title: Breast cancer resistance protein (BCRP/MXR/ABCG2) in adult acute lymphoblastic leukaemia: frequent expression and possible correlation with shorter disease-free survival.
abstract: Drugs used in treatment of adult acute lymphoblastic leukaemia (ALL) are substrates for breast cancer resistance protein (BCRP, MXR, ABCG2), which may thus play a role in resistance in this disease. Pretreatment blasts from 30 adult ALL patients were studied for BCRP mRNA by quantitative reverse transcription polymerase chain reaction analysis, BCRP protein by immunophenotyping with three antibodies and BCRP function by fumitremorgin C modulation of intracellular mitoxantrone retention, measured by flow cytometry. BCRP mRNA in all cases encoded wild type protein (BCRP(R482)), which mediates mitoxantrone and methotrexate resistance, but only low-level anthracycline resistance. The BXP-21, BXP-34 and anti-ABCG2 antibodies stained blasts in 13, 11 and 14 cases (43%, 37% and 47%); BXP-21 correlated well with BXP-34 and anti-ABCG2, but BXP-34 and anti-ABCG2 did not correlate, and antibody staining did not correlate with mRNA levels. BCRP function was seen in 21 cases (70%), but correlated poorly with antibody staining. An exploratory statistical analysis indicated that BXP-21 staining was predictive of shorter disease-free survival (DFS) (P = 0.0374) in this small patient population. Poor correlations between mRNA, protein and function indicate the complex biology of BCRP in adult ALL, and the possible correlation of BCRP expression with DFS should be studied in larger series.
authors.affiliation: Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Attaya
authors.initials: A
authors.lastname: Suvannasankha
authors.forename: Hans
authors.initials: H
authors.lastname: Minderman
authors.forename: Kieran L
authors.initials: KL
authors.lastname: O'Loughlin
authors.forename: Takeo
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Ford
authors.forename: William R
authors.initials: WR
authors.lastname: Greco
authors.forename: Meir
authors.initials: M
authors.lastname: Wetzler
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Ross
authors.forename: Maria R
authors.initials: MR
authors.lastname: Baer
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D045744:Cell Line, Tumor; D019742:Chemokines, CC / Q000378:metabolism; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C116614:ABCG2 protein, human; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D019742:Chemokines, CC; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C070959:Ccl6 protein, mouse