LAUSR

Abstract Tumor microenvironment plays a vital role in tumor progression, metastasis and aggressiveness. The interaction between tumor and surrounding stromal cells, especially fibroblasts, is closely related to antitumor drug sensitivity. We developed a novel 3-dimensional (3D) multicellular tumor model with the coculture of breast cancer MCF-7 and mouse fibroblast NIH-3T3 cells simulating the in vivo tumor microenvironment for cancer drug screening. MCF-7 and NIH-3T3 cells were engineered to express enhanced green fluorescent protein and red fluorescence protein, respectively. These cells were cocultured in polyethylene terephthalate (PET) fibrous matrices as 3D scaffolds in microbioreactors modified from a 384-well plate, and their growth was monitored in real time by the dual fluorescence signals measured with a plate reader. The 3D coculture was used to evaluate cytotoxicity or IC50 of three antitumor drugs: tamoxifen, oxaliplatin and cisplatin. In general, the drug resistance or IC50 of MCF-7 increased significantly when cocultured with NIH-3T3. These drugs also showed lower cytotoxicity to NIH-3T3 cells, versus MCF-7 cells, confirming that they are cancer-specific agents and relatively harmless to non-cancerous cells. The dual fluorescence 3D coculture assay can provide a reliable high throughput platform for screening cancer drugs whose efficacy may be impacted by fibroblasts in tumor stroma.