BACKGROUND/AIM: It was previously reported that γ-secretase inhibitors (GSIs) enhance taxane-induced mitotic arrest and apoptosis in colon cancer cells. To enable the development of taxane-based chemotherapy for pancreatic ductal adenocarcinoma (PDAC), this study investigated the molecular mechanisms by which γ-secretase (GS) complexes regulate taxane sensitivity. MATERIALS AND METHODS: The effect of GS complexes on taxane-induced apoptosis in PDAC cells was evaluated by a cell cycle analysis. GS complexes were examined with small interference RNAs targeted to GS complex-related genes. RESULTS: GSIs and silencing of presenilin 1 (PS1) did not affect cell proliferation but resulted in enhanced taxane-induced G(2)/M accumulation and apoptosis. Silencing of the Notch gene did not induce these effects. However, PS2-specific silencing suppressed proliferation and taxane-induced apoptosis. CONCLUSION: Data from this study indicate that GS complexes regulate the response of PDAC to taxanes through GS-dependent and GS-independent mechanisms.
BACKGROUND/AIM: It was previously reported that γ-secretase inhibitors (GSIs) enhance taxane-induced mitotic arrest and apoptosis in colon cancer cells. To enable the development of taxane-based chemotherapy for pancreatic ductal adenocarcinoma (PDAC), this study investigated the molecular mechanisms by which γ-secretase (GS) complexes regulate taxane sensitivity. MATERIALS AND METHODS: The effect of GS complexes on taxane-induced apoptosis in PDAC cells was evaluated by a cell cycle analysis. GS complexes were examined with small interference RNAs targeted to GS complex-related genes. RESULTS: GSIs and silencing of presenilin 1 (PS1) did not affect cell proliferation but resulted in enhanced taxane-induced G(2)/M accumulation and apoptosis. Silencing of the Notch gene did not induce these effects. However, PS2-specific silencing suppressed proliferation and taxane-induced apoptosis. CONCLUSION: Data from this study indicate that GS complexes regulate the response of PDAC to taxanes through GS-dependent and GS-independent mechanisms.