Out of every hundred investigational cancer drugs that enter clinical trials, only eight prove to be sufficiently safe and effective for FDA approval. Scientists at the Dana-Faber Cancer Institute believe that those odds can be shortened by taking into account neighbouring cells in the tumour microenvironment in preclinical testing.
Although both non-malignant cells and secreted proteins from tumour and stromal cells are recognised to be active participants in cancer progression, early laboratory testing is typically carried out using homogeneous populations of tumour cells. The Dana-Faber group have now developed a tumour cell-specific in vitro bioluminescence imaging (CS-BLI) assay that is suitable for high throughput screening. Cell viability can be measured in tumour cells stably expressing luciferase in the presence or absence of non-malignant accessory cells (for example, stromal cells) or drug treatment.
Unlike conventional screening methods, CS-BLI was able to identify compounds with increased activity against tumour cells interacting with stroma. For example, reversine showed more potent activity in an orthotopic model of diffuse myeloma bone lesions than in conventional subcutaneous xenografts. CS-BLI was also able to identify stroma-induced chemo-resistance such as imatinib resistance in leukaemia cells. The use of CS-BLI should help to identify preclinical candidates that overcome stroma-mediated drug resistance as well as those that can act in a synthetic lethal manner in the context of tumour-stroma interactions, thereby increasing the chances of clinical success.
The study is published in Nature Methods.