Cytochrome P450 expression in oesophageal cancer.
The cytochrome P450 superfamily of enzymes play a central part in the metabolism of carcinogens and anti-cancer drugs. The expression, cellular localisation, and distribution of different forms of P450 and the functionally associated enzymes epoxide hydrolase and glutathione S-transferases have been investigated in oesophageal cancer and non-neoplastic oesophageal tissue using immunohistochemistry. Expression of the different enzymes was confined to epithelial cells in both non-neoplastic samples and tumour samples except the CYP3A was also identified in mast cells and glutathione S-transferase pi was present in chronic inflammatory cells. CYP1A was present in a small percentage of non-neoplastic samples but both CYP2C and CYP3A were absent. Epoxide hydrolase was present in half of the non-neoplastic samples and the different classes of glutathione S-transferase were present in a low number of samples. In carcinomas CYP1A, CYP3A, epoxide hydrolase, and glutathione S-transferase pi were expressed in at least 60% of samples. The expression of glutathione S-transferases alpha and mu were significantly less in adenocarcinoma compared with squamous carcinoma.
Murray
G I
GI
Department of Pathology, University of Aberdeen.
Shaw
D
D
Weaver
R J
RJ
McKay
J A
JA
Ewen
S W
SW
Melvin
W T
WT
Burke
M D
MD
D000230:Adenocarcinoma / Q000201:enzymology*; D001189:Aryl Hydrocarbon Hydroxylases; D002294:Carcinoma, Squamous Cell / Q000201:enzymology*; D019363:Cytochrome P-450 CYP1A1; D019392:Cytochrome P-450 CYP2E1; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D004848:Epithelium / Q000201:enzymology; D004851:Epoxide Hydrolases / Q000032:analysis; D004938:Esophageal Neoplasms / Q000201:enzymology*; D004947:Esophagus / Q000201:enzymology; D005982:Glutathione Transferase / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D006899:Mixed Function Oxygenases / Q000032:analysis*; D010088:Oxidoreductases / Q000032:analysis*; D039181:Steroid 16-alpha-Hydroxylase; D013250:Steroid Hydroxylases / Q000032:analysis*
D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D013250:Steroid Hydroxylases; D019392:Cytochrome P-450 CYP2E1; D001189:Aryl Hydrocarbon Hydroxylases; D019363:Cytochrome P-450 CYP1A1; D039181:Steroid 16-alpha-Hydroxylase; D005982:Glutathione Transferase; D004851:Epoxide Hydrolases