Glutathione S-transferase expression in benign and malignant ovarian tumours

Abstract

Summary Glutathione S-transferase sub-types a, 1t and were assessed by immunocytochemistry in 109 biopsies of ovarian tissue, comprising malignant epithelial tissue in 86 cases and tissue of ovarian origin considered to be normal in 23. Glutathione S-transferase n was the most prevalent, being present in all except one malignant epithelium studied and 83% of non-malignant tissue. There were no significant differences in the overall distribution of positive staining for a, and in the malignant and non-malignant biopsies, although the intensity of staining was greater in the malignant epithelium. Stromal staining was in general more pronounced in the malignant biopsies, and this was particularly prominent in the case of the a sub-type. Positive staining was seen more frequently in the less well-differentiated tumours, and a diffuse cytoplasmic pattern was the most common observation in tumours of moderate and poor differentiation. There was no significant association between survival and the presence or absence of sub-type staining of a and sub-type. For the sub-type at, patient survival was found to correlate with the intensity of staining (on a 0-+ + + scale). Those patients showing resistance to cytotoxic chemotherapy were found to have a higher intensity of staining for GSTi than responding patients.

The relationship between tumour glutathione concentration, glutathione S-transferase isoenzyme expression and response to single agent carboplatin in epithelial ovarian cancer patients

“…In the clinical setting, Green et al (1993) studied GST expression in benign and malignant ovarian tumours and, in agreement with the present study, found that it GST was the most prevalent, being present in the majority of the malignant epithelia and 83% of the non-malignant tissue. There was no significant difference in the overall distribution of positive staining for i, a or p in the malignant and nonmalignant biopsies, although the intensity of staining was greater in malignant epithelia.…”

Glutathione-S-transferase activity and isoenzyme levels measured by two methods in ovarian cancer, and their value as markers of disease outcome

“…However, results contrasting with our study have been found in two further immunohistochemical studies. In the first (Green et al, 1993) the intensity of GST acidic isoenzyme staining was significantly correlated with survival in 78 patients with ovarian carcinoma, the prognosis being poorer in patients with a higher intensity of staining in tumour biopsies. In the second study (Hamada et al, 1994), expression of GST acidic isoenzyme was again examined immunohistochemically in relation to response to chemotherapy in 61 patients with ovarian cancer.…”

Natural Products Modulate the Multifactorial Multidrug Resistance of Cancer

“…GSTs are detoxification enzymes conjugated of glutathione to the electrophilic center of various drugs and resulting in excretion of polar molecules. GSTs are able to metabolized cisplatin, doxorubicin, and melphalan and protecting the cells from environmental or oxidative stress [82].…”