Proteomic analysis of low- to high-grade astrocytomas reveals an alteration of the expression level of raf kinase inhibitor protein and nucleophosmin.
Proteomic approaches have been useful for the identification of aberrantly expressed proteins in complex diseases such as cancer. These proteins are not only potential disease biomarkers, but also targets for therapy. The aim of this study was to identify differentially expressed proteins in diffuse astrocytoma grade II, anaplastic astrocytoma grade III and glioblastoma multiforme grade IV in human tumor samples and in non-neoplastic brain tissue as control using 2-DE and MS. Tumor and control brain tissue dissection was guided by histological hematoxylin/eosin tissue sections to provide more than 90% of tumor cells and astrocytes. Six proteins were detected as up-regulated in higher grade astrocytomas and the most important finding was nucleophosmin (NPM) (p<0.05), whereas four proteins were down-regulated, among them raf kinase inhibitor protein (RKIP) (p<0.05). We report here for the first time the alteration of NPM and RKIP expression in brain cancer. Our focus on these proteins was due to the fact that they are involved in the PI3K/AKT/mTOR and RAS/RAF/MAPK pathways, known for their contribution to the development and progression of gliomas. The proteomic data for NPM and RKIP were confirmed by Western blot, quantitative real-time PCR and immunohistochemistry. Due to the participation of NPM and RKIP in uncontrolled proliferation and evasion of apoptosis, these proteins are likely targets for drug development.
Protein Chemistry Center and Department of Molecular and Cell Biology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
Marcela
M
Gimenez
Vanessa Cristina de Oliveira
VC
Souza
Clarice
C
Izumi
Manuela R
MR
Barbieri
Roger
R
Chammas
Sueli Mieko
SM
Oba-Shinjo
Miyuki
M
Uno
Suely Kazue Nagahashi
SK
Marie
José Cesar
JC
Rosa
D000328:Adult; D000595:Amino Acid Sequence; D001254:Astrocytoma / Q000235:genetics* / Q000473:pathology; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000302:isolation & purification; D000090243:Nucleophosmin; D049488:Phosphatidylethanolamine Binding Protein / Q000235:genetics* / Q000302:isolation & purification; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification; D040901:Proteomics
C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D049488:Phosphatidylethanolamine Binding Protein; D011506:Proteins; D000090243:Nucleophosmin