ERK1/2 is activated in non-small-cell lung cancer and associated with advanced tumours
S. Vicent (1,2), J. M. López-Picazo (3), G. Toledo (4), M. D. Lozano (4), W. Torre (5), C. García-Corchón (2), C. Quero (3), J.C. Soria (6), S. Martín-Algarra (3), R.G. Manzano (1,7) and L. M. Montuenga (1,2,7)
(1) Carcinogenesis Unit, Division of Oncology, Centre for Applied Medical Research (CIMA), University of Navarra, Pamplona 31008, Spain.
(2) Department of Histology and Pathology, University of Navarra, Pamplona 31008, Spain,
(3) Department of Oncology, University Hospital, University of Navarra, Pamplona 31008, Spain,
(4) Department of Pathology, University Hospital, University of Navarra, Pamplona 31008, Spain.
(5) Department of Thoracic Surgery, University Hospital, University of Navarra, Pamplona 31008, Spain
(6) Department of Medical Oncology, Lung Unit, Institut Gustave Roussy, F-94805 Villejuif, France
Activation of the ERK1/2 pathway is involved in malignant transformation both in vitro and in vivo. Little is known about the role of activated ERK1/2 in non-small cell lung cancer (NSCLC). The purpose of this study was to characterise the extent of the activation of ERK1/2 by immunohistochemistry in patients with NSCLC, and to determine the relationship of ERK1/2 activation with clinicopathological variables. Specimens from 111 patients with NSCLC (stages I-IV) were stained for P-ERK.
Staining for epidermal growth factor receptor (EGFR) and Ki-67 was also performed. In all, 34% of the tumour specimens showed activation for ERK1/2, while normal lung epithelial tissue was consistently negative. There was a strong statistical correlation between nuclear and cytoplasmic P-ERK staining and advanced stages (P<0.05 and P<0.001, respectively), metastatic hilar or mediastinal lymph nodes (P<0.01, P<0.001), and higher T stages (P<0.01, P<0.001). We did not find correlation of nuclear or cytoplasmic P-ERK staining with either EGFR expression or Ki-67 expression. Total ERK1/2 expression was evaluated with a specific ERK1/2 antibody and showed that P-ERK staining was not due to ERK overexpression but rather to hyperactivation of ERK1/2. Patients with a positive P-ERK cytoplasmic staining had a significant lower survival (P<0.05).
However, multivariate analysis did not show significant survival difference. Our study indicates that nuclear and cytoplasmic ERK1/2 activation positively correlates with stage, T and lymph node metastases, and thus, is associated with advanced and aggressive NSCLC tumours.
CITATION Br J Cancer. 2004 Mar 8;90(5):1047-52