title: CYP3A4 overexpression enhances the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in CHO cells.
abstract: OBJECTIVE
  To examine how the higher expression level of CYP3A4 isoenzyme influenced the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in Chinese hamster ovary (CHO) cells.
  
  
  METHODS
  Three CHO cell lines were examined: wild-type CHO cells; CHO-HR cells with overexpression of human cytochrome P450 reductase (CPR); and CHO-HR-3A4 cells with coexpression of human CYP3A4 and CPR. Cellular responses caused by C-1305 were monitored using DAPI staining, cell cycle analysis, phosphatydilserine externalization analysis and SA-β-galactosidase expression analysis. Cell viability was assessed with simultaneous FDA and PI staining.
  
  
  RESULTS
  Treatment with C-1305 for 72 h exhibited different levels of cytotoxicity in the 3 cell lines, and the values of IC80 in CHO, CHO-HR and CHO-HR-3A4 cells were 0.087±0.005, 0.032±0.0001, and 0.064±0.0095 μmol/L, respectively. The cell cycle analysis revealed that both CHO and CHO-HR cells underwent transient G(2)/M arrest, whereas CHO-HR-3A4 cells did not accumulate in this phase. Prolonged exposure up to 120 h caused time-dependent increase in the sub-G(1) fraction in all the 3 cell lines. Treatment with C-1305 caused cell death through apoptosis and necrosis. However, these processes were more pronounced in the transfected CHO cells than in the wild-type cells. The cells surviving after C-1305 exposure underwent senescence.
  
  
  CONCLUSIONS
  CYP3A4 overexpression potently enhances the cellular responses (apoptosis, necrosis and senescence) caused by C-1305 in CHO cells.
authors.affiliation: Department of Pharmaceutical Technology and Biochemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza Str. 11/12, Gdańsk, Poland. ewa.augustin@pg.gda.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Augustin
authors.forename: Barbara
authors.initials: B
authors.lastname: Borowa-Mazgaj
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kikulska
authors.forename: Milena
authors.initials: M
authors.lastname: Kordalewska
authors.forename: Monika
authors.initials: M
authors.lastname: Pawłowska
mesh_terms: D000166:Acridines / Q000494:pharmacology*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D016466:CHO Cells; D020169:Caspases / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D051544:Cytochrome P-450 CYP3A / Q000235:genetics*; D003603:Cytotoxins / Q000494:pharmacology*; D006801:Humans; D014230:Triazoles / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D000166:Acridines; D000970:Antineoplastic Agents; C488734:C 1305; D003603:Cytotoxins; D014230:Triazoles; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D020169:Caspases