Research in the Journal of Biomolecular Screening co-authored by InSphero AG and the Institute of Molecular Health Sciences (Zurich) characterizes a high-throughput compatible 3D tumor model system based on InSphero's GravityPLUSTM hanging drop technology. The authors use the co-culture model and RNA interference (RNAi) to reveal differential phenotypic responses to targeted gene disruption that are dependent upon the 2D or 3D manner in which the cells are grown.
Currently, identification of drug targets and primary target validation are typically performed using 2D cell culture systems. These conditions do not reflect the interactive 3D tumor microenvironment in viva The study directly compares 2D and 3D microtissue co-cultures composed of human DLD I colon cancer cells and murine fibroblasts, each genetically modified to allow simple quantification of tumor and fibroblast cell number by fluorescence imaging Upon siRNA-mediated depletion of Kifl I/Eg5, a critical mitotic protein, cancer cell proliferation in 3D microtissues was inhibited, whereas those in 2D monolayers were more resistant to gene depletion and continued to proliferate.
Dr. Jens M. Kelm, Chief Scientific Officer at InSphero AG and corresponding author on the manuscript, states the 3D co-culture model attempts to more accurately reflect the heterotypic interactions seen in vivo, while also being amenable to high-throughput approaches to early target identification and validation. "Our findings reiterate the importance of the cellular context in which gene function analysis studies are performed. Co-cultures grown in 3D may display a dramatically different result in phenotypic screens than in traditional 2D monolayers "