Glial cell line-derived neurotrophic factor/neurturin-induced differentiation and its enhancement by retinoic acid in primary human neuroblastomas expressing c-Ret, GFR alpha-1, and GFR alpha-2.
Neuroblastomas often undergo spontaneous differentiation and/or regression in vivo, which is at least partly regulated by the signals through neurotrophins and their receptors. Recently, glial cell line-derived neurotrophic factor (GDNF) and a second family member, neurturin (NTN), have been found to mediate their signals by binding to a heterotetrameric complex of c-Ret tyrosine kinase receptors and glycosylphosphatidylinositol-linked proteins, GFR alpha-1 (GDNFR-alpha) or GFR alpha-2 (TrnR2/GDNFR-beta/NTNR-alpha/RETL2). Here, we studied the effect of GDNF and NTN on human neuroblastomas in the short-term primary culture system, as well as the expression of c-Ret, GFR alpha-1, GFR alpha-2, GDNF, and NTN. GDNF (1-100 ng/ml) induced morphological differentiation in 34 of 38 primary neuroblastomas and an accompanying increase in c-Fos induction. These effects were markedly enhanced by treatment with 5 microM all-trans-retinoic acid. Although GDNF alone induced a rather weak differentiation independent of the disease stages, the enhancement of neurite outgrowth induced by treatment with both GDNF and all-trans-retinoic acid was significantly correlated with younger age (less than 1 year; P = 0.0039), non-stage 4 diseases (P = 0.0023), a single copy of N-myc (P = 0.027), and high levels of TRK-A expression (P = 0.0062). To examine the expression levels of GFR alpha-1, we cloned a short form of the human GFR alpha-1 gene with a 15-bp deletion by screening a human adult substantia nigra cDNA library. Many primary neuroblastomas expressed c-Ret, GFR alpha-1, and GFR alpha-2 as well as their ligands, GDNF and NTN, suggesting the presence of a paracrine or autocrine signaling system within the tumor tissue. The effect of NTN on primary culture cells of neuroblastoma was similar to that of GDNF. These imply that the GDNF(NTN)/c-Ret/GFR alpha-1(GFR alpha-2) signaling may have an important role in regulating the growth, differentiation, and cell death of neuroblastomas.
Hishiki
T
T
Chiba Cancer Center Research Institute, and Department of Pediatric Surgery, Chiba University School of Medicine, Japan.
Nimura
Y
Y
Isogai
E
E
Kondo
K
K
Ichimiya
S
S
Nakamura
Y
Y
Ozaki
T
T
Sakiyama
S
S
Hirose
M
M
Seki
N
N
Takahashi
H
H
Ohnuma
N
N
Tanabe
M
M
Nakagawara
A
A
D000970:Antineoplastic Agents / Q000494:pharmacology*; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D004268:DNA-Binding Proteins / Q000187:drug effects; D029721:Drosophila Proteins; D051766:Early Growth Response Protein 1; D016762:Genes, fos / Q000187:drug effects; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006801:Humans; D017874:Immediate-Early Proteins; D007223:Infant; D009363:Neoplasm Proteins / Q000187:drug effects* / Q000378:metabolism; D009367:Neoplasm Staging; D009414:Nerve Growth Factors / Q000494:pharmacology* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000494:pharmacology* / Q000502:physiology; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051101:Neurturin; D011518:Proto-Oncogene Proteins / Q000187:drug effects / Q000378:metabolism; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000187:drug effects; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1; C495039:GDNF protein, human; C494987:GFRA1 protein, human; C494990:GFRA2 protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D017874:Immediate-Early Proteins; C495053:NRTN protein, human; D009363:Neoplasm Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D051101:Neurturin; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D014212:Tretinoin; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila