title: CYP3A4 expression in breast cancer and its association with risk factors in Mexican women.
abstract: BACKGROUND
  In Mexico, breast cancer (BCa) is the leading type of cancer in women. Cytochrome P450 (CYP450) is a superfamily of major oxidative enzymes that metabolize carcinogens and many antineoplastic drugs. In addition, these enzymes have influence on tumor development and tumor response to therapy. In this report, we analyzed the protein expression in patients with BCa and in healthy women. Links with some clinic-pathological characteristic were also assessed.
  
  
  METHODS
  Immunohistochemical analyses were conducted on 48 sets of human breast tumors and normal breast tissues enrolled in Hospital Militar de Especialidades de la Mujer y Neonatologia and Hospital Central Militar, respectively, during the time period from 2010 to 2011. Informed consent was obtained from all participants. Statistical analysis was performed using χ2 or Fisher exact tests to estimate associations and the Mann Whitney U test for comparison of group means.
  
  
  RESULTS
  We found a significant CYP3A4 overexpression in BCa stroma and gland regions in comparison with healthy tissue. A significant association between protein expression with smoking, alcoholism and hormonal contraceptives use was also observed. Additionally, we observed estrogen receptor (ER) and progesterone receptor (PR) positive association in BCa.
  
  
  CONCLUSIONS
  We suggest that CYP3A4 expression promotes BCa development and can be used in the prediction of tumor response to different treatments. One therapeutic approach may thus be to block CYP3A4 function.
authors.affiliation: Section of Research and Graduate Studies, Instituto Politecnico Nacional, Mexico City E-mail : floriano_esa@yahoo.com; noemicr2001@yahoo.com.mx.
authors.forename: Esau
authors.initials: E
authors.lastname: Floriano-Sanchez
authors.forename: Noemi Cardenas
authors.initials: NC
authors.lastname: Rodriguez
authors.forename: Cindy
authors.initials: C
authors.lastname: Bandala
authors.forename: Elvia
authors.initials: E
authors.lastname: Coballase-Urrutia
authors.forename: Jaime
authors.initials: J
authors.lastname: Lopez-Cruz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000378:metabolism*; D002277:Carcinoma / Q000453:epidemiology / Q000378:metabolism*; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D005260:Female; D006801:Humans; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D050177:Overweight / Q000453:epidemiology*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human