title: Breast cancer adaptive resistance: HER2 and cancer stem cell repopulation in a heterogeneous tumor society.
abstract: OBJECTIVE
  The lethal effects of cancer are associated with the enhanced tumor aggressiveness in recurrent and metastatic lesions that show resistant phenotype to anti-cancer therapy, a major barrier to improving overall survival of cancer patients. The presence of heterogeneous populations of cancer cells within a specific tumor including the tumor-initiating cells or so-called cancer stem cells (CSCs) has linked the acquired resistance (AR, or adaptive resistance). Herein, we discuss the CSC-mediated tumor repopulation in AR of breast cancer in this review.
  
  
  METHODS
  We emphasize a dynamic feature of gene induction in tumor cells that undergo long-term treatment, and describe a specific HER2-NF-κB-HER2 pro-survival pathway that can be initiated in breast CSCs upon radiation therapy.
  
  
  RESULTS
  Elucidation of HER2-induced pro-survival networks, specifically the force driving tumor repopulation due to radioresistant CSCs during anticancer therapies, will have a significant impact on the generation of new diagnostic and therapeutic targets to control of recurrent and metastatic breast tumors.
authors.affiliation: Center of Excellence in Translational Human Stem Cell Research, California National Primate Research Center, University of California Davis, Sacramento, CA, 95817, USA.
authors.forename: Nadire
authors.initials: N
authors.lastname: Duru
authors.forename: Demet
authors.initials: D
authors.lastname: Candas
authors.forename: Guochun
authors.initials: G
authors.lastname: Jiang
authors.forename: Jian Jian
authors.initials: JJ
authors.lastname: Li
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology*; D005260:Female; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000473:pathology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D016328:NF-kappa B; D018719:Erb-b2 Receptor Tyrosine Kinases