Related Experiment Videos
Detection of the M(r) 190,000 multidrug resistance protein, MRP, with monoclonal antibodies
D R Hipfner1, S D Gauldie, R G Deeley
1Cancer Research Laboratories, Queen's University, Kingston, Ontario, Canada.
Abstract:
MRP is a M(r) 190,000 integral membrane phosphoglycoprotein that is overexpressed in some drug-selected resistant cell lines and has been shown to cause multidrug resistance in transfected cells. Five murine hybridoma cell lines (QCRL-1, QCRL-2, QCRL-3, QCRL-4, and QCRL-6) have been generated which secrete monoclonal antibodies (MAbs) that react specifically with membrane proteins of MRP-overexpressing, multidrug-resistant, drug-selected H69AR cells and MRP-transfected HeLa cells (T5) but not the respective parental (H69) and vector-transfected (C1) cells. The ability of three of these MAbs (QCRL-1, QCRL-2, and QCRL-3) to selectively immunoprecipitate a M(r) 190,000 protein from 35S-labeled H69AR and T5 membranes indicates that these MAbs are specific for MRP. MAb QCRL-1 is also capable of detecting the low levels of MRP present in revertant H69PR cells by immunoblot analysis. Indirect immunofluorescence analyses show that MAbs QCRL-1, QCRL-2, and QCRL-3) strongly and differentially react with fixed T5 and H69AR cells but not with unfixed cells, suggesting that these MAbs recognize intracellular MRP epitopes. The availability of reagents for the specific and sensitive immunodetection of MRP should greatly facilitate biological and clinical studies of this novel drug resistance protein.
Insights
Researchers developed new monoclonal antibodies (MAbs) to detect the multidrug resistance-associated protein (MRP). These MAbs specifically target MRP, aiding studies into drug resistance mechanisms and potential clinical applications.
Area of Science:
- Molecular Biology
- Immunology
- Cancer Research
Background:
- Multidrug resistance-associated protein (MRP) is an integral membrane phosphoglycoprotein implicated in multidrug resistance.
- Overexpression of MRP in drug-selected cell lines contributes to reduced drug efficacy.
- Targeting MRP is crucial for understanding and overcoming drug resistance in various diseases.
Purpose of the Study:
- To generate and characterize monoclonal antibodies (MAbs) specific for the multidrug resistance-associated protein (MRP).
- To utilize these MAbs for the sensitive immunodetection of MRP in drug-resistant cells.
- To facilitate further biological and clinical investigations into MRP's role in drug resistance.
Main Methods:
- Generation of five murine hybridoma cell lines secreting MAbs against MRP-overexpressing cells.
- Immunoprecipitation assays to confirm MAb specificity for a M(r) 190,000 protein (MRP).
- Immunoblot analysis and indirect immunofluorescence to detect MRP in various cell lines.
Main Results:
- Five MAbs (QCRL-1 to QCRL-6) were generated, reacting specifically with MRP in drug-resistant and transfected cells.
- MAbs QCRL-1, QCRL-2, and QCRL-3 selectively immunoprecipitated the M(r) 190,000 MRP.
- Immunofluorescence indicated that these MAbs recognize intracellular MRP epitopes, with differential reactivity observed.
Conclusions:
- The developed MAbs provide specific and sensitive tools for detecting MRP.
- These reagents are valuable for studying the biological functions and clinical relevance of MRP.
- The availability of these MAbs will advance research into multidrug resistance mechanisms.