Novel Diffuse Midline Glioma-on-Chip Recapitulating Tumor Biophysical Microenvironment to Assess the Heterogeneity of Response to Therapies.

Despite significant efforts, Diffuse Midline Gliomas (DMGs) remain incurable. Although promising results are obtained in preclinical studies, most approaches have failed to improve survival in these young patients. In this context, by integrating elements of the biophysical tumor microenvironment known to regulate the response to therapies, a new preclinical tool is developed to better evaluate the efficacy of antitumoral strategies. For this purpose, a novel DMG-on-Chip (DoC) is engineered composed of a 3D dense tumor disk embedded in an extracellular matrix, which is accessible for real-time monitoring using wide-field phase contrast or confocal fluorescence microscopy. By driving the oxygen supply within the chip solely in a radial manner, a hypoxia gradient is established that can be associated with changes in DMG cell phenotype, proliferation, and rewiring of metabolic and stress transcriptomic signatures. Finally, DoC is used to analyze the spatial heterogeneity of the response of DMG cell lines and patient-derived 3D cultures to treatments through cell segmentation. Altogether, these interdisciplinary characterizations validate the new tool as an interesting healthcare solution to understand how cell responses are modulated by biophysical or biochemical cues in the tumor microenvironment.