Phenotypic and morphological characterization of neuroblastoma cells constitutively expressing B-myb.
B-myb gene is expressed in neuroblastoma cells and down-regulated during differentiation. We used B-myb-transfected LAN-5 cells, which constitutively express high level of B-myb, to detect changes at phenotypic and morphological levels in basal and differentiation conditions. Our results demonstrate that the overexpression of B-myb markedly affects the cytoskeletal composition, the pattern of neurotransmitter enzymes and the extracellular matrix expression. In general, B-myb transfected neuroblastoma cells show a broad potentiality without a direction toward a specific neuroectodermal differentiation pathway. On the other hand, we confirm inhibition of the neuronal differentiation upon retinoic acid (RA) treatment of B-myb transfected cells. Furthermore, the ultrastructural analyses are supportive of a change in the metabolism in B-myb transfected cell treated with RA. Our data suggest that B-myb expression is compatible with an early phase of differentiation of neuroectodermal cells, but must be down-regulated for the completion of the differentiative programme.
Scarpa
S
S
Experimental Medicine and Pathology Department, University of Rome La Sapienza, Italy.
Negroni
A
A
Amendola
R
R
Signorelli
P
P
Calabretta
B
B
Modesti
A
A
Raschellà
G
G
D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000502:physiology; D003599:Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008854:Microscopy, Electron; D009447:Neuroblastoma; D016900:Neurofilament Proteins / Q000032:analysis; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure; D014746:Vimentin / Q000032:analysis
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D014746:Vimentin; D007633:Keratins