Phosphatidylinositol turnover is not a general regulator of neuroblastoma cell differentiation: comparison between two differentiating agents, retinoic acid and gamma-interferon.
The turnover of phosphatidylinositol (PI) is believed to constitute a crucial step in the signaling pathways for stimulation of cells by a variety of bioactive substances, including differentiating agents; however decisive evidence for the idea has not been obtained. In the present paper, we investigated the involvement of PI turnover in cell differentiation using a human neuroblastoma cell line, LAN-1, which can be induced to differentiate along the neuronal pathway by both retinoic acid (RA) and gamma-interferon (gamma-IFN). Analysis of labelled phosphatidylinositol metabolites from prelabelled cells indicated a rapid decrease of inositol 1,4,5-trisphosphate and 1,2-diacylglycerol within 1 min of induction of LAN-1 cell differentiation by RA, while no changes were observed in gamma-IFN-treated cells. These findings indicate the occurrence of decreased inositol phospholipid turnover in RA-treated LAN-1 cells and suggest that phosphoinositide-derived metabolites may not constitute general regulators of cellular differentiation.
Lanciotti
M
M
Pediatric Oncology Research Laboratory, G. Gaslini Children's Hospital, Genoa, Italy.
Cornaglia-Ferraris
P
P
Ponzoni
M
M
D002454:Cell Differentiation / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002855:Chromatography, Thin Layer; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009447:Neuroblastoma; D010716:Phosphatidylinositols / Q000378:metabolism* / Q000502:physiology; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D010716:Phosphatidylinositols; D014212:Tretinoin; D007371:Interferon-gamma