Identification of GRP75 as an independent favorable prognostic marker of neuroblastoma by a proteomics analysis.
OBJECTIVE
Neuroblastoma (NB) is a heterogeneous neoplasm. Detailed biological discrimination is critical for the effective treatment of this disease. Because the tumor behavior of NB is closely associated with the histologic state of differentiation, we thus aimed to identify novel differentiation-associated markers of NB with prognostic implication.


METHODS
A human NB cell line SH-SY5Y was used as a model system to explore potential biomarkers for the differentiation of NB by proteomic analyses. Seventy-two NB tumor tissues were subsequently investigated by immunohistochemistry to validate the correlations between the expression of a novel prognostic marker, various clinicopathologic and biological factors, and patient survival.


RESULTS
Using two-dimensional differential gel electrophoresis, we found a total of 24 spots of proteins in SH-SY5Y cells whose expression was enhanced following differentiation. Glucose-regulated protein 75 (GRP75) was unambiguously identified as one of the five proteins that were dramatically up-regulated following differentiation. Immunohistochemical analyses of 72 NB tumor tissues further revealed that positive GRP75 immunostaining is strongly correlated with differentiated histologies (P < 0.001), mass-screened tumors (P = 0.016), and early clinical stages (P < 0.001) but inversely correlated with MYCN amplification (P = 0.010). Univariate and multivariate survival analyses showed that GRP75 expression is an independent favorable prognostic factor.


CONCLUSIONS
The present findings clearly showed that our proteomics-based novel experimental paradigm could be a powerful tool to uncover novel biomarkers associated with the differentiation of NB. Our data also substantiate an essential role of GRP75 in the differentiation of NB.
Hsu
Wen-Ming
WM
Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, 7 Chung-Shan South Road, Taipei, Taiwan.
Lee
Hsinyu
H
Juan
Hsueh-Fen
HF
Shih
Yu-Yin
YY
Wang
Bo-Jeng
BJ
Pan
Chien-Yuan
CY
Jeng
Yung-Ming
YM
Chang
Hsiu-Hao
HH
Lu
Meng-Yao
MY
Lin
Kai-Hsin
KH
Lai
Hong-Shiee
HS
Chen
Wei-Jao
WJ
Tsay
Yeou-Guang
YG
Liao
Yung-Feng
YF
Hsieh
Fon-Jou
FJ
D014408:Biomarkers, Tumor; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism* / Q000628:therapy; D011379:Prognosis; D020543:Proteome; D040901:Proteomics / Q000379:methods*
D014408:Biomarkers, Tumor; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D020543:Proteome; C018551:glucose-regulated proteins