RESUMO
Introduction: Cancer is the second leading cause of death in the United States, surpassed only by cardiovascular disease. However, cancer has now overtaken cardiovascular disease as the main cause of death in 12 countries in Western Europe. The burden of cancer is posing a major challenge to health care systems worldwide and demanding improvements in methods for cancer prevention, diagnosis, and treatment. Alternative and complementary strategies for orthodox surgery, radiotherapy, and chemotherapy need to be developed. Objective: To determine the oncolytic potential of tumor cell-adapted rotavirus in terms of their ability to infect and lysate murine myeloma Sp2/0-Ag14 cells. Materials and methods: We inoculated rotaviruses Wt1-5, WWM, TRUYO, ECwt-O, and WTEW in Sp2/0-Ag14 cells and we examined their infectious effects by immunocytochemistry, immunofluorescence, flow cytometry, and DNA fragmentation assays. Results: Rotavirus infection involved the participation of some heat shock proteins, of protein disulfide isomerase (PDI), and integrin ß3. We detected the accumulation of viral antigens within the virus-inoculated cells and in the culture medium in all the rotavirus isolates examined. The rotavirus-induced cell death mechanism in Sp2/0-Ag14 cells involved changes in cell membrane permeability, chromatin condensation, and DNA fragmentation, which were compatible with cytotoxicity and apoptosis. Conclusions: The ability of the rotavirus isolates Wt1-5, WWM, TRUYO, ECwt-O, and WTEW to infect and cause cell death of Sp2/0-Ag14 cells through mechanisms that are compatible with virus-induced apoptosis makes them potential candidates as oncolytic agents.
Introducción. El cáncer es la segunda causa de muerte en los Estados Unidos, solamente superado por la enfermedad cardiovascular. Sin embargo, el cáncer aventaja a la enfermedad cardiovascular como primera causa de muerte en doce países de Europa occidental. Se requieren mejores métodos de prevención, diagnóstico y tratamiento para afrontar el gran desafío que el cáncer representa mundialmente para los sistemas de salud, y se necesita desarrollar estrategias alternativas y complementarias a la cirugía, la radioterapia y la quimioterapia convencionales. Objetivo. Evaluar el potencial oncolítico de rotavirus adaptados a células tumorales por su capacidad para infectar y lisar células Sp2/0-Ag14 de mieloma de ratón. Materiales y métodos. Los aislamientos de rotavirus Wt1-5, WWM, TRUYO, ECwt-O y WTEW se inocularon en células Sp2/0-Ag14 y se examinaron sus efectos infecciosos mediante inmunocitoquímica, inmunofluorescencia, citometría de flujo y ensayos de fragmentación del ADN. Resultados. La infección con los rotavirus Wt1-5, WWM, TRUYO, ECwt-O y WTEW implicó la participación de algunas proteínas de choque térmico, la proteína disulfuro isomerasa y la integrina ß3. La acumulación de antígenos virales intracelulares y extracelulares se detectó en todos los virus utilizados. Los mecanismos de muerte inducidos por los rotavirus en células Sp2/0-Ag14 indujeron cambios en la permeabilidad de la membrana celular, la condensación de cromatina y la fragmentación de ADN, los cuales fueron compatibles con citotoxicidad y apoptosis. Conclusiones. La capacidad de los rotavirus estudiados para infectar y causar la muerte de células Sp2/0-Ag14 mediante mecanismos compatibles con la apoptosis inducida viralmente los convierte en candidatos potenciales para ser utilizados como agentes oncolíticos.
Assuntos
Vírus Oncolíticos , Neoplasias/terapia , Infecções por RotavirusRESUMO
Globally, rotavirus is the most common cause of diarrhea in children younger than 5 years of age, however, a quantitative understanding of the infection dynamics is still lacking. In this paper, we present the first study to extract viral kinetic parameters for in vitro rotavirus infections in the REH cell tumor line. We use a mathematical model of viral kinetics to extract parameter values by fitting the model to data from rotavirus infection of REH cells. While accurate results for some of the parameters of the mathematical model were not achievable due to its global non-identifiability, we are able to quantify approximately the time course of the infection for the first time. We also find that the basic reproductive number of rotavirus, which gives the number of secondary infections from a single infected cell, is much greater than one. Quantifying the kinetics of rotavirus leads not only to a better understanding of the infection process, but also provides a method for quantitative comparison of kinetics of different strains or for quantifying the effectiveness of antiviral treatment.
