RESUMO
In this work we hypothesized that the chemokine fractalkine can serve as a cancer molecular target. We engineered aptamer micelles functionalized with an outer poly(ethylene glycol) (PEG) corona, and investigated the extent and efficacy of using them as a targeting tool against fractalkine-expressing colon adenocarcinoma cells. In vitro cell binding results showed that aptamer micelles bound and internalized to fractalkine-expressing cancer cells with the majority of the micelles found free in the cytoplasm. Minimal surface binding was observed by healthy cells. Even though partial PEGylation did not prevent serum adsorption, micelles were highly resistant to endonuclease and exonuclease degradation. In vivo biodistribution studies and confocal studies demonstrated that even though both aptamer and control micelles showed tumor accumulation, only the aptamer micelles internalized into fractalkine-expressing cancer cells, thus demonstrating the potential of the approach and showing that fractalkine may serve as a specific target for nanoparticle delivery to cancer cells.
Assuntos
Adenocarcinoma/tratamento farmacológico , Aptâmeros de Nucleotídeos/administração & dosagem , Quimiocina CX3CL1/metabolismo , Neoplasias do Colo/tratamento farmacológico , Fibroblastos/efeitos dos fármacos , Micelas , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Aptâmeros de Nucleotídeos/química , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Técnicas In Vitro , Camundongos , Polietilenoglicóis/química , Células Tumorais CultivadasRESUMO
Spontaneous mouse models of cancer show promise to more accurately recapitulate human disease and predict clinical efficacy. Transgenic mice or viral vectors have been required to generate spontaneous models of glioma, a lethal brain tumor, because nonviral gene transfer is typically transient. To overcome this constraint, we used the Sleeping Beauty transposable element to achieve chromosomal integration of human oncogenes into endogenous brain cells of immunocompetent mice. Genetically engineered, spontaneous brain tumors were induced with plasmid DNA in a matter of weeks in three separate mouse strains. The phenotype of tumors was influenced by the combination of oncogenes delivered, resembling human astrocytoma or glioblastoma in the majority of cases. At least five different genes can be cotransfected simultaneously including reporters, allowing measurement of tumor viability by in vivo imaging. This model can accelerate brain tumor research in a variety of ways such as generation of "humanized" models for high throughput drug screening and candidate gene validation with exceptional speed and flexibility.