Ultrastructural alterations in plasma membranes from drug-resistant P388 murine leukemia cells.
Freeze-fracture studies of daunomycin-sensitive and daunomycin-resistant P388 cell lines, reveal a significant increase in the numerical density of intramembrane particles at both, the protoplasmic and the exoplasmic leaflets of the plasma membrane from the drug-resistant cells. Such change in plasma membrane architecture is not accompanied by overexpression of P-glycoproteins. Furthermore, drug-sensitive cells exhibited an increased number of exo-endocytotic images when compared to drug-resistant cells. Our observations suggest that there are global changes in the structural organization of the plasma membrane, which are related to the acquisition of the cellular drug-resistant phenotype.
García-Segura
L M
LM
Cajal Institute, C.S.I.C., Madrid, Spain.
Ferragut
J A
JA
Ferrer-Montiel
A V
AV
Escriba
P V
PV
Gonzalez-Ros
J M
JM
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure*; D003630:Daunorubicin / Q000494:pharmacology*; D004351:Drug Resistance / Q000235:genetics; D005089:Exocytosis; D005614:Freeze Fracturing; D007941:Leukemia P388 / Q000188:drug therapy / Q000473:pathology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D010641:Phenotype; D014407:Tumor Cells, Cultured / Q000648:ultrastructure
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D003630:Daunorubicin