Abstract

The occurrence of multidrug resistance (MDR) is one of the main obstacles in the successful chemotherapeutic treatment of cancer. In this study The gene expressions of multidrug resistance-associated protein (MRP), c-myc and c-fos were investigated in L1210 cells. Adriamycin- or vincristine-resistant L1210 cells, L1210AdR or L1210VcR, respectively, has been identified to overexpression of mdrl gene. The expression leve of MRP gene in L1210AdR and L1210Cis was more decreased than that in L1210 cells. The c-myc and c-fos genes were expressed both in L1210 and resistant sublines. In L1210VcR and L1210Cis, c-myc and c-fos genes were decreased than in L1210. However, in L1210VcR and L1210Cis, c-myc and c-fos gene expression were rather increased than L1210. These results suggested that MRP does not contribute in resistance of drug-resistant L1210 cells and there is no relations between MRP and mdrl gene expression. The expression of c-myc and c-fos gene may be changed during transformation of L1210 to drug-resistant sublines.

• Keywords: Multidrug resistance-associated Protein;c-myc;c-fos;