Real time RT-PCR shows correlation between retinoid-induced apoptosis and NGF-R mRNA levels.
Neurotrophins and retinoic acid have a critical role in the differentiation and the survival of neurons. All-trans-, 9-cis-retinoic acid (10(-6) M) or NGF (50-100 ng/ml) induced morphologic differentiation and inhibited cell growth in SH-SY5Y neuroblastoma cells after 7 days of culture. Continuous treatment of undifferentiated cells with all-trans- or 9-cis-retinoic (10(-6) M) did not induce apoptosis, whereas NGF-differentiated cells showed dramatic apoptosis after 2 to 4 days of retinoic acid treatment as evidenced by TUNEL reaction and flow cytometry analysis following propidium iodide staining. Addition of Ro41-5253 blocked all-trans-retinoic-induced apoptosis, suggesting that the apoptotic signaling pathway was mediated by RARs. The effects of all-trans- or 9-cis-retinoic acid on the expression of NGF receptors was evaluated using real-time fluorescence reverse transcription-PCR. A slight transient increase in the expression of p75(NGFR) mRNA was observed by 2 to 4 h after retinoid treatment of undifferentiated cells, whereas a larger increase in the expression of both TrkA and p75(NGFR) mRNA up to threefold the basal level, was observed by 2 to 6 h after retinoid treatment of NGF-differentiated cells. Our results suggest that NGF-differentiated cells may be more susceptible to retinoid-induced apoptosis than undifferentiated cells.
Vuillaume
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I
Faculté de Médecine, INSERM U459, Place de Verdun, 59045 Lille Cedex, France.
Schraen-Maschke
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S
Formstecher
P
P
Sablonnière
B
B
D000077556:Alitretinoin; D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D005434:Flow Cytometry; D007700:Kinetics; D020932:Nerve Growth Factor / Q000494:pharmacology; D016501:Neurites / Q000187:drug effects; D009447:Neuroblastoma; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020800:Receptor, Nerve Growth Factor / Q000096:biosynthesis* / Q000235:genetics; D020917:Receptor, trkA / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015533:Transcriptional Activation; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D020800:Receptor, Nerve Growth Factor; D000077556:Alitretinoin; D014212:Tretinoin; D020932:Nerve Growth Factor; D020917:Receptor, trkA