Just observing the behavior of cancer cells can help doctors find how they act in the human body.

Researchers at Stanford University of Medicine have for the first time transformed normal tissue into three-dimensional cancers to study how they behave as they divide.

"Studies of this type, which used to take months in animal models, can now occur on a time scale of days," said Paul Khavari, MD, PhD, the Carl J. Herzog Professor and chair of dermatology at Stanford. However such studies might not be able to accurately reflect the activity of cancer cells in humans.

Initially, the researchers analyzed normal human epithelial cells collected over a period of time from surgical samples from various parts of the body, including skin, cervix, esophagus and throat. Researchers further used viruses to make these normal cells cancerous, and added these pre-cancerous epithelial cells to a tissue culture dish containing other components of human skin.

“This reflects what we see happening in spontaneous human tumors,” said Khavari. “Cells go from a pre-malignant state to invasive cancers, often over the course of years. Only in this intact, human-tissue model it occurs much more quickly.”

On studying the pattern of gene expression in the cells that were artificially made cancerous, researchers found it closely matched with those occurring spontaneously. “This tells us that conclusions drawn from studying cells grown in two-dimensional culture need to be correlated with other findings to help ensure clinical relevance,” said Khavari.

Now, researchers have started to take advantage of the new “tumor-in-a-dish” model to check the effectiveness of cancer drugs.