The protooncogene Wnt-1 is a secreted glycoprotein capable of both acting as a growth factor and modulating gene transcription and thus cell fate. Its link to tumorigenesis has been assumed to involve either or both of these functions. But on page 87, Chen et al. report that Wnt-1 can increase cell survival by reducing apoptosis in response to chemotherapeutic drugs.
Chen et al. find that cells producing Wnt-1 show less than half the amount of apoptotic death seen in wild-type cells in response to treatment with the antimicrotubule chemotherapeutic drugs vincristine and vinblastine. Wnt-1 signaling normally inhibits the constitutive phosphorylation and degradation of β-catenin, allowing the β-catenin to enter the nucleus and activate gene expression by interaction with members of the Lef/Tcf family of transcription factors. In the current paper, full levels of apoptosis are restored in the presence...
