Investigation of the activity of multidrug resistance GST in the plasma of breast cancer patients with its clinical significance

Objective:To investigate the activity of multidrug resistance gene GST in the plasma of breast cancer patients,analyze the expression of GST before and after chemotherapy and evaluate the clinical value.Methods:The plasma of patients and chemical reagents were mixed distributed into the 96-well plate,and read the absorbance once every minute at 340 nm to obtain at least 5 time points.Plotting the absorbance values to obtain the slope of the linear portion of the curve and use the formula to calculate the GST activity for each sample.Results:The mean concentration of GST activity was (842±606) nmol·min-1·mL-1 before chemotherapy and (796±587) nmol·min-1·mL-1 after chemotherapy.The mean concentration of plasma GST activity was significantly increased in patients with positive lymph node metastasis and negative lymph node metastasis (P0.05).Conclusion:The results of this preliminary study suggested that GST expression in plasma of patients played an important role in the selection of drugs for treatment of breast cancer patients.