Overexpression of the ATP-binding cassette transporter ABCG2 reportedly causes multidrug resistance, whereas altered drug-resistance profiles and substrate specificity are implicated for certain variant forms of ABCG2. At least three variant forms of ABCG2 have been hitherto documented on the basis of their amino acid moieties (i.e., arginine, glycine and threonine) at position 482. In the pres...

ABCG2 is a key human ATP-binding cassette (ABC) transporter mediating cancer cell chemoresistance. In the case of ABCC1, another multidrug transporter, earlier findings documented that certain modulators greatly increase ABCC1-mediated glutathione (GSH) efflux and, upon depletion of intracellular GSH, induce "collateral sensitivity" leading to the apoptosis of multidrug resistant cells. Recentl...

We investigated the role of the breast cancer resistance protein (BCRP/ABCG2) in drug resistance in multiple myeloma (MM). Human MM cell lines, and MM patient plasma cells isolated from bone marrow, were evaluated for ABCG2 mRNA expression by quantitative polymerase chain reaction (PCR) and ABCG2 protein, by Western blot analysis, immunofluorescence microscopy, and flow cytometry. ABCG2 functio...

The human ABCG2 protein is an important primary active transporter for hydrophobic compounds in several cell types, and its overexpression causes multidrug resistance in tumors. A monoclonal antibody (5D3) recognizes this protein on the cell surface. In ABCG2-expressing cells 5D3 antibody showed a saturable labeling and inhibited ABCG2 transport and ATPase function. However, at low antibody con...

ABCG2/BCRP is a member of the adenosine triphosphate–binding cassette (ABC) transporter family and is expressed in intestine, kidney, and liver, where it modulates the absorption and excretion of xenobiotic compounds. ABCG2 is also expressed in hematopoietic stem cells and erythroid cells; however, little is known regarding its role in hematopoiesis. Abcg2 null mice have increased levels of pro...

ABCG2, member of ATP-binding cassette (ABC) transporter family, is known as crucial regulator related to multi-drug resistance in human tumors and has recently been putatively studied as human carcinoma cell biomarker. While, effects of ABCG2 on human gastric cancer (GC) has not been illustrated thoroughly. In this study, by applying biostatistics mining methods, we observed that ABCG2 is frequ...

ABCG2 is a potential biomarker causing multidrug resistance (MDR) in Non-Small Cell Lung Cancer (NSCLC). We conducted this study to investigate whether Icotinib, a small-molecule inhibitor of EGFR tyrosine kinase, could interact with ABCG2 transporter in NSCLC. Our results showed that Icotinib reversed ABCG2-mediated MDR by antagonizing the drug efflux function of ABCG2. Icotinib stimulated the...

One activity potentially limiting the efficacy of camptothecin anticancer agents is their cellular efflux by the ATP-binding cassette half-transporter, ABCG2. Homocamptothecins are novel anticancer drugs that inhibit topoisomerase 1 with a greater potency than camptothecins. Homocamptothecins differ from camptothecins by their E-ring, which is seven-membered instead of the six-membered ring of ...

Background. Despite improvement in treatment, the prognosis of hepatocellular carcinoma (HCC) remains disastrous. Cancer stem cells (CSCs) may be responsible for cancer malignant behaviors. ATP-binding cassette, subfamily G, member 2 (ABCG2) is widely expressed in both normal and cancer stem cells and may play an important role in cancer malignant behaviors. Methods. The expression of ABCG2 in ...

Multidrug resistance (MDR) to chemotherapeutic drugs is a formidable barrier to the success of cancer chemotherapy. Expressions of ATP-binding cassette (ABC) transporters contribute to clinical MDR phenotype. In this study, we found that afatinib, a small molecule tyrosine kinase inhibitor (TKI) targeting EGFR, HER-2 and HER-4, reversed the chemoresistance mediated by ABCG2 in vitro, but had no...