EFFECT OF PROTON PUMP INHIBITOR ON CELL-GROWTH AND SENSITIVITY TO CIS-DIAMINEDICHLOROPLATINUM(II) IN NONSMALL CELL LUNG-CANCER CELL-LINES

Recently, the importance of the potassium pump in the cellular accumul ation of cis-diamminedichloroplatinum (II) (CDDP) has been reported. I n this study we evaluated the role of the proton pump as a determinant of the sensitivity to CDDP in non-small cell lung cancer cell lines i n vitro by using a selective proton pump inhibitor; AG-2000. PC-9 and PC-9/CDDP cell lines which are sensitive ol resistant to CDDP, were us ed for these experiments. PC-9/CDDP was 17.4-fold mole resistant to CD DP than PC-9 cells. Relative resistance was not altered by coincubatio n with a non-cytotoxic dosage of AG-2000. A om these studies, it was s hown that the proton pump inhibitor AG-2000 did not enhance the sensit ivity to CDDP. However; as AG-2000 is not cytotoxic and does not compr omise the CDDP-sensitivity in NSCLC cells at the concentration of clin ical use for gastroduodenal ulcer; AG-2000 can be used with CDDP in ch emotherapy for hmg cancer.