Free and N-(2-hydroxypropyl)methacrylamide copolymer-bound geldanamycin derivative induce different stress responses in A2780 human ovarian carcinoma cells.
The effects of geldanamycin (GA), 17-(3-aminopropylamino)-17-demethoxygeldanamycin (AP-GA), and N-(2-hydroxypropyl)methacrylamide copolymer-AP-GA conjugate [P(AP-GA)] on A2780 human ovarian carcinoma cells at an equitoxic dose (2x IC(50)) were compared by the gene expression array analysis. All treatments resulted in similar gene expression profiles up to 12 h (e.g., down-regulation of CDK4 and up-regulation of APAF-1), although P(AP-GA)-treated cells showed delayed gene expression because of time-dependent internalization of the conjugate and intracellular drug release from P(AP-GA). However, AP-GA-treated cells showed elevated expression of HSP70 and HSP27 after 6 h compared with that observed by GA and P(AP-GA) treatments. Depletion of C-Raf, an HSP90 client protein, was observed in all treatments up to 12 h. Confocal microscopy using mesochlorin e(6) as a model drug revealed that drug release caused by the lysosomal cleavage of glycylphenylalanylleucylglycine oligopeptide spacer, used as GA derivative copolymer attachment/release point, was moderately fast. These results suggested that AP-GA treatment may activate stress-response pathways, whereas P(AP-GA) treatment may suppress them and trigger signaling pathways essential to cell growth arrest and death by inducing an HSP90-active factor. Although GA and P(AP-GA) treatments induced a time-dependent increase in HSP70 and HSP27 protein expression (detected by Western blotting analysis), AP-GA treatment resulted in more rapid and more intense expression of both proteins. Our results suggest that conjugation of AP-GA to N-(2-hydroxypropyl)methacrylamide copolymer may be able to modulate the cell stress responses induced by AP-GA because of differences in its internalization mechanism, subcellular localization, and intracellular concentration gradients.
Nishiyama
Nobuhiro
N
Department of Pharmaceutics and Pharmaceutical Chemistry/Center for Controlled Chemical Delivery (CCCD), University of Utah, 30 South 2000 East, Room 301, Salt Lake City, UT 84112, USA.
Nori
Aparna
A
Malugin
Alexander
A
Kasuya
Yuji
Y
Kopecková
Pavla
P
Kopecek
Jindrich
J
D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000494:pharmacology*; D016227:Benzoquinones; D015153:Blotting, Western; D045744:Cell Line, Tumor; D005260:Female; D020869:Gene Expression Profiling; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D006360:Heat-Shock Proteins; D006801:Humans; D020128:Inhibitory Concentration 50; D047029:Lactams, Macrocyclic; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000096:biosynthesis; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D011109:Polymethacrylic Acids / Q000737:chemistry* / Q000494:pharmacology; D011809:Quinones / Q000737:chemistry / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
C481162:17-(3-aminopropylamino)-17-demethoxygeldanamycin; D000903:Antibiotics, Antineoplastic; D016227:Benzoquinones; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D011109:Polymethacrylic Acids; D011809:Quinones; C011533:Duxon; C001277:geldanamycin