[Establishment of MRP-overexpression subline of bladder carcinoma and its MDR phenotype].
OBJECTIVE
To investigate MRP expression and multidrug resistance(MDR) phenotype of a bladder carcinoma subline transfected with the full length MRP cDNA.


METHODS
After transfection, a stable MRP-overexpressed subline named EJ/MRP was established. Gene expression of MRP and mdr1 were detected by using RT-PCR and immunohistochemistry methods. Drug sensitivity testing of the EJ/MRP cells to 11 kinds of anti-cancer agents was examined.


RESULTS
Compared with EJ/Vect which was mock transfected, MRP mRNA level of EJ/MRP increased 14.3 fold and MRP expression was mainly located in cytosol and plasma membrane. The relative resistance (RR) to VP-16, vincristine increased more than 10 fold, and that to doxorubicin, hydroxycamptothecin, thiotepa, mitomycin and cyclophosphamide increased 3 to 10 fold.


CONCLUSIONS
Bladder carcinoma with stably over-expressed MRP presents typical MDR phenotype but without mdr1/P-gp expression. It provides a good model and positive control for the study of MRP-mediated MDR.
Zhang
X
X
Department of Urology, Xiehe Hospital, Tongji Medical University, Wuhan 430022, China.
Yang
H
H
Lu
G
G
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D018432:Drug Resistance, Multiple / Q000502:physiology*; D006801:Humans; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis* / Q000235:genetics; D010641:Phenotype; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger