Patient profile: Mice help treat breast cancer

By Patty Wood

When Alice Burgess learned in January 1995 that she had breast cancer, there was a bit of irony in the diagnosis. After managing public relations programs for medical research centers for nearly a decade, she had written plenty of patient information materials. Suddenly, however, she was reading them instead of writing them.

As the director of public relations for Fred Hutchinson Cancer Research Center in Seattle, Alice helped produce the media campaign for a statewide breast cancer awareness month. Fortunately, she took some of the advice she had written for other women and performed regular breast self-exams. The lump she found was undetectable by mammogram - too frequently the case in younger women. But Alice wasn't just thankful she had been diligent about performing the simple self-exam. She was also grateful that, because of the humane use of animals in biomedical research, the discovery of a lump in her breast was not a death sentence.

"I was amazed and comforted by the sophistication of the diagnosis and treatment for that little tumor," she said. "It was just a tiny bit of tissue, yet my doctors were able to create a 15-part profile of the cancer. That detailed analysis was used to determine the best treatment for me. The technology that Alice's doctors used to identify the kind of cancer she had and determine how to treat it effectively was developed through the use of animals in cancer research. Most of the research has been done using mice, which get some breast tumors naturally and can easily be induced to produce them. As part of her treatment, Alice underwent chemotherapy for six months. Every three weeks, she had one day of treatment and then needed three days to recover from the side effects.

Because her doctors had such extensive diagnostic capabilities, they were able to determine that she did not need to take a drug the would have caused her to lose her hair. As a result, many of her professional colleagues never knew she was in treatment for cancer.

Now apparently cancer-free, Alice is counting on the continued use of animals in research to help ensure her long-term health.

"The bad news is that the type of breast tumor I had is an aggressive form of the disease," she said, "The good news is that the University of Washington is beginning human trials on a vaccine to prevent its recurrence. It is the only form of breast cancer for which researchers are even close to developing a vaccine."

The vaccine has been tested on rats with very promising results. When the university researchers are ready to try it on women with Alice's medical profile, she hopes to participate in the study. Alice, her husband, and their cat Tipitina live in Seattle. She enjoys back-country skiing, llama packing, and traveling.

Protein sets stage for colon cancer in susceptible mice New research on mice in Texas may help explain why high-fat American diets seem to predispose people to colon cancer. Researchers at the University of Texas Medical Branch at Galveston believe they have discovered what causes one of the early cellular changes that lets colon cancer take root.

Like other cancers, colon cancer develops gradually through a complex series of steps that eventually leads to uncontrolled cell growth and division. The American Cancer Society estimates that 94,700 new cases of colon cancer will be diagnosed in 1999. Colon cancer is the second-most common malignancy in the United States, according to the National Cancer Institute. A high-fat diet, such as those typical in Western cultures, is considered to significantly increase colon cancer risk, but it has always been a mystery why.

In a report in the May 17 Journal of Cell Biology, UTMB molecular cell biologists Alan Fields, Nicole Murray, and colleagues suggest that the process leading to colon cancer could be set in motion by a form of a protein called protein kinase C. When this protein, known as PKC-beta II, is present in elevated amounts in cells lining the colon, it causes these cells to divide more rapidly than normal, and such rapid cell division increases the chance that cancer-causing mutations will linger and cause disease.

Although many of the final steps that lead to colon cancer have been worked out, how the whole process gets triggered is still unclear. But Fields and his colleagues were intrigued by the fact that PKC-beta II - which is found at elevated levels in colon tumors of both human beings and of mice - binds to and is activated by some of the dietary fatty acids implicated to increase colon cancer risk. In people who eat a diet rich in fatty foods, the scientists postulate, PKC-beta II-induced cell proliferation could be turned up, increasing susceptibility to colon cancer development.

"We don't know this with certainty yet," Fields notes, stressing that this connection has yet to be proved either in humans or in mice, "but our results strongly imply that PKC-beta II is a link between a high-fat diet and this disease."

The researchers will continue to study their genetically altered mice to learn whether they develop colon cancer more quickly than the controls. They also plan to test whether dietary changes will reduce PKC-beta II-induced cell proliferation and the risk of colon cancer.