Resistance through repopulation

摘要

Initial or acquired resistance to anticancer drugs limits their effectiveness. Many papers have described mechanisms underlying such drug resistance, but most have evaluated molecular changes in single tumour cells, with the emphasis on stable genetic changes that may be induced by therapy or selected for. However, causes of drug resistance are multiple and complex, and in this issue, Kurtova et al.1 (page 209) explore an alternative mechanism - the repopulation of tumours by cancer stem cells that survive treatment. The authors show that, in certain bladder tumours, repopulation is stimulated by the hormone-like lipid molecule prostaglandin E_2 (PGE_2), which is released from tumour cells that are killed by the initial chemotherapy. Furthermore, the authors show that repopulation can be inhibited by the drug celecoxib, which inhibits PGE_2 synthesis.