title: Insulin receptor substrates (IRSs) and breast tumorigenesis.
abstract: Insulin receptor substrate (IRS)-1 and IRS-2 are adaptor proteins in the insulin-like growth factor I (IGF-I)/IGF-I receptor (IGF-IR) pathway that mediate cell proliferation, migration, and survival. In addition to their role as scaffolding proteins in the cytoplasm, they are able to translocate into the nucleus and regulate gene transcription. IRS levels are developmentally and hormonally regulated in the normal mammary gland and both are essential for normal mammary gland bud formation and lactation. Both IRS-1 and IRS-2 are transforming oncogenes, and induce transformation and metastasis in vitro and in vivo. In breast cancer IRSs have unique functions, with IRS-1 being mainly involved in cell proliferation and survival, whereas IRS-2 has clear roles in cell migration and metastasis. In this review we will discuss the roles of IRSs in mammary gland development and breast cancer.
authors.affiliation: Lester and Sue Smith Breast Center, Department of Medicine and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Bonita Tak-Yee
authors.initials: BT
authors.lastname: Chan
authors.forename: Adrian V
authors.initials: AV
authors.lastname: Lee
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D006801:Humans; D055504:Insulin Receptor Substrate Proteins / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000378:metabolism; D042361:Mammary Glands, Human / Q000254:growth & development / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D055504:Insulin Receptor Substrate Proteins; D015513:Oncogene Proteins