The expression of cytochrome P450 enzymes in human breast tumours and normal breast tissue

Breast Cancer Res Treat. 2001 Nov;70(1):47-54. doi: 10.1023/a:1012526406741.


Environmental chemicals are one of the risk factors in breast cancer genesis. Cytochrome P450 (CYP) enzymes play a major role in the activation of these chemicals. Using highly specific and sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. the expression profile of all major xenobiotic metabolizing CYP forms was screened in breast tumour and surrounding tumour free (control) breast tissue in a series of 20 sample pairs obtained from females with infiltrating ductal carcinoma. The levels of CYPIAI mRNA were very low in both tumour and normal tissue. CYP1B1, CYP2B6, CYP2C, CYP2D6, CYP2E1, CYP4B1, and CYP11A1 expressions were positive in both tumours and control tissue. CYP2A6, CYP2A7, CYP2A13, CYP2F1, CYP3A4, CYP3A5. and CYP3A7 mRNAs were expressed neither in tumours nor in control tissue. These results show that several CYPs. responsible for the activation of a quite large number of procarcinogens and genotoxic estrogen metabolites. are expressed in breast tissue with a lack of qualitative differences in CYP expression at mRNA level between breast tumours and surrounding normal breast.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Breast / enzymology*
  • Breast Neoplasms / enzymology*
  • Breast Neoplasms / genetics*
  • Case-Control Studies
  • Cytochrome P-450 Enzyme System / genetics*
  • Female
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Middle Aged
  • RNA, Messenger / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Risk Factors


  • RNA, Messenger
  • Cytochrome P-450 Enzyme System