P-glycoprotein expression in normal and reactive bone marrows.
The expression of mdr1 gene product P-glycoprotein (P-gp) was investigated in 53 normal and reactive bone marrows by means of immunocytochemistry, using the monoclonal antibody (mAb) C219 and the alkaline phosphatase anti-alkaline phosphatase method. In a limited number of patients, data were confirmed by using the mAb MRK16 or a polymerase chain reaction assay for mdr1 gene expression. There was no history of prior chemotherapy or any malignancy in this group. Bone marrow aspirates were obtained as part of a routine diagnostic programme in bone marrow donors or in patients presenting with a variety of diagnoses such as unexplained gammopathy, fever, anaemia, other changes in peripheral blood smear, rheumatoid arthritis, vasculitis, or urticaria pigmentosa. Morphologically the bone marrow was normal in 23 patients, a megaloblastic erythropoiesis was seen in two patients and unspecific changes were seen in 28 patients. Twenty-seven of 53 samples were found to be positive for P-gp expression with the percentage of positive cells ranging from 2%-80% (mean = 24%). With a cutoff point of 10%, five of 23 normal (22%) and 13 of 28 reactive bone marrows (46%) were considered positive for P-gp expression. There was no obvious correlation between diagnosis or age and P-gp expression. Additional staining for the early surface marker CD-34 was performed in 12 samples, with none of them revealing more than 1% positivity. Since P-gp expression has so far been described only in CD-34 positive bone marrow cells, data suggest that P-gp expression may be reinduced in CD-34 negative cells under conditions which remain to be determined.
Hegewisch-Becker
S
S
Medical University Clinic of Hamburg, Department of Oncology and Haematology, Germany.
Fliegner
M
M
Tsuruo
T
T
Zander
A
A
Zeller
W
W
Hossfeld
D K
DK
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000737:chemistry*; D001856:Bone Marrow Examination; D002460:Cell Line; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000235:genetics; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D012333:RNA, Messenger / Q000032:analysis
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger