Free and N-(2-hydroxypropyl)methacrylamide copolymer-bound geldanamycin derivative induce different stress responses in A2780 human ovarian carcinoma cells.

Abstract

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.

• Authors: Nobuhiro Nishiyama, Aparna Nori, Alexander Malugin, Yuji Kasuya, Pavla Kopecková, Jindrich Kopecek
• Journal: Cancer research (Cancer Res) Vol. 63 Issue 22 Pg. 7876-82 (Nov 15 2003) ISSN: 0008-5472 [Print] United States
• PMID: 14633716 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• 17-(3-aminopropylamino)-17-demethoxygeldanamycin
• Antibiotics, Antineoplastic
• Benzoquinones
• HSP27 Heat-Shock Proteins
• HSP70 Heat-Shock Proteins
• HSPB1 protein, human
• Heat-Shock Proteins
• Lactams, Macrocyclic
• Molecular Chaperones
• Neoplasm Proteins
• Polymethacrylic Acids
• Quinones
• Duxon
• geldanamycin

Topics

• Antibiotics, Antineoplastic (chemistry, pharmacology)
• Benzoquinones
• Blotting, Western
• Cell Line, Tumor
• Female
• Gene Expression Profiling
• HSP27 Heat-Shock Proteins
• HSP70 Heat-Shock Proteins (biosynthesis)
• Heat-Shock Proteins
• Humans
• Inhibitory Concentration 50
• Lactams, Macrocyclic
• Microscopy, Fluorescence
• Molecular Chaperones
• Neoplasm Proteins (biosynthesis)
• Ovarian Neoplasms (drug therapy, genetics, metabolism)
• Polymethacrylic Acids (chemistry, pharmacology)
• Quinones (chemistry, pharmacology)
• Reverse Transcriptase Polymerase Chain Reaction