Zaitsu M, Ishii E, Hamasaki Y
Department of Pediatrics, Saga Medical School, Saga, Japan.
Prostaglandins Leukot Essent Fatty Acids. 2002 Dec;67(6):405-10. doi: 10.1054/plef.2002.0450.
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 TXA(2) synthase, in dimethyl sulfoxide (DMSO)-differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR), and A23187-stimulated TXB(2) production, a stable metabolite of TXA(2), by radioimmunoassay (RIA). A23187-stimulated TXB(2) production, and mRNA abundance for COX-2, were not detected in non-treated HL-60 cells. TXA(2) synthase mRNA were barely detected in non-treated HL-60 cells. DMSO-induced HL-60 cells gained induction of TXB(2) synthesis and mRNA for COX-2 and TXA(2) synthase during granulocytic differentiation. COX-1 mRNA was constitutively expressed. A23187-stimulated TXB(2) production in DMSO-treated cells was inhibited by NS-398, a specific COX-2 inhibitor. These results demonstrated that TXB(2) production in granulocytic HL-60 cells was regulated at both the enzyme level of COX-2 and TXA(2) synthase.
人类白血病（HL）-60细胞可被多种试剂诱导分化，随着细胞分化，前列腺素（PGs）和血栓素（TX）的合成活性增加。我们通过逆转录聚合酶链反应（RT-PCR）检测了二甲基亚砜（DMSO）诱导分化的HL-60细胞中TX合成酶、环氧化酶（COX）-1、COX-2和TXA₂合酶的信使核糖核酸（mRNA）表达，并通过放射免疫测定法（RIA）检测了A23187刺激后TXB₂的产生，TXB₂是TXA₂的一种稳定代谢产物。未处理的HL-60细胞中未检测到A23187刺激后的TXB₂产生以及COX-2的mRNA丰度。未处理的HL-60细胞中几乎检测不到TXA₂合酶mRNA。在粒细胞分化过程中，DMSO诱导的HL-60细胞获得了TXB₂合成以及COX-2和TXA₂合酶mRNA的诱导表达。COX-1 mRNA呈组成性表达。NS-398（一种特异性COX-2抑制剂）可抑制DMSO处理细胞中A23187刺激后的TXB₂产生。这些结果表明，粒细胞HL-60细胞中TXB₂的产生在COX-2和TXA₂合酶的酶水平上均受到调控。
