Gamma secretase inhibition by BMS-906024 enhances efficacy of paclitaxel in lung adenocarcinoma
Menée sur des lignées cellulaires de cancer du poumon non à petites cellules et à l'aide de xénogreffes d'adénocarcinome pulmonaire, cette étude met en évidence l'intérêt d'un inhibiteur de la sécrétase gamma pour sensibiliser les cellules tumorales au paclitaxel
Notch signaling is aberrantly activated in approximately one third of non-small cell lung cancers (NSCLC). We characterized the interaction between BMS-906024, a clinically relevant Notch gamma secretase inhibitor (GSI), and front-line chemotherapy in preclinical models of NSCLC. Chemosensitivity assays were performed on 14 human NSCLC cell lines. There was significantly greater synergy between BMS-906024 and paclitaxel than BMS-906024 and cisplatin (mean CI value = 0.54 and 0.85, respectively, P = 0.01). On an extended panel of 31 NSCLC cell lines, 25 of which were adenocarcinoma, the synergy between BMS-906024 and paclitaxel was significantly greater in KRAS- and BRAF-wildtype than KRAS- or BRAF-mutant cells (mean CI = 0.43 vs. 0.90, respectively; P = 0.003). Paclitaxel-induced Notch1 activation was associated with synergy between BMS-906024 and paclitaxel in the KRAS- or BRAF-mutant group. Knockdown of mutant KRAS increased the synergy between BMS-906024 and paclitaxel in heterozygous KRAS-mutant cell lines. Among KRAS- or BRAF-mutant NSCLC, there was a significant correlation between synergy and mutant or null TP53 status, as well as between synergy and a low H2O2 pathway signature. Exogenous overexpression of activated Notch1 or Notch3 had no effect on the enhanced sensitivity of NSCLC to paclitaxel by BMS-906024. In vivo studies with cell line- and patient-derived lung adenocarcinoma xenografts confirmed enhanced antitumor activity for BMS-906024 plus paclitaxel versus either drug alone via decreased cell proliferation and increased apoptosis. These results show that BMS-906024 sensitizes NSCLC to paclitaxel, and that wildtype KRAS and BRAF status may predict better patient response to the combination therapy.
http://mct.aacrjournals.org/content/early/2017/10/04/1535-7163.MCT-17-0439.abstract