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Induction of thromboxane A2 synthesizing enzymes in DMSO-induced granulocytic differentiation of HL-60 cells

2002; Elsevier BV; Volume: 67; Issue: 6 Linguagem: Inglês

10.1054/plef.2002.0450

1532-2823

Masafumi Zaitsu, E Ishii, Yuhei Hamasaki,

Estrogen and related hormone effects

Human leukemia (HL)-60 cells were differentiated by several agents, and prostaglandins (PGs) and thromboxane (TX) synthesizing activity increased in response to the differentiation of the cells. We examined the expression of messenger RNA (mRNA) for TX-synthesizing enzymes, cyclooxygenase (COX)-1, COX-2 and TXA2 synthase, in dimethyl sulfoxide (DMSO)-differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR), and A23187-stimulated TXB2 production, a stable metabolite of TXA2, by radioimmunoassay (RIA). A23187-stimulated TXB2 production, and mRNA abundance for COX-2, were not detected in non-treated HL-60 cells. TXA2 synthase mRNA were barely detected in non-treated HL-60 cells. DMSO-induced HL-60 cells gained induction of TXB2 synthesis and mRNA for COX-2 and TXA2 synthase during granulocytic differentiation. COX-1 mRNA was constitutively expressed. A23187-stimulated TXB2 production in DMSO-treated cells was inhibited by NS-398, a specific COX-2 inhibitor. These results demonstrated that TXB2 production in granulocytic HL-60 cells was regulated at both the enzyme level of COX-2 and TXA2 synthase.