Inhibition of heat shock protein 90 function by ansamycins causes the morphological and functional differentiation of breast cancer cells Journal Article


Authors: Münster, P. N.; Srethapakdi, M.; Moasser, M. M.; Rosen, N.
Article Title: Inhibition of heat shock protein 90 function by ansamycins causes the morphological and functional differentiation of breast cancer cells
Abstract: 17-(Allylamino)-17-demethoxygeldanamycin (17-AAG) is an ansamycin antibiotic that binds to a conserved pocket in Hsp90 and induces the degradation of proteins that require this chaperone for conformational maturation. 17-AAG causes a retinoblastoma (RB)-dependent G1 block in cancer cells and is now in clinical trial. In breast cancer cells, G1 block is accompanied by differentiation and followed by apoptosis. The differentiation is characterized by specific changes in morphology and induction of milk fat proteins and lipid droplets. In cells lacking RB, neither G1 arrest nor differentiation occurs; instead, they undergo apoptosis in mitosis. Introduction of RB into these cells restores the differentiation response to 17-AAG. Inhibitors of the ras, mitogen-activated protein kinase, and phosphatidylinositol 3-kinase pathways cause accumulation of milk fat proteins and induction of lipid droplets when associated with G1 arrest but do not cause morphological changes. Thus, regulation of Hsp90 function by 17-AAG in breast cancer cells induces RB-dependent morphological and functional mammary differentiation. G1 arrest is sufficient for some but not all aspects of the phenotype. Induction of differentiation may be responsible for some of the antitumor effects of this drug.
Keywords: mitogen activated protein kinase; controlled study; unclassified drug; human cell; phenotype; cell division; cell structure; apoptosis; breast cancer; tumor differentiation; cell differentiation; drug effect; drug screening; tumor cells, cultured; breast neoplasms; phosphorylation; phosphatidylinositol 3 kinase; protein induction; heat shock protein 90; hsp90 heat-shock proteins; quinones; ras protein; antibiotics, antineoplastic; retinoblastoma protein; glycoproteins; cell cycle g1 phase; g1 phase; benzoquinones; lactams, macrocyclic; rifabutin; lipid composition; glycolipids; ansamycin derivative; 17 allylamino 17 demethoxygeldanamycin; milk proteins; human; priority journal; article; milk fat; milk protein
Journal Title: Cancer Research
Volume: 61
Issue: 7
ISSN: 0008-5472
Publisher: American Association for Cancer Research  
Date Published: 2001-04-01
Start Page: 2945
End Page: 2952
Language: English
PUBMED: 11306472
PROVIDER: scopus
DOI/URL:
Notes: Export Date: 21 May 2015 -- Source: Scopus
Citation Impact
MSK Authors
  1. Mark M Moasser
    56 Moasser
  2. Neal Rosen
    425 Rosen
  3. Pamela Munster
    30 Munster