Taking a Closer Look at Cancer

Cancer often isn't detected until it has progressed to late stages, making it difficult to treat. With the goal of improving cancer prevention, SPH associate professor Betsy Wattenberg is working to understand the very earliest stages of the disease--namely what happens to cells when cancer strikes.

In her lab, Wattenberg and colleagues are studying the changes in cells that lead to cancer. Cells are normally highly regulated and in constant communication with each other through a network of "switches." When cancer develops, that high level of communication is disrupted and switches within the cells are turned permanently on or off.

"These switches act like brakes or accelerators in a car," explains Wattenberg.

Wattenberg is studying a switch called Ras, which is defective in 30 percent of human cancers, including those of the lung, colon, and pancreas. Ras is a powerful switch because it is so far "upstream" in the complex cell pathway of communication.

Scientists had assumed that when Ras is damaged, it causes a chain reaction that permanently turns on other switches downstream in the pathway. But Wattenberg's team discovered that this isn't the case. When Ras is damaged, the cell tries to readjust itself by producing a protein called a phosphatase that turns off the switches that have been turned on.

Wattenberg says that this discovery may explain why these cells don't develop into cancerous tumors.

"If Ras is broken, it doesn't necessarily lead to cancer," says Wattenberg. "The cell tries to adapt to behave as normally as possible."

While the Ras-damaged cells don't always lead to cancer, they are vulnerable. "Future prevention strategies might focus on how to help these vulnerable cells," says Wattenberg.