CHARACTERIZATION OF MULTIDRUG RESISTANCE IN SEWA MOUSE-TUMOR CELLS - INCREASED GLUTATHIONE TRANSFERASE-ACTIVITY AND REVERSAL OF RESISTANCE WITH VERAPAMIL

  • 1 January 1987
    • journal article
    • research article
    • Vol. 7  (1) , 65-70
Abstract
The glutathione transferase (EC 2.5.1.18) activity of multidrug-resistant and drug-sensitive SEWA mouse tumor cells was determined. Increase in activity was found in all multidrug-resistant sublines. Electrophoretic separation of cytosolic proteins and immunodetection, using antisera against Class Alpha, Class Mu and Class Pi glutathione transferase, revealed a two-fold increase of the Class Pi transferase in the resistant cells. The role of glutathione transferase of Class Pi in the multidrug resistance and its distinction from the overproduction 21,000 dalton protein p21 is discussed. Reversal of the resistance, using the calcium antagonist verapamil, and different sensitivity to verapamil between different sublines are also reported.