Building on basics

The mouse that roared

Robert Cardiff is fond of beginning pathology lectures by projecting slides of invasive breast cancer tumors on the screen behind the lectern and asking listeners which is from the mouse and which is from the human. He's done it hundreds of times and even pathologists in the audience can't tell which is which.

"They all get it wrong," the UC Davis professor of pathology says with a grin. "Every time."

That's the point. Mice and men have more in common than the title of a Steinbeck novel. They share 80 percent of the same DNA. They both get cancer. Genes that cause cancer in mice are very similar to genes that cause cancer in humans. And with the advent of transgenic mice - mice bred to express or not express specific genes -the rodent's role as primary animal model for cancer studies has never been more important.

Likewise, Cardiff's blend of expertise in human and mouse biology has never been in greater demand.

Transgenic mice are vital to cancer research for many reasons. They act as sentinels for an array of molecular changes - cellular and genetic anomalies that can develop into cancer. At the same time, they give scientists a way to analyze the interaction of specific genes in a living, breathing mammal. Knockout mice, for example, have genes that have been artificially removed from the mouse genome, while knock-in mice have genes artificially activated.

Upper right: UC Davis pathologist Robert Cardiff
helps cancer investigators interpret
mutations in genetic mice.