Format

Send to

Choose Destination
Cancer Biol Ther. 2005 Jun;4(6):650-8. Epub 2005 Jun 11.

Effect of ABCG2 genotype on the oral bioavailability of topotecan.

Author information

1
Clinical Pharmacology Research Core, National Cancer Institute, Bethesda, Maryland, USA. w.loos@erasmusmc.nl

Abstract

ABCG2 (BCRP/MXR/ABCP) functions as an efflux transporter for many agents, including topotecan, and the protein is expressed at high levels in the human intestine. Some individuals possess a nonsynonymous variant in the ABCG2 gene at nucleotide 421, substituting lysine for glutamine on position 141 at exon 5. The present pilot study indicates that this genotype results in a 30% reduced efflux transport of topotecan in vitro compared to the wild-type. In a preliminary fashion, the heterozygous CA allele observed in two patients was associated with a 1.34-fold increased oral bioavailability of topotecan compared to the bioavailability in ten patients with the wild-type allele (42.0% versus 31.4%; p = 0.037). It is suggested that the high frequency of the A allele in certain ethnic groups may have therapeutic implications for individuals treated with topotecan or other ABCG2 substrates.

PMID:
15908806
DOI:
10.4161/cbt.4.6.1731
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Taylor & Francis
Loading ...
Support Center