Down-regulation of phospholipase C-γ1 during the differentiation of U937 cells

AbstractPhospholipase C (PLC)-γ1 and -γ2 play a pivotal role in signal transduction for cell proliferation and differentiation. The enzyme activity and protein level of PLC-γ1 were markedly decreased in the human histiocytic leukemia U937 cell line during the differentiation process which is induced by phorbol 12-myristate 13-acetate (PMA) but those of PLC-γ2 were not altered. Northern blot analysis showed that the levels of PLC-γ1 and -γ2 transcripts were not changed. These results suggest that the expression of PLC-γ1 during the PMA-induced differentiation may be down-regulated by post-transcriptional processing