Active transport of glutathione S-conjugate in human colon adenocarcinoma cells.

Article Details

Citation

Copy to clipboard

Zhang K, Wong KP

Active transport of glutathione S-conjugate in human colon adenocarcinoma cells.

Cancer Lett. 1996 Nov 12;108(1):143-51. doi: 10.1016/s0304-3835(96)04457-6.

PubMed ID

8950221 [ View in PubMed

]

Abstract

The formation of the glutathione S-conjugate of monochlorobimane (GSH-bimane) in human colon adenocarcinoma cells was identified by HPLC-fluorimetry and its transport from the cells was found to be temperature-sensitive, saturable and ATP-dependent. The apparent K(m) and Vmax values were 2.4 +/- 0.5 nmol GSH-bimane/10(6) cells and 0.5 +/- 0.1 nmol GSH-bimane/min per 10(6) cells, respectively. This active transport of GSH-bimane was inhibited by low micromolar concentrations of classical uncouplers of oxidative phosphorylation, namely carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), carbonylcyanide m-chlorophenylhydrazone (CCCP) and 2,4-dinitrophenol (DNP). The efflux of GSH-bimane was competitively inhibited by chlorambucil (CMB) and 1-chloro-2,4-dinitrobenzene (CDNB), two other substrates of GST. This study demonstrates the presence and kinetic measurements of the glutathione S-conjugate export (GS-X) pump in human colon cancer cells, an export pump whose function has been implicated in the phenomenon of multidrug resistance.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Chlorambucil	Glutathione S-transferases (Cytosolic) (Protein Group)	Protein group	Humans	Unknown	Substrate	Details