Sensitivity of Daudi cells to tumor necrosis factor alpha: early changes in polyphosphoinositide metabolism.

The effects of recombinant Tumor Necrosis Factor alpha (r-TNF alpha) on polyphosphoinositide metabolism were examined in a Burkitt Lymphoma cell line (Daudi cells). After 1 h of in vitro treatment with r-TNF alpha, the incorporation of 32Pi into phosphatidylinositol 4,5-phosphate (PtdInsP2), phosphatidylinositol 4-phosphate (PtdInsP) and phosphatidylinositol (PtdIns) was reduced compared with controls, confirming previous findings observed in other cell lines of a specific PtdIns breakdown following r-TNF alpha treatment. The novelty of this study is therefore the demonstration of early changes in polyphosphoinositide metabolism during the antiproliferative response elicited by this cytokine in Daudi cells.