Original Article
Subject Category: Acquired and Multigenic Disease
Molecular Therapy (2009); doi:10.1038/mt.2009.227
Amphiregulin Promotes Resistance to Gefitinib in NonSmall Cell Lung Cancer Cells by Regulating Ku70 Acetylation
Benoît Busser1,2,3, Lucie Sancey1,2, Véronique Josserand1,2, Carole Niang1,2, Saadi Khochbin1,2, Marie C Favrot1,2,3, Jean-Luc Coll1,2 and Amandine Hurbin1,2
- 1INSERM, U823, Institut Albert Bonniot, Grenoble, France
- 2Université Joseph Fourier, Grenoble, France
- 3CHRU Grenoble, Hôpital Michallon, UF Cancérologie Biologique et Biothérapie, Grenoble, France
Correspondence: Amandine Hurbin, INSERM U823, Institut Albert Bonniot, BP170 Grenoble, F-38042 cedex 9, France. E-mail: amandine.hurbin@ujf-grenoble.fr
Received 20 March 2009; Accepted 9 September 2009; Published online 13 October 2009.
Abstract
Multiple molecular resistance mechanisms reduce the efficiency of receptor tyrosine kinase inhibitors such as gefitinib in non-small cell lung cancer (NSCLC). We previously demonstrated that amphiregulin (Areg) inhibits gefitinib-induced apoptosis in NSCLC cells by inactivating the proapoptotic protein BAX. In this part of the investigation, we studied the molecular mechanisms leading to BAX inactivation. We show that Areg prevents gefitinib-mediated acetylation of Ku70. This augments the BAX-Ku70 interaction and therefore prevents BAX-mediated apoptosis. Accordingly, Areg or Ku70 knock down restore BAX activation and apoptosis in gefitinib-treated H358 cells in vitro. In addition, overexpression of the histone acetyltransferase (HAT) CREB-binding protein (CBP) or treatments with histone deacetylase (HDAC) inhibitors sensitize H358 cells to gefitinib. Moreover, a treatment with vorinostat, a HDAC inhibitor strongly sensitized tumors to gefitinib in vivo. These findings suggest new prospects in combining both HDAC and epidermal growth factor receptor inhibitors for the treatment of NSCLC.
