These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: In vitro effect of P-glycoprotein (P-gp) modulators on drug sensitivity of leukemic progenitors (CFU-L) in acute myelogenous leukemia (AML).
    Author: Marie JP, Helou C, Thevenin D, Delmer A, Zittoun R.
    Journal: Exp Hematol; 1992 Jun; 20(5):565-8. PubMed ID: 1350249.
    Abstract:
    Cyclosporine A (CyA), a potent reversant of multidrug resistance (mdr), was studied for its effects on the sensitivity of leukemic progenitors (leukemia colony-forming units, CFU-L) to daunorubicin (DNR) and mitoxantrone. CyA was first compared to verapamil and cefoperazone for reversion of mdr in the mdr1+ cell line K562/DOX. A dramatic increase of sensitivity to 10(-6) M DNR was noted with CyA (0.5 and 1 microgram/ml) and verapamil (1 and 5 micrograms/ml), but not for cefoperazone (0.3 and 0.6 mg/ml). The sensitivity of K562/DOX to 10(-6) M mitoxantrone was also slightly enhanced by CyA. The change in CFU-L drug sensitivity in the presence of CyA was then tested in 12 relapsing/resisting patients and in 3 untreated patients with acute myelogenous leukemia (AML). No change in CFU-L sensitivity to DNR was noted, despite the presence of a subset of P-glycoprotein positive (P-gp+) cells in three out of the ten evaluable cases. Among the six evaluable cases tested with mitoxantrone and CyA, an increase of 50% in CFU-L sensitivity to mitoxantrone was noted in one (of three) P-gp+ patient. These data suggest that the CFU-L in AML rarely expressed the P-gp and that other mechanisms of drug resistance could be involved in AML.
    [Abstract] [Full Text] [Related] [New Search]