SCREENING SYSTEM BASED ON EXPRESSION OF ABCG2 HALF TRANSPORTER PROTEIN

摘要

The overexpression of an ABC half-transporter, ABCG2 (MXR/BCRP) transporter causes multidrug resistance in tumors. The present invention is based on the in vitro expression of the ABCG2 protein in insect cells as an expression system free of other, closely related, functional ABC transporters. In particular, the invention is related to a method for testing drugs for their effect on ABCG2 protein, method for the expression of active ABCG2, isolated ABCG2 homooligomers, preferably homodimers and uses thereof for testing drugs. The invention is further related to cell membrane preparations and cells, preferably insect cells comprising active ABCG2 and reagent kits for testing drugs for their effect on an ABCG2 half transporter protein. The invention is also related to a method for identifying ABCG2 activity in a biological sample, utilizing its substrate/inhibitor specificity.