VP16CREB-induced differentiation of neuroblastoma.
OBJECTIVE
Drug-induced differentiation is commonly used as a therapeutic modality for the treatment of neuroblastoma tumors. Increased level of cyclic adenosine 3', 5'-monophosphate (cAMP) mediates terminal differentiation in some neuroblastoma cell lines through activation of several signaling networks, including cAMP response element binding protein (CREB). Objective was to test whether cAMP-induced differentiation in a murine neuroblastoma cell line (NBP2) is partly mediated by CREB.


METHODS
Fluorescent microscopy was used to document neuron-like morphological changes imparted by a constitutively active CREB (VP16CREB). Real time PCR (RT-PCR) was performed to verify changes in the expression of cAMP/CREB responsive genes.


RESULTS
It was found that transient expression of VP16CREB into NBP2 cells resulted in morphological changes that were characteristics of terminally differentiated neurons. Furthermore, increased expression of cAMP responsive genes was compromised in cells resisting VP16CREB-mediated differentiation.


CONCLUSIONS
A constitutively active CREB induces terminal differentiation in a subset of NBP2 cell population. Altered expression of cAMP responsive genes may account for differentiation resistant phenotype in NBP2 cells.
Nahreini
Piruz
P
Department of Gastroenterology and Hepatology, University of Colorado Health Sciences Center (UCHSC) and Denver Health Medical Center (DHMC), Denver, CO 80204, USA. piruz.nahreini@uchsc.edu
Andreatta
Cynthia P
CP
Prasad
Kedar N
KN
Toribara
Neil W
NW
D000818:Animals; D050882:CREB-Binding Protein / Q000235:genetics / Q000378:metabolism*; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000235:genetics / Q000502:physiology; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D015870:Gene Expression; D005822:Genetic Vectors / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism*; D051379:Mice; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D016133:Polymerase Chain Reaction; D011987:Receptors, Steroid; D015398:Signal Transduction / Q000235:genetics; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000473:pathology
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D017405:Herpes Simplex Virus Protein Vmw65; C539818:Nr4a1 protein, mouse; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011987:Receptors, Steroid; D049452:Green Fluorescent Proteins; D000242:Cyclic AMP; D050882:CREB-Binding Protein; C494364:Crebbp protein, mouse