Researchers at Lombardi Comprehensive Cancer Center at Georgetown University Medical Center have shown why a protein known as cyclin D1 may be the Achilles heel for breast tumors that are estrogen receptor positive (ER+) - which is the most common type of breast cancer.
Writing in the journal Oncogene, investigators say the findings support testing an experimental class of drugs that aim to inhibit the cyclin D1 protein in women with ER+ breast cancers. These agents are currently being tested in this disease as well as in many other types of cancer, the researchers say, and the study provides additional molecular support for their use in breast cancer.
“Everyone knows that cyclin D1 is a huge player in breast cancer, but no one has shown what happens when cyclin D1 is absent at the same time that the estrogen receptor is being over-expressed on tumors. Now we know the answers, and we hope these insights help further our understanding and treatment of breast cancer,” said the study’s lead author, Maria Silvina Frech, Ph.D., who is currently a postdoctoral researcher at the National Cancer Institute but who worked on the study at Georgetown.
“These findings give insight into how drugs that indirectly inhibit cyclin D1 function, either those in testing or ones to be developed, might help a significant number of women with breast cancer,” said Priscilla Furth, M.D., a professor at the Lombardi Comprehensive Cancer Center who is the study’s senior investigator.
Cyclin D1 belongs to a family of cyclin genes whose proteins regulate cyclin-dependent kinases (CDKs), which in turn control cell division. CDKs are the main facilitators of cell proliferation cycle. Over-production of the Cyclin D1 protein or amplification (extra copies) of the gene have been observed in a number of cancers, and this study continued a body of research in Furth’s lab that has examined the relationship between ER+ breast cancer and cyclin D1.
SOURCES:
Oncogene, online edition, December 10, 2007
Georgetown University Lombardi Comprehensive Cancer Center (http://lombardi.georgetown.edu)
