Rol de los receptores activadores de la proliferación de peroxisomas del subtipo gamma el el cáncer de vejiga

PPARg es miembro de la superfamilia de receptores nucleares que son factores de transcripción activados por su ligando. BCG es el tratamiento de elección para el cáncer devejiga (CaV) que no invade músculo. Nos propusimos estudiar el rol de éste receptor bajo el tratamiento de BCG en ésta patología. Encontramos que BCG es capaz de inducir la expresión de PPARg en células de CaV murinas, MB49 y los ligandos de PPARg potencian este efecto. La actividad transcripcional de PPARg también es aumentada por BCG y potenciada por 15-d-PGJ2, ligando de PPARg. Al mismo tiempo BCG induce en las líneas de CaV la expresión de iNOS y la consecuente producción de óxido nítrico (NO). Los ligandos de PPARg inhibirían la producción de NO inducida por BCG, por un mecanismo PPARg independiente pero dependiente de la vía de NF-kB. In vivo, BCG inhibe el crecimiento de tumores, efecto bloqueado por BADGE, antagonista de PPARg indicando que parte del mecanismo de acción de BCG es a través de PPARg. BCG induce la expresión de colágeno, SMA-alfa y FGF-2, al mismo tiempo induce la proliferación de los fibroblastos in vitro. RO revierte el efecto inhibitorio ejercido por BCG, inhibiendo diferentes funciones de macrófagos y fibroblastos. BCG media su mecanismo de acción antitumoral, en parte, a través de PPARg pero su activación in vivo con agonistas exógenos puede ser contraproducente dado su funcionalidad en el sistema inmune. Obtuvimos una nueva línea celular, MB49-I y desarrollamos un modelo murino ortotópico con distinto grado de invasión. Al evaluar la expresión de PPARg en éste modelo, observamos que PPARg está aumentado en tumores superficiales comparado con la vejiga normal, mientras que se pierde en vejigas portadoras de tumor invasor. En tumores vesicales de pacientes observamos que un mayor número de pacientes con tumores invasores expresa bajos niveles de PPARg comparado con aquellos pacientes con tumores no invasores, sugiriendo que PPARg podría estar involucrado en la progresión de tumores de vejiga

Role of the peroxisome proliferator-activated receptor subtipo gamma in bladder cancer

PPARg es miembro de la superfamilia de receptores nucleares que son factores de transcripción activados por su ligando. BCG es el tratamiento de elección para el cáncer devejiga (CaV) que no invade músculo. Nos propusimos estudiar el rol de éste receptor bajo el tratamiento de BCG en ésta patología. Encontramos que BCG es capaz de inducir la expresión de PPARg en células de CaV murinas, MB49 y los ligandos de PPARg potencian este efecto. La actividad transcripcional de PPARg también es aumentada por BCG y potenciada por 15-d-PGJ2, ligando de PPARg. Al mismo tiempo BCG induce en las líneas de CaV la expresión de iNOS y la consecuente producción de óxido nítrico (NO). Los ligandos de PPARg inhibirían la producción de NO inducida por BCG, por un mecanismo PPARg independiente pero dependiente de la vía de NF-kB. In vivo, BCG inhibe el crecimiento de tumores, efecto bloqueado por BADGE, antagonista de PPARg indicando que parte del mecanismo de acción de BCG es a través de PPARg. BCG induce la expresión de colágeno, SMA-alfa y FGF-2, al mismo tiempo induce la proliferación de los fibroblastos in vitro. RO revierte el efecto inhibitorio ejercido por BCG, inhibiendo diferentes funciones de macrófagos y fibroblastos. BCG media su mecanismo de acción antitumoral, en parte, a través de PPARg pero su activación in vivo con agonistas exógenos puede ser contraproducente dado su funcionalidad en el sistema inmune. Obtuvimos una nueva línea celular, MB49-I y desarrollamos un modelo murino ortotópico con distinto grado de invasión. Al evaluar la expresión de PPARg en éste modelo, observamos que PPARg está aumentado en tumores superficiales comparado con la vejiga normal, mientras que se pierde en vejigas portadoras de tumor invasor. En tumores vesicales de pacientes observamos que un mayor número de pacientes con tumores invasores expresa bajos niveles de PPARg comparado con aquellos pacientes con tumores no invasores, sugiriendo que PPARg podría estar involucrado en la progresión de tumores de vejiga.Peroxisome proliferatoractivated receptor gamma (PPARg) is a member of the nuclear receptor superfamily of ligand-activated transcription factors that is involved in cell growth and differentiation as well as inflammatory processes. We found that BCG is able to induce PPARg expresión in bladder murine cell line MB49. Transcriptional activity of PPARg is also increased by BCG and it is enhanced by 15-d-PGJ2, a PPARg ligand. At the same time, PPARg ligands enhance BCG-induced cell death. BCG also induces iNOS expression and NO production. PPARg ligands inhibits NO production induced by BCG. In vivo, BCG inhibits tumor growth, but RO reverses that effect. RO inhibits different functions associated to activated macrophages induced by BCG. In vitro, BCG induces fibroblast proliferation and in vivo, induces collagen, FGF-2 and alpha-SMA expresión. RO decreases that induction. We have generated a new cell line, MB49-I and we developped a new murine ortothopic model with different levels of invasion. PPARg is increased in superficial tumors compared to normal bladder, meanwhile, this expression is reduced in invasive tumors. In patients, we observed that invasive tumors express low level of PPARg compared to those with non-invasive tumors. PPARg is involved in the mechanism of action of BCG, but his activation could be not recommended in vivo, since it has a relevant role in the inmune system. PPARg expression is decreased in invasive tumors, which suggests that this transcription factor plays a key role during progresion in bladder tumors.Fil:Lodillinsky, Catalina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Role of Peroxisome Proliferator Activated Receptor-Gamma in Bacillus Calmette-Guérin Bladder Cancer Therapy

Purpose: We evaluated the effects of combined PPARg agonist with bacillus Calmette-Guérin in bladder cancer growth in vitro and in vivo, focusing on the tissue remodeling mechanisms induced by bacillus Calmette-Guérin. Materials and Methods: PPARs are a superfamily of nuclear receptors that are transcription factors activated by ligands. Activation of PPARg, the subtype, causes proliferation inhibition or differentiation of tumor cells. Previously, we reported that the inhibition of murine bladder tumor growth induced by bacillus Calmette-Guérin, which is the standard treatment for patients with nonmuscle invasive, high grade bladder cancer, increased PPARg expression in vitro and in vivo. In vitro the cell growth inhibition induced by bacillus Calmette-Guérin was enhanced by the PPARg agonist 15-d-PGJ2, raising the possibility that PPARg activation may be a therapeutic modality for this disease. Results: In MB49 cells bacillus Calmette-Guérin and 15-d-PGJ2 induced PPARg expression, nuclear translocation and transcriptional activity. In vivo bacillus Calmette-Guérin reduced tumor size, an effect that was partially reversed when bacillus Calmette-Guérin was combined with the PPARg agonist rosiglitazone. The same result was found when we analyzed the effect of the PPARg antagonist BADGE (Fluka Chemical, Buchs, Switzerland) combined with bacillus Calmette- Guérin. Analysis of the activation of macrophages and fibroblasts demonstrated that rosiglitazone inhibited the tissue remodeling mechanisms induced by bacillus Calmette-Guérin. Conclusions: Results suggest that PPARg is involved in the antitumor action of bacillus Calmette-Guérin. However, exogenous PPARg agonists would not be a favorable therapeutic modality because they can inhibit the tissue remodeling needed for an overall satisfactory bacillus Calmette-Guérin response.Fil: Langle, Yanina Verónica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lodillinsky, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; ArgentinaFil: Belgorosky, Denise. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sandes, Eduardo Omar. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; ArgentinaFil: Eiján, Ana Maria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología; Argentin

Cathepsin B is involved in the apoptosis intrinsic pathway induced by Bacillus Calmette-Guérin in transitional cancer cell lines

Bacillus Calmette-Guérin (BCG) is the most effective treatment for superficial and in situ transitional bladder cancer. Although the complete mechanisms for its effect are not fully understood yet, both immunological and direct effects on tumor cells have been proposed. It has been proposed that apoptotic tumor cells could be better inducers of immunity than necrotic ones. Thus, apoptosis of bladder cancer cells could contribute to a global response to BCG. Lysosomal hydrolase cathepsin B (CB) is involved in the apoptotic process and has a key role in breast cancer cell programmed death through the activation of a pro-apoptotic protein BID. Truncated BID participates in the mitochondrial apoptotic pathway that involves the activation of pro-caspase 9. The possibility that CB can be involved in apoptosis of TCC line has not been explored yet. Therefore, we analyzed the participation of CB in BCG-induced apoptosis of human and murine TCC lines. Apoptosis was evaluated by a morphologic assay and CB activity by a substrate-specific colorimetric method. Expression of CB, BID and pro-caspase 9 was determined by Western blotting. BCG induced apoptosis of murine (MBT2, MB49) and human (T24) TCC lines. An increase in both CB activity and protein was also observed. The apoptosis of T24 and MB49 cell lines was mediated by activation of pro-caspase 9 and BID, both proteins are involved in mitochondrial apoptosis. Apoptosis and activation of pro-caspase 9 and BID were inhibited by CA-074Me (CA), a cell permeable CB inhibitor. Thus, CB is involved in BCG-induced apoptosis of TCC lines, using at least in part the mitochondrial pathway.Fil: Sandes, Eduardo Omar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Lodillinsky, Catalina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cwirenbaum, Ruth Ana. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Argüelles, Claudia Lidia. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Casabé, Alberto. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Eijan, Ana Maria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Bacillus Calmette Guerin Induces Fibroblast Activation Both Directly and through Macrophages in a Mouse Bladder Cancer Model

BACKGROUND: Bacillus Calmette-Guerin (BCG) is the most effective treatment for non-muscle invasive bladder cancer. However, a failure in the initial response or relapse within the first five years of treatment has been observed in 20% of patients. We have previously observed that in vivo administration of an inhibitor of nitric oxide improved the response to BCG of bladder tumor bearing mice. It was described that this effect was due to a replacement of tumor tissue by collagen depots. The aim of the present work was to clarify the mechanism involved in this process. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that BCG induces NIH-3T3 fibroblast proliferation by activating the MAPK and PI3K signaling pathways and also differentiation determined by alpha-smooth muscle actin (alpha-SMA) expression. In vivo, intratumoral inoculation of BCG also increased alpha-SMA and collagen expression. Oral administration of L-NAME enhanced the pro-fibrotic effect of BCG. Peritoneal macrophages obtained from MB49 tumor-bearing mice treated in vivo with combined treatment of BCG with L-NAME also enhanced fibroblast proliferation. We observed that FGF-2 is one of the factors released by BCG-activated macrophages that is able to induce fibroblast proliferation. The involvement of FGF-2 was evidenced using an anti-FGF2 antibody. At the same time, this macrophage population improved wound healing rate in normal mice and FGF-2 expression was also increased in these wounds. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that fibroblasts are targeted by BCG both directly and through activated macrophages in an immunotherapy context of a bladder murine model. We also described, for the first time, that FGF-2 is involved in a dialog between fibroblasts and macrophages induced after BCG treatment. The fact that L-NAME administration improves the BCG effect on fibroblasts, NO inhibition, might represent a new approach to add to the conventional BCG therapy

Effect of nitric oxide inhibition in Bacillus Calmette-Guerin bladder cancer treatment

Background: Bacillus Calmette-Guerin (BCG) is the standard treatment for patients with high-risk non-muscle invasive bladder cancer (BC). Despite its success, about 30–50% of patients are refractory. It was reported that inducible nitric oxide synthase (iNOS) tumor expression is presented in 50% of human BC, associated with bad prognosis and BCG failure. Objective: to evaluate in human bladder tumors the association between iNOS expression and the tumor microenvironment focusing on the immunosuppressive protein S100A9. Also, investigate in a preclinical murine MB49-BC model the tumor immunoresponse induced by BCG in combination with the nitric oxide production inhibitor L-NAME. Results: In human bladder tumors, we detected a positive association between iNOS and S100A9 tumor expression, suggesting a relationship between both immunomodulatory proteins. We also found a positive correlation between iNOS tumor expression and the presence of S100A9+ tumor-infiltrating cells, suggesting an immunosuppressive tumor microenvironment induced by the nitric oxide production. Using the subcutaneous murine BC model, we show that similarly to the human pathology, MB49 tumors constitutively expressed iNOS and S100A9 protein. MB49 tumor-bearing mice presented an immunosuppressive systemic profile characterized by fewer cytotoxic cells (CD8+ and NK) and higher suppressor cells (Treg and myeloid-derived suppressor cells -MDSC-) compared to normal mice. BCG treatment reduced tumor growth, increasing local CD8+-infiltrating cells and induced a systemic increase in CD8+ and a reduction in Treg. BCG combined with L-NAME, significantly reduced tumor growth compared to BCG alone, diminishing iNOS and S100A9 tumor expression and increasing CD8+-infiltrating cells in tumor microenvironment. This local response was accompanied by the systemic increase in CD8+ and NK cells, and the reduction in Treg and MDSC, even more than BCG alone. Similar results were obtained using the orthotopic BC model, where an increase in specific cytotoxicity against MB49 tumor cells was detected. Conclusion: The present study provides preclinical information where NO inhibition in iNOS-expressing bladder tumors could contribute to improve BCG antitumor immune response. The association between iNOS and S100A9 in human BC supports the hypothesis that iNOS expression is a negative prognostic factor and a promising therapeutic target.Fil: Langle, Yanina Verónica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Balarino, Natalia Patricia. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Belgorosky, Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Cresta Morgado, Pablo Damián. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Sandes, Eduardo Omar. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Marino, Lina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Rojas Bilbao, Erica. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Zambrano, Macarena. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Lodillinsky, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Eijan, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentin

Ephrin-B1 Is a novel biomarker of bladder cancer aggressiveness. studies in murine models and in human samples

Bladder cancer (BC) is the ninth most common cancer worldwide, but molecular changes are still under study. During tumor progression, Epithelial cadherin (E-cadherin) expression is altered and β-catenin may be translocated to the nucleus, where it acts as co-transcription factor of tumor invasion associated genes. This investigation further characterizes E-cadherin and β-catenin associated changes in BC, by combining bioinformatics, an experimental murine cell model (MB49/MB49-I) and human BC samples. In in silico studies, a DisGeNET (gene-disease associations database) analysis identified CDH1 (E-cadherin gene) as one with highest score among 130 BC related-genes. COSMIC mutation analysis revealed CDH1 low mutations rates. Compared to MB49 control BC cells, MB49-I invasive cells showed decreased E-cadherin expression, E- to P-cadherin switch, higher β-catenin nuclear signal and lower cytoplasmic p-Ser33-β-catenin signal, higher Ephrin-B1 ligand and EphB2 receptor expression, higher Phospho-Stat3 and Urokinase-type Plasminogen Activator (UPA), and UPA receptor expression. MB49-I cells transfected with Ephrin-B1 siRNA showed lower migratory and invasive capacity than control cells (scramble siRNA). By immunohistochemistry, orthotopic MB49-I tumors had lower E-cadherin, increased nuclear β-catenin, lower pSer33-β-catenin cytoplasmic signal, and higher Ephrin-B1 expression than MB49 tumors. Similar changes were found in human BC tumors, and 83% of infiltrating tumors depicted a high Ephrin-B1 stain. An association between higher Ephrin-B1 expression and higher stage and tumor grade was found. No association was found between abnormal E-cadherin signal, Ephrin-B1 expression or clinical-pathological parameter. This study thoroughly analyzed E-cadherin and associated changes in BC, and reports Ephrin-B1 as a new marker of tumor aggressiveness.Fil: Mencucci, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Lapyckyj, Lara. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Rosso, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Besso, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Belgorosky, Denise. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Isola, Mariana. Hospital Italiano; ArgentinaFil: Vanzulli, Silvia. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Lodillinsky, Catalina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Eiján, Ana María. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Tejerizo, Juan Carlos. Hospital Italiano; ArgentinaFil: González, Matías Ignacio. Hospital Italiano; ArgentinaFil: Zubieta, María Ercilia. Hospital Italiano; ArgentinaFil: Vazquez, Monica Hebe. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

An essential role for decorin in bladder cancer invasiveness

Muscle-invasive forms of urothelial carcinomas are responsible for most mortality in bladder cancer. Finding new treatments for invasive bladder tumours requires adequate animal models to decipher the mechanisms of progression, in particular the way tumours interact with their microenvironment. Herein, using the murine bladder tumour cell line MB49 and its more aggressive variant MB49-I, we demonstrate that the adaptive immune system efficiently limits progression of MB49, whereas MB49-I has lost tumour antigens and is insensitive to adaptive immune responses. Furthermore, we unravel a parallel mechanism developed by MB49-I to subvert its environment: de novo secretion of the proteoglycan decorin. We show that decorin overexpression in the MB49/MB49-I model is required for efficient progression, by promoting angiogenesis and tumour cell invasiveness. Finally, we show that these results are relevant to muscle-invasive human bladder carcinomas, which overexpress decorin together with angiogenesis- and adhesion/migration-related genes, and that decorin overexpression in the human bladder carcinoma cell line TCCSUP is required for efficient invasiveness in vitro. We thus propose decorin as a new therapeutic target for these aggressive tumours.Fil: El Behi, Mohamed. Institute Curie; Francia. Centre de Recherche de I; Francia. Inserm; FranciaFil: Krumeich, Sophie. Institute Curie; Francia. Inserm; FranciaFil: Lodillinsky, Catalina. Institute Curie; Francia. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kamoun, Aurélie. Institute Curie; FranciaFil: Tibaldi, Lorenzo. Institute Curie; Francia. Inserm; FranciaFil: Sugano, Gaël. Institute Curie; Francia. Inserm; FranciaFil: de Reynies, Aurélien. Ligue Nationale Contre le Cancer; FranciaFil: Chapeaublanc, Elodie. Institute Curie; Francia. Centre National de la Recherche Scientifique; FranciaFil: Laplanche, Agnès. Centre National de la Recherche Scientifique; Francia. Institut de Cancérologie Gustave Roussy; FranciaFil: Lebret, Thierry. Hôpital Foch. Service d; Francia. Université de Versailles; FranciaFil: Allory, Yves. Inserm; FranciaFil: Radvanyi, François. Institute Curie; Francia. Centre National de la Recherche Scientifique; FranciaFil: Lantz, Olivier. Institute Curie; Francia. Inserm; FranciaFil: Eijan, Ana Maria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bernard Pierrot, Isabelle. Institute Curie; Francia. Centre National de la Recherche Scientifique; FranciaFil: Théery, Clotilde. Institute Curie; Francia. Inserm; Franci

Social networking in tumor cell communities is associated with increased aggressiveness

Extracellular vesicles (EVs) are lipid-bilayer-enclosed vesicles that contain proteins, lipids and nucleic acids. EVs produced by cells from healthy tissues circulate in the blood and body fluids, and can be taken up by unrelated cells. As they have the capacity to transfer cargo proteins, lipids and nucleic acids (mostly mRNAs and miRNAs) between different cells in the body, EVs are emerging as mediators of intercellular communication that could modulate cell behavior, tissue homeostasis and regulation of physiological functions. EV-mediated cell-cell communications are also proposed to play a role in disease, for example, cancer, where they could contribute to transfer of traits required for tumor progression and metastasis. However, direct evidence for EV-mediated mRNA transfer to individual cells and for its biological consequences in vivo has been missing until recently. Recent studies have reported elegant experiments using genetic tracing with the Cre recombinase system and intravital imaging that visualize and quantify functional transfer of mRNA mediated by EVs in the context of cancer and metastasis