title: Reversal of paclitaxel resistance in human ovarian cancer cells with redox-responsive micelles consisting of α-tocopheryl succinate-based polyphosphoester copolymers.
abstract: P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) is a major obstacle in achieving the therapeutic benefits of paclitaxel (PTX) in the treatment of human ovarian carcinoma. This study is aimed to develop an efficient PTX drug delivery approach to overcome MDR. Redox-responsive micelles consisting of amphiphilic polymers containing disulfide linkages, ie, poly (phosphate ester)-SS-D-α-tocopheryl succinate (POPEA-SS-TOS, PSST) were prepared. PTX-loaded PSST micelles (PTX/PSST-M) designed to display synergistic functions, including reversible inhibition of P-gp, intracellular redox-sensitive release and potent anticancer activities. The average size of PTX/PSST-M was 68.1±4.9 nm. The encapsulated PTX was released quickly through redox-triggered dissociation of micelles. The inhibition of P-gp activity and enhanced cellular accumulation of the PSST micelles were validated. PTX/PSST-M showed significantly increased cytotoxicity against PTX-resistant human ovarian cancer A2780/PTX cells: when the cells were treated with PTX/PSST-M for 48 h, the equivalent IC50value of PTX was reduced from 61.51 to 0.49 μmol/L. The enhanced cytotoxic effects of PTX/PSST-M against A2780/PTX cells were attributed to their synergistic effects on reducing the mitochondrial transmembrane potential, ATP depletion, ROS production, and activation of apoptotic pathways. Furthermore, PTX/PSST-M significantly increased cell apoptosis/necrosis and cell cycle arrest at the G2/M phase in A2780/PTX cells. These results demonstrate that the redox-responsive PSST micelles inhibit P-gp activity and have a good potential to effectively reverse PTX resistance in human ovarian carcinoma cells by activating intrinsic apoptotic pathways.
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
authors.forename: Feng-Qian
authors.initials: FQ
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.|College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Xie-Fan
authors.initials: XF
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yu
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Science, Beijing 100700, China.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Liu
authors.affiliation: Institute of Chinese Materia Medica, China Academy of Chinese Medical Science, Beijing 100700, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
authors.forename: Mei-Wan
authors.initials: MW
authors.lastname: Chen
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis / Q000378:metabolism; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004354:Drug Screening Assays, Antitumor; D004952:Esters / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D006801:Humans; D008823:Micelles; D015394:Molecular Structure; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010084:Oxidation-Reduction; D017239:Paclitaxel / Q000737:chemistry / Q000494:pharmacology; D011122:Polyphosphates / Q000737:chemistry / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D013329:Structure-Activity Relationship; D013386:Succinates / Q000737:chemistry / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D024502:alpha-Tocopherol / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D004952:Esters; D008823:Micelles; D011122:Polyphosphates; D017382:Reactive Oxygen Species; D013386:Succinates; D000251:Adenosine Triphosphatases; D024502:alpha-Tocopherol; D017239:Paclitaxel