MODULATION OF P-GLYCOPROTEIN-MEDIATED MULTIDRUG-RESISTANCE BY MONOCLONAL-ANTIBODIES, IMMUNOTOXINS OR ANTISENSE OLIGODEOXYNUCLEOTIDES IN KIDNEY CARCINOMA AND NORMAL KIDNEY-CELLS

In the present investigation we show that both monoclonal antibodies a gainst P-170 (265/F4, MRK 16, and HYB 612) and 265/F4-ricin alpha-chai n immunotoxin are useful tools for the eradication of kidney carcinoma and normal kidney primary cell cultures with high P-170 expression, w hereas kidney tumor and normal kidney cell lines with low amounts of P -170 are less affected. Furthermore, we found that the expression of P -170 in both kidney tumor and normal kidney cell cultures with high am ounts of P-170 was inhibited by anti-sense oligodeoxynucleotides compl ementary to base pairs - 9 to + 6 of the MDR1 gene. These data indicat e that these approaches for the eradication of P- 1 70 expressing mult idrug-resistant cells are not limited to tumors but also affect P- 1 7 0 expressing normal cells.