title: CYP3A4 overexpression enhances apoptosis induced by anticancer agent imidazoacridinone C-1311, but does not change the metabolism of C-1311 in CHO cells.
abstract: OBJECTIVE
  To examine whether CYP3A4 overexpression influences the metabolism of anticancer agent imidazoacridinone C-1311 in CHO cells and the responses of the cells to C-1311.
  
  
  METHODS
  Wild type CHO cells (CHO-WT), CHO cells overexpressing cytochrome P450 reductase (CPR) [CHO-HR] and CHO cells coexpressing CPR and CYP3A4 (CHO-HR-3A4) were used. Metabolic transformation of C-1311 and CYP3A4 activity were measured using RP-HPLC. Flow cytometry analyses were used to examine cell cycle, caspase-3 activity and cell apoptosis. The expression of pH 6.0-dependent β-galactosidase (SA-β-gal) was studied to evaluate accelerated senescence. ROS generation was analyzed with CM-H2 DCFDA staining.
  
  
  RESULTS
  CYP3A4 overexpression did not change the metabolism of C-1311 in CHO cells: the levels of all metabolites of C-1311 increased with the exposure time to a similar extent, and the differences in the peak level of the main metabolite M3 were statistically insignificant among the three CHO cell lines. In CHO-HR-3A4 cells, C-1311 effectively inhibited CYP3A4 activity without affecting CYP3A4 protein level. In the presence of C-1311, CHO-WT cells underwent rather stable G2/M arrest, while the two types of transfected cells only transiently accumulated at this phase. C-1311-induced apoptosis and necrosis in the two types of transfected cells occurred with a significantly faster speed and to a greater extent than in CHO-WT cells. Additionally, C-1311 induced ROS generation in the two types of transfected cells, but not in CHO-WT cells. Moreover, CHO-HR-3A4 cells that did not die underwent accelerated senescence.
  
  
  CONCLUSIONS
  CYP3A4 overexpression in CHO cells enhances apoptosis induced by C-1311, whereas the metabolism of C-1311 is minimal and does not depend on CYP3A4 expression.
authors.affiliation: Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Pawłowska
authors.affiliation: Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Augustin
authors.affiliation: Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Mazerska
mesh_terms: D000609:Aminoacridines / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D051544:Cytochrome P-450 CYP3A / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000609:Aminoacridines; D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; C098965:C 1311