A Northwestern University cancer researcher may have found a way to fence in breast cancer and keep it from spreading, according to a recent study in the British Journal of Cancer.
In the study, Dr. Seth Corey and his colleagues combined dasatinib, a drug for chronic myeloid leukemia, with doxorubicin, a drug commonly used in breast cancer chemotherapy. They observed that the chemotherapy cocktail halved the number of breast cancer metastases, or cell invasions, to other organs. The dasatinib targets Src (pronounced “sarc,” short for sarcoma) kinase, an enzyme that increases the rate of cell migration and plays a role in cancer growth, Corey said.
Corey drew an air traffic analogy to demonstrate dasatinib’s ability to target specifically the Src kinase enzymes.
“If you knock out O’Hare, you can still fly around the country,” Corey said. “But if you knock out O’Hare, LAX and La Guardia, you’re knocking out a lot of air traffic.”
Corey said dasatinib could work as a “magic bullet” to knock out just O’Hare. Previous forms of chemotherapy knocked out several “airports” and weakened the body’s overall ability to function properly.
“The idea is to really change the way chemotherapy is designed so that it’s much smarter and more effective with less side effects,” said Corey, a professor of cancer biology and chemotherapy at the Feinberg School of Medicine.
Breast cancer can become fatal if it metastasizes and spreads beyond the mammary ducts, reaching the brain, liver and lungs. Common forms of chemotherapy can curb only the division of cancer cells within the mammary ducts. But Corey’s new combo could suggest a step forward in chemotherapy treatment—preventing cancer from going beyond the breast, rather than treating it once it’s there.
Several years ago, one of Corey’s graduate students at MD Anderson Cancer Center in Houston came to his lab with an interest in breast cancer. Together, they decided to look at the effects of dasatinib on a variety of breast cancer cells. They realized there was little effect on cell growth itself, but that a cancerous cell’s ability to invade neighboring tissue was hampered.
“The combination was very effective in stopping cancer cell invasion,” Corey said.
Though there is no connection between leukemia and breast cancer, Corey said, most cancers involve the “inappropriate activation of growth pathways inside a cell, so they typically involve the same sort of proteins.” The purpose of dasatinib, he added, is to prevent the breast cancer cells from moving outside the mammary ducts and setting up residence elsewhere as a metastasis.
Dr. Richard Gorlick, an oncologist at the Montefiore Medical Center in New York, said he supported Corey’s research.
“Dasatinib is a Src kinase inhibitor and it’s believed to have some anti-metastatic properties,” he said. “Clearly I think the approach is right, and I think what Dr. Corey is doing is very important work.”
While the research thus far has employed doxorubicin, he said the next step is to determine if there may be a more effective chemotherapy drug to combine with dasatinib. Beyond that, Corey said the use of dasatinib in chemotherapy could have anti-metastatic effects on cells involved in lung cancer, colorectal cancer and even prostate cancer.
Corey said clinical trials of dasatinib with chemotherapy are being conducted with humans at several laboratories, including the MD Anderson Cancer Center, Memorial Sloan-Kettering Cancer Center in New York, and the Baylor College of Medicine.