Understanding metabolism, hypoxia and cell–cell interactions in tumour microenvironments is key to developing effective therapeutics. Limited vascularisation within tumours causes gradated, spatial disparities in oxygen and nutrient availability, which can promote mutagenesis and resistance to therapies. These metabolic gradients can be studied in animal, organoid and cell culture models; however, varying limitations exist. The metabolic microenvironment chamber (MEMIC) is a cell culture system that creates precise metabolite gradients and allows cellular co-culturing. It is cost-efficient, scalable and available to any lab with access to a 3D printer.
This Resource article from Carlos Carmona-Fontaine and colleagues expands upon MEMIC system development and provides extensive guidelines for replication of the methodology. The authors demonstrated how fixed-cell and live-cell imaging can be used to analyse indicators of hypoxia and nutrient deprivation. They fine-tuned parameters, such as cell density and chamber dimensions, that affect metabolite gradients in this system and exemplified its further refinement by incorporating a polymer membrane that diffused nutrients yet allowed unlimited oxygen permeability.
Levels of nutrients and oxygen have major effects on many cellular signalling pathways; therefore, to further demonstrate the application of this technology, the authors showed that gradual metabolite depletion correlated with a decline in cell proliferation. The MEMIC is also amenable to co-culture. The authors added macrophages to tumour cells, which exacerbated the effects of ischaemia on tumour cell morphology.
Animal and cell culture models are valuable tools in this research area and can now be combined with the MEMIC system that models the complexity of the tumour microenvironment in an accurate and high-throughput manner. Importantly, many biological features observed in this system recapitulated those seen in patient-derived tumour samples. To further enhance accessibility of the MEMIC, the authors made available image analysis software that enables single-cell and spatial analysis. The MEMIC is a resource for the community that can help researchers dissect hypoxia and nutrient deprivation and identify novel cancer therapeutics, especially if utilised for high-throughput drug screens.