GST-pi and P-170 co-expression in multiple myeloma.
Bone marrow samples from 40 patients affected by multiple myeloma either treated or untreated were examined for expression of glutathione-S-transferase pi (GST-pi), P-glycoprotein and the protein product of ras oncogenes family, p-21, on plasma cells, by immunocytochemical detection. 72% of evaluated samples were positive for P-170 and 82% for GST-pi without any correlation with clinical or prognostic parameters. A significant relationship between GST-pi expression and P-170 positivity was found and co-expression was observed in 91% of evaluated samples. Expression of P-170 and GST-pi was found both in treated and untreated patients. However, patients evaluated before and after therapy showed an increase in the percentage of plasma cells positive for GST-pi or P-170 or both. Expression of p-21 was not associated with these mechanisms of drug resistance. These data suggest that different resistance mechanisms are present in multiple myeloma.
Petrini
M
M
Department of Haematology, University of Pisa, Italy.
Di Simone
D
D
Favati
A
A
Mattii
L
L
Valentini
P
P
Grassi
B
B
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000378:metabolism*; D047428:Protein Kinase Inhibitors
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D047428:Protein Kinase Inhibitors; D005982:Glutathione Transferase