MONDAY, April 9, 2007 (HealthDay News) -- Researchers have identified a protein that may play an important role in the spread of about one quarter of all breast cancers.
This protein, Akt1, could be a potential target for new drugs to stop or slow the growth and progression of the disease.
Akt1 normally plays a role in keeping healthy cells alive by interfering with programmed cell death. Breast and other cancer cells have an overabundance of Akt1.
In this study, the researchers bred mice that lacked the gene for Akt1 with mice that over-produced the HER2-neu (ErbB2) gene, which causes about 25 percent of all breast cancers. Offspring that lacked two copies of the gene that produces Akt1 rarely developed tumors. Mice that carried only one copy of the Akt1 gene developed some small tumors that developed slowly, while mice with both copies of the Akt1 gene rapidly developed major cancer.
The finding, by researchers at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia, appears online this week in the journal Proceedings of the National Academy of Sciences.
"The finding was exciting, because it told us that Akt1 is a potentially useful target for ErbB2-positive breast cancer," Dr. Richard Pestell, Kimmel Cancer Center director and professor and chairman of cancer biology at Jefferson Medical College, said in a prepared statement.
"More interesting was that even if the mouse developed a tumor, it didn't develop metastases (cancer spread). We proved that there was a requirement for Akt1 in metastasis, which makes Akt1 an exciting target for metastatic breast cancer. We knew that Akt1 could play a role in cell growth and size, but the idea that it could play a role in migration and metastasis was an unexpected new finding," Pestell said.
He and his team also found that Akt1 causes cancer cells to secrete a factor called CXCL16 that promotes breast cancer cell migration.
The American Cancer Society has more about breast cancer.