ATP-binding cassette sub-family G member 2 (BCRP) (ABCG2)

ATP-binding cassette sub-family G member 2 (ABCG2), commonly known as Breast Cancer Resistance Protein (BCRP), is a critical efflux transporter expressed on the apical membranes of the intestine, liver, and blood-brain barrier (UniProt Q9UNQ0). It plays a pivotal role in the pharmacokinetics of various drugs, most notably rosuvastatin, by limiting its absorption in the gut and promoting its excretion into the bile (FDA Crestor Label). Genetic variations in the ABCG2 gene, specifically the c.421C>A polymorphism, lead to reduced transporter activity and are associated with significantly higher plasma levels of rosuvastatin, increasing the risk of adverse effects such as myopathy (PubMed PMID: 23588310). Beyond drug transport, ABCG2 is essential for the homeostasis of endogenous substances like uric acid; its impairment is a major genetic risk factor for hyperuricemia and gout (PubMed PMID: 19454521). In the field of oncology, BCRP is frequently overexpressed in tumor cells, where it contributes to multidrug resistance by actively pumping out chemotherapeutic agents like mitoxantrone and topotecan (PubMed PMID: 10373431). Understanding BCRP function is therefore vital for predicting drug-drug interactions and tailoring therapeutic regimens to individual genetic profiles.

Other names

Breast cancer resistance proteinCDw338Mitoxantrone resistance-associated proteinPlacenta-specific ABC transporterABCPMXR

ATP-dependent efflux transporter that pumps substrates out of the cytoplasm or cell membrane into the extracellular space or organellar lumen, thereby regulating the absorption, distribution, and elimination of drugs and endogenous compounds (UniProt Q9UNQ0).