Elevated expression of P-glycoprotein in kidney and urinary bladder cancers.
A monoclonal antibody, MRK16, recognizing specifically an epitope of P-glycoprotein (P-GP), a highly active efflux transporter of chemotherapeutic agents, was used to determine the degree of expression of P-GP in the normal human kidney and urinary bladder, and in kidney and urinary bladder cancers. P-glycoprotein was localized in the microvilli of the epithelial cells of the proximal renal tubules by immunoelectron microscopy, and detected immunohistochemically in 6 of 20 untreated kidney cancers and 11 of 31 untreated urinary bladder cancers. Some of the cancerous tissues were further examined with regard to P-GP expression by immunoprecipitation. In urinary bladder cancers, the degree of P-GP expression seemed to be somewhat correlated with tumor grading. These results indicate that our method to detect the degree of expression of P-GP by MRK16 may be applicable for the diagnosis of clinical multidrug resistant urinary cancers.
Department of Pathology, University of Tokyo, Japan.
M
M
Moriyama
I
I
Sugawara
H
H
Hamada
T
T
Tsuruo
T
T
Kato
K
K
Sato
T
T
Hikage
T
T
Watanuki
S
S
Mori
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D004351:Drug Resistance; D006801:Humans; D007124:Immunoenzyme Techniques; D007680:Kidney Neoplasms / Q000737:chemistry*; D007687:Kidney Tubules, Proximal / Q000737:chemistry; D008562:Membrane Glycoproteins / Q000032:analysis*; D016253:Microscopy, Immunoelectron; D008871:Microvilli / Q000737:chemistry; D009363:Neoplasm Proteins / Q000032:analysis*; D001749:Urinary Bladder Neoplasms / Q000737:chemistry*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins