26 March 2014
Vol 6, Issue 229

About The Cover

Cover image expansion

ONLINE COVER Pas de Trois. This image of chromosomes about to separate during cell division shows an abnormal tripolar mitotic spindle and chromosomes being pulled in three directions instead of two. In this week's issue, Zasadil and colleagues show that this happens to breast cancer cells exposed to clinically relevant concentrations of paclitaxel, a common chemotherapeutic agent. The traditional understanding of paclitaxel's mechanism was that treated cells undergo mitotic arrest, but now the authors discovered that at realistic concentrations of the drug, breast cancer cells continue to divide on abnormal mitotic spindles with three, four, or even more poles instead of two, leading to tumor cell death. [CREDIT: C. BICKEL/SCIENCE TRANSLATIONAL MEDICINE]