title: RNA expression of cytochrome P450 in breast cancer patients.
abstract: BACKGROUND
  The expression pattern of cytochrome P450 genes (CYPs) affected by tumorigenesis may have an important role in the progression of cancer and in the metabolism of anticancer drugs. The aim of the study was to determine the expression patterns of four cytochrome P450 genes (CYP1B1, 2C9, 2E1 and 3A4) in breast cancer patients.
  
  
  METHODS
  mRNA expression was quantified by real-time PCR. Analyses of 40 sets of human breast tumors, adjacent non-tumor tissues and of 18 peripheral blood lymphocyte samples were performed. Expression levels were tested for correlation with clinical and pathological data of patients.
  
  
  RESULTS
  Expression levels of CYP2C9 and CYP3A4 were negligible. CYP1B1 expression was on average 50-fold higher than that of CYP2E1 with overexpression detected in one third of the tumors. Correlation of CYP1B1 expression in lymphocytes with that in non-tumor tissues was found. Significantly higher CYP2E1 expression was associated with an invasive lobular type of tumor, locally advanced disease as well as with non-tumor tissue of progesterone receptor-negative patients.
  
  
  CONCLUSIONS
  CYP2E1 expression has a potential role as a breast cancer prognosis marker. The observed high CYP1B1 expression in tumor cells may evoke changes in their response to drugs which are substrates of P450 1B1 and influence metabolism or activation of environmental carcinogens.
authors.affiliation: Group for Biotransformations, Center of Occupational Diseases, National Institute of Public Health, Srobarova 48, 100 42 Praha 10, Czech Republic. rvaclavikova@szu.cz
authors.forename: Radka
authors.initials: R
authors.lastname: Vaclavikova
authors.forename: Miluse
authors.initials: M
authors.lastname: Hubackova
authors.forename: Jana
authors.initials: J
authors.lastname: Stribrna-Sarmanova
authors.forename: Roman
authors.initials: R
authors.lastname: Kodet
authors.forename: Marcela
authors.initials: M
authors.lastname: Mrhalova
authors.forename: Jan
authors.initials: J
authors.lastname: Novotny
authors.forename: Ivan
authors.initials: I
authors.lastname: Gut
authors.forename: Pavel
authors.initials: P
authors.lastname: Soucek
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D003577:Cytochrome P-450 Enzyme System