title: Liberation of doxorubicin from HPMA copolymer conjugate is essential for the induction of cell cycle arrest and nuclear fragmentation in ovarian carcinoma cells.
abstract: Despite intensive study, the molecular mechanism for cell toxicity of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bound doxorubicin remains unclear. Moreover, the ability of the released drug to accumulate in the nucleus has also been questioned. We have hypothesized that the pattern of cell cycle progression is a useful indicator for the presence of free doxorubicin in the nucleus and its interaction with nuclear DNA. The effects of HPMA copolymer-bound doxorubicin on cell cycle progression were evaluated in this study in cultured human ovarian cancer A2780 cells. We determined that P-GFLG-DOX, but not P-GG-DOX, initiates cell cycle arrest and nuclear fragmentation in the same manner as free DOX, but with a time-delay. Our data indicate that drug release from the conjugate is required for the apoptotic activity associated with the conjugate.
authors.affiliation: Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: A
authors.initials: A
authors.lastname: Malugin
authors.forename: P
authors.initials: P
authors.lastname: Kopecková
authors.forename: J
authors.initials: J
authors.lastname: Kopecek
mesh_terms: D000178:Acrylamides / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001682:Biological Availability; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects*; D004317:Doxorubicin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D005260:Female; D006801:Humans; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D000178:Acrylamides; D000903:Antibiotics, Antineoplastic; C482378:N-(2-hydroxypropyl)methacrylamide co-polymer-doxorubicin conjugate; D004317:Doxorubicin