A 3D-microtissue-based phenotypic screening of radiation resistant XXXX cells with synchronized chemotherapeutic treatment.

@entity0 @entity23974 @entity5 @entity1205 @entity5713
BACKGROUND: Radiation resistance presents a challenge to the effective treatment of @entity5 . If therapeutic compounds were capable of resensitizing resistant @entity5 then a concurrent chemo-radiation treatment could be used to overcome radiation resistance. METHODS: We have developed a phenotypic assay to investigate the response of radiation resistant @entity0 cells grown in 3D-microtissue spheroids to combinations of radiation and established chemotherapeutic drugs. The effects were quantified by real time high content imaging of GFP detection area over 14  days. Ten established chemotherapeutic drugs were tested for their ability to enhance the effects of radiation. RESULTS: Of ten analysed chemotherapeutics, @entity5713 was the most effective compound, with @entity1205 and @entity23974 being less effective in combination with radiation. To investigate the response in a model closer to the in vivo situation we investigated the response of heterotypic 3D microtissues containing both fibroblasts and @entity0 cells. Drug treatment of these heterotypic 3D cultures confirmed treatment with radiation plus @entity5713 to be additive in causing @entity0 growth inhibition. We have validated the screen by comparing radiation sensitizing effects of known chemotherapeutic agents. In both monotypic and heterotypic models the concurrent treatment of @entity5713 and radiation proved more effective inhibitors of mammary @entity5 cell growth. The effective concentration range of both @entity5713 and radiation are within the range used in treatment, suggesting the 3D model will offer a highly relevant screen for novel compounds. CONCLUSIONS: For the first time comfortable 3D cell-based phenotypic assay is available, that allows high throughput screening of compounds with radiation therapy modulating capacity, opening the field to drug discovery.
