Disruption of P-glycoprotein anticancer drug efflux activity by a small recombinant single-chain Fv antibody fragment targeted to an extracellular epitope.
Inherent and acquired MDR is characterized by simultaneous resistance to diverse anticancer drugs and continues to be a major impediment in the curative chemotherapy of cancer. The MDR1 gene product, Pgp, is an ATP-driven efflux pump, which extrudes a variety of dissimilar hydrophobic cytotoxic compounds from MDR cells. Pgp overexpression results in MDR of tumor cell lines in vitro as well as of a variety of human malignancies. Thus, one major goal is to develop strategies aimed at specifically disrupting Pgp drug-efflux activity. To this end, we have developed a small recombinant antibody capable of potent reversal of MDR, by disrupting Pgp drug-efflux activity. Using a phage display approach, we isolated a small scFv recombinant antibody fragment that specifically reacts with the first extracellular loop of human Pgp. This scFv fragment binds specifically to various Pgp-overexpressing human MDR carcinoma cell lines, consequently disrupts Pgp drug-efflux function and thereby reverses the MDR phenotype. We have successfully disrupted anticancer drug-extrusion pump activity in MDR cells using a small recombinant scFv fragment. We propose that these novel small Fv-based recombinant antibody molecules may lead to the development of a new class of antibody fragment-based agents that specifically inhibit Pgp drug extrusion. Hence, these small recombinant antibody fragments may be applied in combination chemotherapy to overcome MDR in various human cancers.
Haus-Cohen
Maya
M
Department of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
Assaraf
Yehuda G
YG
Binyamin
Liat
L
Benhar
Itai
I
Reiter
Yoram
Y
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000187:drug effects* / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015195:Drug Design; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007128:Immunoglobulin Fragments; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship; D015854:Up-Regulation
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D007128:Immunoglobulin Fragments; D011994:Recombinant Proteins