Immunocytochemical identification and localization of the Mr 22,000 calcium-binding protein (sorcin) in an adriamycin-resistant myelogenous leukemia cell line.
Monoclonal antibody against the Mr 22,000 calcium-binding protein (sorcin) from an adriamycin-resistant myelogenous leukemia cell line K562 (K562/ADM) was prepared and used as a probe to study the localization of sorcin in K562/ADM cells and the parental cell line, K562. Analysis of extracts from K562/ADM cells by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorescence image analysis showed that K562/ADM cells possessed abundant sorcin in the cytoplasm which was almost entirely absent from the drug-sensitive parental cell line, K562. Furthermore, immuno-electron microscopic studies revealed that sorcin was closely associated with free ribosomes, rough endoplasmic reticulum, mitochondria, microfilament bundles and perinuclear membranes. These observations provide the first clue that the Ca-binding protein, sorcin, may play an important role in the development of the multidrug resistance phenomenon, although the relationship between sorcin and P-glycoprotein is still unknown.
Sugawara
I
I
Department of Pathology, University of Tokyo.
Mizumoto
K
K
Ohkochi
E
E
Hamada
H
H
Tsuruo
T
T
Mori
S
S
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002135:Calcium-Binding Proteins / Q000032:analysis*; D004317:Doxorubicin / Q000494:pharmacology*; D004351:Drug Resistance; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis*; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C503113:SRI protein, human; D004317:Doxorubicin