Cancer is perhaps one of the most widely studied diseases in the world, yet it continues to baffle researchers. The complex nature and behavior of cancer cells makes them extremely tricky to study, but in recent years, a multicellular tumor spheroid (MCTS) model has become a commonly adopted method in cancer biology. MCTS models provide an accurate representation of the physiology of tumors and are gradually making a significant contribution to our understanding of cancer biology.

An ideal model

Spheroids have several structural, functional and physiological similarities to tumors in vivo. Both are made up of heterogeneous cells and have similar secretory and metabolic activity. MCTS models generally use spheroids between 200–500 µm and are grown in a 3D culture as opposed to a monolayer.

This 3D system exposes cells, enabling them to communicate with each other as well as their surroundings, providing an optimal environment for the cells to respond like they would in a tumor. Within such a representative environment, spheroids are able to express chemical gradients of the various nutrients, oxygen and catabolites found in a tumor – something that can assist in drug development.

In need of oxygen

One of the most defining features of a tumor is its hypoxic core, and this is also replicated in spheroids. As the tumor grows, the cells will often run out of adequate blood supply, leaving the center of the tumor with a very low oxygen and nutrient concentration. These oxygen starved cells grow very slowly, are acidic and tend to be resistant to therapy. Many researchers believe that this hypoxic core is the culprit behind the failure of cancer drugs and treatments to date.

Since spheroids mimic this hypoxic core, MCTS models are ideal to study the effects of changing oxygen levels within the tumor. These models can be used to find ways to promote oxygenation for cells low in oxygen, as well as in the development of cancer drugs that specifically target the hypoxic core. In addition to this, the reproducibility and reliability of the recently developed spheroid culture systems make them more adaptable for use in cancer research.

Looking for more?

Innovative technologies continue to proliferate, striving to advance your cancer research. You can learn more about some of these innovations and growing 3D cultures in Harnessing New Dimensions in Your Research, a Cell Culture Cafe on-demand webinar.