Studying how tumors grow and spread in laboratory animals is tricky, expensive and time consuming. Now Stanford researcher Paul Khavari, MD, PhD, has discovered how to coax samples of normal human epithelial cells - the kind that line the cavities and surfaces of the body - to become cancerous in a laboratory dish. From our release:
[The researchers] then added the altered, pre-cancerous epithelial cells to a tissue culture dish containing other components of human skin. Epithelial cells normally sit on a thin partition called the basement membrane that separates them from a lower layer of skin called the stroma. They found that at first the cells nestled down on the basement membrane and formed what looked like a normal, three-dimensional cross-section of skin. But within about six days, the cells started to behave more ominously - punching through the membrane and invading the stromal tissue below.
“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.” In contrast, unaltered cells remained obediently on their side of the basement membrane.
The new three-dimensional model system of cancer progression offers a way to quickly observe what happens when cells go over to the dark side, and to test the ability of experimental drugs to block disease progression.
Khavari is chair of the Department of Dermatology and serves as dermatology service chief at the Veterans Affairs Palo Alto Health Care System. He worked with former postdoctoral scholar Todd Ridky, MD, PhD, now a faculty member at the University of Pennsylvania, to conduct the work. Their study appears in Nature Medicine.