important new finding--Fox M1 identified as cause of herceptin,paclitaxel resistance

[Lani]

it may not be the only one, but each one identified and used as a target for drug development helps make herceptin/paclitaxel be effective against more her2+ breast cancers in more patients
Cancer Res. 2010 Jun 8. [Epub ahead of print]
FoxM1 Mediates Resistance to Herceptin and Paclitaxel.
Carr JR, Park HJ, Wang Z, Kiefer MM, Raychaudhuri P.

Authors' Affiliation: Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, College of Medicine, Chicago, Illinois.
Abstract
Inherent and acquired therapeutic resistance in breast cancer remains a major clinical challenge. In human breast cancer samples, overexpression of the oncogenic transcription factor FoxM1 has been suggested to be a marker of poor prognosis. In this study, we report that FoxM1 overexpression confers resistance to the human epidermal growth factor receptor 2 monoclonal antibody Herceptin and microtubule-stabilizing drug paclitaxel, both as single agents and in combination. FoxM1 altered microtubule dynamics to protect tumor cells from paclitaxel-induced apoptosis. Mechanistic investigations revealed that the tubulin-destabilizing protein Stathmin, whose expression also confers resistance to paclitaxel, is a direct transcriptional target of FoxM1. Significantly, attenuating FoxM1 expression by small interfering RNA or an alternate reading frame (ARF)-derived peptide inhibitor increased therapeutic sensitivity. Our findings indicate that targeting FoxM1 could relieve therapeutic resistance in breast cancer. Cancer Res; 70(12); 5054-63. (c)2010 AACR.

PMID: 20530690