We investigated the expression of the drug-transporter proteins P-glycoprotein (P-gp) and multidrug-resistance protein 1 (MRP1) in cell lines (N = 24) and primary cell cultures (N = 36) from neuroectodermal tumors, as well as in brain tumor extracts (N = 18) and normal human astrocytes (N = 1).
The expression levels of each of the chemoresistance-related genes, except MRP, were generally higher in brain tumors than those in non-neoplastic brain tissues.