ABSTRACT
7-Ethoxylesorufin O-deethylase (EROD) (mainly catalyzed by cytochrome P450 (CYP) 1A1 and used as a marker for CYP 1A1) activity was measured in the breast tumor and surrounding tumor free (normal) tissues of 37 female breast cancer patients with infiltrating ductal carcinoma. About 11% of the tumor and normal breast tissue samples lacked the enzyme activity. Large interindividual variations in the activities of EROD were found in both tumor and normal tissues ranging from 0 to 283 and 0 to 801 fmol/mg/min, respectively. However, no significant difference was noted between the mean EROD activities of tumor and normal breast tissues. This tendency did not change with the stage and grade of the malignancy and menopausal status. No significant correlation was observed between the EROD activity and stage or grade of malignancy (p > 0.05). Thus, it appears that EROD activity is not capable of reflecting the overall malignant potential of breast cancer tissue.
Subject(s)
Breast Neoplasms/enzymology , Cytochrome P-450 CYP1A1/metabolism , Adult , Aged , Breast Neoplasms/pathology , Female , Humans , Menopause/metabolism , Middle Aged , Neoplasm Metastasis , PrognosisABSTRACT
An investigation was made of ethoxyresorufin O-deethylase (EROD) activity, a cytochrome P450 (CYP) dependent enzyme mainly catalyzed by CYP1A1, glutathione S-transferase (GST) activity toward the substrates 1-chloro-2,4- dinitrobenzene (CDNB) and ethacrynic acid (EAA), reduced glutathione (GSH) levels, and antioxidant enzyme (AOE) activity namely catalase (CAT) and selenium- dependent glutathione peroxidase (Se-GPx) in tumor and surrounding tumor-free (normal) tissues in female breast cancer patients. Wide interindividual variations were found in the enzyme activities in both tumor and normal breast tissues. No significant differences were noted between mean EROD and CAT activities in tumor and normal breast tissues. The mean activities of CDNB GST, EAA GST and Se-GPx and GSH levels in tumor tissue were significantly higher than those in normal breast tissue. These results show that CYP, GST and AOE behave differentially in breast tumors.
