TY - JOUR
T1 - HDAC inhibition impedes epithelial-mesenchymal plasticity and suppresses metastatic, castration-resistant prostate cancer
AU - Ruscetti, M.
AU - Dadashian, E. L.
AU - Guo, W.
AU - Quach, B.
AU - Mulholland, D. J.
AU - Park, J. W.
AU - Tran, L. M.
AU - Kobayashi, N.
AU - Bianchi-Frias, D.
AU - Xing, Y.
AU - Nelson, P. S.
AU - Wu, H.
N1 - Funding Information:
We thank members of the Hong Wu lab for their critical comments and suggestions. We also thank Drs Yang Zong and Owen Witte for generously supplying us with HMGA2 antibodies, and Dr Shumin Wu for supplying protein lysates from mouse ES cells. MR was supported by NIH T32 CA009056. WG was supported by a General Financial Grant from the China Postdoctoral Science Foundation (2015M570010), and in part by the Postdoctoral Fellowship of Peking-Tsinghua Center for Life Sciences. DJM was supported by NIH F32 CA112988-01, CIRM TG2-01169 and a Prostate Cancer Foundation Young Investigator Award. This work has been supported, in part, by awards from the Prostate Cancer Foundation (to HW), and grants from the NIH (P50CA097186 and P01 CA163227 to PSN, P50 CA092131 to YX and HW, and R01CA107166, RO1 CA121110 and U01 CA164188 to HW).
Publisher Copyright:
© 2016 Macmillan Publishers Limited.
PY - 2016/7/21
Y1 - 2016/7/21
N2 - PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial-mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial-mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial-mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
AB - PI3K (phosphoinositide 3-kinase)/AKT and RAS/MAPK (mitogen-activated protein kinase) pathway coactivation in the prostate epithelium promotes both epithelial-mesenchymal transition (EMT) and metastatic castration-resistant prostate cancer (mCRPC), which is currently incurable. To study the dynamic regulation of the EMT process, we developed novel genetically defined cellular and in vivo model systems from which epithelial, EMT and mesenchymal-like tumor cells with Pten deletion and Kras activation can be isolated. When cultured individually, each population has the capacity to regenerate all three tumor cell populations, indicative of epithelial-mesenchymal plasticity. Despite harboring the same genetic alterations, mesenchymal-like tumor cells are resistant to PI3K and MAPK pathway inhibitors, suggesting that epigenetic mechanisms may regulate the EMT process, as well as dictate the heterogeneous responses of cancer cells to therapy. Among differentially expressed epigenetic regulators, the chromatin remodeling protein HMGA2 is significantly upregulated in EMT and mesenchymal-like tumors cells, as well as in human mCRPC. Knockdown of HMGA2, or suppressing HMGA2 expression with the histone deacetylase inhibitor LBH589, inhibits epithelial-mesenchymal plasticity and stemness activities in vitro and markedly reduces tumor growth and metastasis in vivo through successful targeting of EMT and mesenchymal-like tumor cells. Importantly, LBH589 treatment in combination with castration prevents mCRPC development and significantly prolongs survival following castration by enhancing p53 and androgen receptor acetylation and in turn sensitizing castration-resistant mesenchymal-like tumor cells to androgen deprivation therapy. Taken together, these findings demonstrate that cellular plasticity is regulated epigenetically, and that mesenchymal-like tumor cell populations in mCRPC that are resistant to conventional and targeted therapies can be effectively treated with the epigenetic inhibitor LBH589.
UR - http://www.scopus.com/inward/record.url?scp=84949256403&partnerID=8YFLogxK
U2 - 10.1038/onc.2015.444
DO - 10.1038/onc.2015.444
M3 - Article
C2 - 26640144
AN - SCOPUS:84949256403
SN - 0950-9232
VL - 35
SP - 3781
EP - 3795
JO - Oncogene
JF - Oncogene
IS - 29
ER -