title: Dynamic Phenotypic Transition of Breast Cancer CellsIn VitroRevealed by Self-floating Cell Culture.
abstract: Breast tumor heterogeneity leads to phenotypic diversity, such as tumor-initiating and metastatic properties and drug sensitivity.
  
  
  
  We found that a self-floating cell (SFC) culture enriches a drug-resistant subpopulation in a HER2-positive breast cancer cell line. SFCs were analyzed for cancer stem cell markers, gene expression profiles, and sensitivity for anticancer drugs.
  
  
  
  SFCs expressed cancer stem cell markers, such as aldehyde dehydrogenase (ALDH) activity and elevated HER2 autophosphorylation. Gene expression profiles of SFCs showed a dramatic difference compared to those of parental or forced floating cells. SFCs also expressed CD133, a marker of drug resistance, and resisted cytotoxic drugs by drug efflux transporters. In contrast, HER2 kinase inhibitors efficiently reduced SFC viability.
  
  
  
  SFCs enrich drug-resistant subpopulations even in vitro and might reflect the highly plastic nature of breast cancer cells even in vitro.
authors.affiliation: Departments of Integrated Information for Pharmaceutical Sciences, Iwate Medical University School of Pharmacy, Iwate, Japan yoku@iwate-med.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Oku
authors.affiliation: Departments of Integrated Information for Pharmaceutical Sciences, Iwate Medical University School of Pharmacy, Iwate, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nishiya
authors.affiliation: Departments of Integrated Information for Pharmaceutical Sciences, Iwate Medical University School of Pharmacy, Iwate, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Tsuda
authors.affiliation: Department of Tumor Biology, Institute of Biomedical Science, Iwate Medical University, Iwate, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shibazaki
authors.affiliation: Department of Tumor Biology, Institute of Biomedical Science, Iwate Medical University, Iwate, Japan.
authors.forename: Chihaya
authors.initials: C
authors.lastname: Maesawa
authors.affiliation: Departments of Integrated Information for Pharmaceutical Sciences, Iwate Medical University School of Pharmacy, Iwate, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Uehara
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000231:Adenocarcinoma, Papillary / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D066298:In Vitro Techniques; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D000444:Aldehyde Dehydrogenase
keywords: HER2; Tumor heterogeneity; breast cancer; drug resistance