Expression of cytochrome P450s and glutathione S-transferases in human esophagus with squamous-cell carcinomas.
In order to clarify the expression of cytochrome P450 and glutathione S-transferase in human esophagus, 41 samples of human esophagus with squamous-cell carcinoma were investigated by immunoblot analysis and enzyme assays. Cytochrome P450 1A2/1 was clearly expressed in microsomes, and the amount in samples with tumorous tissue was significantly greater than that in samples without tumourous tissues or in liver; cytochrome P450 2B6 and 3A4/3 were expressed polymorphically. Aryl hydrocarbon hydroxylase activity was detected in microsomes and was greater in samples from smokers than non-smokers. Patients who both smoked and drank alcohol, however, had activity similar to that of patients without these habits. Glutathione S-transferase M1 and A1/2 protein existed polymorphically in cytosol, and glutathione S-transferase P1-1 was detected in all samples. The frequency of expression of the glutathione S-transferase A1/2 protein was greater in patients with M1 protein than in those without; no difference in the expression was seen for glutathione S-transferase P1-1. Neither smoking nor drinking influenced the expression or activity of glutathione S-transferase. Our data support the idea that some carcinogens can be directly activated or inactivated in human esophageal epithelium.
Nakajima
T
T
Department of Hygiene, Shinshu University School of Medicine, Matsumoto, Japan.
Wang
R S
RS
Nimura
Y
Y
Pin
Y M
YM
He
M
M
Vainio
H
H
Murayama
N
N
Aoyama
T
T
Iida
F
F
D000428:Alcohol Drinking; D000704:Analysis of Variance; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D016009:Chi-Square Distribution; D002681:China; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004938:Esophageal Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D004947:Esophagus / Q000201:enzymology; D005260:Female; D005982:Glutathione Transferase / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012907:Smoking
D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; D005982:Glutathione Transferase