ATP-binding cassette sub-family G member 2 (ABCG2) is a protein that plays a crucial role in the transport of various substances across cell membranes, including drugs, lipids, and xenobiotics.
ABCG2 is often high and associated with poor prognosis.
BCRP (ABCG2; breast cancer resistance protein) is an ATP-binding cassette efflux transporter that can export multiple anticancer drugs from cancer cells. In tumors, increased BCRP activity may lower intracellular drug accumulation and contribute to multidrug resistance, reduced chemotherapy response, and survival of resistant cancer stem-like or side-population cells. Therefore, for anti-cancer interpretation, BCRP/ABCG2 downregulation or inhibition is generally favorable when the therapeutic goal is to increase intracellular exposure to BCRP-substrate drugs. However, BCRP also protects normal tissues such as intestinal epithelium, liver, kidney, placenta, and blood-brain barrier, so systemic inhibition may alter drug distribution and toxicity.
|