TY - JOUR
T1 - Reversing ABCB1-mediated multi-drug resistance from within cells using translocating immune conjugates
AU - Wellhöner, Hans
AU - Weiss, Aryeh
AU - Schulz, Axel
AU - Adermann, Knut
AU - Braitbard, Ori
AU - Bar-Sinai, Allan
AU - Hochman, Jacob
PY - 2012/6
Y1 - 2012/6
N2 - Multi-drug resistance (MDR) is still a major cause of the eventual failure of chemotherapy in cancer treatment. Different approaches have been taken to render these cells drug sensitive. Here, we attempted sensitizing drug-resistant cells from within, using a translocating immune conjugate approach. To that effect, a monoclonal antibody, C219, directed against the intracellular ATP-binding site of the membrane-anchored MDR transporter ABCB1 [P-glycoprotein (P-gp), MDR1], was conjugated to human immunodeficiency virus [HIV(3772)Tat] translocator peptide through a disulfide bridge. Fluorescence-labelled IgG-Tat conjugates accumulated in drug resistant Chinese hamster ovary (CHO) cells within less than 20 min. Preincubation with C219-S-S-(3772)Tat conjugate augmented calcein accumulation in drug-resistant CHO and mouse lymphoma cells, indicating reduction in ABCB1 transporter activity. A thioether conjugate C219-S-(3772)Tat was ineffective, as were disulfide and thioether conjugates of an irrelevant antibody. Furthermore, in the presence of C219-S-S-(3772)Tat, drug resistant cells were sensitized to colchicine and doxorubicin. Taken together, these findings demonstrate, as proof of principle, a novel approach for the reversal of MDR from within cells, by delivery of translocating immune conjugates as sensitizing agents towards chemotherapy.
AB - Multi-drug resistance (MDR) is still a major cause of the eventual failure of chemotherapy in cancer treatment. Different approaches have been taken to render these cells drug sensitive. Here, we attempted sensitizing drug-resistant cells from within, using a translocating immune conjugate approach. To that effect, a monoclonal antibody, C219, directed against the intracellular ATP-binding site of the membrane-anchored MDR transporter ABCB1 [P-glycoprotein (P-gp), MDR1], was conjugated to human immunodeficiency virus [HIV(3772)Tat] translocator peptide through a disulfide bridge. Fluorescence-labelled IgG-Tat conjugates accumulated in drug resistant Chinese hamster ovary (CHO) cells within less than 20 min. Preincubation with C219-S-S-(3772)Tat conjugate augmented calcein accumulation in drug-resistant CHO and mouse lymphoma cells, indicating reduction in ABCB1 transporter activity. A thioether conjugate C219-S-(3772)Tat was ineffective, as were disulfide and thioether conjugates of an irrelevant antibody. Furthermore, in the presence of C219-S-S-(3772)Tat, drug resistant cells were sensitized to colchicine and doxorubicin. Taken together, these findings demonstrate, as proof of principle, a novel approach for the reversal of MDR from within cells, by delivery of translocating immune conjugates as sensitizing agents towards chemotherapy.
KW - C219 antibody
KW - HIV-Tat
KW - Immune conjugates
KW - MDR
UR - http://www.scopus.com/inward/record.url?scp=84861079627&partnerID=8YFLogxK
U2 - 10.3109/1061186X.2012.685473
DO - 10.3109/1061186X.2012.685473
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C2 - 22577854
AN - SCOPUS:84861079627
SN - 1061-186X
VL - 20
SP - 445
EP - 452
JO - Journal of Drug Targeting
JF - Journal of Drug Targeting
IS - 5
ER -