title: Cancer stem cells in breast cancer.
abstract: There is increasing evidence that cancer stem cells (CSCs) play a critical role in breast cancer initiation, progression, metastasis and drug resistance. It is thought that they are either generated from normal mammary stem/progenitor cells or from mammary epithelial cells by epithelial-mesenchymal transition. Breast CSCs are characterized by the activation of stemness-related pathways, such as the Notch and Wnt pathways, and by the expression of certain stem cell markers, such as CD44, EpCAM and ALDH1. CSCs form a minor population, whose proportion depends on various factors, including environmental conditions. Since CSCs are highly resistant to chemotherapy, additional treatment of breast cancer patients with CSC-specific drugs, such as salinomycin and gamma-secretase inhibitors which target the Wnt or Notch pathway, respectively, will be required. Interestingly, an equilibrium seems to exist between CSCs and non-stem cancer cells, and there are indications that CSCs can be recruited from non-stem cancer cells. As a consequence, it may be necessary to combine a therapy targeting CSCs with common chemotherapy that targets the bulk tumor to avoid the regeneration of CSCs.
authors.affiliation: Klinik für Gynäkologie, Universität Halle, Halle/Saale, Germany. juergen.dittmer@medizin.uni-halle.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Dittmer
authors.forename: Achim
authors.initials: A
authors.lastname: Rody
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology; D051379:Mice; D009362:Neoplasm Metastasis; D014411:Neoplastic Stem Cells / Q000166:cytology*; D010641:Phenotype; D017434:Protein Structure, Tertiary; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D051880:Receptors, Notch; D016212:Transforming Growth Factor beta