Hsu J.-L.Pan S.-L.Ho Y.-F.Hwang T.-L.FAN-LU KUNGJIH-HWA GUH2021-06-022021-06-022011225347https://www.scopus.com/inward/record.uri?eid=2-s2.0-79953799722&doi=10.1016%2fj.juro.2010.12.091&partnerID=40&md5=43502710a24980da0d7d5eb6b2d0a8efhttps://scholars.lib.ntu.edu.tw/handle/123456789/564817Purpose: Costunolide is a natural sesquiterpene lactone. We elucidated what to our knowledge is a novel mechanism to highlight its potential in chemotherapy for prostate cancer, particularly androgen refractory prostate cancer. Materials and Methods: Several pharmacological and biochemical assays were used to characterize the apoptotic signaling pathways of costunolide (ChromaDex?) in prostate cancer cells. Results: Costunolide showed effective antiproliferative activity against hormone dependent (LNCaP) and independent (PC-3 and DU-145) prostate cancer cells (ATCC?) by sulforhodamine B assay, clonogenic test and flow cytometric analysis of carboxyfluorescein succinimidyl ester labeling. In PC-3 cells data showed that costunolide induced a rapid overload of nuclear Ca2+, DNA damage response and ATR phosphorylation. Costunolide induced G1-phase cell cycle arrest, which was supported by p21 up-regulation and its association with the cyclin dependent kinase 2/cyclin E complex. The association resulted in inhibition of the complex activity and inhibition of Rb phosphorylation. Costunolide mediated effects were substantially inhibited by glutathione, the reactive oxygen species scavenger and glutathione precursor N-acetylcysteine, and the Ca2+ chelator BAPTA-AM other than the reactive oxygen species scavenger Trolox?. This indicated the crucial role of intracellular Ca 2+ mobilization and thiol depletion but not of reactive oxygen species production in apoptotic signaling. Conclusions: Data suggest that costunolide induces the depletion of intracellular thiols and overload of nuclear Ca2+ that cause DNA damage and p21 up-regulation. The association of p21 with the cyclin dependent kinase 2/cyclin E complex blocks cyclin dependent kinase 2 activity and inhibits Rb phosphorylation, leading to G1 arrest of the cell cycle and subsequent apoptotic cell death in human prostate cancer cells. ? 2011 American Urological Association Education and Research, Inc.[SDGs]SDG3chromadex; costunolide; cyclin dependent kinase; cyclin dependent kinase 2; cyclin E; protein p21; unclassified drug; antineoplastic activity; apoptosis; article; calcium balance; calcium transport; cancer cell; cell cycle arrest; cell cycle G1 phase; cell cycle regulation; cell proliferation; controlled study; DNA damage; flow cytometry; gene expression regulation; human; human cell; immunoprecipitation; priority journal; prostate cancer; protein depletion; protein phosphorylation; signal transduction; upregulation; Analysis of Variance; Antineoplastic Agents, Phytogenic; Apoptosis; Blotting, Western; Calcium; Cell Cycle; Cell Nucleus; Cell Proliferation; Comet Assay; DNA Damage; Flow Cytometry; Humans; Immunoprecipitation; Male; Prostatic Neoplasms; Reactive Oxygen Species; Sesquiterpenes; Signal Transduction; Tumor Cells, Culturedjournal article10.1016/j.juro.2010.12.091214212372-s2.0-79953799722