title: Role of IGF1R in Breast Cancer Subtypes, Stemness, and Lineage Differentiation.
abstract: Insulin-like growth factor (IGF) signaling is fundamental for growth and survival. A large body of evidence (laboratory, epidemiological, and clinical) implicates the exploitation of this pathway in cancer. Up to 50% of breast tumors express the activated form of the type 1 insulin-like growth factor receptor (IGF1R). Breast cancers are categorized into subtypes based upon hormone and ERRB2 receptor expression and/or gene expression profiling. Even though IGF1R influences tumorigenic phenotypes and drug resistance across all breast cancer subtypes, it has specific expression and function in each. In some subtypes, IGF1R levels correlate with a favorable prognosis, while in others it is associated with recurrence and poor prognosis, suggesting different actions based upon cellular and molecular contexts. In this review, we examine IGF1R expression and function as it relates to breast cancer subtype and therapy-acquired resistance. Additionally, we discuss the role of IGF1R in stem cell maintenance and lineage differentiation and how these cell fate influences may alter the differentiation potential and cellular composition of breast tumors.
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, PA , USA ; Women's Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, University of Pittsburgh , Pittsburgh, PA , USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Farabaugh
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, PA , USA ; Women's Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, University of Pittsburgh , Pittsburgh, PA , USA.
authors.forename: David N
authors.initials: DN
authors.lastname: Boone
authors.affiliation: Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, PA , USA ; Women's Cancer Research Center, Magee-Womens Research Institute, University of Pittsburgh Cancer Institute, University of Pittsburgh , Pittsburgh, PA , USA ; Department of Human Genetics, University of Pittsburgh , Pittsburgh, PA , USA.
authors.forename: Adrian V
authors.initials: AV
authors.lastname: Lee
keywords: ER+; ERBB2+; IGF1R; breast cancer subtypes; lineages; luminal; triple negative