In vivo analysis of human multidrug resistance protein 1 (MRP1) activity using transient expression of fluorescently tagged MRP1.
The multidrug resistance protein 1 (MRP1) contributes cellular resistance to a wide array of physiological toxins and chemotherapeutic agents. Its in vivo activity has been studied primarily in cells that have been continuously drug selected, culture conditions that might confound the effects of MRP1 expression with the effects of a cell's detoxification machinery. Transient transfection with a MRP1-green fluorescent protein (EGFP) fusion protein allowed us to measure the activity of MRP1 in cells that had insufficient time to induce other chemoprotective proteins. Furthermore, separate transfections with MRP1-yellow fluorescent protein and a fluorescently tagged P-glycoprotein (MDR1-cyan fluorescent protein) permitted the drug-resistant properties of MRP1-expressing cells to be compared with those of MDR1-expressing cells. Our data showed that the expression of MRP1-EGFP results in significantly decreased cellular accumulation of tetramethylrhodamine ethyl ester (TMRE) and daunorubicin, mildly decreased cellular accumulation of mitoxantrone, and decreased nuclear accumulation of doxorubicin. Additionally, MRP1-EGFP expression protected cells from the microtubule depolymerization caused by vincristine and colchicine, but not by vinblastine.
Rajagopal
Asha
A
Laboratory of Cellular Biophysics, The Rockefeller University, New York, New York 10021, USA.
Pant
Alok C
AC
Simon
Sanford M
SM
Chen
Yu
Y
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000493:pharmacokinetics / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D003630:Daunorubicin / Q000493:pharmacokinetics / Q000494:pharmacology; D004317:Doxorubicin / Q000493:pharmacokinetics / Q000494:pharmacology; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects; D008942:Mitoxantrone / Q000493:pharmacokinetics / Q000494:pharmacology; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D001426:Bacterial Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D004317:Doxorubicin; D008942:Mitoxantrone; D003630:Daunorubicin