title: The alterations in SATB1 and nuclear F-actin expression affect apoptotic response of the MCF-7 cells to geldanamycin.
abstract: BACKGROUND
  The function and localization of actin in the nucleus have not yet been fully described. However, actin seems to be a key protein in nuclear processes interacting with chromatin and matrix proteins. The aim of the study was to evaluate the effect of controlled expression of nuclear pool of F-actin and special AT-rich sequence-binding protein 1 (SATB1) on the in vitro induction of active cell death by geldanamycin (GA).
  
  
  METHODS
  The expression of SATB1 was regulated by the transfection of non-aggressive breast cancer MCF-7 cells with siRNA against SATB1 or expression plasmid with cloned cDNA of SATB1. The altered expression of cofilin-1 in these cells was used to regulate the nuclear expression and localization of F-actin. The effect of GA was analyzed in the context of cell death induction and cell cycle alterations.
  
  
  RESULTS
  Our studies revealed that the targeted regulation of SATB1 and cofilin-1 expression changed the apoptotic response of the MCF-7 cells to GA. The overexpression of these proteins potentiated GA-induced arrest of the cells in the G1 phase of cell cycle and increased the population of the hypodiploid cells.
  
  
  CONCLUSIONS
  The alterations in the nuclear expression of SATB1 and F-actin in MCF-7 cells may affect their active cell death in response to GA.
authors: Department and Clinic of Dermatology, Sexually Transmitted Diseases and Immunodermatology, Nicolaus Copernicus University in Torun, Collegium Medicum in Bydgoszcz, Poland. d_gr@me.com.
authors: Dariusz
authors: D
authors: Grzanka
authors: Magdalena
authors: M
authors: Izdebska
authors: Anna
authors: A
authors: Klimaszewska-Wisniewska
authors: Maciej
authors: M
authors: Gagat
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000633:toxicity*; D017209:Apoptosis; D016227:Benzoquinones / Q000633:toxicity*; D059447:Cell Cycle Checkpoints; D002467:Cell Nucleus / Q000378:metabolism; D051338:Cofilin 1 / Q000235:genetics / Q000378:metabolism; D047029:Lactams, Macrocyclic / Q000633:toxicity*; D061986:MCF-7 Cells; D036961:Matrix Attachment Region Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D000903:Antibiotics, Antineoplastic; D016227:Benzoquinones; D051338:Cofilin 1; D047029:Lactams, Macrocyclic; D036961:Matrix Attachment Region Binding Proteins; C076189:SATB1 protein, human; C001277:geldanamycin