Studies of human tumor cells implanted in mice have shown that the abnormal activation of four genes drives the spread of breast cancer to the lungs. The new studies by Howard Hughes Medical Institute researchers reveal that the aberrant genes work together to promote the growth of primary breast tumors. Cooperation among the four genes also enables cancerous cells to escape into the bloodstream and penetrate through blood vessels into lung tissues.
Although shutting off these genes individually can slow cancer growth and metastasis, the researchers found that turning off all four together had a far more dramatic effect on halting cancer growth and metastasis. Metastasis occurs when cells from a primary tumor break off and invade another organ. It is the deadliest transformation that a cancer can undergo, and therefore researchers have been looking for specific genes that propel metastasis.
In the newly published experiments, the researchers also found that they could reduce the growth and spread of human breast tumors in mice by simultaneously targeting two of the proteins produced by these genes, using drugs already on the market. The researchers are exploring clinical testing of combination therapy with the drugscetuximab (trade name Erbitux) and celecoxib (Celebrex)to treat breast cancer metastasis.
The research team, led by Howard Hughes Medical Institute investigator Joan Massagu at the Memorial Sloan-Kettering Cancer Center, published its findings in articles in the April 12, 2007, issue of the journal Nature and in the online early edition of the Proceedings of the National Academy of Sciences on April 9, 2007.
In an earlier study, Massagu and his colleagues had identified 18 genes whose abnormal activity is associated with breast cancers ability to spread to the lungs. In the new study published in Nature, Massagu and his colleagues at Sloan-Kettering, along with researchers from Hospital Clinic de Barcelona and the Institute for Res
Contact: Jim Keeley
Howard Hughes Medical Institute