Researchers breed cancer resistant mice

October 14, 1999
Web posted at: 12:01 a.m. EDT (0401 GMT)

NEW YORK (CNN) -- In a medical first, researchers from New York's Memorial Sloan Kettering Cancer Center say they have bred mice resistant to cancer.

According to a study published in the journal Nature, Dr. Robert Benezra and his colleagues have identified two genes responsible for the formation of the blood vessels which cancers need to grow and spread -- a process called angiogenesis. These so-called "id" genes are normally present in mice and humans.

VIDEO CNN's Dr. Steve Salvatore reports on the discovery of cancer fighting genes in mice Windows Media 28K 80K

VIDEO Medical Correspondent Rhonda Rowland reports on the progress against cancer since 'war' on the disease was declared in 1971 Real 28K 80K Windows Media 28K 80K

Researchers injected cancer cells under the skin of normal mice with the "id" genes and those specially bred without working "id" genes. Those mice with disabled genes did not develop cancer.

"So far, every cancer that we supplanted under the skin of the animal resisted growth and development by virtue of the fact that blood vessels were not forming properly," Benezra said.

The "id" genes are vital for the growth and development of blood vessels in the human fetus, but as a person enters adulthood these genes are rarely active. Cancerous cells, however, rely on the genes for the construction of new blood vessels to supply them oxygen and nutrients to help them grow and spread.

According to Dr. Benezra, "That means, we have the possibility of inactivating them in an adult and have very few side effects."

The authors warn this research is preliminary and only in mice. They are currently conducting further studies on mice bred to develop cancer the way humans do. They expect results from that study in about six months.

If successful, the researchers hope to develop drugs that would work to disable the genes in humans. These drugs could work hand in hand with other angiogenesis inhibitors such as the experimental drugs endostatin and angiostatin.

Benezra says this is only the tip of the iceberg. He has seen the "id" proteins affect the work of other proteins that are involved in the angiogenic process.