Use of radiolabelled choline as a pharmacodynamic marker for the signal transduction inhibitor geldanamycin

Liu, D; Hutchinson, OC; Osman, S; Price, P; Workman, P; Aboagye, EO

doi:https://dx.doi.org/10.1038/sj.bjc.6600558

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Use of radiolabelled choline as a pharmacodynamic marker for the signal transduction inhibitor geldanamycin.pdf (173.74 KB)

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Author(s)

Liu, D

Hutchinson, OC

Osman, S

Price, P

Workman, P

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Type

Journal Article

Abstract

There is an urgent need to develop non-invasive pharmacodynamic endpoints for the evaluation of new molecular therapeutics that inhibit signal transduction. We hypothesised that, when labelled appropriately, changes in choline kinetics could be used to assess geldanamycin pharmacodynamics, which involves inhibition of the HSP90 molecular chaperone-->Raf1-->Mitogenic Extracellular Kinase-->Extracellular Signal-Regulated Kinase 1 and 2 signal transduction pathway. Towards identifying a potential pharmacodynamic marker response, we have studied radiolabelled choline metabolism in HT29 human colon carcinoma cells following treatment with geldanamycin. We studied the effects of geldanamycin, on net cellular accumulation of (methyl-(14)C)choline and (methyl-(14)C)phosphocholine production. In parallel experiments, the effects of geldanamycin on extracellular signal-regulated kinase 1 and 2 phosphorylation and cell viability were also assessed. Additional validation studies were carried out with the mitogenic extracellular kinase inhibitor U0126 as a positive control; a cyclin-dependent kinase-2 inhibitor roscovitine and the phosphatidylinositol 3-kinase inhibitor LY294002 as negative controls. Hemicholinium-3, an inhibitor of choline transport and choline kinase activity was included as an additional control. In exponentially growing HT29 cells, geldanamycin inhibited extracellular signal-regulated kinase 1 and 2 phosphorylation in a concentration- and time-dependent manner. These changes were associated with a reduction in (methyl-(14)C)choline uptake, (methyl-(14)C) phosphocholine production and cell viability. Brief exposure to U0126, suppressed phosphocholine production to the same extent as Hemicholinium-3. In contrast to geldanamycin and U0126, which act upstream of extracellular signal-regulated kinase 1 and 2, roscovitine and LY294002 failed to suppress phosphocholine production. Our results suggest that when labelled with carbon-11 isotope, (methyl-(11)C)choline may be a useful pharmacodynamic marker for the non-invasive evaluation of geldanamycin analogues. doi:10.1038/sj.bjc.6600558 www.bjcancer.comCopyright 2002 Cancer Research UK

Date Issued

2002

Date Acceptance

2002-07-22

Citation

Br J Cancer, 2002, 87 (7), pp.783-789

URI

http://hdl.handle.net/10044/1/70333

DOI

https://dx.doi.org/10.1038/sj.bjc.6600558

ISSN

0007-0920

Publisher

Springer Nature [academic journals on nature.com]

Start Page

783

End Page

789

Journal / Book Title

Br J Cancer

Volume

87

Issue

7

Copyright Statement

© 2002 Cancer Research UK. All rights reserved. From twelve months after its original publication, this work is licensed under the Creative Commons Attribution-NonCommercial-Share Alike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/

Identifier

http://www.nature.com/cgi-taf/DynaPage.taf?file=/bjc/journal/v87/n7/full/6600558a.html&filetype=pdf

Subjects

Science & Technology

Life Sciences & Biomedicine

Oncology

choline

ERK1/2

geldanamycin

phosphocholine

pharmacodynamic

HSP90 MOLECULAR CHAPERONE

CYCLIN-DEPENDENT KINASES

PHOSPHATIDYLINOSITOL 3-KINASE

GROWTH-FACTORS

CELL-LINES

PROTEIN

RAF-1

TUMOR

17-ALLYLAMINO-17-DEMETHOXYGELDANAMYCIN

DESTABILIZATION

Benzoquinones

Blotting, Western

Carbon Radioisotopes

Cell Division

Cell Survival

Choline

Humans

Lactams, Macrocyclic

MAP Kinase Signaling System

Mitogen-Activated Protein Kinases

Phosphorylation

Phosphorylcholine

Quinones

Tumor Cells, Cultured