Breast Cancer Drug Fulvestrant Appears More Effective In The Presence Of CK8 And CK18
Posted Mar 10 2010 4:04pm
Women’s responsiveness to the second-line breast cancer drug fulvestrant may depend on whether the cancer cells are expressing two key proteins, Indiana University Bloomington scientists report in this month’s Cancer Biology & Therapy.
Fulvestrant appeared to exert maximum anti-cancer effects in vitro when cells produced normal or elevated quantities of the cytokeratins CK8 and CK18, structural proteins that help give the nucleus its shape.
For fulvestrant to work well, the cells must also be responsive to estrogen, and producing the estrogen receptor ER-alpha. ER-alpha’s importance to fulvestrant’s anti-estrogenic action had been established in previous reports. The present study confirms fulvestrant’s binding relationship to ER-alpha, while also showing two other proteins, cytokeratins 8 and 18, can strongly enhance fulvestrant’s anti-estrogenic activity. Testing for the presence of these three proteins, and perhaps many others, could help doctors decide whether fulvestrant should be prescribed to their patients.