Figure 2. Organ-on-a-chip models for cancer research.

a | A microvascular endothelium-on-a-chip created in a compartmentalized microfluidic device enabled basal stimulation and activation of endothelial cells grown on a porous membrane using chemokines to study the attachment of circulating breast tumour cells involved in cancer metastasis. The effect of chemokines, such as tumour necrosis factor, was investigated by adding these agents to the bottom channel. More cancer cells attached to the endothelium that was pre-treated with tumour necrosis factor than to untreated endothelium. b | The metastasis of breast cancer cells to bone was studied using human umbilical vein endothelial cells grown in a microfluidic channel adjacent to a 3D collagen gel containing bone cells differentiated from human bone marrow-derived mesenchymal stem cells (MSCs). Migration of the cancer cells into the bone was observed. c | To study epithelial–mesenchymal transition in cancer, lung cancer spheroids were embedded in micropatterned 3D matrices immediately contiguous to a microchannel lined with endothelial cells. Analysis of epithelial–mesenchymal transition is conducted using microfluorometry to detect dispersion of the cancer spheroids. PDMS, poly(dimethylsiloxane).