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Disease Markers
Volume 24 (2008), Issue 3, Pages 157-165

An Increase in N-Ras Expression is Associated with Development of Hormone Refractory Prostate Cancer in a Subset of Patients

Pamela Traynor,1 Liane M. McGlynn,1 Rono Mukhergee,1 Samuel J. S. Grimsley,1 John M. S. Bartlett,2 and Joanne Edwards1

1University Department of Surgery, Division of Cancer Sciences and Molecular Pathology, Glasgow Royal Infirmary, Glasgow, UK
2Endocrine cancer group, Edinburgh Cancer Research Centre, Western General Hospital, Crew Road South, Edinburgh, UK

Received 28 February 2008; Accepted 28 February 2008

Copyright © 2008 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Protein expression of H, K and N-Ras was assessed in hormone sensitive and hormone refractory prostate tumour pairs from 61 patients by immunohistochemistry. Expression of H-Ras and K- Ras was not associated with any known clinical parameters. In contrast an increase in N-Ras membrane expression in the transition from hormone sensitive to hormone refractory prostate cancer was associated with shorter time to relapse (p = 0.01) and shorter disease specific survival (p = 0.008). In addition, patients with an increase in N-Ras membrane expression had lower levels of PSA at relapse (p = 0.02) and expression correlated with phosphorylated MAP kinase (p = 0.010) and proliferation index (Ki67, p = 0.02). These results suggest that in a subgroup patients N-Ras expression is associated with development of hormone refractory prostate cancer via activation of the MAP kinase cascade.