P-glycoprotein as multidrug transporter: a critical review of current multidrug resistant cell lines

The human MDR (P-glycoprotein) gene family is known to include two members, MDR1 and MDR2. The product of the MDR1 gene, which is responsible for resistance to different cytotoxic drugs (multidrug resistance), appears to serve as an energy-dependent efflux pump for various lipophilic compounds. The function of the MDR2 gene remains unknown. We have examined the structure of the human MDR gene family by Southern hybridization of DNA from different multidrug-resistant cell lines with subfragments of MDR1 cDNA and by cloning and sequencing of genomic fragments. We have found no evidence for any other cross-hybridizing MDR genes. The sequence of two exons of the MDR2 gene was determined from genomic clones. Hybridization with single-exon probes showed that the human MDR1 gene is closely related to two genes in mouse and hamster DNA, whereas MDR2 corresponds to one rodent gene. The human MDR locus was mapped by field-inversion gel electrophoresis, and both MDR genes were found to be linked within 330 kilobases. The expression patterns of the human MDR genes were examined by enzymatic amplification of cDNA. In multidrug-resistant cell lines, increased expression of MDR1 mRNA was paralleled by a smaller increase in the levels of MDR2 mRNA. In normal human tissues, MDR2 was coexpressed with MDR1 in the liver, kidney, adrenal gland, and spleen. MDR1 expression was also detected in colon, lung, stomach, esophagus, muscle, breast, and bladder.

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Validation of a single point flow cytometric assay for determining P-glycoprotein activity in multidrug resistant cell lines

Clinical & Laboratory Haematology ◽

10.1111/j.1365-2257.1994.tb00419.x ◽

2008 ◽

Vol 16 (3) ◽

pp. 261-272 ◽

Cited By ~ 1

Author(s):

I. CHIN-YEE ◽

M.A. CROWTHER ◽

MICHAEL KEENEY ◽

L. WRIGHT ◽

S. DALY

Keyword(s):

Cell Lines ◽

Single Point ◽

Multidrug Resistant ◽

Resistant Cell ◽

Flow Cytometric Assay ◽

Flow Cytometric ◽

P Glycoprotein

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Spontaneous Reversal of P-Glycoprotein Expression in Multidrug Resistant Cell Lines*

Pharmacology & Toxicology ◽

10.1111/j.1600-0773.2003.pto930608.x ◽

2003 ◽

Vol 93 (6) ◽

pp. 297-304 ◽

Cited By ~ 10

Author(s):

Henrik Green ◽

Kourosh Lotfi ◽

Anna-Lena Zackrisson ◽

Curt Peterson

Keyword(s):

Cell Lines ◽

Multidrug Resistant ◽

Resistant Cell ◽

P Glycoprotein ◽

Spontaneous Reversal

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Subcellular immunolocalization of P-glycoprotein in multidrug resistant cell lines

Anti-Cancer Drugs ◽

10.1097/00001813-199409001-00027 ◽

1994 ◽

Vol 5 ◽

pp. 13

Author(s):

K Scotlandi ◽

N Baldini ◽

M Serra ◽

N Zini ◽

M C Manara ◽

...

Keyword(s):

Cell Lines ◽

Multidrug Resistant ◽

Resistant Cell ◽

P Glycoprotein

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Structure and expression of the human MDR (P-glycoprotein) gene family

Molecular and Cellular Biology ◽

10.1128/mcb.9.9.3808-3820.1989 ◽

1989 ◽

Vol 9 (9) ◽

pp. 3808-3820

Author(s):

J E Chin ◽

R Soffir ◽

K E Noonan ◽

K Choi ◽

I B Roninson

Keyword(s):

Gene Family ◽

Cell Lines ◽

Efflux Pump ◽

Expression Patterns ◽

Multidrug Resistant ◽

Resistant Cell ◽

Mdr1 Gene ◽

Glycoprotein Gene ◽

P Glycoprotein ◽

Mdr Genes

The human MDR (P-glycoprotein) gene family is known to include two members, MDR1 and MDR2. The product of the MDR1 gene, which is responsible for resistance to different cytotoxic drugs (multidrug resistance), appears to serve as an energy-dependent efflux pump for various lipophilic compounds. The function of the MDR2 gene remains unknown. We have examined the structure of the human MDR gene family by Southern hybridization of DNA from different multidrug-resistant cell lines with subfragments of MDR1 cDNA and by cloning and sequencing of genomic fragments. We have found no evidence for any other cross-hybridizing MDR genes. The sequence of two exons of the MDR2 gene was determined from genomic clones. Hybridization with single-exon probes showed that the human MDR1 gene is closely related to two genes in mouse and hamster DNA, whereas MDR2 corresponds to one rodent gene. The human MDR locus was mapped by field-inversion gel electrophoresis, and both MDR genes were found to be linked within 330 kilobases. The expression patterns of the human MDR genes were examined by enzymatic amplification of cDNA. In multidrug-resistant cell lines, increased expression of MDR1 mRNA was paralleled by a smaller increase in the levels of MDR2 mRNA. In normal human tissues, MDR2 was coexpressed with MDR1 in the liver, kidney, adrenal gland, and spleen. MDR1 expression was also detected in colon, lung, stomach, esophagus, muscle, breast, and bladder.

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Isolation and characterization of Drosophila multidrug resistance gene homologs

Molecular and Cellular Biology ◽

10.1128/mcb.11.8.3940-3948.1991 ◽

1991 ◽

Vol 11 (8) ◽

pp. 3940-3948

Author(s):

C T Wu ◽

M Budding ◽

M S Griffin ◽

J M Croop

Keyword(s):

Amino Acid ◽

Cell Lines ◽

Multidrug Resistant ◽

Amino Acid Identity ◽

Resistant Cell ◽

Cross Resistance ◽

Multidrug Resistance Gene ◽

Isolation And Characterization ◽

P Glycoprotein

Mammalian multidrug-resistant cell lines, selected for resistance to a single cytotoxic agent, display cross-resistance to a broad spectrum of structurally and functionally unrelated compounds. These cell lines overproduce a membrane protein, the P-glycoprotein, which is encoded by a member(s) of a multigene family, termed mdr or pgp. The amino acid sequence of the P-glycoprotein predicts an energy-dependent transport protein with homology to a large superfamily of proteins which transport a wide variety of substances. This report describes the isolation and characterization of two Drosophila homologs of the mammalian mdr gene. These homologs, located in chromosomal sections 49EF and 65A, encode proteins that share over 40% amino acid identity to the human and murine mdr P-glycoproteins. Fly strains bearing disruptions in the homolog in section 49EF have been constructed and implicate this gene in conferring colchicine resistance to the organism. This work sets the foundation for the molecular and genetic analysis of mdr homologs in Drosophila melanogaster.

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Differential amplification and disproportionate expression of five genes in three multidrug-resistant Chinese hamster lung cell lines.

Molecular and Cellular Biology ◽

10.1128/mcb.6.12.4717 ◽

1986 ◽

Vol 6 (12) ◽

pp. 4717-4722 ◽

Cited By ~ 73

Author(s):

M H de Bruijn ◽

A M Van der Bliek ◽

J L Biedler ◽

P Borst

Keyword(s):

Cell Line ◽

Cell Lines ◽

Actinomycin D ◽

Cdna Probe ◽

Chinese Hamster ◽

Multidrug Resistant ◽

Resistant Cell ◽

Ovary Cell ◽

P Glycoprotein ◽

Differential Amplification

At least five linked genes are amplified in the multidrug-resistant Chinese hamster ovary cell line CHRC5, selected with colchicine (A. M. Van der Bliek, T. Van der Velde-Koerts, V. Ling, and P. Borst, Mol. Cell. Biol. 6:1671-1678, 1986). We report here that only a subset of these, encoding the 170-kilodalton P-glycoprotein, are consistently amplified in three different multidrug-resistant Chinese hamster lung cell lines, selected with vincristine, daunorubicin, or actinomycin D. Within each cell line, genomic sequences homologous to the P-glycoprotein cDNA probe were amplified to different levels. The pattern of differential amplification was consistent with the presence of at least two and possibly three P-glycoprotein genes. In the actinomycin D-selected cell line, these genes were disproportionately overexpressed relative to the associated levels of amplification. These results underline a central role for P-glycoprotein in multidrug resistance. In the daunorubicin-selected cell line, another, as yet uncharacterized, gene was amplified but disproportionately underexpressed. Its amplification was therefore fortuitous. We present a tentative map of the region in the hamster genome that is amplified in the multidrug-resistant cell lines which were analyzed.

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