Induction of cell aggregates generation from cells adhered on two-dimensional environment: Proposal for the creation of tumorigenesis and growth models.

抄録

[Objective] Few culture models have been proposed that can mimic the process of tumorigenesis in vivo, in which single tumor cell grow from two-dimensional (2D) attachment state on normal tissues to form three-dimensional (3D) cell aggregated tissues. In this study, we aimed to demonstrate the feasibility of generating tumor-like 3D cell aggregates from 2D adherent cells by using our cell self-aggregation technique (CAT) for adherent cells, which can induce cell aggregation via the cell adhesion state on the culture dish surfaces. [Materials and Method] CAT-inducing circle regions (CAT-spots) of approximately 2 mm in diameter were prepared by dropping 0.5 µL of a CAT-inducing polymer solution on the surface of ultralow-cell attachment culture dishes and drying. Human glioma cells were seeded onto culture dishes at different cell densities. [Results] Within 1 hour after seeding, cells adhered and spread only on the circular CAT-spot regardless of seeding density, and confluent cell monolayers were formed at seeding densities of approximately 10×10³ cells/cm² or higher. After about 2 days of culturing, dozens of cell aggregates with a diameter of 0.1-0.3 mm began to generate on the confluent cell monolayer formed on the CAT-spot, and these cell aggregates grew into more than 1 mm diameter after next 1 week of culturing as a result of cell proliferation and fusion with neighboring cell aggregates. Cells seeded at a density of less than 10×10³ cells/cm² proliferated on the CAT-spot in monolayer state, and after reaching confluence, they also generated dozens of cell aggregates and subsequently grew at least up to 1 mm in diameter. [Conclusion] These results demonstrate the initial potential of using CAT to generate 3D tumor-like cell aggregates from 2D surface-attached cells leading to the tumorigenesis culture models creation.