title: Chemotherapeutic agents enhance cell migration and epithelial-to-mesenchymal transition through transient up-regulation of tNOX (ENOX2) protein.
abstract: BACKGROUND
  Tumor-associated NADH oxidase (tNOX; ENOX2) is a growth-related protein expressed in transformed cells. High concentrations of numerous chemotherapeutic agents have shown to inhibit tNOX activity and protein levels leading to a reduction in cell growth while little is known for the effects of low concentrations of chemotherapeutic agents on tNOX expression.
  
  
  METHODS
  Effects of chemotherapeutic agents on cell function were evaluated with traditional in vitro assays and the xCELLigence System. Western blot analyses were used to study protein expression profiles of the epithelial-to-mesenchymal transition.
  
  
  RESULTS
  We showed that doxorubicin treatment transiently up-regulates tNOX expression in human lung carcinoma A549 cells in association with enhanced cell migration. Similar results were observed in tamoxifen-exposed A549 cells. Furthermore, protein marker analyses revealed that the enhanced migration induced by tamoxifen was correlated with epithelial-to-mesenchymal transition, as evidenced by down-regulation of epithelial markers and up-regulation of mesenchymal markers. Importantly, tNOX overexpression enhanced cell migration, confirming the essential role of tNOX in cell migration.
  
  
  CONCLUSIONS
  Based on these findings, we conclude that doxorubicin and tamoxifen induce a transient up-regulation of tNOX expression, leading to enhanced cell migration and EMT.
  
  
  CONCLUSIONS
  These findings establish an essential role for tNOX in cell migration and survival and may provide a rational framework for the further development of tNOX inhibitors as a novel class of antitumor agents.
authors: Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taiwan, Republic of China.
authors: Yu-Ching
authors: YC
authors: Su
authors: Yu-Han
authors: YH
authors: Lin
authors: Zih-Ming
authors: ZM
authors: Zeng
authors: Kuo-Ning
authors: KN
authors: Shao
authors: Pin Ju
authors: PJ
authors: Chueh
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D018384:Oxidative Stress; D013629:Tamoxifen / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D000970:Antineoplastic Agents; D013629:Tamoxifen; D004317:Doxorubicin; D009247:NADH, NADPH Oxidoreductases; C431909:tumor-associated NADH oxidase