Amoureux et al. BMC Cancer 2010, 10:91 http://www.biomedcentral.com/1471-2407/10/91 R E S E A R C H A R T I C L E Open Access Polysialic Acid Neural Cell Adhesion Molecule (PSA-NCAM) is an adverse prognosis factor in glioblastoma, and regulates olig2 expression in glioma cell lines Marie-Claude Amoureux1,2*, Béma Coulibaly3,4, Olivier Chinot5, Anderson Loundou6, Philippe Metellus7, Geneviève Rougon1, Dominique Figarella-Branger3 Abstract Background: Glioblastoma multiforme (GBM) is the most aggressive and frequent brain tumor, albeit without cure. Although patient survival is limited to one year on average, significant variability in outcome is observed. The assessment of biomarkers is needed to gain better knowledge of this type of tumor, help prognosis, design and evaluate therapies. The neurodevelopmental polysialic acid neural cell adhesion molecule (PSA-NCAM) protein is overexpressed in various cancers. Here, we studied its expression in GBM and evaluated its prognosis value for overall survival (OS) and disease free survival (DFS). Methods: We set up a specific and sensitive enzyme linked immunosorbent assay (ELISA) test for PSA-NCAM quantification, which correlated well with PSA-NCAM semi quantitative analysis by immunohistochemistry, and thus provides an accurate quantitative measurement of PSA-NCAM content for the 56 GBM biopsies analyzed. For statistics, the Spearman correlation coefficient was used to evaluate the consistency between the immunohistochemistry and ELISA data. Patients’ survival was estimated by using the Kaplan-Meier method, and curves were compared using the log-rank test. On multivariate analysis, the effect of potential risk factors on the DFS and OS were evaluated using the cox regression proportional hazard models. The threshold for statistical significance was p = 0.05. Results: We showed that PSA-NCAM was expressed by approximately two thirds of the GBM at variable levels. On univariate analysis, PSA-NCAM content was an adverse prognosis factor for both OS (p = 0.04) and DFS (p = 0.0017). On multivariate analysis, PSA-NCAM expression was an independent negative predictor of OS (p = 0.046) and DFS (p = 0.007). Furthermore, in glioma cell lines, PSA-NCAM level expression was correlated to the one of olig2, a transcription factor required for gliomagenesis. Conclusion: PSA-NCAM represents a valuable biomarker for the prognosis of GBM patients. Background Progress in GBM treatment has been limited. The dis- ease is still characterized by a mortality rate approaching 100% and a lifespan of a few months from point of diag- nosis. One of the main impediments to long-term survi- val is recurrence despite resection of the primary tumor. Recently, radiotherapy associated to adjuvant * Correspondence: amoureux@ibdml.univ-mrs.fr 1Université de la Méditerranée CNRS UMR6216, Institut de Biologie du Développement de Marseille Luminy, Marseille, France Temozolomide chemotherapy has increased median sur- vival to 14.2 months [1]. However, the development of more efficient drugs as well as the use of more appro- priate therapeutic protocols requires an improved knowledge of the disease, at the molecular level. Mole- cular diagnostics have emerged as a powerful tool to discover new genes and therapeutic targets, and have realized the proof of principle that personalized medi- cine can increase survival and cure cancer patients [2]. Various genetic alterations have been identified in GBM, © 2010 Amoureux et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.