Immunohistochemical evaluation of Pi class glutathione S-transferase expression in invasive breast carcinoma.

Objectives: The aim of our work was to determine the expression of Pi class glutathione S-transferase (GSTP1) in 43 samples of invasive breast carcinoma and compare results versus normal breast cells.
Background: Breast cancer is the commonest cancer in women. Despite advances in early detection and more efficacious adjuvant chemotherapy, a part of patients with early-stage have reccurent disease. In these cases the development of resistance to therapy is observed. The glutathione S-transferases (GSTs) are potentially involved in tumour chemoresistance.
Methods: Enzyme immunohistochemical method was chosen for the detection of GSTP1 and its expression was compared in breast cancer cells versus normal breast cells.
Results: We have found that majority (63%) of breast carcinomas shows GSTP1 positivity (nuclear and cytoplasmic immunoreactivity). It is expected that GSTP1 positive tumours would show a poorer prognosis than GSTP1 negative ones.
Conclusion: Immunohistochemistry is a useful method for investigating the expression and cellular localization of GSTP1 within tumours. It may be applied to a routine clinical test and it can serve as a marker for resistance to chemotherapy (Tab. 1, Fig. 4, Ref. 20). Full Text in free PDF www.bmj.sk.