Disheveled-1 Interacts with Claudin-5 and Contributes to Norrin-Induced Endothelial Barrier Restoration.

Previous studies have revealed that norrin can reverse vascular endothelial-growth-factor (VEGF)-induced permeability in a ß-catenin-dependent pathway. Here, we have explored the contribution of disheveled-1 (DVL1) in norrin-induced blood-retinal barrier (BRB) restoration. We provide evidence that in addition to canonical signaling, DVL1 promotes tight junction (TJ) stabilization through a novel, non-canonical signaling pathway involving direct claudin-5 (CLDN5) binding. Immunofluorescence staining of rat retinal cross-sections showed enriched expression of DVL1 and 3 at endothelial capillaries and co-localization with CLDN5 and ZO-1 at the TJ complex in primary bovine retinal endothelial cells (BRECs). Barrier properties of BRECs were determined via measurements of trans-endothelial electrical resistance (TEER) or permeability to 70 kDa RITC-dextran. These studies demonstrated that norrin restoration of barrier properties after VEGF treatment required DVL1 as an siRNA knockdown of Dvl1 but not Dvl2 or Dvl3, reduced basal barrier properties and ablated norrin-induced barrier restoration. However, loss of Dvl1 did not decrease ß-catenin signaling activity as measured by Axin2 mRNA expression, suggesting the contribution of a non-canonical pathway. DVL and TJ protein interactions were analyzed via co-immunoprecipitation of endogenous protein in BRECs, which demonstrated that DVL1 interacts with both CLDN5 and ZO-1, while DVL3 interacts only with ZO-1. These interactions were most abundant after inducing BRB restoration by treating BRECs with VEGF and norrin. DVL has previously been shown to form intramolecular bindings between the C-terminal PDZ-binding motif (PDZ-BM) with an internal PDZ domain. Co-transfection of HEK293 cells with DVL1 and CLDN5 or relevant mutants revealed that DVL1 interacts with CLDN5 through the DVL PDZ domain binding, CLDN5 PDZ-BM, in competition with DVL1 PDZ-BM, since DVL/CLDN5 interaction increases with deletion of the DVL1 PDZ-BM and decreases by co-expressing the C-terminal fragment of DVL1 containing the PDZ-BM or through deletion of CLDN5 PDZ-BM. In BREC cells, transfection of the C-terminal fragment of DVL1 downregulates the expression of CLDN5 but does not affect the expression of other proteins of the TJs, including ZO-1, occludin, CLDN1 or VE-cadherin. Blocking DVL1/CLDN5 interaction increased basal permeability and prevented norrin induction of barrier properties after VEGF. Combined with previous data, these results demonstrate that norrin signals through both a canonical ß-catenin pathway and a non-canonical signaling pathway by which DVL1 directly binds to CLDN5 to promote barrier properties.

Impact of left atrial appendage closure in patients on anticoagulation for atrial fibrillation and recurrent or chronic gastrointestinal bleeding / Impacto del cierre de la orejuela izquierda en pacientes anticoagulados por fibrilación auricular y con sangrado gastrointestinal recurrente o crónico

Background: Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption. Methods: Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre. Results: Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed. Conclusions: LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA. (AU)

Introducción: La anticoagulación oral en la fibrilación auricular no valvular se asocia a un incremento del riesgo de sangrado, especialmente gastrointestinal, lo que conlleva la retirada del tratamiento hasta en el 50% de los pacientes e implica un mayor riesgo de padecer un evento embólico. El cierre de la orejuela izquierda (COI) puede ser una alternativa a la anticoagulación crónica. Nuestro objetivo es describir el impacto del COI en pacientes con sangrado gastrointestinal (SGI) o anemia crónica ferropénica (ACF) en el consumo de recursos sanitarios. Métodos: Estudio observacional retrospectivo de pacientes sometidos a COI por SGI o ACF. Resultados: Diecinueve pacientes con una mediana de edad de 74años y una mediana del índice de Charlson de 6puntos fueron incluidos en el estudio. Las angiodisplasias fueron la causa más frecuente de SGI o ACF. La tasa de éxito técnico del COI fue del 100%, con una duración mediana del tratamiento anticoagulante y antiagregante de 92días. Tras un año del COI, se observó una mejoría significativa del valor mínimo de hemoglobina, así como una reducción en el número de transfusiones de concentrados de hematíes, en la necesidad de hospitalización por SGI o ACF y en el número de endoscopias. Un paciente falleció debido a un tromboembolismo pulmonar. Ningún paciente falleció por SGI. Conclusiones: El COI parece una alternativa segura y efectiva a la anticoagulación en pacientes con SGI o ACF. (AU)

CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells.

The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1low cells present a migratory and invasive phenotype, while EWSR1::FLI1high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.

Impact of left atrial appendage closure in patients on anticoagulation for atrial fibrillation and recurrent or chronic gastrointestinal bleeding.

BACKGROUND: Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption. METHODS: Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre. RESULTS: Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed. CONCLUSIONS: LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA.

Efficacy of Dry Needling for Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Objective: To evaluate the current evidence of the effectiveness of dry needling in patients with chronic low back pain (LBP). Methods: PubMed, Medline, ScienceDirect, Web of Science, CINAHL and PEDro databases were searched until 2020. Study selection: Randomised controlled trials (RCTs) that used dry needling as the main treatment and which included participants diagnosed with chronic LBP. Data extraction: Two reviewers independently screened articles, scored methodologic quality, and extracted data. The primary outcomes were pain intensity and functional disability at post-intervention and follow-up. Results: A total of 8 RCTs involving 414 patients were included in the meta-analysis. All trials examined the efficacy of DN in patients with chronic LBP. Results suggested that compared with other treatments, dry needling combined was more effective in alleviating the pain intensity of LBP post-intervention (standardised mean difference [SMD], -0.42; 95% confidence interval [CI], -0.79 to -0.05; P = .03) and at short- term (SMD -0.99, 95% CI -1.61 to -0.37, P = .002). Conclusion: Current evidence showed that dry needling, especially if associated with other therapies, could be recommended to relieve the pain intensity of LBP at post-intervention and at short-term follow up. There is no evidence that dry needling alone or in combination improves disability at post-immediate or at short-term follow up. Registration: This review was registered on PROSPERO (PROSPERO CRD42020215781) and was aligned with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for reporting systematic reviews that evaluate healthcare interventions.

N-antigenemia detection by a rapid lateral flow test predicts 90-day mortality in COVID-19: A prospective cohort study.

OBJECTIVES: To evaluate if the detection of N antigen of SARS-CoV-2 in plasma by a rapid lateral flow test predicts 90-day mortality in COVID-19 patients hospitalized at the wards. METHODS: The presence of N-antigenemia was evaluated in the first 36 hours after hospitalization in 600 unvaccinated COVID-19 patients, by using the Panbio COVID-19 Ag Rapid Test Device from Abbott (Abbott Laboratories Inc., Chicago, IL, USA). The impact of N-antigenemia on 90-day mortality was assessed by multivariable Cox regression analysis. RESULTS: Prevalence of N-antigenemia at hospitalization was higher in nonsurvivors (69% (82/118) vs. 52% (250/482); p < 0.001). The patients with N-antigenemia showed more frequently RNAemia (45.7% (148/324) vs. 19.8% (51/257); p < 0.001), absence of anti-SARS-CoV-2 N antibodies (80.7% (264/327) vs. 26.6% (69/259); p < 0.001) and absence of S1 antibodies (73.4% (240/327) vs. 23.6% (61/259); p < 0.001). The patients with antigenemia showed more frequently acute respiratory distress syndrome (30.1% (100/332) vs. 18.7% (50/268); p = 0.001) and nosocomial infections (13.6% (45/331) vs. 7.9% (21/267); p = 0.026). N-antigenemia was a risk factor for increased 90-day mortality in the multivariable analysis (HR, 1.99 (95% CI,1.09-3.61), whereas the presence of anti-SARS-CoV-2 N-antibodies represented a protective factor (HR, 0.47 (95% CI, 0.26-0.85). DISCUSSION: The presence of N-antigenemia or the absence of anti-SARS-CoV-2 N-antibodies after hospitalization is associated to increased 90-day mortality in unvaccinated COVID-19 patients. Detection of N-antigenemia by using lateral flow tests is a quick, widely available tool that could contribute to early identify those COVID-19 patients at risk of deterioration.

ZO-2 favors Hippo signaling, and its re-expression in the steatotic liver by AMPK restores junctional sealing.

ZO-2 is a peripheral tight junction (TJ) protein whose silencing in renal epithelia induces cell hypertrophy. Here, we found that in ZO-2 KD MDCK cells, in compensatory renal hypertrophy triggered in rats by a unilateral nephrectomy and in liver steatosis of obese Zucker (OZ) rats, ZO-2 silencing is accompanied by the diminished activity of LATS, a kinase of the Hippo pathway, and the nuclear concentration of YAP, the final effector of this signaling route. ZO-2 appears to function as a scaffold for the Hippo pathway as it associates to LATS1. ZO-2 silencing in hypertrophic tissue is due to a diminished abundance of ZO-2 mRNA, and the Sp1 transcription factor is critical for ZO-2 transcription in renal cells. Treatment of OZ rats with metformin, an activator of AMPK that blocks JNK activity, augments ZO-2 and claudin-1 expression in the liver, reduces the paracellular permeability of hepatocytes, and serum bile acid content. Our results suggest that ZO-2 silencing is a common feature of hypertrophy, and that ZO-2 is a positive regulator of the Hippo pathway that regulates cell size. Moreover, our observations highlight the importance of AMPK, JNK, and ZO-2 as therapeutic targets for blood-bile barrier dysfunction.

Predictors of the need for necrosectomy in patients with walled-off pancreatic necrosis treated with lumen apposition metal stents.

BACKGROUND AND AIMS: Endoscopic necrosectomy through lumen apposition metal stents (LAMS) is increasingly being used for complicated walled-off pancreatic necrosis (WOPN), but the need for necrosectomy after stent placement is not well understood. The aim of this study was to evaluate clinical, endoscopic, and radiologic predictors of the need for necrosectomy in patients treated with LAMS. METHODS: We retrospectively reviewed patients with WOPN treated with LAMS from 2014 to 2017. Necrosectomy was performed only in patients who had recurrent fever or hemodynamic instability during follow-up. Univariate and multivariate analyses were performed. RESULTS: We included 15 patients, 67% men and median age was 75 (54-76) years. Two (13%) presented adverse events, one immediate and one delayed. In the first case, the stent migrated to the gastric cavity during deployment but was relocated in the same procedure. In the second case, the patient presented bleeding on day 36 due to a pseudoaneurysm that was successfully treated with embolization. Clinical success was 100%, but five patients (33%) required endoscopic necrosectomy (4 mechanical and 1 irrigation) and one (7%) required surgical necrosectomy of distant collections. The percentage of necrosis in the collection detected in a previous CT scan (45 [35-66]% vs 10 [5-17]%) was the only factor to predict the need for necrosectomy in the multivariate analysis (OR 1.18 [1.01-1.39]). CONCLUSION: LAMS is efficient to treat WOPN but more than a third will need necrosectomy. The percentage of necrosis in the collection detected in the CT scan seems to predict the need for necrosectomy.

The Transcription Factor FEZF1, a Direct Target of EWSR1-FLI1 in Ewing Sarcoma Cells, Regulates the Expression of Neural-Specific Genes.

Ewing sarcoma is a rare pediatric tumor characterized by chromosomal translocations that give rise to aberrant chimeric transcription factors (e.g., EWSR1-FLI1). EWSR1-FLI1 promotes a specific cellular transcriptional program. Therefore, the study of EWSR1-FLI1 target genes is important to identify critical pathways involved in Ewing sarcoma tumorigenesis. In this work, we focused on the transcription factors regulated by EWSR1-FLI1 in Ewing sarcoma. Transcriptomic analysis of the Ewing sarcoma cell line A673 indicated that one of the genes more strongly upregulated by EWSR1-FLI1 was FEZF1 (FEZ family zinc finger protein 1), a transcriptional repressor involved in neural cell identity. The functional characterization of FEZF1 was performed in three Ewing sarcoma cell lines (A673, SK-N-MC, SK-ES-1) through an shRNA-directed silencing approach. FEZF1 knockdown inhibited clonogenicity and cell proliferation. Finally, the analysis of the FEZF1-dependent expression profile in A673 cells showed several neural genes regulated by FEZF1 and concomitantly regulated by EWSR1-FLI1. In summary, FEZF1 is transcriptionally regulated by EWSR1-FLI1 in Ewing sarcoma cells and is involved in the regulation of neural-specific genes, which could explain the neural-like phenotype observed in several Ewing sarcoma tumors and cell lines.

Therapeutic Potential of EWSR1-FLI1 Inactivation by CRISPR/Cas9 in Ewing Sarcoma.

Ewing sarcoma is an aggressive bone cancer affecting children and young adults. The main molecular hallmark of Ewing sarcoma are chromosomal translocations that produce chimeric oncogenic transcription factors, the most frequent of which is the aberrant transcription factor EWSR1-FLI1. Because this is the principal oncogenic driver of Ewing sarcoma, its inactivation should be the best therapeutic strategy to block tumor growth. In this study, we genetically inactivated EWSR1-FLI1 using CRISPR-Cas9 technology in order to cause permanent gene inactivation. We found that gene editing at the exon 9 of FLI1 was able to block cell proliferation drastically and induce senescence massively in the well-studied Ewing sarcoma cell line A673. In comparison with an extensively used cellular model of EWSR1-FLI1 knockdown (A673/TR/shEF), genetic inactivation was more effective, particularly in its capability to block cell proliferation. In summary, genetic inactivation of EWSR1-FLI1 in A673 Ewing sarcoma cells blocks cell proliferation and induces a senescence phenotype that could be exploited therapeutically. Although efficient and specific in vivo CRISPR-Cas9 editing still presents many challenges today, our data suggest that complete inactivation of EWSR1-FLI1 at the cell level should be considered a therapeutic approach to develop in the future.

Analysis of Both Lipid Metabolism and Endocannabinoid Signaling Reveals a New Role for Hypothalamic Astrocytes in Maternal Caloric Restriction-Induced Perinatal Programming.

Maternal malnutrition in critical periods of development increases the risk of developing short- and long-term diseases in the offspring. The alterations induced by this nutritional programming in the hypothalamus of the offspring are of special relevance due to its role in energy homeostasis, especially in the endocannabinoid system (ECS), which is involved in metabolic functions. Since astrocytes are essential for neuronal energy efficiency and are implicated in brain endocannabinoid signaling, here we have used a rat model to investigate whether a moderate caloric restriction (R) spanning from two weeks prior to the start of gestation to its end induced changes in offspring hypothalamic (a) ECS, (b) lipid metabolism (LM) and/or (c) hypothalamic astrocytes. Monitorization was performed by analyzing both the gene and protein expression of proteins involved in LM and ECS signaling. Offspring born from caloric-restricted mothers presented hypothalamic alterations in both the main enzymes involved in LM and endocannabinoids synthesis/degradation. Furthermore, most of these changes were similar to those observed in hypothalamic offspring astrocytes in culture. In conclusion, a maternal low caloric intake altered LM and ECS in both the hypothalamus and its astrocytes, pointing to these glial cells as responsible for a large part of the alterations seen in the total hypothalamus and suggesting a high degree of involvement of astrocytes in nutritional programming.

Impact of immunosuppressants on SARS-CoV-2 infection in elderly patients with inflammatory bowel disease.

BACKGROUND: Older age has been reported as a risk factor for severe SARS-CoV-2 disease (COVID-19). The impact of immunosuppressants (IMS) on COVID-19 is still under debate. AIM: To describe the incidence and severity of COVID-19 in elderly patients with inflammatory bowel disease (IBD) in relation to the use of IMS. METHODS: IBD patients over 65 years of age were selected and grouped in terms of IMS use. Confirmed COVID-19, adherence to IST, comorbidities and concomitant non-IBD-related treatments between 1st of March 2020 to 1st of March 2021 were recorded. RESULTS: Out of 418 patients included, 89 (21.3%) were on IMS. Thirty-two patients (7.7%) had COVID-19, 7 of whom were on IMS (7.6% not on IMS vs. 7.9% on IMS; P = 0.933) and 7 (22%) patients died. CONCLUSIONS: Incidence of COVID-19 among elderly IBD patients was similar to that reported in the background population, regardless of the use of IMS.

Tight junction protein ZO-2 modulates the nuclear accumulation of transcription factor TEAD.

The presence of tight junction protein zonula occludens 2 (ZO-2) at the nucleus inhibits the transcription of genes regulated by TEAD transcription factor. Here, we analyzed whether the movement of ZO-2 into the nucleus modulates the nuclear concentration of TEAD. In sparse cultures of ZO-2 knockdown Madin-Darby canine kidney cells, nuclear TEAD was diminished, as in parental cells transfected with a ZO-2 construct without nuclear localization signals, indicating that ZO-2 facilitates the entry of TEAD into the nucleus. Inhibition of nPKCδ in parental cells triggers the interaction between ZO-2 and TEAD at the cytoplasm and facilitates TEAD/ZO-2 complex nuclear importation. Using proximity ligation, immunoprecipitation, and pull-down assays, TEAD/ZO-2 interaction was confirmed. Nuclear TEAD is phosphorylated, and its exit in parental cells is enhanced by activation of a ZO-2 nuclear exportation signal by nPKCε, while the nuclear accumulation of ZO-2 triggered by the mutation of ZO-2 nuclear export signals induces no change in TEAD nuclear concentration. In summary, our results indicate that the movements of ZO-2 in and out of the nucleus modulate the intracellular traffic of TEAD through a process regulated by nPKCδ and ε and provide a novel role of ZO-2 as a nuclear translocator of TEAD.

Treatment Adherence and Clinical Outcomes of Patients with Inflammatory Bowel Disease on Biological Agents During the SARS-CoV-2 Pandemic.

BACKGROUND: The outbreak of COVID19 evolved rapidly into a global pandemic, forcing hospitals, including inflammatory bowel disease (IBD) referral units, to change their practices to ensure quality of care. AIMS: To describe the clinical outcomes and the fulfilment of the treatment schedule of patients with IBD treated with biological agents in a single-center of a red-zone of the pandemic, and to report the patients' perceptions about COVID-19 and the measures adopted at our center. METHODS: Therapeutic adherence and clinical outcomes were collected for all patients undergoing treatment with intravenous biologicals and subcutaneous biologicals at our center. A telephone survey was also performed to assess these patients' perceptions of the COVID pandemic and the related measures adopted at their IBD unit. RESULTS: A total of 234 patients were included (117 on intravenous and 117 on subcutaneous biologicals). Only 10% of patients postponed intravenous infusions intentionally and 5% postponed the collection of subcutaneous biologicals at the hospital pharmacy. Only five confirmed COVID-19 cases were registered (2.1%), all of them of mild severity. One hundred and fifty-five patients participated in the survey (77 on intravenous and 78 on subcutaneous drugs). Fear of going to the hospital was the most common reason for postponing biological administrations. Among those on combination therapy, only 7% admitted to have withdrawn immunosuppressants. CONCLUSIONS: Adherence to intravenous and subcutaneous biological therapies during the pandemic was high in a single-center cohort of IBD patients even though the cumulative incidence of confirmed COVID-19 was low.

Sarcoma treatment in the era of molecular medicine.

Sarcomas are heterogeneous and clinically challenging soft tissue and bone cancers. Although constituting only 1% of all human malignancies, sarcomas represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. More than 100 histological subtypes have been characterized to date, and many more are being discovered due to molecular profiling. Owing to their mostly aggressive biological behavior, relative rarity, and occurrence at virtually every anatomical site, many sarcoma subtypes are in particular difficult-to-treat categories. Current multimodal treatment concepts combine surgery, polychemotherapy (with/without local hyperthermia), irradiation, immunotherapy, and/or targeted therapeutics. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the latest advances in the molecular biology of sarcomas and their effects on clinical oncology; it is meant for a broad readership ranging from novices to experts in the field of sarcoma.

Epidermal Growth Factor Potentiates Migration of MDA-MB 231 Breast Cancer Cells by Increasing NaV1.5 Channel Expression.

INTRODUCTION: Breast cancer is one of the leading causes of death worldwide and is the result of dysregulation of various signaling pathways in mammary epithelial cells. The mortality rate in patients suffering from breast cancer is high because the tumor cells have a prominent invasive capacity towards the surrounding tissues. Previous studies carried out in tumor cell models show that voltage-gated ion channels may be important molecular actors that contribute to the migratory and invasive capacity of the tumor cells. METHODS: In this study, by using an experimental strategy that combines cell and molecular biology assays with electrophysiological recording, we sought to determine whether the voltage-dependent sodium channel NaV1.5 regulates the migratory capacity of the human breast cancer cell line MDA-MB 231, when cells are maintained in the presence of epidermal growth factor (EGF), as an inductor of the epithelial-mesenchymal transition. RESULTS: Our data show that EGF stimulates the migratory capacity of MDA-MB 231 cells, by regulating the functional expression of NaV1.5 channels. Consistent with this, the stimulatory actions of the growth factor were prevented by the use of tetrodotoxin, an Na+ channel selective blocker, as well as by resveratrol, an antioxidant that can also affect Na+ channel activity. DISCUSSION: The understanding of molecular mechanisms, such as the EGF pathway in the progression of breast cancer is fundamental for the design of more effective therapeutic strategies for the disease.

ZO-2 Is a Master Regulator of Gene Expression, Cell Proliferation, Cytoarchitecture, and Cell Size.

ZO-2 is a cytoplasmic protein of tight junctions (TJs). Here, we describe ZO-2 involvement in the formation of the apical junctional complex during early development and in TJ biogenesis in epithelial cultured cells. ZO-2 acts as a scaffold for the polymerization of claudins at TJs and plays a unique role in the blood-testis barrier, as well as at TJs of the human liver and the inner ear. ZO-2 movement between the cytoplasm and nucleus is regulated by nuclear localization and exportation signals and post-translation modifications, while ZO-2 arrival at the cell border is triggered by activation of calcium sensing receptors and corresponding downstream signaling. Depending on its location, ZO-2 associates with junctional proteins and the actomyosin cytoskeleton or a variety of nuclear proteins, playing a role as a transcriptional repressor that leads to inhibition of cell proliferation and transformation. ZO-2 regulates cell architecture through modulation of Rho proteins and its absence induces hypertrophy due to inactivation of the Hippo pathway and activation of mTOR and S6K. The interaction of ZO-2 with viral oncoproteins and kinases and its silencing in diverse carcinomas reinforce the view of ZO-2 as a tumor regulator protein.

Periostin: A Matricellular Protein With Multiple Functions in Cancer Development and Progression.

Tumor microenvironment is considered nowadays as one of the main players in cancer development and progression. Tumor microenvironment is highly complex and consists of non-tumor cells (i.e., cancer-associated fibroblast, endothelial cells, or infiltrating leukocytes) and a large list of extracellular matrix proteins and soluble factors. The way that microenvironment components interact among them and with the tumor cells is very complex and only partially understood. However, it is now clear that these interactions govern and modulate many of the cancer hallmarks such as cell proliferation, the resistance to death, the differentiation state of tumor cells, their ability to migrate and metastasize, and the immune response against tumor cells. One of the microenvironment components that have emerged in the last years with strength is a heterogeneous group of multifaceted proteins grouped under the name of matricellular proteins. Matricellular proteins are a family of non-structural matrix proteins that regulate a variety of biological processes in normal and pathological situations. Many components of this family such as periostin (POSTN), osteopontin (SPP1), or the CNN family of proteins have been shown to regulate key aspect of tumor biology, including proliferation, invasion, matrix remodeling, and dissemination to pre-metastatic niches in distant organs. Matricellular proteins can be produced by tumor cells themselves or by tumor-associated cells, and their synthesis can be affected by intrinsic and/or extrinsic tumor cell factors. In this review, we will focus on the role of POSTN in the development and progression of cancer. We will describe their functions in normal tissues and the mechanisms involved in their regulation. We will analyze the tumors in which their expression is altered and their usefulness as a biomarker of tumor progression. Finally, we will speculate about future directions for research and therapeutic approaches targeting POSTN.