Implications of Three-Dimensional Cell Culture in Cancer Therapeutic Research

Abstract

Replicating the naturalistic biomechanical milieu of cells is a primary requisite to uncover the fundamental life processes. The native milieu is significantly not replicated in the two-dimensional (2D) cell cultures. Alternatively, the current three-dimensional (3D) culture techniques can replicate the properties of extracellular matrix (ECM), though the recreation of the original microenvironment is challenging. The organization of cells in a 3D manner contributes to better insight about the tumorigenesis mechanism of the in vitro cancer models. Gene expression studies are susceptible to alterations in their microenvironment. Physiological interactions among neighboring cells also contribute to gene expression, which is highly replicable with minor modifications in 3D cultures. 3D cell culture provides a useful platform for identifying the biological characteristics of tumor cells, particularly in the drug sensitivity area of translational medicine. It promises to be a bridge between traditional 2D culture and animal experiments and is of great importance for further research in tumor biology. The new imaging technology and the implementation of standard protocols can address the barriers interfering with the live cell observation in a natural 3D physiological environment.

Keywords: 3D culture; biomimetic; cancer; drug discovery; gene expression; microenvironment.

Figure 1

Scaffold-free and anchor-independent three-dimensional cell cultures. The hanging drop technique uses the surface tension of a droplet of cell suspension and gravity to suspend the droplet of cells onto the base of a lid which could promote cell aggregation into a spheroid. In the ultra-low attachment plate technique, the plate surface is coated with an inert substance that minimizes cell attachment and promotes cell aggregation. Suspension culture methods produce tumor spheroids using bioreactors, such as spinner flask and rotating flasks. Microfluidics can create uniform-sized spheroids for high-throughput screening applications. In the magnetic levitation method, cells with magnetic iron oxide were held at the air–medium interface using magnetic force. Micropatterning techniques control the position of cells and their shape.

Figure 2

Scaffold-based and anchor-dependent three-dimensional cell cultures. Hydrogels with interconnected pores promote cell growth by providing a 3D environment and supporting the transport of oxygen, nutrients, and metabolites required for cell growth. Sponges, with their porous structure, support cell growth and migration. Microcarrier is a support matrix in bioreactors that supports the development of multi-cellular spheroids. Filter-well insert in culture plates promotes the growth of 3D cell culture.