Role of GalNAc4S-6ST in astrocytic tumor progression.
N-Acetylgalactosamine 4-sulfate 6-O-sulfotransferase (GalNAc4S-6ST) is the sulfotransferase responsible for biosynthesis of highly sulfated chondroitin sulfate CS-E. Although involvements of CS-E in neuronal cell functions have been extensively analyzed, the role of GalNAc4S-6ST in astrocytic tumor progression remains unknown. Here, we reveal that GalNAc4S-6ST transcripts were detected in astrocytic tumors derived from all 30 patients examined using quantitative reverse transcription-PCR analysis. Patients with high GalNAc4S-6ST mRNA expression had significantly worse outcome compared with patients with low expression, and multivariate survival analysis disclosed that GalNAc4S-6ST is an independent poor prognostic factor for astrocytic tumors. We then tested whether CS-E enhanced haptotaxic migration of glioblastoma U251-MG cells that endogenously express both the CS-E's scaffold tyrosine phosphatase ζ (PTPζ) and GalNAc4S-6ST, in the presence of CS-E's preferred ligands, pleiotrophin (PTN) or midkine (MK), using a modified Boyden chamber method. Haptotaxic stimulation of cell migration by PTN was most robust on control siRNA-transfected U251-MG cells, while that enhancing effect was cancelled following transduction of GalNAc4S-6ST siRNA. Similar results were obtained using MK, suggesting that both PTN and MK enhance migration of U251-MG cells by binding to CS-E. We also found that PTPζ as well as PTN and MK were frequently expressed in astrocytic tumor cells. Thus, our findings indicate that GalNAc4S-6ST mRNA expressed by astrocytic tumor cells is associated with poor patient prognosis likely by enhancing CS-E-mediated tumor cell motility in the presence of PTN and/or MK.
Department of Molecular Pathology, Shinshu University Graduate School of Medicine, Matsumoto, Japan.
Tatsuya
T
Kobayashi
Huimin
H
Yan
Yasuhiro
Y
Kurahashi
Yuki
Y
Ito
Hiroshi
H
Maeda
Tsuyoshi
T
Tada
Kazuhiro
K
Hongo
Jun
J
Nakayama
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D002809:Chondroitin Sulfates / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D000078792:Midkine; D015999:Multivariate Analysis; D011379:Prognosis; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism; D016019:Survival Analysis
D002352:Carrier Proteins; D016207:Cytokines; C066845:pleiotrophin; D000078792:Midkine; D002809:Chondroitin Sulfates; C416670:N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase; D015238:Sulfotransferases; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5