% (41.1% stent/graft failure, 32.1% progression of coronary disease, and 10.5% residual disease). SR was performed in 70.1%, preferably by percutaneous intervention (95%). The POCE rate at 1 year was 14% in the overall cohort, with 6.4% all-cause death. In the multivariate analysis, lower POCE rates were found in the groups without MRF (9.4%) and with disease progression (11%) compared with graft/stent failure (17%) and residual disease (18%), hazard ratio 0.67 (95% confidence interval: 0.45-0.99), p = 0.043. At 1 year, the SR group had less chronic persistent angina (19% vs. 34%, p < 0.001), but a higher rate of repeat revascularization (9% vs. 2.9%, p < 0.001). CONCLUSION: MRF was found in 84% of patients with prior revascularization referred for coronary angiography. Stent/graft failure and residual coronary disease were associated with a worse prognosis. SR provided better symptom control at the expense of a higher rate of new revascularization.

Neuroendocrine Tumor Metastases to the Breast: A Case Report and Review of the Literature.

Breast metastases from neuroendocrine neoplasms (NENs) are considered infrequent. We report a case of a patient with ileocecal neuroendocrine tumor (NET) metastases to both breasts, for whom the initial clinical presentation was chronic diarrhea. Breast metastasis was initially suspected by a 68-Gallium DOTANOC positron emission tomography (PET)/CT and was confirmed by histopathology. We also performed a literature review in which we identified 116 cases of NENs metastatic to the breast reported so far. Most cases occurred in older women, were caused by NETs, and had the gastrointestinal tract as the primary site.

Parthenolide inhibits proliferation and invasion, promotes apoptosis, and reverts the cell-cell adhesion loss through downregulation of NF-κB pathway TNF-α-activated in colorectal cancer cells.

The activation of the nuclear factor-κB (NF-κB) pathway has been associated with the development and progression of colorectal cancer (CRC). Parthenolide (PTL), a well-known inhibitor of the NF-κB pathway, has emerged as an alternative treatment. However, whether PTL activity is tumor cell-specific and dependent on the mutational background has not been defined. This study investigated the antitumor role of PTL after tumor necrosis factor-α (TNF-α) stimulation in various CRC cell lines with different mutational statuses of TP53. We observed that CRC cells displayed different patterns of basal p-IκBα levels; PTL reduced cell viability according to p-IκBα levels and p-IκBα levels varied among the cell lines according to the time of TNF-α stimulation. High concentrations of PTL reduced more effectively p-IκBα levels than low doses of PTL. However, PTL increased total IκBα levels in Caco-2 and HT-29 cells. In addition, PTL treatment downregulated p-p65 levels in HT-29 and HCT-116 cells stimulated by TNF-α in a dose-dependent manner. Moreover, PTL induced cell death via apoptosis and reduced the proliferation rate of TNF-α-treated HT-29 cells. Finally, PTL downregulated the messenger RNA levels of interleukin-1ß, a downstream cytokine of NF-κB, reverted the E-cadherin-mediated disorganization of cell-cell contacts, and decreased the invasion of HT-29 cells. Together, these results suggest a differential antitumoral activity of PTL on CRC cells with different mutational statuses of TP53, modulating cell death, survival, and proliferation underlying the NF-κB pathway TNF-α-induced. Therefore, PTL has emerged as a potential treatment for CRC in an inflammatory NF-κB-dependent manner.

Mechanisms of radioresistance and the underlying signaling pathways in colorectal cancer cells.

Radiotherapy is one of the most common modalities for the treatment of a wide range of tumors, including colorectal cancer (CRC); however, radioresistance of cancer cells remains a major limitation for this treatment. Following radiotherapy, the activities of various cellular mechanisms and cell signaling pathways are altered, resulting in the development of radioresistance, which leads to therapeutic failure and poor prognosis in patients with cancer. Furthermore, even though several inhibitors have been developed to target tumor resistance, these molecules can induce side effects in nontumor cells due to low specificity and efficiency. However, the role of these mechanisms in CRC has not been extensively studied. This review discusses recent studies regarding the relationship between radioresistance and the alterations in a series of cellular mechanisms and cell signaling pathways that lead to therapeutic failure and tumor recurrence. Our review also presents recent advances in the in vitro/in vivo study models aimed at investigating the radioresistance mechanism in CRC. Furthermore, it provides a relevant biochemical basis in theory, which can be useful to improve radiotherapy sensitivity and prolong patient survival.

Videoconferencias para residentes de Histología en la Universidad de Ciencias Médicas de Sancti Spíritus / Videoconferences to Histology residents at the Sancti Spíritus University of Medical Sciences

Fundamento: No se conoce cómo aceptan los residentes de Histología la inclusión de un sistema de videoconferencias sobre la estructura microscópica del cuerpo humano en su estrategia de autoaprendizaje. Objetivo: Explorar en profundidad la experiencia de los residentes de Histología de la Universidad de Ciencias Médicas de Sancti Spíritus que utilizaron un sistema de videoconferencias para su formación profesional. Metodología: Estudio cualitativo en el que se realizó una entrevista a profundidad con los especialistas y residentes de Histología que han utilizado el sistema de videoconferencias en la Universidad de Ciencias Médicas de Sancti Spíritus. Se transcribieron las entrevistas, se codificaron y se seleccionaron los principales temas abordados. Resultados: Se entrevistaron 5 usuarios del sistema de videoconferencias; de la entrevista surgieron 5 temas: 1) Como los residentes insertan las videoconferencias en su estrategia de autoaprendizaje, 2) Preferencia de las videoconferencias sobre los libros de texto, 3) Aciertos y desaciertos de las videoconferencias, 4) ¿Qué aportan las videoconferencias a la formación del residente, ventajas y desventajas? y 5) Sugerencias para mejorar las videoconferencias. Conclusiones: Un sistema de videoconferencias sobre la estructura microscópica del cuerpo humano puede ocupar un papel protagónico en la estrategia de aprendizaje de residentes de Histología. La preferencia que muestran los residentes por las videoconferencias sobre otros medios didácticos puede estar asociada a la capacidad de la multimedia para disminuir la carga cognitiva y facilitar el aprendizaje cuando se siguen los principios de Mayer al elaborar estos medios. La presencia de imágenes digitales en estas videoconferencias fue clave para su aceptación.

Background: It is not known how Histology residents accept the inclusion of a videoconferencing system on the microscopic structure of the human body in their self-learning strategy. Objective: To explore to depth the experience of Histology residents at the Sancti Spíritus University of Medical Sciences who used a videoconferencing system for their professional training. Methodology: Qualitative study with in-depth interview was conducted with Histology specialists and residents who have used the videoconferencing system at the Sancti Spíritus University of Medical Sciences. The interviews were transcribed, coded and the main topics addressed were selected. Results: 5 users of the videoconferencing system were interviewed; 5 themes emerged from the interview: 1) How residents insert videoconferences into their self-learning strategy, 2) Preference for videoconferences over textbooks, 3) Successes and failures of videoconferences, 4) What do videoconferences contribute to the training of the resident, advantages and disadvantages?, 5) Suggestions to improve videoconferences. Conclusions: A videoconferencing system on the microscopic structure of the human body can play a leading role in the learning strategy of Histology residents. The preference shown by residents for videoconferencing over other teaching media may be associated with the ability of multimedia to reduce cognitive load and facilitate learning when Mayer's principles are followed to developing these media. The presence of digital images in these videoconferences was essential to their acceptance.

Coordination copolymerization monitoring of ethylene and alfa-olefins by in-line Raman spectroscopy.

Copolymerizations of ethylene and alfa-olefins, using Ziegler-Natta or metallocene catalysts, testing two methods of co-monomer addition, through batch or dossing mode during the reactions, are reported in this work. Copolymerizations are monitored by in line Raman spectroscopy, comparing the effect of the kind of catalyst and the co-monomer addition modes on the chemical composition of the copolymers produced. The global co-monomer composition is determined by 13C NMR spectroscopy, compared with the monitoring by Raman spectroscopy along the reactions, where it is possible to define homogeneous or heterogeneous co-monomer distributions. Batch addition achieves higher incorporations of co-monomers, compared to dosed addition, where it is possible to determine the maximal co-monomer addition without affecting activities by transfer reactions. The incorporation mode of alfa-olefins in this type of reaction has been little reported, and until it is known, there is no rapid technique available to determine the uniformity of the co-monomer incorporations in real time. Copolymerization kinetics are also reported here and correlated to the addition method of the comonomers in both kinds of reactions. Homogeneous and heterogeneous co-monomer incorporations promoted by a single site catalyst (metallocene) or multisite system (Ziegler-Natta) is related to the homogeneous or heterogeneous co-monomer distributions detected by Raman spectroscopy, using each kind of catalytic system.

Extended anticoagulation for venous thromboembolism: A survey of the American Venous Forum and the European Venous Forum.

OBJECTIVE: Extended anticoagulation therapy should always be considered after standard treatment of an unprovoked episode of venous thromboembolism (VTE). It can also be considered for selected patients with provoked VTE. However, the evidence-based protocols suggested by some clinical guidelines and risk assessment tools to guide this practice are limited and ambiguous. The goal of the present survey research was to analyze current practices in applying extended anticoagulation therapy for patients with VTE among members of the American Venous Forum (AVF) and European Venous Forum (EVF). METHODS: An online survey was created by the AVF Research Committee. The survey consisted of 16 questions to identify the country of practice, specialty, experience of the participating physicians, and their clinical practice patterns in applying extended anticoagulation therapy for VTE patients. The survey was distributed via e-mail to the members of the AVF and EVF. RESULTS: A total of 144 practitioners, 48 AVF members (33%) and 96 EVF members (66%), participated in the survey. Most of the respondents identified themselves as vascular specialists with primary certification in vascular surgery (70%), vascular medicine or angiology (9%), and venous disease or phlebology (3%). Of the 144 respondents, 72% believed that the risk of VTE recurrence will generally overweigh the risk of bleeding for patients with unprovoked VTE. Extended anticoagulation therapy might be used by 97% of providers. Different patterns in real world clinical practice were identified. More than one half of the practitioners estimated the VTE recurrence and bleeding risk subjectively. The antithrombotic drugs most commonly used for secondary prophylaxis were rivaroxaban, apixaban, warfarin, dabigatran, and aspirin, in decreasing order of frequency. Among the reasons selected for not regularly considering extended anticoagulation therapy were the lack of specific clinical practice guidelines (24%), lack of reported evidence (9%), and absence of valid VTE and/or bleeding risk prediction calculators (8%). Twelve participants (8%) stated that extended anticoagulation therapy would not be beneficial for most patients with VTE. Ten participants (7%) indicated that prescribing extended anticoagulation therapy was outside the scope of their specialty. CONCLUSIONS: Different practice patterns exist regarding extending anticoagulation therapy beyond the standard treatment for patients with VTE. Major gaps in knowledge remain a serious challenge at least partially explaining the inaccuracy and inconsistency in long-term VTE management. Appropriately designed studies are needed to evaluate risk stratification tools when contemporary best medical therapy is used, accurately predict VTE recurrence and its long-term outcomes, and tailor safe and effective secondary prophylaxis.

Design and Rationale for a Real-World Prospective, Multicenter Registry of Myocardial Revascularization Failure and Secondary Revascularization: The REVASEC Study.

AIM: To investigate key aspects of the problem of myocardial revascularization failure (MRF) and repeat or secondary myocardial revascularization (SR) in contemporary practice. METHODS: The registry of secondary revascularization (REVASEC) is an investigator-initiated, multicenter, prospective registry enhanced with data monitoring and independent event adjudication (ClinicalTrials.govNCT03349385). It includes patients with prior revascularization referred to coronary angiography for suspected MRF with broad inclusion criteria. The main objectives are to describe the characteristics of patients with prior revascularization referred for repeat angiography, to describe and the rate and mechanisms of MRF (stent or graft failure, coronary artery disease progression or residual coronary artery disease); to evaluate the management including medical treatment and SR of these patients; and to assess the prognosis according to the outlined causative mechanisms. The registry has one year follow up for the primary endpoint (Patient-oriented composite endpoint including all-cause death, any myocardial infarction or any new unplanned revascularization according to subsets of MRF), but extended follow-up will be carried out up to 5 years. CONCLUSION: The REVASEC Registry will provide updated data on the characteristics, patterns of treatment, and 1-year outcomes of patients with MRF and SR in contemporary clinical practice.

Review of the current evidence for topical treatment for venous leg ulcers.

OBJECTIVE: The development of a venous leg ulcer (VLU) represents the most severe clinical manifestation of a chronic venous disease. Despite major progress, our understanding of the VLU pathogenesis and wound healing biology has remained limited. Treatment of VLUs remains a serious challenge for physicians of different specialties. In the present review, we focused on describing the rationale and scientific basis for topical wound care in the management of VLUs. METHODS: A literature review was performed to summarize the methods with proven efficacy in VLU management. A systematic search was also performed to identify new evidence from the randomized controlled trials reported from 2014 to 2021. The scientific challenges, clinical practice concerns, economic obstacles, and possible directions for further research have been discussed. RESULTS: Hundreds of topical products have been advertised for the treatment of VLUs. However, the reported data on the topical treatment of venous ulcers are insufficient, scattered, and weak, with significant methodologic flaws. A total of 43 randomized controlled trials on the topical treatment of VLUs were reported from 2014 to 2021. Thus, the clinical practice guidelines require updating. We identified major gaps in knowledge and have provided suggestions for future research directions. CONCLUSIONS: The American Venous Forum Research Committee would like to bring attention to the use of topical wound care for VLUs as a critical gap in knowledge and to encourage scientists, practitioners, and industry to collaborate to fill this gap.

Caracterización de la tuberculosis multidrogorresistente y resistente a rifampicina en Colombia / Characterization of rifampin-resistant/multidrug-resistant tuberculosis in Colombia

RESUMEN Objetivo Caracterizar la población afectada por tuberculosis multidrogorresistente y resistente a rifampicina (TB-MDR/RR) en Colombia. Métodos Estudio transversal a partir de la información nominal de los pacientes con TB-MDR/RR tratados y reportados en Colombia desde 2009 hasta 2020, usando la totalidad de las fuentes de información oficiales. Se compararon, además, las tasas de TB-MDR/RR de diferentes grupos de riesgo con la de la población general y se evaluaron variables asociadas a la TB-MDR/RR extrapulmonar y a resistencias medicamentosas. Resultados La TB-MDR/RR ha aumentado progresivamente durante la última década y se ha concentrado en hombres (64% vs. 36%, p<0,001), edades medias (mediana: 39,5 años; RIC: 27) y zonas de mayor densidad poblacional (59% de los casos en Antioquia, Valle del Cauca y Santiago de Cali). Además, al compararlas con las poblaciones de referencia que aplicaran, se evidenciaron tasas 2, 10 y 200 veces mayores en población indígena (9,45/1 000 000 vs. 4,31/1 000 000; p=0,02), prisioneros (169/1 000 000 vs. 16,9/1 000 000; p<0,001) y habitantes de calle (21/100000 vs. 0,1/100 000; p<0,001), respectivamente. Conclusiones El aumento en los casos de TB-MDR/RR y sus grupos de riesgo deben tenerse en cuenta para la planeación de políticas, distribución de recursos y atención clínica.

ABSTRACT Objective To describe the population affected by rifampin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB) in Colombia. Methods Cross-sectional study on all the patients treated for RR/MDR-TB in Colombia between 2009 and 2020, using all the official sources of information. In addition, a comparison was made between the rates of RR/MDR-TB in some higher-risk groups and average population. Finally, the variables associated to pulmonary versus extrapulmonary RR/MDR-TB and those associated to resistance to other drugs were evaluated. Results RR/MDR-TB cases have progressively increased during the last decade. These cases were concentrated in men (64% vs. 36%, p<0.001), middle aged adults (median: 39.5 years old; IQR: 27), and in geographic regions with higher population density (59% of cases in Antioquia, Valle del Cauca and Santiago de Cali). Also, the rate of RR/MDR-TB was 2, 10 and 200 times higher in indigenous (9.45/1 000 000 vs. 4.31/1 000 000; p=0.02), prisoners (169/1 000 000 vs. 16.9/1 000 000; p<0.001), and homeless population (21/100 000 vs. 0.1/100 000; p<0.001), respectively. Conclusions The increase in RR/MDR-TB cases and their concentration in higher-risk groups must be kept in mind to make better policies, a more efficient distribution of resources, and better patient care.

Targeted gene expression analysis of human deep veins.

OBJECTIVE: Endothelial-derived molecules involved in thrombosis and hemostasis have been investigated mainly in arteries and in experimental animals. The actual presence and integral function of these molecules in the human deep venous system have received less attention. Our aim was to evaluate the expression of certain prothrombotic and antithrombotic genes in the normal human deep veins of the lower extremities. METHODS: Macroscopically intact and competent valve-containing segments of human deep veins were prospectively collected from patients who had undergone above-knee amputation. Vein samples were separated into four zones: zone 1, postvalve (downstream, proximal) vein wall; zone 2, the valve cusp; zone 3, prevalve (upstream, distal) vein wall; and zone 4, vein wall within the valve cusp (cusp removed). Real-time quantitative polymerase chain reaction for principal genes involved in coagulation, fibrinolysis, and inflammation was performed to quantify messenger RNA. Selected protein gene products were measured by the western blot assay. One additional valve-containing segment underwent mass spectrometry analysis to investigate global differences in the proteome between the study zones. RESULTS: Seventeen valve-containing vein segments were analyzed. Significant upregulation of antithrombotic (protein C receptor [PROCR], thrombomodulin [THBD], tissue factor pathway inhibitor [TFPI]), prothrombotic (con Willebrand factor [VWF]), and proinflammatory (selectin P [SELP], intercellular adhesion molecule 1 [ICAM1]) genes was found in the valve cusp compared with the vein wall (P < .05). PROCR and THBD demonstrated the highest level of upregulation in the valve cusp. PROCR, serpin peptidase inhibitor, clade E, member 1 (SERPINE1), and SELP were upregulated in the valve cusp at the protein level (P < .05). Messenger RNA composition in the vein wall within the valve cusp was similar to the prevalve and postvalve vein wall for all genes, except for two times overexpressed ICAM1 (P < .05). Substantial differences within the proteome between the study zones were observed with mass spectrometry. CONCLUSIONS: The biological properties of the valve cusp, vein wall within the valve cusp, and vein wall beyond the valve cusp are different. The endothelium of the valve cusps of a normal competent deep venous valve may be naturally less thrombogenic compared with the vein wall. The endothelium of the valve cusp may have a higher potential to interact with white blood cells compared with the vein wall. Mass spectrometry demonstrates substantial differences in the proteome between the vein wall and the valve cusps that were not anticipated before. (J Vasc Surg Venous Lymphat Disord 2021;9:770-80.) CLINICAL RELEVANCE: Deep vein thrombosis (DVT) is a major cause of mortality, morbidity, and impaired quality of life. Multiple risk factors have been identified, although their relative weight and pathophysiologic interactions remain obscure. Many patients with multiple risk factors for DVT never develop this condition. Conversely, in numerous cases DVT cannot be attributed to any known clinical risk factor. The molecular mechanisms that initiate DVT are unclear. An improved understanding of the normal biology of human deep veins will serve as an important foundation for new hypotheses of the pathogenesis of DVT. The latter may suggest new projects on novel therapeutic strategies.

TGF-ß acts as a dual regulator of COX-2/PGE2 tumor promotion depending of its cross-interaction with H-Ras and Wnt/ß-catenin pathways in colorectal cancer cells.

Transforming growth factor-ß (TGF-ß) plays a dual role acting as tumor promoter or suppressor. Along with cyclooxygenase-2 (COX-2) and oncogenic Ras, this multifunctional cytokine is deregulated in colorectal cancer. Despite their individual abilities to promote tumor growth and invasion, the mechanisms of cross regulation between these pathways is still unclear. Here, we investigate the effects of TGF-ß, Ras oncogene and COX-2 in the colorectal cancer context. We used colon adenocarcinoma cell line HT-29 and Ras-transformed IEC-6 cells, both treated with prostaglandin E2 (PGE2 ), TGF-ß or a combined treatment with these agents. We demonstrated that PGE2 alters the subcellular localization of E-cadherin and ß-catenin and enhanced the tumorigenic potential in HT-29 cells. This effect was inhibited by TGF-ß, indicating a tumor suppressor role. Conversely, in Ras-transformed IEC-6 cells, TGF-ß induced COX-2 expression and increased invasiveness, acting as a tumor promoter. In IEC-6 Ras-transformed cells, TGF-ß increased nuclear ß-catenin and Wnt/ß-catenin activation, opposite to what was seen in the PGE2 and TGF-ß joint treatment in HT-29 cells. Together, our findings show that TGF-ß increases COX-2 levels and induces invasiveness cooperating with Ras in a Wnt/ß-catenin activation-dependent manner. This shows TGF-ß dual regulation over COX-2/PGE2 tumor promotion depending on the H-Ras and Wnt/ß-catenin pathways activation status in intestinal cancer cells.

N­glycosylation and receptor tyrosine kinase signaling affect claudin­3 levels in colorectal cancer cells.

Changes in protein levels in different components of the apical junctional complex occur in colorectal cancer (CRC). Claudin­3 is one of the main constituents of tight junctions, and its overexpression can increase the paracellular flux of macromolecules, as well as the malignant potential of CRC cells. The aim of this study was to investigate the molecular mechanisms involved in the regulation of claudin­3 and its prognostic value in CRC. In silico evaluation in each of the CRC consensus molecular subtypes (CMSs) revealed that high expression levels of CLDN3 (gene encoding claudin­3) in CMS2 and CMS3 worsened the patients' long­term survival, whereas a decrease in claudin­3 levels concomitant with a reduction in phosphorylation levels of epidermal growth factor receptor (EGFR) and insulin­like growth factor 1 receptor (IGF1R) could be achieved by inhibiting N­glycan biosynthesis in CRC cells. We also observed that specific inactivation of these receptor tyrosine kinases (RTKs) led to a decrease in claudin­3 levels, and this regulation seems to be mediated by phospholipase C (PLC) and signal transducer and activator of transcription 3 (STAT3) in CRC cells. RTKs are modulated by their N­linked glycans, and inhibition of N­glycan biosynthesis decreased the claudin­3 levels; therefore, we evaluated the correlation between N­glycogenes and CLDN3 expression levels in each of the CRC molecular subtypes. The CMS1 (MSI immune) subtype concomitantly exhibited low expression levels of CLDN3 and N­glycogenes (MGAT5, ST6GAL1, and B3GNT8), whereas CMS2 (canonical) exhibited high gene expression levels of CLDN3 and N­glycogenes (ST6GAL1 and B3GNT8). A robust positive correlation was also observed between CLDN3 and B3GNT8 expression levels in all CMSs. These results support the hypothesis of a mechanism integrating RTK signaling and N­glycosylation for the regulation of claudin­3 levels in CRC, and they suggest that CLDN3 expression can be used to predict the prognosis of patients identified as CMS2 or CMS3.

Gold nanoparticles regulate tight junctions and improve cetuximab effect in colon cancer cells.

Aim: Colon cancer (CC) is the second cause of cancer death worldwide. The use of nanoparticles for drug delivery has been increasing in cancer clinical trials over recent years. Materials & methods: We evaluated cytotoxicity of citrate-capped gold nanoparticles (GNPs) and the role they play on cell-cell adhesion. We also used GNP for delivery of cetuximab into different CC cell lines. Results: CC cells with well-formed tight junctions impair GNP uptake. Noncytotoxic concentration of GNP increases paracellular permeability in Caco-2 cells in a reversible way, concomitantly to tight junctions proteins CLDN1 and ZO-1 redistribution. GNP functionalized with cetuximab increases death of invasive HCT-116 CC cells. Conclusion: GNP can be used for drug delivery and can improve efficiency of CC therapy.

Loss of the p53 transactivation domain results in high amyloid aggregation of the Δ40p53 isoform in endometrial carcinoma cells.

Dysfunctional p53 formation and activity can result from aberrant expression and subcellular localization of distinct p53 isoforms or aggregates. Endometrial carcinoma (EC) is a cancer type in which p53 status is correlated with prognosis, and TP53 mutations are a frequent genetic modification. Here we aimed to evaluate the expression patterns of different p53 isoforms and their contributions to the formation and subcellular localization of p53 amyloid aggregates in both EC and endometrial nontumor cell lines. We found that full-length (fl) p53 and a truncated p53 isoform, Δ40p53, resulting from alternative splicing of exon 2 or alternative initiation of translation at ATG-40, are the predominantly expressed p53 variants in EC cells. However, Δ40p53 was the major p53 isoform in endometrial nontumor cells. Immunofluorescence assays revealed that Δ40p53 is mainly localized to cytoplasmic punctate structures of EC cells, resembling solid-phase structures similar to those found in neurodegenerative pathologies. Using light-scattering kinetics, CD, and transmission EM, we noted that the p53 N-terminal transactivation domain significantly reduces aggregation of the WT p53 DNA-binding domain, confirming the higher aggregation tendency of Δ40p53, which lacks this domain. This is the first report of cytoplasmic Δ40p53 in EC cells being a major component of amyloid aggregates. The differential aggregation properties of p53 isoforms in EC cells may open up new avenues in the development of therapeutic strategies that preferentially target specific p53 isoforms to prevent p53 amyloid aggregate formation.

Adenosine receptor agonism protects against NETosis and thrombosis in antiphospholipid syndrome.

Potentiation of neutrophil extracellular trap (NET) release is one mechanism by which antiphospholipid antibodies (aPL Abs) effect thrombotic events in patients with antiphospholipid syndrome (APS). Surface adenosine receptors trigger cyclic AMP (cAMP) formation in neutrophils, and this mechanism has been proposed to regulate NETosis in some contexts. Here we report that selective agonism of the adenosine A2A receptor (CGS21680) suppresses aPL Ab-mediated NETosis in protein kinase A-dependent fashion. CGS21680 also reduces thrombosis in the inferior vena cavae of both control mice and mice administered aPL Abs. The antithrombotic medication dipyridamole is known to potentiate adenosine signaling by increasing extracellular concentrations of adenosine and interfering with the breakdown of cAMP. Like CGS21680, dipyridamole suppresses aPL Ab-mediated NETosis via the adenosine A2A receptor and mitigates venous thrombosis in mice. In summary, these data suggest an anti-inflammatory therapeutic paradigm in APS, which may extend to thrombotic disease in the general population.

Annexin A2 overexpression associates with colorectal cancer invasiveness and TGF-ß induced epithelial mesenchymal transition via Src/ANXA2/STAT3.

Annexin A2 (ANXA2) is upregulated in several malignancies, including colorectal cancer (CRC). However, there is little knowledge on the molecular mechanisms involved to its upregulation. The aim of this study was to identify the mechanism through which ANXA2 overexpression leads to CRC progression and evaluate its potential prognostic value. We used human CRC samples to analyse the correlation between ANXA2 levels and tumour staging. ANXA2 expression was increased in CRC tissues compared to normal colon tissues. In addition, we observe increased ANXA2 levels in stage IV tumours and metastasis, when compared to stage I-III. Whereas E-cadherin, an epithelial marker, decreased in stage II-IV and increased in metastasis. We've also shown that TGF-ß, a classic EMT inductor, caused upregulation of ANXA2, and internalization of both E-cadherin and ANXA2 in CRC cells. ANXA2 silencing hindered TGF-ß-induced invasiveness, and inhibitors of the Src/ANXA2/STAT3 pathway reversed the EMT. In silico analysis confirmed overexpression of ANXA2 and association to the consensus moleculars subtypes (CMS) with the worst prognosis. Therefore, ANXA2 overexpression play a pivotal role in CRC invasiveness through Src/ANXA2/STAT3 pathway activation. The association of ANXA2 to distinct CMSs suggests the possible use of ANXA2 as a prognostic marker or directed target therapy.