title: Expression profile of CYP1A1 and CYP1B1 enzymes in colon and bladder tumors.
abstract: BACKGROUND
  The cytochrome P450 CYP1A1 and CYP1B1 enzymes are involved in carcinogenesis via activation of pro-carcinogenic compounds to carcinogenic metabolites. CYP1A1 and CYP1B1 have shown elevated levels in human tumors as determined by qRT-PCR and immunohistochemical studies. However studies that have examined CYP1 expression by enzyme activity assays are limited.
  
  
  RESULTS
  In the current study the expression of CYP1A1 and CYP1B1 was investigated in a panel of human tumors of bladder and colorectal origin by qRT-PCR and enzyme activity assays. The results demonstrated that 35% (7/20) of bladder tumors and 35% (7/20) of colon tumors overexpressed active CYP1 enzymes. CYP1B1 mRNA was overexpressed in 65% and 60% of bladder and colon tumors respectively, whereas CYP1A1 was overexpressed in 65% and 80% of bladder and colon tumors. Mean mRNA levels of CYP1B1 and CYP1A1 along with mean CYP1 activity were higher in bladder and colon tumors compared to normal tissues (p<0.05). Statistical analysis revealed CYP1 expression levels to be independent of TNM status. Moreover, incubation of tumor microsomal protein in 4 bladder and 3 colon samples with a CYP1B1 specific antibody revealed a large reduction (72.5 ± 5.5 % for bladder and 71.8 ± 7.2% for colon) in catalytic activity, indicating that the activity was mainly attributed to CYP1B1 expression.
  
  
  CONCLUSIONS
  The study reveals active CYP1 overexpression in human tumors and uncovers the potential use of CYP1 enzymes and mainly CYP1B1 as targets for cancer therapy.
authors.affiliation: Laboratory of Toxicology, Department of Morphology, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece ; Laboratory of Clinical Virology, Department of Laboratory Medicine, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.
authors.forename: Vasilis P
authors.initials: VP
authors.lastname: Androutsopoulos
authors.affiliation: First Department of Surgery, University of Athens, Laiko Hospital, Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Spyrou
authors.affiliation: Department of Urology, "Asklipeio" General Hospital, Voula, Athens, Greece.
authors.forename: Achilles
authors.initials: A
authors.lastname: Ploumidis
authors.affiliation: First Department of Surgery, University of Athens, Laiko Hospital, Athens, Greece.
authors.forename: Alexandros Eystathios
authors.initials: AE
authors.lastname: Papalampros
authors.affiliation: Laboratory of Toxicology, Department of Morphology, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.
authors.forename: Michalis
authors.initials: M
authors.lastname: Kyriakakis
authors.affiliation: Department of Urology, "Asklipeio" General Hospital, Voula, Athens, Greece.
authors.forename: Demetrios
authors.initials: D
authors.lastname: Delakas
authors.affiliation: Laboratory of Clinical Virology, Department of Laboratory Medicine, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
authors.affiliation: Laboratory of Toxicology, Department of Morphology, Faculty of Medicine, University of Crete, Heraklion, Crete, Greece.
authors.forename: Aristidis M
authors.initials: AM
authors.lastname: Tsatsakis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics* / Q000378:metabolism; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics* / Q000378:metabolism; D065633:Cytochrome P-450 CYP1B1; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D001749:Urinary Bladder Neoplasms / Q000201:enzymology* / Q000473:pathology
chemical_list: D001189:Aryl Hydrocarbon Hydroxylases; C569463:CYP1A1 protein, human; C585496:CYP1B1 protein, human; D019363:Cytochrome P-450 CYP1A1; D065633:Cytochrome P-450 CYP1B1