alpha-Internexin expression identifies 1p19q codeleted gliomas.

Abstract

BACKGROUND:

alpha-Internexin (INA) is a proneural gene encoding a neurofilament interacting protein that is upregulated in some gliomas, particularly oligodendrogliomas.

METHODS:

INA expression was evaluated by immunohistochemistry in a series of 122 gliomas, and correlated to the 1p19q codeletion, a favorable prognostic marker of oligodendroglial tumors.

RESULTS:

INA expression was strong (>10% positive cells) in 22 cases (22 oligodendroglial tumors and 0 astrocytic tumors), weak (<10% cells) in 14 cases (12 oligodendroglial tumors, 2 glioblastoma with an oligodendroglial component, and 0 astrocytic tumors), and negative in 86 cases (49 oligodendroglial tumors, 9 glioblastoma with an oligodendroglial component, and 28 astrocytic tumors). Among the 27 tumors exhibiting the 1p19q codeletion (all with an oligodendroglial phenotype), INA was detected in 96% (26/27, 18 strong, 8 weak) as compared to 11% (10/95, 4 strong, 6 weak) in the tumors without 1p19q codeletion (with an oligodendroglial or an astrocytic phenotype) (p < 0.001). In oligodendroglial tumors, INA expression specificity for 1p19q codeletion was 86%, sensitivity 96%, positive predictive value 76%, and negative predictive value was 98%. The prognostic impact of INA expression could be evaluated in grade III oligodendroglial tumors. Similar to 1p19q deletion, positive INA expression was correlated with better progression-free survival (52.6 vs 8.7 months [p = 0.001]) and overall survival (121.1 vs 31.4 months [p = 0.0001]).

CONCLUSION:

alpha-Internexin (INA) expression appears to be a simple, reliable prognostic marker and a surrogate marker of 1p19q codeletion.

• Authors: F Ducray, E Crinière, A Idbaih, K Mokhtari, Y Marie, S Paris, S Navarro, F Laigle-Donadey, C Dehais, J Thillet, K Hoang-Xuan, J-Y Delattre, M Sanson
• Journal: Neurology (Neurology) Vol. 72 Issue 2 Pg. 156-61 (Jan 13 2009) ISSN: 1526-632X [Electronic] United States
• PMID: 19139367 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Intermediate Filament Proteins
• alpha-internexin

Topics

• Brain Neoplasms (diagnosis, genetics)
• Chromosomes, Human, Pair 1 (genetics)
• Chromosomes, Human, Pair 19 (genetics)
• DNA Mutational Analysis
• Disease Progression
• Gene Deletion
• Genes
• Genetic Predisposition to Disease (genetics)
• Genetic Testing
• Genotype
• Glioma (diagnosis, genetics)
• Humans
• Intermediate Filament Proteins (genetics)
• Mutation (genetics)
• Oligodendroglioma (diagnosis, genetics)
• Predictive Value of Tests
• Prognosis