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A new monoclonal antibody that specifically recognises the MDR‐3 ‐encoded gene product
Author(s) -
Larkin Annemarie,
Moran Elizabeth,
Alexander Denis,
Doherty Gerard,
Connolly Lisa,
Kennedy Susan M.,
Clynes Martin
Publication year - 1999
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19990118)80:2<265::aid-ijc16>3.0.co;2-#
Subject(s) - antibody , monoclonal antibody , biology , polyclonal antibodies , p glycoprotein , microbiology and biotechnology , multiple drug resistance , gene product , cancer research , immunology , gene , drug resistance , gene expression , biochemistry , genetics
The MDR‐3‐ encoded P‐glycoprotein (Pgp) is highly expressed in liver and is thought to function as a hepatic transporter of phospholipids into bile. However its role, if any, in other tissues remains undefined. Although transfection experiments have indicated that it may be unable to confer drug resistance, there is evidence that it may be involved in drug resistance in certain B‐cell leukaemias. To date, most work on clinical samples has been performed at the mRNA level; limited work has been performed using polyclonal antibodies raised to MDR‐3 and mdr‐2 (the murine equivalent of MDR‐3 ). We have generated a new monoclonal antibody, termed 6/1G, which specifically recognises the human MDR‐3 gene‐encoded product. Antibody 6/1G was produced by in vitro immunisation of spleen cells from BALB/c mice with a synthetic 12‐amino acid peptide. Cells from MDR‐3 transgenic mice showed consistent membranous staining with antibody 6/1G. Immunoblotting with 6/1G identifed a band at 170 kDa on lysates of MDR‐3 transgenic cells. Preliminary results with a range of B‐cell leukaemias suggest that MDR‐3 Pgp positivity may be a marker for a more malignant phenotype in B‐CLL. Antibody 6/1G may be useful in defining a role for MDR‐3 in malignancy and drug resistance, as well as in certain liver diseases such as progressive familial intracholeostasis. Int. J. Cancer 80:265–271, 1999. © 1999 Wiley‐Liss, Inc.