PURPOSE: We evaluated the antitumor effects of docetaxel (Sigma®) and histone deacetylase inhibitors in hormone refractory prostate cancer cells, and analyzed the mechanism by which combination treatment induced cell death. MATERIALS AND METHODS: We used LNCaP, DU145 and PC3 cells (ATCC®) to evaluate the in vitro apoptotic effects of histone deacetylase inhibitors and their combinations with docetaxel as well as the molecular mechanisms. The DU145 xenograft model was used to evaluate the in vivo efficacy of PXD101 combined with docetaxel. RESULTS: Suberoylanilide hydroxamic acid or PXD101 inhibited the growth of hormone dependent LNCaP cells, and hormone independent DU145 and PC3 cells. It increased sub-G1 population and activated caspase-8, 9 and 3, indicating apoptosis induction. Pretreating DU145 cells with docetaxel followed by histone deacetylase inhibitors showed significant synergistic cytotoxicity compared with that of simultaneous co-treatment or reverse sequential treatment. Pretreatment with docetaxel followed by histone deacetylase inhibitors increased the apoptotic sub-G1 population, caspase activation and tubulin acetylation compared with that of docetaxel alone. Combination treatment decreased Mcl-1 and Bcl-xl, and increased t-Bid, Bik and Bim. Combined docetaxel and PXD101 reduced tumor size with efficacy equivalent to that of a double dose of docetaxel alone in the DU145 xenograft model. CONCLUSIONS: These preclinical results indicate that the sequential combination of docetaxel and histone deacetylase inhibitors led to a synergistic increase in the death of hormone refractory prostate cancer cells via intrinsic and extrinsic apoptotic pathways by modulating Bcl-2 family proteins and tubulin in vitro and in vivo. Results suggest that this combination may be a new therapeutic modality in patients with hormone refractory prostate cancer.
PURPOSE: We evaluated the antitumor effects of docetaxel (Sigma®) and histone deacetylase inhibitors in hormone refractory prostate cancer cells, and analyzed the mechanism by which combination treatment induced cell death. MATERIALS AND METHODS: We used LNCaP, DU145 and PC3 cells (ATCC®) to evaluate the in vitro apoptotic effects of histone deacetylase inhibitors and their combinations with docetaxel as well as the molecular mechanisms. The DU145 xenograft model was used to evaluate the in vivo efficacy of PXD101 combined with docetaxel. RESULTS:Suberoylanilide hydroxamic acid or PXD101 inhibited the growth of hormone dependent LNCaP cells, and hormone independent DU145 and PC3 cells. It increased sub-G1 population and activated caspase-8, 9 and 3, indicating apoptosis induction. Pretreating DU145 cells with docetaxel followed by histone deacetylase inhibitors showed significant synergistic cytotoxicity compared with that of simultaneous co-treatment or reverse sequential treatment. Pretreatment with docetaxel followed by histone deacetylase inhibitors increased the apoptotic sub-G1 population, caspase activation and tubulin acetylation compared with that of docetaxel alone. Combination treatment decreased Mcl-1 and Bcl-xl, and increased t-Bid, Bik and Bim. Combined docetaxel and PXD101 reduced tumor size with efficacy equivalent to that of a double dose of docetaxel alone in the DU145 xenograft model. CONCLUSIONS: These preclinical results indicate that the sequential combination of docetaxel and histone deacetylase inhibitors led to a synergistic increase in the death of hormone refractory prostate cancer cells via intrinsic and extrinsic apoptotic pathways by modulating Bcl-2 family proteins and tubulin in vitro and in vivo. Results suggest that this combination may be a new therapeutic modality in patients with hormone refractory prostate cancer.
Authors: Aaron P Havas; Kameron B Rodrigues; Anvi Bhakta; Joseph A Demirjian; Seongmin Hahn; Jack Tran; Margarethakay Scavello; Ana A Tula-Sanchez; Yi Zeng; Monika Schmelz; Catharine L Smith Journal: Cancer Biol Ther Date: 2016-10-28 Impact factor: 4.742
Authors: Leigh Ellis; Kristin Lehet; Swathi Ramakrishnan; Remi Adelaiye; Kiersten M Miles; Dan Wang; Song Liu; Peter Atadja; Michael A Carducci; Roberto Pili Journal: PLoS One Date: 2011-11-07 Impact factor: 3.240
Authors: Channing J Paller; Michel D Wissing; Janet Mendonca; Anup Sharma; Eugene Kim; Hea-Soo Kim; Madeleine S Q Kortenhorst; Stephanie Gerber; Marc Rosen; Faraz Shaikh; Marianna L Zahurak; Michelle A Rudek; Hans Hammers; Charles M Rudin; Michael A Carducci; Sushant K Kachhap Journal: Cancer Med Date: 2014-07-03 Impact factor: 4.452