RESUMO
This article is focused on the main pathways used by viruses to achieve infection and lysis of unicellular eukaryotes described as pathogenic for multicellular organisms. In light of the recent discussions on how tumor cells exhibit unicellular behavior, highly malignant cells can be considered as another unicellular pathogenic entity, but with endogenous origin. Thus, a comparative panel of viral lysis of exogenous pathogenic unicellular eukaryotes such as Acanthamoeba sp., yeast, and tumors is presented. The important intracellular parasite Leishmania sp is also presented, which, in contrast, has its virulence improved by viral infections. The possible exploitation of viral-mediated eukaryotic cell lysis to overcome infections of Leishmania sp is discussed.
Assuntos
Leishmania , Leishmaniose , Neoplasias , Vírus , Humanos , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Leishmania/metabolismo , Morte Celular , Saccharomyces cerevisiaeRESUMO
The transforming properties of oncogenes are derived from gain-of-function mutations, shifting cell signaling from highly regulated homeostatic to an uncontrolled oncogenic state, with the contribution of the inactivating mutations in tumor suppressor genes P53 and RB, leading to tumor resistance to conventional and target-directed therapy. On the other hand, this scenario fulfills two requirements for oncolytic virus infection in tumor cells: inactivation of tumor suppressors and presence of oncoproteins, also the requirements to engage malignancy. Several of these oncogenes have a negative impact on the main interferon antiviral defense, the double-stranded RNA-activated protein kinase (PKR), which helps viruses to spontaneously target tumor cells instead of normal cells. This review is focused on the negative impact of overexpression of oncogenes on conventional and targeted therapy and their positive impact on viral oncolysis due to their ability to inhibit PKR-induced translation blockage, allowing virion release and cell death.
RESUMO
El cáncer es una enfermedad compleja de etiología desconocida. Factores genéticos y epigenéticos se asocian al incremento en el riesgo de desarrollar esta enfermedad. A pesar del avance en los tratamientos tradicionales contra el cáncer, el pronóstico de los pacientes no ha mejorado significativamente. Estudios en la patogénesis molecular del cáncer han evidenciado la existencia de dianas moleculares con potencial terapéutico que permiten trasladar los conocimientos de la investigación básica a la clínica implementando nuevas terapias para el beneficio del paciente. El conocimiento del genoma viral, su función, replicación y los mecanismos de infección a la célula tumoral han permitido el desarrollo de la terapia génica viral que puede ser la herramienta ideal para el tratamiento del cáncer. Este artículo revisa diferentes metodologias desarrolladas para el diseno de una terapia génica contra el cáncer, abordada desde diferentes contextos biológicos, y su aplicación clínica para el tratamiento del cáncer.
Cancer is a complicated disease of unknown etiology. Genetic and epigenetic factors are associated with an increased risk for developing this disease. Despite the progress in the traditional cancer therapies, the prognosis of patients has not improved significantly. Studies on the molecular pathogenesis of cancer have demonstrated the existence of molecular targets with therapeutic potential. Furthermore, knowledge of the viral genome function and replication, as well as of the mechanisms of tumor cell infection, have made it possible to develop an ideal tool for gene therapy against cancer and thus, enable the transfer of knowledge from basic to clinical research for the benefit of patients. This article reviews different methodologies developed to design a cancer gene therapy and its clinical application for treating cancer, addressed from various biological contexts.