Phorbol ester induction of leukemic cell differentiation is a membrane-mediated process.
Phorbol ester induction of leukemic cell differentiation is a membrane-mediated process.
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佛波酯诱导白血病细胞分化是一个膜介导的过程。
DOI：
10.1073/pnas.79.9.2865
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发表时间：
1982
影响因子：
11.1
通讯作者：
Kuo,AL
中科院分区：
文献类型：
--
作者：
Cooper,RA;Braunwald,AD;Kuo,AL
佛波酯是HL-60早幼粒细胞白血病细胞系中巨噬细胞样分化的有效诱导剂。人们对它们带来这种转变的事件顺序知之甚少。然而，已知佛波醇酯与HL-60细胞的表面膜结合，也与各种其它细胞结合。我们的研究旨在确定这种膜结合的生物学重要性。[3 H]佛波醇二丁酸酯（PBu 2）与HL-60细胞特异性结合，Kd为23 nM，每个细胞有1.9 × 10（5）个[3 H] PBu 2结合位点。结合的[3 H] PBu 2没有内化。在新鲜培养基中洗涤后，特异性结合是完全可逆的，此后加入的[3 H] PBu 2与其受体正常结合。在10分钟的结合，PBu 2刺激[14 C]胆碱掺入磷脂酰胆碱，与一个快速恢复正常后，去除PBu 2。膜结合的PBu 2逐步抑制DNA合成，与70%的抑制8 hr. This过程被中断，如果PBu 2被删除，和以前抑制细胞中发生的DNA合成几乎没有恢复。在8和16小时之间，PBu 2诱导细胞粘附到塑料上，但仅在刺激磷脂酰胆碱合成的那些细胞中，如果在16小时之前除去PBu 2，该过程也被中断。的诱导细胞暴露于PBu 2为最初的16小时，但不是在细胞暴露5小时。这些研究表明，佛波醇酯发挥其作用，而保留在细胞表面。细胞生长的抑制和表征巨噬细胞的表面和酶性质的获得是可分离的事件，其中每一个都通过受体介导的跨膜过程进行。磷脂酰胆碱合成的刺激似乎是该过程的一部分。
Phorbol esters are potent inducers of macrophage-like differentiation in the HL-60 promyelocytic leukemia cell line. The sequence of events by which they bring about this transition is poorly understood. However, it is known that phorbol esters bind to the surface membrane of HL-60 cells and to various other cells as well. Our studies were directed toward determining the biologic importance of this membrane association. [3H]Phorbol dibutyrate (PBu2) was specifically bound by HL-60 cells with a Kd of 23 nM and with 1.9 X 10(5) binding sites for [3H]PBu2 per cell. There was no internalization of bound [3H]PBu2. Specific binding was fully reversible upon washing in fresh medium, and [3H]PBu2 added thereafter bound normally to its receptor. Within 10 min of binding, PBu2 stimulated [14C]choline incorporation into phosphatidylcholine, with a rapid return to normal upon removal of the PBu2. Membrane-bound PBu2 progressively inhibited DNA synthesis, with 70% inhibition by 8 hr. This process was interrupted if the PBu2 was removed, and little recovery of DNA synthesis occurred in previously inhibited cells. Between 8 and 16 hr, PBu2 induced adherence of cells to plastic, but only in those cells in which phosphatidylcholine synthesis was stimulated, and this process was also interrupted if PBu2 was removed prior to 16 hr. Similarly, nonspecific esterase, which develops after 72 hr of incubation, was induced in cells exposed to PBu2 for the initial 16 hr but not in cells exposed for 5 hr. These studies demonstrate that phorbol esters exert their effects while retained at the cell surface. Inhibition of cell growth and the acquisition of surface and enzymatic properties that characterize macrophages are separable events, each of which proceeds through a receptor-mediated, transmembrane process. The stimulation of phosphatidylcholine synthesis appears to be a part of that process.