Extracellular signals regulate the biogenesis of extracellular vesicles

Extracellular vesicles (EVs) are naturally released membrane vesicles that act as carriers of proteins and RNAs for intercellular communication. With various biomolecules and specific ligands, EV has represented a novel form of information transfer, which possesses extremely outstanding efficiency and specificity compared to the classical signal transduction. In addition, EV has extended the concept of signal transduction to intercellular aspect by working as the collection of extracellular information. Therefore, the functions of EVs have been extensively characterized and EVs exhibit an exciting prospect for clinical applications. However, the biogenesis of EVs and, in particular, the regulation of this process by extracellular signals, which are essential to conduct further studies and support optimal utility, remain unclear. Here, we review the current understanding of the biogenesis of EVs, focus on the regulation of this process by extracellular signals and discuss their therapeutic value.

Estudo das vesículas extracelulares de Toxoplasma gondii e a correlação com o sistema imune de hospedeiros infectados / Study of extracellular vesicles of Toxoplasma gondii and the correlation with the immune system of infected hosts

As vesículas extracelulares (EVs) são nanopartículas produzidas e liberadas por células eucarióticas e procarióticas com propriedades biológicas. EVs desempenham um papel importante no sistema imunológico, transporte de moléculas e comunicação celular. A fim de compreender a participação das EVs na resposta imune durante a infecção por Toxoplasma gondii, este estudo teve com objetivo, investigar as respostas humoral e celular, em camundongos imunizados com EVs liberadas por taquizoítos e desafiados com T. gondii. As EVs de T. gondii (EVs-toxo) foram purificadas a partir de taquizoítos mantidos em culturas celulares. A seguir, um grupo de camundongos foi imunizado com as EVs-toxo e Alum como adjuvante (EV-IM). Como controles, o grupo negativo (N) recebeu somente Alum e os camundongos do grupo positivo (CHR) foram infectados com a cepa ME-49. O grupo EV-IM apresentou altos níveis de IgG1 do que IgM ou IgG2a. IgGs purificadas de soros destes camundongos foram capazes de opsonizar taquizoítos (cepa RH) e, quando os camundongos foram desafiados com a cepa RH tiveram a mortalidade atrasada em 48h. Células do cérebro e do baço deste grupo expressaram mais IFN-y, IL-10 e TNF-α. As EVs dos soros destes camundongos foram purificadas por ultracentrifugação. As análises das EVs de camundongo (EVs-mouse) mostraram que as concentrações de EVs liberadas de soros do grupo N foram menores que as do grupo EV-IM e a presença de exossomos foi confirmada pelo immunoblot das EVs. Esplenócitos de camundongos foram estimulados com EVs-toxo. Esplenócitos dos camundongos do grupo EV-IM expressaram mais IFN-y; TNF-α e IL-17, que os do grupo N. Curiosamente, a IL-10 foi altamente expressa apenas em esplenócitos do grupo EV-IM. Os resultados da expressão gênica de microRNAs (miRNAs) mostraram que os camundongos do grupo EV-IM expressaram mais miR-155-5p, miR-29c-3p e miR-125b-5p do que os do grupo N. Todos esses dados sugerem a participação das EVs na interação T. gondii-hospedeiro. Além disso, os miRNAs liberados pelas EVs interagem com a modulação da resposta imune celular anti T. gondii. A imunização com EVs foi capaz de induzir proteção imunológica. Esses dados fornecem subsídios para propor a diferenciação entre hospedeiros infectados e não infectados pela concentração de EVs. (AU)

Extracellular vesicles (EVs) are nanoparticles produced and released by eukaryotic and prokaryotic cells with biological properties. EVs play an important role in the immune system, transport of molecules and cellular communication. In order to understand the participation of EVs in the immune response during Toxoplasma gondii infection, this study aimed to investigate the humoral and cellular responses in mice immunized with EVs released by tachyzoites and challenged with T. gondii. T. gondii EVs (toxo-EVs) were purified from tachyzoites maintained in cell cultures. Then, a group of mice was immunized with EVs-toxo and Alum as an adjuvant (EV-IM). As controls, the negative group (N) received only Alum and the mice in the positive group (CHR) were infected with strain ME-49. The EV-IM group had higher levels of IgG1 than IgM or IgG2a. IgGs purified from the sera of these mice were able to opsonize tachyzoites (RH strain) and, when mice were challenged with the RH strain, mortality was delayed by 48h. Brain and spleen cells from this group expressed more IFN-γ, IL-10 and TNF-α. The EVs from the sera of these mice were purified by ultracentrifugation. Analysis of mouse EVs (mouse EVs) showed that the concentrations of EVs released from sera from the N group were lower than those from the EV-IM group and the presence of exosomes was confirmed by the immunoblot of EVs. Mouse splenocytes were stimulated with EVs-toxo. Splenocytes from EV-IM group mice expressed more IFN-y; TNF-α and IL-17 than those of the N group. Interestingly, IL-10 was highly expressed only in splenocytes of the EV-IM group. The results of gene expression of microRNAs (miRNAs) showed that mice in the EV-IM group expressed more miR-155-5p, miR-29c-3p and miR-125b-5p than those in the N group. participation of EVs in T. gondii host interaction. Furthermore, miRNAs released by EVs interact with the modulation of the cellular immune response against T. gondii. Immunization with EVs was able to induce immune protection. These data provide subsidies to propose the differentiation between infected and uninfected hosts by the concentration of EVs. (AU)

Retos y oportunidades en el estudio de vesículas extracelulares: contexto institucional a nivel mundial y situación actual en Colombia / Challenges and opportunities in the study of extracellular vesicles: Global institutional context and national state of the art

Resumen En la última década se ha incrementado el número de estudios y publicaciones sobre las vesículas extracelulares y los exosomas. En Colombia, ha habido interés y avances en su estudio, lo que se evidencia en el aumento de publicaciones y proyectos de investigación. Sin embargo, este es un campo de investigación aún en desarrollo, con desafíos analíticos y limitaciones técnicas, por lo cual, en el planteamiento de los proyectos de investigación y desarrollo, es necesario considerar cuál es el estado del campo científico a nivel mundial en cuanto a la nomenclatura y la clasificación de las vesículas extracelulares, las técnicas, recursos, requisitos y especificaciones de calidad y las instituciones que regulan el campo. La respuesta a esta pregunta permitirá desarrollar estudios que cumplan con los estándares internacionales, y las exigencias y recomendaciones institucionales. Sin embargo, la información científica disponible se encuentra dispersa y no todos los aspectos son tratados a cabalidad. En este actualización se condensa la información disponible y se presentan los términos oficiales para denominar las vesículas extracelulares y la nomenclatura aceptada actualmente, así como la evolución del campo, la homogenización de los parámetros experimentales, el establecimiento de autoridades científicas, instituciones y recursos, y las recomendaciones que se han generado a nivel mundial para el desarrollo de investigaciones en vesículas extracelulares, incluidos su aislamiento, caracterización y estudio funcional. Por último, se analiza el contexto nacional de una forma crítica, teniendo en cuenta las fortalezas institucionales, los errores usualmente cometidos, y las técnicas y tecnologías analíticas disponibles.

Abstract In the last decade, the number of studies and publications on extracellular vesicles (EV) and exosomes has boomed. Colombia has displayed interest and progress in their study as shown in the increase of research project publications and products. However, this research field is still developing and has its own analytical challenges and technical limitations. For planning research projects and developing EV studies it is necessary to consider what is the state of the scientific field worldwide concerning EV nomenclature and classification, available techniques, resources, requirements and quality specifications, and the institutions that regulate the field. Answering this question will elicit EV studies that comply with international standards and respond to institutional demands and recommendations. However, the scientific information available is scattered and not all the aspects are considered in full. In this update, the available information is condensed and the official terms and currently defined nomenclature is presented, as well as the evolution of the field, the homogenization of the experimental parameters, the establishment of scientific authorities, institutions, and resources, and the recommendations generated worldwide for their development and research including their isolation, characterization, and functional studies. Finally, I analyzed the national context in a critical way, considering institutional strengths, common mistakes, and available analytical techniques and technologies.

Bases inmunológicas de la enfermedad neumocócica y el candidato vacunal PVC7-TT / Immunological bases of pneumococcal disease and vaccine candidate PVC7-TT

Introducción: Las enfermedades infecciosas del tracto respiratorio se encuentran entre las primeras causas de entidades respiratorias en edades extremas de la vida. Objetivo: Describir las bases inmunológicas de la enfermedad y el nuevo candidato vacunal conjugado antineumocócico PCV7-TT desarrollado en Cuba. Métodos: Se realizó una búsqueda en las bases de datos Medline, Pubmed, SciELO, LILACS, Cochrane Library y Web of Science, de documentos publicados entre mayo del 2018 y marzo del 2020. Se seleccionaron los 64 artículos de mayor relevancia y novedad. Resultados: Streptococcus pneumoniae es el agente etiológico de la enfermedad neumocócica; se le atribuye alrededor de un millón de defunciones anuales, principalmente en países en vías de desarrollo. Es un coco Gram-positivo, anaerobio facultativo y encapsulado que se encuentra dividido en 48 serogrupos y 97 serotipos tipificados. Presenta varios factores de virulencia que garantizan su mecanismo de patogenicidad; uno de los más importantes es el polisacárido capsular que constituye la diana de las vacunas antineumocócicas conjugadas y no conjugadas existentes. En el presente artículo se consideró la proteína de superficie C del neumococo como un posible candidato en la investigación y desarrollo de vacunas preventivas. Asimismo, las vesículas extracelulares podría ser un posible candidato para adyuvante vacunal con fines preventivos y terapéuticos. Conclusiones: El neumococo es un problema de salud a nivel global y el uso de vacunas conjugadas antineumocócicas constituye la herramienta más eficaz para su prevención. El candidato vacunal PCV7-TT desarrollado en Cuba es seguro, bien tolerado, inmunogénico y no inferior a las vacunas actualmente registradas(AU)

Introduction: Infectious diseases of the respiratory tract are among the leading causes of respiratory conditions in patients at extreme ages. Objective: Describe the immunological bases of the disease and the new conjugate pneumococcal vaccine candidate PCV7-TT developed in Cuba. Methods: A search was conducted in the databases Medline, Pubmed, SciELO, LILACS, Cochrane Library and Web of Science for documents published from May 2018 to March 2020. The 64 most relevant and novel papers were selected. Results: Streptococcus pneumoniae is the causative agent of pneumococcal disease, a condition causing about one million deaths a year worldwide, mainly in developing countries. It is a Gram-positive facultative anaerobic encapsulated coccus divided into 48 serogroups and 97 typified serotypes. Several virulence factors ensure its pathogenicity mechanism. One of the most important of these is the capsular polysaccharide constituting the target of the existing conjugate and non-conjugate pneumococcal vaccines. The study considered pneumococcal surface protein C as a possible candidate for the research and development of preventive vaccines. On the other hand, extracellular vesicles could be a possible vaccine adjuvant candidate for preventive and therapeutic use. Conclusions: Pneumococcus is a global health problem, and the use of conjugate pneumococcal vaccines is the most effective tool for its prevention. The vaccine candidate PCV7-TT developed in Cuba is safe, well-tolerated, immunogenic and not inferior to the vaccines so far registered(AU)

Overexpression of serum extracellular vesicle microRNA-215-5p is associated with early tumor recurrence and poor prognosis of gastric cancer

OBJECTIVES: Extracellular vesicle microRNAs (EV-miRNAs) have been demonstrated to be reliable candidate biomarkers for clinical applications. However, the clinical application potential of serum EV-miR-215-5p for gastric cancer (GC) remains poorly understood. The goal of our study was to determine the efficacy of serum EV-miR-215-5p in predicting the prognosis of GC. METHODS: Blood samples were collected from 118 patients with GC, 60 patients with benign gastric disease and BGD and 70 healthy controls. The relative levels of serum EV-miR-215-5p were measured using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Compared to patients with BGD and normal controls, GC patients exhibited remarkably higher serum EV-miR-215-5p level, especially those with early tumor recurrence (ETR). Receiver operating characteristic (ROC) curve analysis showed that serum EV-miR-215-5p was able to distinguish GC patients from BGD patients or healthy controls and GC patients with ETR from those without ETR. In addition, increased serum EV-miR-215-5p levels were notably correlated with invasive depth, TNM stage, and lymph node metastasis. Moreover, serum EV-miR-215-5p levels were greatly decreased after surgical treatment, but increased at the time of ETR. Survival analysis showed that patients with higher serum EV-miR-215-5p had shorter survival. Furthermore, serum EV-miR-215-5p was an independent risk factor for GC. CONCLUSIONS: Serum EV-miR-215-5p might be a novel biomarker for predicting ETR and prognosis of GC.

Overexpression of serum extracellular vesicle microRNA-215-5p is associated with early tumor recurrence and poor prognosis of gastric cancer

OBJECTIVES: Extracellular vesicle microRNAs (EV-miRNAs) have been demonstrated to be reliable candidate biomarkers for clinical applications. However, the clinical application potential of serum EV-miR-215-5p for gastric cancer (GC) remains poorly understood. The goal of our study was to determine the efficacy of serum EV-miR-215-5p in predicting the prognosis of GC. METHODS: Blood samples were collected from 118 patients with GC, 60 patients with benign gastric disease and BGD and 70 healthy controls. The relative levels of serum EV-miR-215-5p were measured using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Compared to patients with BGD and normal controls, GC patients exhibited remarkably higher serum EV-miR-215-5p level, especially those with early tumor recurrence (ETR). Receiver operating characteristic (ROC) curve analysis showed that serum EV-miR-215-5p was able to distinguish GC patients from BGD patients or healthy controls and GC patients with ETR from those without ETR. In addition, increased serum EV-miR-215-5p levels were notably correlated with invasive depth, TNM stage, and lymph node metastasis. Moreover, serum EV-miR-215-5p levels were greatly decreased after surgical treatment, but increased at the time of ETR. Survival analysis showed that patients with higher serum EV-miR-215-5p had shorter survival. Furthermore, serum EV-miR-215-5p was an independent risk factor for GC. CONCLUSIONS: Serum EV-miR-215-5p might be a novel biomarker for predicting ETR and prognosis of GC.

BM-MSC-derived small extracellular vesicles (sEV) from trained animals presented nephroprotective potential in unilateralureteral obstruction model

Background: The efficacy of bone marrow mesenchymal stromal cells (BM-MSC) and its extracellular vesicles has been demonstrated for a broad spectrum of indications, including kidney diseases. However, BM-MSC donor characteristics and their potential are not usually considered. Therefore, the present work aims to evaluate the nephroprotective capacity of sEV secreted by BM-MSC from trained rats inunilateral ureteral obstruction (UUO) model. Methods: BM-MSC was characterized by their differentiation potential and immunophenotypic markers. The sEV were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis and western blot. Its miRNA cargo was examined by quantitative PCR analysis for miR-26a, 126a, and 296. Wistar rats were submitted to UUO procedure and concomitantly treated with sEV secreted by BM-MSC from the untrained andtrained rats. The kidney tissue from all groups was evaluated for fibrosis mediators (transforming growth factor beta1 and collagen), CD34-angiogenesis marker, and hypoxia-inducible factor 1 alpha (HIF-1α). Results: Treadmill training stimulated in BM-MSC the production of sEV loaded with pro-angiogenic miR-296. The treatment with this sEVin UUO-rats was able to attenuate collagen accumulation and increase CD34 and HIF-1α in the kidney tissue when compared to untrained ones. Tubular proximal cells under hypoxia and exposed to BM-MSC sEV demonstrate accumulation in HIF-1α and NFR-2 (nuclear factor erythroid 2-related factor 2), possibly to mediate the response to hypoxia and oxidative stress, under these conditions. Conclusion: The BM-MSC sEV from trained animals presented an increased nephroprotective potential compared to untrained vesicles by carrying 296-angiomiR and contributing to angiogenesis in UUO model.(AU)

Estudo das vesículas extracelulares de Toxoplasma gondii e a correlação com a infecção humana / Study of the extracellular vesicles of Toxoplasma gondii and the correlation with human infection

Toxoplasma gondii é causador da toxoplasmose, uma das doenças mais prevalentes no mundo. Estudos recentes mostraram que vesículas extracelulares (EVs) liberadas por parasitas participam no processo de invasão e replicação no hospedeiro, porém o mecanismo de infecção ainda não está completamente elucidado. O objetivo desse trabalho foi identificar e caracterizar EVs produzidas por taquizoítos das cepas RH, ME-49 e VEG de T. gondii e a participação na patogênese da toxoplasmose. Purificação de EVs liberadas das três cepas de T. gondii foi realizada por cromatografia de exclusão de tamanho seguida por ELISA. Concentração e tamanho das vesículas isoladas foram analisados por Nanoparticle Tracking Analysis, o qual mostrou que as três cepas possuem perfis de liberação de EVs similares, com maior produção observada pela cepa RH. Quando analisados diferentes tempos de incubação, observou-se que em 2 horas de incubação ocorreu maior liberação de EVs do que em 24 horas de incubação, para as três cepas. A maior parte das vesículas encontradas possuía tamanho entre 100-200 nm, caracterizadas como microvesículas. Observou-se através de imagens capturadas por Microscopia Eletrônica de Varredura que a cepa RH liberou mais EVs do que as cepas VEG e ME-49. Após a análise de taquizoítos da cepa RH por Microscopia Eletrônica de Transmissão, observou-se que no...(AU)

Toxoplasma gondii is the agent of toxoplasmosis, one of the most prevalent diseases in the world. Recent studies show that extracellular vesicles (EVs) released by parasites are involved in the invasion and replication mechanisms in the host, however they are not completely clear. The aim of this study was to identify and characterize EVs released by tachyzoites from RH, ME-49 and VEG strains of T. gondii and their role in toxoplasmosis pathogenesis. EVs purification was performed by size exclusion chromatography followed by ELISA. Size and concentration of EVs was analysed by Nanoparticle Tracking Analysis, which showed similar EVs release profile from the three strains, however RH strain showed higher production of EVs. When analysed different incubation periods, it was observed higher production of EVs in 2 hours rather than 24 hours of incubation, for the three strains. The majority size of EVs found was of 100-200 nm which is classified by microvesicles. Images captured by Scanning Electron Microscopy showed that tachyzoites from RH strain released more EVs than tachyzoites from ME-49 and VEG strains. Also, images captured by Transmission Electron Microscopy of tachyzoites from RH strain showed that in the beginning of incubation period starts the formation of multivesicular bodies with vesicles inside ready to be released in the lumen. After 24 hours, it was able to observe intense release of EVs from the plasmatic membrane, as well as from posterior pore and apical ring. Furthermore, it was found that T. gondii was able to express the same miRNAs found in infected hosts. miR-155-5p, miR-125b-5p e miR-423-3p were the most expressed in tachyzoites as well as in EVs released from them in the three strains. Experiments with laboratory mice infected with tachyzoites of RH strain mixed with EVs, especially for EVs released from RH strain, showed that EVs can enhance parasitemia and virulence, decreasing mice's survival. Protein extracted from EVs of the three strains demonstrated similar electrophoretic profiles, but when EVs were incubated with sera from patients with toxoplasmosis, in Immunoblot analysis, EVs from ME-49 and VEG strains reacted poorly, unlike EVs from RH strains which reacted with sera from patients with gestational and cerebral toxoplasmosis. Stimulus of EVs released form the three strains in mice splenocytes in vitro produced similar concentrations of IL-10 and IFN- after 24 and 48 hours, in the three strains. EVs released from RH strain stimulated the production of more TNF- than EVs released from ME-49 and VEG strains. Finally, these results suggest that EVs released from tachyzoites of three T. gondii strains, especially the ones released from RH strain, were able to stablish communication between host cells and parasites, modulating host immune system, although they unbalance the host immune response since they carry virulence factors. (AU)

Extracellular vesicles in infectious diseases caused by protozoan parasites in buffaloes

Extracellular vesicles (EVs) are small membrane-bound vesicles of growing interest in vetetinary parasitology. The aim of the present report was to provide the first isolation, quantification and protein characterization of EVs from buffalo (Bubalus bubalis) sera infected with Theileria spp. Methods: Infected animals were identified through optical microscopy and PCR. EVs were isolated from buffalo sera by size-exclusion chromatography and characterized using western blotting analysis, nanoparticle tracking analysis and transmission electron microscopy. Subsequently, the proteins from isolated vesicles were characterized by mass spectrometry. Results: EVs from buffalo sera have shown sizes in the 124-140 nm range and 306 proteins were characterized. The protein-protein interaction analysis has evidenced biological processes and molecular function associated with signal transduction, binding, regulation of metabolic processes, transport, catalytic activity and response to acute stress. Five proteins have been shown to be differentially expressed between the control group and that infected with Theileria spp., all acting in the oxidative stress pathway. Conclusions: EVs from buffaloes infected with Theileria spp. were successfully isolated and characterized. This is an advance in the knowledge of host-parasite relationship that contributes to the understanding of host immune response and theileriosis evasion mechanisms. These findings may pave the way for searching new EVs candidate-markers for a better production of safe biological products derived from buffaloes.(AU)

Vesículas extracelulares como predictores tempranos de diabetes gestacional / Extracellular vesicle concentration in maternal plasma as an early marker of gestational diabetes

Background During pregnancy, there is an increase in the amount of extracellular vesicles, especially placental exosomes, in maternal plasma. Aim To isolate and characterize extracellular vesicles from blood during the three trimesters of pregnancy and to evaluate their capacity to identify patients at risk of developing gestational diabetes. Material and Methods A case-control study was conducted in a cohort of 50 pregnant women with plasma samples taken in each trimester. Six women who developed gestational diabetes were paired with three healthy controls per case (a total of 19). Clinical characteristics were recorded at first prenatal appointment, and blood samples were obtained during the first, second and third trimesters. Extracellular vesicles were isolated from plasma by the commercial kit, ExoQuick™. Nanoparticle tracking analysis, was used to characterize the obtained extracellular vesicles. Results The total concentration of extracellular particles isolated from maternal plasma increased along with gestational age. The size of the extracellular vesicles obtained in the first trimester of pregnancy was very similar between groups (144 ± 37 nm for controls and 143 ± 34 nm for patients with gestational diabetes mellitus). Moreover, the concentration of extracellular vesicles collected in the first trimester, was significantly higher in patients who developed gestational diabetes mellitus later in pregnancy compared to normoglycemic pregnant women (7.94 x 10 8 and 5.15 x 10 8 , p = 0.03). Conclusions Our results provide an insight into the potential capacity of first trimester plasma extracellular vesicles as early biomarkers for the prediction of gestational diabetes mellitus.

Identification of the alpha-enolase P46 in the extracellular membrane vesicles of Bacteroides fragilis

BACKGROUND Members of the Bacteroides fragilis group are the most important components of the normal human gut microbiome, but are also major opportunistic pathogens that are responsible for significant mortality, especially in the case of bacteraemia and other severe infections, such as intra-abdominal abscesses. Up to now, several virulence factors have been described that might explain the involvement of B. fragilis in these infections. The secretion of extracellular membrane vesicles (EMVs) has been proposed to play a role in pathogenesis and symbiosis in gram-negative bacteria, by releasing soluble proteins and other molecules. In B. fragilis, these vesicles are known to have haemagglutination and sialidosis activities, and also contain a capsular polysaccharide (PSA), although their involvement in virulence is still not clear. OBJECTIVE The aim of this study was to identify proteins in the EMV of the 638R B. fragilis strain by mass spectrometry, and also to assess for the presence of Bfp60, a surface plasminogen (Plg) activator, previously shown in B. fragilis to be responsible for the conversion of inactive Plg to active plasmin, which can also bind to laminin-1. METHODS B. fragilis was cultured in a minimum defined media and EMVs were obtained by differential centrifugation, ultracentrifugation, and filtration. The purified EMVs were observed by both transmission electron microscopy (TEM) and immunoelectron microscopy (IM). To identify EMV constituent proteins, EMVs were separated by 1D SDS-PAGE and proteomic analysis of proteins sized 35 kDa to approximately 65 kDa was performed using mass spectrometry (MALDI-TOF MS). FINDINGS TEM micrographs proved the presence of spherical vesicles and IM confirmed the presence of Bfp60 protein on their surface. Mass spectrometry identified 23 proteins with high confidence. One of the proteins from the B. fragilis EMVs was identified as an enolase P46 with a possible lyase activity. MAIN CONCLUSIONS Although the Bfp60 protein was not detected by proteomics, α-enolase P46 was found to be present in the EMVs of B. fragilis. The P46 protein has been previously described to be present in the outer membrane of B. fragilis as an iron-regulated protein.

Papel das vesículas extracelulares secretadas por adenocarcinomas gástricos na resposta ao tratamento quimioterápico / Role of extracellular vesicles secreted by gastric adenocarcinomas in response to chemotherapy

O adenocarcinoma gástrico (AdG) é a terceira causa mais comum de morte por câncer no mundo e um dos tumores com maior índice de mortalidade no Brasil. Estes tumores aparecem em terceiro lugar na incidência entre homens e em quinto nas mulheres. A quimioterapia neoadjuvante (QT) com 5-fluorouracil (5-FU) pode melhorar a ressecabilidade e a sobrevida dos pacientes com AdG, porém sua eficácia está limitada pela resistência à droga. Apenas pacientes que respondem a esta terapia com toxicidade tolerável são potencialmente beneficiados, entretanto não é possível identificar e separar clinicamente estes indivíduos. Assim, identificar marcadores preditivos de resposta para selecionar os pacientes que se beneficiariam deste tratamento é relevante. Vesículas extracelulares (VEs) são componentes secretados pelas células incluindo células tumorais, cujo conteúdo é regulado e composto por moléculas que podem ter uma miríade de funções locais e a distância. Muitas destas moléculas podem ser também usadas como biomarcadores séricos por conterem informações importantes sobre o tumor. Desta forma, este trabalho tem como objetivo identificar marcadores de resistência a 5-FU em VEs secretadas por linhagens celulares humanas de câncer gástrico e avaliar o papel das VEs na quimioresistência. Para tanto, foram geradas células de AdG derivadas da linhagem AGS, resistentes a 5-FU (rAGS_FU) de onde foram isoladas, quantificadas e caracterizadas VEs. Células rAGS-FU secretam cerca de 2 vezes mais VEs que as células parentais (AGS), entretanto a distribuição destas por tamanho é semelhante. As células rAGS_FU apresentaram maior proliferação, capacidade de formação de colônias e invasão que as células AGS. Interessantemente, as VEs provenientes de células resistentes a 5-FU, rAGS_FU, são capazes de transferir à células AGS os fenótipos de resistência ao quimioterápico bem como um aumento na capacidade de formação de colônias e invasão. As células AGS que se tornam resistentes ao tratamento não têm este fenótipo revertido pela remoção das VEs da células resistentes nem pelo tratamento com VEs de células AGS parental, indicando que o fenótipo de resistência adquirido após o tratamento é irreversível, pelo menos pelo período estudado. O conteúdo proteico das VEs das células AGS e rAGS_FU e suas respectivas VEs foi comparado por proteômica. Nessa abordagem foram identificadas 1.915 proteínas nas células e 1.638 proteínas em VEs das quais 309 proteínas eram diferencialmente expressas em células e 66 em VEs. Entre as proteínas com expressão diferencial entre as duas células e também nas suas respectivas VEs, selecionamos e validamos por western blotting a proteina fascina. Esta parece ser um potencial candidato a biomarcador de resistência a 5-FU uma vez que sua expressão é indetectável na célula AGC e suas VEs e altamente expressa nas células rAGS_FU e suas vesículas. A fascina é uma proteína do citoesqueleto com um papel chave nas interações célula-célula, adesão e motilidade celulares e é associada a agressividade tumoral. Estes dados apontam o papel das VEs nos mecanismos relacionados à resistência a 5-FU em células de AdG e sugerem que fascina possa estar associada ao mecanismo de resistência a este quimioterápico e que também seja um potencial biomarcador deste fenótipo

Gastric adenocarcinoma (GAd) is the third most common cause of cancer related death worldwide, and one of the tumors with the highest mortality rates in Brazil. In men, this cancer ranks the third most common cancer, while in women, it ranks fifth. 5-fluorouracil (5-FU) based neoadjuvant chemotherapy can improve tumor resectability and patient's survival rates. Its effectiveness however, is limited by drug resistance. Thus, an effort to identify predictive markers of response to neoadjuvant therapy and select patients who could benefit from this treatment is relevant. One such approach could be to use contents of extracellular vesicles (EVs). EVs are components secreted by cells including tumor cells, whose contents are composed of molecules that can have a myriad of local and distance functions and many of these molecules can also be used as serum biomarkers since they contain important information about the tumor. This work aims to identify 5-FU resistance markers in EVs secreted by human gastric cancer cell line and to evaluate the role of EVs in chemoresistance. GAd cells resistant to 5-FU (rAGS_FU) were generated from the AGS cell line and EVs secreted by rAGS_FU cells and parental AGS cells were isolated, quantified and characterized. Our results showed that AGS_FU cells secrete about 2 times more EVs than parental AGS cells, however their size distribution is similar. The resistant rAGS_FU cells showed higher proliferation rates, capacity of colony formation and invasion properties. Interestingly, EVs from 5-FU resistant cells, rAGS_FU, are able to transfer to the AGS cells the phenotypes of resistance to chemotherapy as well as an increase in the capacity of colony formation and invasion. AGS cells that become resistant to treatment do not have this phenotype reversed by removal of the EVs from the resistant cells or by treatment with EVs from parental AGS cells, indicating that the resistance phenotype acquired after treatment is irreversible, at least for the period studied. The protein content of the AGS and rAGS_FU cells and their respective EVs was compared by proteomics. In this approach, 1,915 proteins were identified in cells and 1,638 proteins in EVs of which 309 proteins were differentially expressed in cells and 66 in EVs. Among the proteins with differential expression between the two cells and also in their respective EVs, we selected and validated by western blotting the protein fascin. Fascin protein appears to be a potential candidate for biomarker of 5-FU resistance since its expression is undetectable in AGS cells and their EVs and highly expressed in rAGS_FU cells and their vesicles. Fascin is a cytoskeletal protein with a key role in cellcell interactions, cell adhesion and motility and is associated with tumor aggressiveness. These data point to the role of EVs in the mechanisms related to 5-FU resistance in GAd cells and suggest that fascin may be associated with the mechanism of resistance to this chemotherapeutic agent and that it is also a potential biomarker of this phenotype

Vesículas extracelulares derivadas de macrófagos alteram o potencial de invasão, proliferação e migração de linhagens celulares do carcinoma de células escamosas de língua oral / Macrophage-derived extracellular vesicles alter the potential for invasion, proliferation, and migration of oral tongue squamous cell carcinoma cell lines

O câncer é composto pelas células malignas em proliferação associadas às diferentes células circunjacentes, formando o microambiente tumoral (TME), onde há uma constante troca de informações. Uma das formas de comunicação entre os diferentes tipos celulares do TME se dá por meio da liberação de vesículas extracelulares (EVs), um campo de estudo ainda pouco explorado. O presente estudo se propôs a avaliar os efeitos das EVs liberadas por macrófagos do TME, células altamente plásticas em seu fenótipo (M1 ­ perfil antitumoral; M2 ­ perfil pró-tumoral), em diferentes linhagens do carcinoma de células escamosas de língua oral (CCELO) no tocante à capacidade invasiva, proliferativa e migratória. Foi observado que as amostras de EVs extraídas dos macrófagos eram relativamente puras em EVs, porém subtipo inespecíficas. No ensaio de invasão em miomas, quando colocadas as células inflamatórias em cocultura com as células HSC-3, as células M1 inibiram a invasão e M2 aumentaram a capacidade invasiva das células malignas. Por outro lado, o tratamento com M1 EVs aumentou a capacidade invasiva das células HSC-3 e o tratamento com EVs de M2 inibiu a invasão dessas células, sendo observado um perfil semelhante nas células SCC-25 e SAS quando submetidas aos mesmos tratamentos. Na análise do marcador Ki-67 nos miomas, tanto as células HSC-3 quanto SCC-25 e SAS apresentaram o mesmo padrão de proliferação independentemente do tratamento utilizado, quando comparados com os respectivos controles negativos. Quando analisada a proliferação das células malignas no IncuCyte®, tratadas com EVs dos diferentes tipos de macrófagos em diferentes concentrações, foi identificado um aumento na capacidade proliferativa de células HSC-3 e SAS tratadas com M1 EVs em um padrão dose dependente. Um aumento da capacidade proliferativa seguindo um padrão dose dependente também ocorreu quando as células SAS foram tratadas com M2 EVs. Nos demais ensaios de proliferação no IncuCyte® também foram identificados efeitos na capacidade proliferativa, no entanto um padrão dose dependente não foi observado. No ensaio de migração no IncuCyte®, foram identificadas diferenças significativas na capacidade migratória de células SCC-25 e SAS tratadas com diferentes tipos de EVs nas diferentes concentrações, quando comparadas ao controle negativo. Os achados deste estudo sugerem que as EVs derivadas de macrófagos são fatores importantes na tumorigênese do CCELO, bem como abre discussões sobre os diferentes efeitos das células inflamatórias no TME a depender do tipo de comunicação celular executada (AU).

Cancer is an entity composed of proliferating malignant cells associated with the different types surrounding cells, forming the tumor microenvironment (TME), where there is a constant exchange of information. One of the ways of communicating between different types of TME cells is through the release of extracellular vesicles (EVs), a field of study that remains poorly understood. The aim of the present study was to evaluate the effects of EVs released from TME macrophages, which are cells highly plastic in their phenotype (M1 showing an anti-tumor profile and M2 exhibiting a pro-tumor profile) in different cell lines of tongue squamous cells carcinoma (TSCC) regarding to invasive, proliferative and migratory capacity. It was observed that EVs samples obtained from macrophages were relatively pure in EVs, although they were non-specific subtypes. In the myoma invasion assay, it was observed that when inflammatory cells were co-cultured with HSC-3 cells, M1 cells inhibited invasion and M2 increased the invasive ability of the malignant cells. On the other hand, treatment with M1 EVs increased the invasive capacity of HSC-3 cells, and treatment with M2 EVs inhibited the invasion of these malignant cells, and a similar profile was observed in SCC-25 and SAS cells when they were submitted to the same treatments. In the analysis of the Ki-67 marker in myomas, HSC-3, SCC-25 and SAS cells showed the same proliferation pattern regardless the type of the treatment used when compared to the respective negative controls. When it was analyzed the proliferation of malignant cells in IncuCyte® treated with EVs derived from different types of macrophages at different concentrations, an increase in the proliferative ability of HSC-3 and SAS cells treated with M1 EVs was observed in a dosedependent pattern. An increase in proliferative ability in dose-dependent profile was also observed when SAS cells were treated with M2 EVs. In the other proliferation assays performed in IncuCyte®, effects on proliferative capacity were also highlighted, however a dose-dependent pattern was not observed. In the IncuCyte® migration assay, significant differences were observed in the migration capacity of SCC-25 and SAS cells treated with different types of EVs at different concentrations when compared to the negative control. The findings of this study suggest that macrophages-derived EVs are pivotal factors in TSCC tumorigenesis, as well as permits discussions on the different effects of inflammatory cells on TME depending on the type of cell communication performed (AU).

En el Infarto agudo al miocardio los niveles plasmáticos de microvesículas extracelulares se elevan más precozmente que el aumento de la Troponina-I / Plasma levels of extracellular macrovesicles are elevated earlier than troponin-I in patients with myocardial infarction

Introducción: La Troponina I (TnI) plasmática es el biomarcador "Gold" estándar utilizado en diagnóstico de Infarto Agudo al Miocardio (IAM), indicando necrosis cardíaca. Las microvesículas extracelulares (MVEC), participan en comunicación celular, por lo que estudiar su distribución entregaría información respecto del evento isquémico, antesala del infarto. Objetivo: Estudiar las MVECs plasmáticas en pacientes con Síndrome Coronario Agudo (SCA) y compararlas con los niveles de TnI. Métodos: Plasma de 22 pacientes controles se recolectó 0-2hrs post-ingreso a urgencia. Plasma de 45 pacientes SCA se recolectó 0-2, 6-8 y 10-14hrs post ingreso, junto con la toma de muestra para estudio de TnI. Las MVECs plasmáticas fueron enriquecidas mediante kit comercial. La determinación de la concentración y tamaño MVECs se realizó por NTA (Nanoparticles Tracking Assay) usando el equipo Nanosight. Resultados: La concentración promedio de MVECs 0-2 hrs post ingreso fue 7,2 veces superior en plasma de pacientes con SCA vs controles y la moda del tamaño disminuyó en pacientes con SCA. La TnI no mostró diferencias significativas en 0-2 hrs post ingreso en el grupo estudiado. La concentración de las MVEC disminuyó significativamente después de 10-14 hrs post ingreso, mientras que la concentración promedio TnI se mantuvo invariable demostrando el aumento de MVECs previo al incremento de TnI. Conclusión. El aumento de MVECs previo al incremento de la TnI en pacientes infartados, sugiere que las MVECs aumentan en la fase previa del IAM, como respuesta al daño tisular. Actualmente, estudiamos el contenido molecular de las MVECs, para establecer un método diagnóstico del Síndrome Coronario Agudo basado en MVECs.

Background: Troponin I (TnI) is the gold standard used to establish the diagnosis of myocardial infarction (AMI), indicating the presence of myocardial necrosis. Extracellular micro vesicles are involved in cellular communication. Their distribution may provide information relating to the development of AMI in patients with acute coronary syndromes (ACS) Aim: to study plasma levels of ECMV compared to those of TnI in patients with ACS. Methods: The plasma levels of TnI and ECMV from 22 control patients coming to the emergency units was compared to plasma from 45 patients with ACS. Levels of both parameters were determined 0-2, 6-8 and 10-14 hours post admission. ECMVs were enriched by means of a commercial kit. Concentration and size of ECMV was determined by NTA (Nanoparticles tracking assay) using the Nanosight equipment. Results: Plasma concentration of ECMV was 7.2 times higher than that of TnI 0-2 hrs post admission. The mode of ECMV size was lower in patients with ACS. Concentration of ECMV had decreased significantly 10-14 hrs post admission, whereas the TnI levees remained stable. Conclusion: The increase in ECMV earlier than TnI in AMI suggests that ECMV are elevated in the pre-AMI phase, as a response to early tissue damage. A study of cellular content of ECMV, being carried out, may lead to develop a method for the early diagnosis of AMI in patients with ACS.

Genomics and epidemiology for gastric adenocarcinomas

Whereas the pathological aspects of Gastric Adenocarcinomas (GACs) have been well defined, the actual knowledge of its genesis and evolution remains to be translated to better diagnosis and to more effective therapeutics. As a consequence, the current treatment modalities are not yet able to modify the natural history of the disease, which still presents high mortality-rates worldwide. In this review we highlight the current status of relevant epidemiologic, therapeutic and genomics aspects of GACs and point to some of the current knowledge gaps that, if fully addressed, could contribute to a more effective treatment and better management of the patients that suffer from this often-lethal disease (AU)

Marcadores e mecanismos de resistência à terapia neoadjuvante e o papel das vesículas extracelulares secretadas pelas células tumorais no câncer de reto / Biomarkers and mechanisms of resistance to neoadjuvnat therapy and the role of extracelular vesicles secreted by tumor cells in rectal cancer

O câncer de reto é o segundo tumor mais comum no intestino grosso correspondendo a um terço do total de casos de câncer colorretal (CCR). Pacientes com câncer de reto em estádios II e III são tratados com radioquimioterapia neoadjuvante seguida de ressecção cirúrgica do tumor. Análises das peças cirúrgicas ressecadas mostraram que apenas 10-45% dos pacientes obtém resposta patológica completa (RCp) à terapia neoadjuvante, estando essa associada com uma diminuição da recorrência local, melhora da sobrevida livre de doença e aumento na preservação esfincteriana. Apesar da melhora na sobrevida nas últimas décadas, a resposta à terapia neoadjuvante continua variável e imprevisível e não é possível identificar e separar clinicamente os grupos de pacientes que terão ou não resposta completa ao tratamento neoadjuvante. Além disso, os mecanismos de resistência à radioquimioterapia nos tumores de reto são pouco compreendidos. Dessa forma, o objetivo principal deste estudo foi identificar marcadores e mecanismos celulares relacionados à resistência à terapia neoadjuvante em adenocarcinoma de reto e o papel das vesículas extracelulares (VEs) nesse processo. O estudo proteômico comparativo entre biópsias obtidas de tumores pré-tratamento com o tumor residual removido cirurgicamente pós-tratamento radioquimioterápico mostrou uma importante alteração no perfil de expressão proteica. Entre as proteínas que aumentam a expressão após a neoadjuvância estão as proteínas de reparo de dano de DNA, Ku70 e Ku80, e a proteína de tráfego intracelular Rab5C. Em um modelo in vitro, foi demonstrado que Rab5C orquestra um mecanismo de resistência à radioterapia nos tumores de reto através da modulação da internalização de EGFR promovida por radiação ionizante (RI). O EGRF intracelular por sua vez é essencial para regular a expressão de Ku70 e Ku80 e a resistência celular à RI. Estes dados apontam Rab5C e EGFR como potenciais alvos terapêuticos para sensibilizar células de câncer de reto resistentes ao tratamento neoadjuvante. Também foi observado que a RI promove alterações epigenéticas predominantemente de hipometilação, e entre os genes alterados estão SPG20 e TBC1D16, sendo o primeiro importante para a internalização de EGFR e o segundo para a regulação de Rab5C e modulação de EGFR. O perfil de expressão proteica foi ainda comparado entre biópsias pré-tratamento de pacientes com RCp e sem resposta patológica, e o resultado mostrou que esses dois grupos de pacientes apresentam um diferente perfil de expressão proteica. Nos pacientes com RCp as proteínas com aumento da expressão estão atuando em vias que favorecem a resposta à terapia, como a detoxificação de glutationa e degradação de glicogênio, enquanto as proteínas com aumento da expressão em pacientes sem RCp estão envolvidas em vias do metabolismo energético do tumor as quais contribuem para a resistência tumoral à terapia. As diferenças observadas nestes grupos devem ser amplamente exploradas uma vez que podem ser marcadores preditivos de resposta ao tratamento radioquimioterápico. A realização de estudos funcionais foi viabilizada pela geração de um modelo celular de tumor de reto resistente à radioterapia. Ao analisar as VEs secretadas por estas células foi observado que a RI não altera a quantidade e o tamanho médio das VEs secretadas, porém é capaz de alterar o carregamento proteico das mesmas. De fato, as VEs de células irradiadas apresentam um perfil proteico diferente quando comparadas as VEs de células não irradiadas, onde encontramos aumento da expressão de Ku70, Ku80 e Rab5C, além das metiltransferases NSUN2 e GLYM nas VEs de células pós RI. Interessantemente, as VEs secretadas por células irradiadas são capazes de transmitir a resistência à RI às células não irradiadas. Além disso os resultados mostraram que o tratamento com VEs de células irradiadas promove metilação em 98% do DNA avaliado em células SW837 em comparação ao tratamento com VEs de células não irradiadas. Os genes hipermetilados estão envolvidos em vias relacionadas ao sistema imune, como a apresentação de antígeno, sinalização de imunodeficiência primária e maturação de células dendríticas. Por fim, foi identificado que a expressão da proteína A33 está relacionada ao grau de diferenciação dos tumores colorretais, e que essa proteína está presente em VEs secretadas por células de adenocarcinoma de reto, indicando que a mesma pode ser usada para isolar VEs específicas do tecido colorretal. Os dados obtidos neste trabalho apontam mecanismos relacionados à resistência à terapia neoadjuvante no adenocarcinoma de reto e que em conjunto permitirão identificar novos alvos terapêuticos com potencial de melhorar a resposta à radioquimioterapia, além de identificar marcadores de resposta à terapia neoadjuvante antes do tratamento e dessa forma, poupar os pacientes não respondedores de terapias tóxicas e melhorar a sustentabilidade na saúde poupando os custos com drogas não eficientes para um grupo de pacientes.

Rectal cancer is the second most common cancer in large intestine, corresponding to one third of total cases of colorectal cancer (CRC). Patients with rectal cancer in stage II and III are treated with neoadjuvant chemoradiation followed by surgical resection. Analyzes of the resected tumor demonstrated that only 10-45% of the patients achieve pathological complete response (pCR) after neoadjuvant therapy, which is associated with a decrease in local recurrence, improvement of disease free survival and increase in sphincter preservation. Despite the improvement in survival in the last decades, the response to neoadjuvant therapy is still variable and unpredictable, and before the surgery it is not possible to identify and separate clinically the group of patients that will or will not have complete response to neoadjuvant treatment. Moreover, the mechanisms of resistance of rectal tumors to chemoradiation are poorly understood. Thus, the main objective of this work was to identify biomarkers and cellular mechanisms related to the resistance to neoadjuvant therapy in rectal adenocarcinomas and the role of extracellular vesicles (EVs) in this process. The comparative proteomic study between biopsy obtained from tumors pretreatment with residual tumor, post chemoradiation treatment, removed by surgery showed an important alteration in the protein expression profile. Among the proteins with increased expression after neoadjuvant therapy are the DNA repair proteins Ku70 and Ku80, and the protein involved in the intracellular trafficking, Rab5C. It was demonstrated in vitro that Rab5C orchestrates a mechanism of radioresistance in rectal tumors by modulating the EGFR internalization promoted by ionizing radiation (IR). The intracellular EGFR is essential to regulate Ku70 and Ku80 expression and the cell resistance to IR. These data pointed Rab5C and EGFR as potential therapeutic targets to sensitize rectal cancer cells resistant to neoadjuvant treatment. It was also observed that IR promotes epigenetic alterations, predominantly hypomethylation, and between the altered genes are SPG20 and TBC1D16, the first is important to EGFR internalization, while the second regulates Rab5C and modulates EGFR. The protein expression profile was further compared between biopsy pretreatment of patients with and without pCR, and the results showed that these two groups of patients present a different protein expression profile. In patients with pCR the proteins with increased expression are involved in pathways favoring the response to therapy, as glutathione-mediated detoxification and glycogen degradation, while the proteins with increased expression in patients without pCR are involved in tumor energetic metabolism pathways that contribute to tumor resistance to therapy. The observed differences in these groups should be widely explored since they may be predictive markers of response to chemoradiation treatment. The performance of functional studies was possible by generation of a cellular model of rectal tumor resistant to radiotherapy. The analysis of the EVs secreted by these cells showed that IR does not alter the amount and the medium size of secreted EVs, but is able to change their protein content. EVs from irradiated cells presented a different protein profile when compared to EVs from non-irradiated cells, where it was found the increased expression of Ku70, Ku80 and Rab5C, besides the methyltransferases NSUN2 and GLYM in EVs after irradiation. Interestingly, the EVs secreted by irradiated cells are capable of transfering resistance to IR to non-irradiated cells. Moreover, the results showed that the treatment of SW837 cells with EVs from irradiated cells promoted methylation in 98% of the analyzed DNA in comparison with the treatment with EVs from non-irradiated cells. The hypermethylated genes are involved in pathways related to immune system, as antigen presentation, primary immunodeficiency signaling and dendritic cells maturation. Lastly, it was identified that the A33 expression is related to the colorectal tumors differentiation degree, and this protein is present in EVs secreted by rectal adenocarcinoma, indicating that it may be used to isolate EVs specific from colorectal tissues. The data obtained in this work pointed to mechanisms related to resistance to neoadjuvant therapy in rectal adenocarcinoma that together will allow to identify new therapeutic targets with the potential to improve the response to chemoradiation, as well as to identify markers of response to neoadjuvant therapy before the treatment, and, in this way, avoid the non-responder patients to receive toxic therapies and improve health sustainability, sparing cost with non-efficient drugs for a group of patients.

Papel do complexo PrPc-HOP e vesículas extracelulares em câncer colorretal / Role of PrPC-HOP complex and extracellular vesicles in colorectal cancer

O câncer colorretal (CCR) é o terceiro tipo de câncer mais comum no mundo. Apesar dos avanços nos tratamentos convencionais, aproximadamente dois terços dos pacientes com CCR são submetidos à cirurgia potencialmente curativa. Entretanto, grande parte desses pacientes evolui mal, apresentando recidivas e/ou metástases. A busca de novos alvos moleculares para a terapia do CCR revelou a proteína celular Prion (PrPC) como um possível candidato. Trabalhos recentes sugerem participação direta ou indireta de PrPC no crescimento de tumores, na formação de metástases, na composição de complexos multiproteicos e na indução de vias de sinalização envolvidas em diversos processos biológicos, como proliferação. Além disso, PrPC foi descrito como um importante modulador do crescimento de tumor colorretal. Resultados prévios mostraram que a interação da proteína PrPC com a proteína HSP70/HSP90 Organizing Protein (HOP) induz proliferação em glioblastomas. HOP é uma proteína predominantemente citoplasmática, podendo também ser secretada associada às vesículas extracelulares. Assim, o presente estudo objetivou avaliar o papel do complexo PrPC-HOP e das vesículas extracelulares no desenvolvimento e progressão dos tumores colorretais. Os nossos resultados mostram que HOP induziu migração e invasão em linhagens de CCR de maneira dependente de PrPC, uma vez que o uso do peptídeo sem atividade que compete pelo sítio ligação de HOP a PrPC inibiu estes processos. Além disso, nossos dados apontaram que o aumento de migração e invasão das células de CCR induzida pela interação PrPC-HOP é mediada pela ativação da via ERK1/2. Os achados in vitro estimularam a avaliação do perfil de expressão de PrPC e HOP por imuno-histoquímica em tecidos de pacientes com diferentes tipos de tumores colorretais. Nossos resultados sugeriram que essas proteínas são importantes no início do desenvolvimento tumoral e na transição de adenomas para adenocarcinomas, não havendo correlação entre a presença de HOP e/ou PrPC com metástase, linfonodos acometidos, estadiamento, sobrevida ou região tumoral versus tecido normal. Em relação ao papel das vesículas extracelulares na progressão dos tumores colorretais, nossos resultados mostraram que linhagens celulares que apresentam padrões parecidos de agressividade tumoral podem ter perfis de secreção de proteínas e vesículas extracelulares bastante diferentes, induzindo, portanto, processos biológicos com intensidades distintas. O meio condicionado e as vesículas extracelulares da linhagem WiDr apresentaram maior potencial de indução de migração quando comparado com a linhagem HCT8. Além disso, a modulação negativa da proteína VPS4, uma das responsáveis pela formação dos corpos multivesiculares, mostrou-se uma abordagem interessante no estudo da secreção de vesículas por células de CCR, uma vez que o dominante negativo de VPS4 promoveu diminuição do cargo proteico e da secreção de vesículas extracelulares, redução da proliferação celular e do efeito indutor do processo de migração na linhagem WiDr. Assim, em conjunto, o presente trabalho indicou que o complexo PrPC-HOP pode ser um bom alvo terapêutico nos processos de migração e invasão em CCR. Ainda, essas proteínas se mostraram importantes nos estágios iniciais da formação dos tumores. A modulação da secreção de vesículas extracelulares pode contribuir para retardar a progressão dos tumores colorretais

Colorectal cancer (CRC) is the third most common type of cancer in the world. Despite improvements in conventional treatments, approximately two-thirds of CRC patients undergo potentially curative surgery. However, most of these patients evolve poorly, showing recurrence and/or metastasis. Search of new molecular targets for CRC therapy revealed the cellular protein Prion (PrPC) as a putative candidate. Recent studies have shown that PrPC exhibit direct or indirect participation in tumor growth, formation of metastasis, composition of multiprotein complexes and induction of signaling pathways involved in many biological processes such as proliferation. Moreover, PrPC has been described as an important modulator of colorectal tumor growth. Previous findings showed that the interaction between PrPC and its ligand HSP70/90 heat shock organizing protein (HOP) induces gliobastoma proliferation. It is well known that HOP localizes mainly in the cytoplasm but HOP is also secreted associated with extracellular vesicles. In this way, the present study sought to evaluate the role of PrPC-HOP complex and extracellular vesicles in the development and progression of CRC. We demonstrate that HOP induces the migration and invasion of CRC cell lines in a PrPC-dependent manner because the use of HOP peptide, which is able to bind to PrPC, blocking PrPC-HOP complex formation, inhibited the migration and invasion processes. In addition, our data showed that the enhancement of migration and invasion induced by PrPC-HOP interaction is mediated by ERK1/2 pathway activation. These in vitro results lead us to evaluate the PrPC and HOP expression by immunohistochemistry in tissues from patients with different tumor types. Our data showed that these proteins could be important for the initial steps of tumor development, represented by the transition from adenoma to adenocarcinoma. No correlation was found among HOP and/or PrPC expression and metastasis, lymph node involvement, staging, survival or tumor area versus normal tissue. Regarding the role of extracellular vesicles in the progression of colorectal tumors, our results showed that cell lines exhibiting similar aggressive tumor behavior can have a different protein secretion pattern and a distinct profile of extracellular vesicles release, which could induce biological process with different intensities. The conditioned medium and the extracellular vesicles derived from WiDr cell line showed a higher potential to induce migration than HCT8 cell line. Moreover, the negative modulation of VPS4, one of the proteins responsible for multivesicular body formation, showed to be an interesting approach in the study of extracellular vesicles secretion secreted by CRC cells; the negative dominant of VPS4 promoted in the WiDr cell line a reduction in the protein cargo and secretion of the extracellular vesicles, a decrease of cell proliferation and induction of migration process. Therefore, taken together, our data highlights that PrPC-HOP complex can be considered a new therapeutic target in migration and invasion processes of CRC. Moreover, these proteins appeared to be important at onset of tumor formation. The modulation of extracellular vesicles secretion may contribute for delaying the progression of colorectal tumors

Análise do papel dos exossomos derivados das linhagens celulares SCC-15 e HSC-3 no processo de angiogênese tumoral / Analysis of the role of exosomes derived from cell lines SCC-15 and HSC-3 in the process of tumor angiogenesis

Os exossomos são vesículas extracelulares originadas por brotamento interno da membrana de endossomos tardios que representam uma eficiente forma de comunicação intercelular. Devido às suas múltiplas funções biológicas, o foco de alguns estudos atuais tem se concentrado na análise do seu papel no desenvolvimento do câncer, progressão da doença, invasão, angiogênese e formação de metástases tumorais. Nesta perspectiva, o presente estudo objetivou caracterizar os exossomos secretados por duas linhagens celulares de carcinomas epidermoide oral (CEO) (SCC-15 e HSC-3) e avaliar seus efeitos sobre uma linhagem de células endoteliais (HUVEC), em relação à sua capacidade de formação de estruturas vasculares, taxas de migração, proliferação e índices de apoptose/necrose. Médias significativamente maiores de células com potencial invasivo (p<0,0001) e migratório (p<0,0001) foram observadas para a linhagem HSC-3. Ultraestruturalmente, verificou-se que as partículas derivadas da linhagem SCC-15 exibiram morfologia arredondada e diâmetro inferior a 150 nm. Nenhuma diferença estatisticamente significativa foi revelada entre as linhagens celulares estudadas, considerando a quantificação de nanovesículas (p=0,2252) e tamanho exossomal (p=0,1765). Por imunofluorescência indireta, identificou-se que 22,15% dos exossomos secretados pelas células SCC-15 e 18,37% dos exossomos derivados da linhagem HSC-3 expressaram o anticorpo anti-Anexina. No que se refere aos ensaios funcionais com as HUVECs, o tratamento com exossomos derivados da linhagem SCC-15 induziu um aumento significativo da capacidade de formação de estruturas vasculares (p<0,0001), potencial migratório (p=0,0016) e taxa de apoptose (p<0,0001), enquanto que uma redução da proliferação celular foi apontada (p=0,0030). Por outro lado, o tratamento com exossomos secretados pela linhagem HSC-3 promoveu uma redução significativa da formação tubular (p<0,0001), motilidade (p=0,0042) e proliferação celular (p=0,0010), ao passo que nenhuma diferença estatisticamente significativa foi observada no índice apoptótico (p=0,3004). Os resultados do presente estudo indicaram a participação dos exossomos derivados de linhagens de CEO no processo de angiogênese tumoral, onde as células SCC-15 exibiram forte resposta proangiogênica e a linhagem HSC-3 demonstrou efeito antiangiogênico (AU).

Exosome are extracellular microvesicles originated by inward budding of late endosomal membrane that represent an efficient form of intercellular communication. Because of its multiple biological functions, the focus of some recent studies has concentrated on the analysis of its role in cancer development, disease progression, invasion, angiogenesis and tumor metastasis formation. In this perspective, the present study aimed to characterize the secreted exosomes by two cell lines of oral squamous cell carcinomas (OSCC) (SCC-15 and HSC-3) and to evaluate its effects on a cell line of endothelial cells (HUVEC), in relation to their ability to form vascular structures, rates of migration, proliferation, and apoptosis / necrosis indices. Significantly higher means of cells with invasive (p<0.0001) and migratory potential (p = <0.0001) were observed for the HSC-3 cell line. Ultrastructurally, it was found that particles derived from the SCC-15 cell line exhibited a rounded morphology and diameter of less than 150 nm. No statistically significant difference was revealed between the studied cell lines, considering the nanovesicles quantization (p=0.2252) and exossomal size (p=0.1765). By indirect immunofluorescence, it was found that 22.15% of exosomes secreted by SCC-15 cells and 18.37% of exosomes derived from HSC-3 cells expressed anti-annexin antibody. With regard to the functional tests with HUVECs, treatment with exosomes derived from SCC-15 cell line induced a significant increase in their capacity of formation of vascular structures (p = <0.0001), migratory potential (p=0.0016) and rate of apoptosis (p<0.0001), while a decrease in cell proliferation was noted (p = 0.0030). On the other hand, the treatment with exosomes secreted by HSC-3 cell line produced a significant reduction in tubule formation (p<0.0001), motility (p = 0.0042) and cell proliferation (p=0.0010), whereas no statistically significant difference was observed in the apoptotic index (p=0.3004). The results of this study indicated the involvement of exosomes derived from OSCC cell lines in tumor angiogenesis process, in which the SCC-15 cells exhibited strong proangiogenic response and HSC-3 cell line showed antiangiogenic effect (AU).