ABC transporters do not contribute to extracellular translocation of hyaluronan in human breast cancer in vitro.

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Thomas NK, Brown TJ

ABC transporters do not contribute to extracellular translocation of hyaluronan in human breast cancer in vitro.

Exp Cell Res. 2010 Apr 15;316(7):1241-53. doi: 10.1016/j.yexcr.2010.01.004. Epub 2010 Jan 11.

PubMed ID

20060827 [ View in PubMed

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Abstract

Extracellular translocation of the polysaccharide, hyaluronan (HA) has been thought to be mediated via its transmembrane synthetic enzyme, hyaluronan synthase (HAS) but recent studies have indicated that the ATP-Binding-Cassette (ABC) transporter, MRP5 contributes to this process. Liberated and cell-associated HA contributes to breast cancer initiation and progression, and therefore the inhibition of ABC transporters and consequently HA transport could provide therapeutic benefit in the treatment of breast cancer. Quantitation of ABC transporter genes, MRP1-5, BCRP and MDR1 were determined in six breast cancer cell lines selected for their differential HA synthetic rates. Low endogenous expression of transporters was detected but no significant correlation existed between ABC transporter and HAS gene expression or HA production. A dose titration of up to ten times the IC(50) of ten small molecule ABC transporter inhibitors did not significantly inhibit HA export in four breast cancer cell lines. Unlike the changes observed after inhibition of HA synthesis by the characterised inhibitor 4-MU, inhibition of ABC transporters did not alter the cell morphology, HA glycocalyx or the intracellular quantity or localisation of HA. Collectively these data indicate that ABC transporters do not contribute to the extracellular transport of HA in breast cancer, supporting a role for the hyaluronan synthase in translocation.

DrugBank Data that Cites this Article

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Hyaluronic acid	Multidrug resistance-associated protein 5	Protein	Humans	Unknown	Substrate	Details