3D spheroid culture to examine adaptive therapy response in invading tumor cells

Abstract

3D in vitro culture models of cancer cells in extracellular matrix (ECM) have been developed to investigate drug targeting and resistance or, alternatively, mechanisms of invasion; however, models allowing analysis of shared pathways mediating invasion and therapy resistance are lacking. To evaluate therapy response associated with cancer cell invasion, we here used 3D invasion culture of tumor spheroids in 3D fibrillar collagen and applied Ethanol-Ethyl cinnamate (EtOH-ECi) based optical clearing to detect both spheroid core and invasion zone by subcellular-resolved 3D microscopy. When subjected to a single dose of irradiation (4 Gy), we detected significant cell survival in the invasion zone. By physical separation of the core and invasion zone, we identified differentially regulated genes preferentially engaged in invading cells controlling cell division, repair, and survival. This imaging-based 3D invasion culture may be useful for the analysis of complex therapy-response patterns in cancer cells in drug discovery and invasion-associated resistance development.

Addressing Genetic Tumor Heterogeneity, Post-Therapy Metastatic Spread, Cancer Repopulation, and Development of Acquired Tumor Cell Resistance

“…Accordingly, novel biomodulatory combinations may be established and drug repurposing exploited, particularly with respect to edited non-oncogene addiction ( Table 1 , Figure 1 ) [ 37 , 147 ]. Molecular imaging, imaging-based 3D invasion culture, imaging mass cytometry and ‘omic’ technologies could be pivotal techniques for studying mechanisms involved in providing therapeutically relevant tumor plasticity and for guiding the appropriate selection of biomodulatory active drugs addressing the M-CRAC problem ( Figure 4 ) [ 148 , 149 , 150 , 151 , 152 ].…”