Insulin-like growth factors in breast cancer.
Insulin-like growth factor (IGF)-I is one of the most potent mitogens to many breast cancer cell lines in vitro. Effective growth inhibition in vitro may be achieved by antibodies to the type I IGF receptor (IGF-IR) or by using antisense strategies. Most human breast cancers express IGF-IR in vivo. Thus, different therapeutic strategies aimed at inhibiting ligand stimulation of the IGF-IR may be an attractive treatment option against breast cancer. Several drugs commonly used in breast cancer influence the IGF system both in vitro and in vivo. While antioestrogens such as tamoxifen and droloxifene reduce the expression of IGF-IR in vitro and suppress plasma levels of IGF-I but elevate IGF-binding protein-1 in vivo, megestrol acetate may reduce the delivery of IGFs to the tissues by inhibition of IGFBP-3 protease activity.
Helle
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Department of Oncology, Haukeland University Hospital, Bergen, Norway.
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D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D004965:Estrogen Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D008535:Megestrol / Q000494:pharmacology / Q000627:therapeutic use; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000378:metabolism*; D017451:Receptors, Somatomedin / Q000187:drug effects*; D013002:Somatomedins / Q000378:metabolism*; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D004965:Estrogen Antagonists; D018970:Insulin-Like Growth Factor Binding Protein 1; D017451:Receptors, Somatomedin; D013002:Somatomedins; D013629:Tamoxifen; C038345:droloxifene; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D008535:Megestrol; D010450:Endopeptidases; C080473:insulin-like growth factor binding protein-3 protease