Bunce C M, Mountford J C, French P J, Mole D J, Durham J, Michell R H, Brown G
Department of Immunology, University of Birmingham, Edgbaston, UK.
Biochim Biophys Acta. 1996 May 28;1311(3):189-98. doi: 10.1016/0167-4889(96)00005-5.
HL60 cells are human promyeloid cells that can be induced to differentiate by physiological stimuli (e.g. all-trans retinoic acid (ATRA), 1 alpha,25-dihydroxyvitamin D3 (D3), granulocyte colony-stimulating factor (G-CSF)) and by non-physiological agents such as dimethysulphoxide (DMSO) and protein kinase C-activating phorbol esters. The sensitivity of HL60 cells to physiological differentiating agents, but not to DMSO, is enhanced when cells are exposed to 'anti-inflammatory agents' (e.g. indomethacin) or are 'primed' (pretreated) with a small amount of ATRA: alone, neither treatment induces differentiation. We earlier suggested that indomethacin might act by inhibiting the endogenous formation of a differentiation-suppressing prostanoid (Bunce, C.M., et al. (1994) Leukemia 8, 595-604). Studies of the formation of prostanoids by HL60 cells and of the effects of prostanoids on these cells failed to identify any prostanoid that could be implicated in sensitization by indomethacin. 3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) is another target of such 'anti-inflammatory agents'. Steroid inhibitors of 3 alpha-HSD sensitized HL60 cells to inducers of differentiation in a manner similar to indomethacin. 3 alpha-HSD is a member of the aldoketoreductase enzyme family, which comprises many enzymes of similar size and primary sequence. A protein that was recognised by an antiserum to 3 alpha-HSD was found in HL60 cells, but the cells showed no detectable 3 alpha-HSD activity. The 3 alpha-HSD-like protein was strikingly down-regulated by 'priming' doses of ATRA. When treatment with a differentiation-sensitizing 'anti-inflammatory agent' or steroid was combined with ATRA "priming', the effects of the different treatments were not additive: the resulting increase in sensitivity equalled that achievable by either treatment alone. We conclude that interference with a single intracellular regulatory mechanism underlies the increases in sensitivity of cells to differentiating agents that are caused by anti-inflammatory agents, by certain steroids and by 'priming' with ATRA. Decreased activity of a yet-to-be-identified member of the aldoketoreductase family of dehydrogenases is likely to be a central feature of a previously unrecognised mechanism that controls the responsiveness of cells to environmental stimuli such as retinoids and D3.
HL60细胞是人类早幼粒细胞，可被生理刺激物（如全反式维甲酸（ATRA）、1α,25-二羟基维生素D3（D3）、粒细胞集落刺激因子（G-CSF））以及非生理因子如二甲基亚砜（DMSO）和激活蛋白激酶C的佛波酯诱导分化。当细胞暴露于“抗炎剂”（如吲哚美辛）或用少量ATRA“预处理”（预激）时，HL60细胞对生理分化剂而非DMSO的敏感性增强：单独使用这两种处理均不会诱导分化。我们之前曾提出吲哚美辛可能通过抑制一种抑制分化的前列腺素的内源性形成而起作用（Bunce, C.M., 等人（1994年）《白血病》8, 595 - 604）。对HL60细胞前列腺素形成以及前列腺素对这些细胞影响的研究未能鉴定出任何可能与吲哚美辛致敏有关的前列腺素。3α-羟基类固醇脱氢酶（3α-HSD）是此类“抗炎剂”的另一个靶点。3α-HSD的类固醇抑制剂使HL60细胞对分化诱导剂的敏感性增强，其方式与吲哚美辛类似。3α-HSD是醛酮还原酶家族的成员之一，该家族包含许多大小和一级序列相似的酶。在HL60细胞中发现了一种能被抗3α-HSD抗血清识别的蛋白质，但这些细胞未显示出可检测到的3α-HSD活性。3α-HSD样蛋白在经ATRA“预激”剂量处理后显著下调。当用一种使分化敏感的“抗炎剂”或类固醇与ATRA“预激”联合处理时，不同处理的效果并非相加：所产生的敏感性增加等同于单独使用任何一种处理所能达到的增加程度。我们得出结论，对单一细胞内调节机制的干扰是抗炎剂、某些类固醇以及ATRA“预激”导致细胞对分化剂敏感性增加的基础。醛酮还原酶脱氢酶家族中一个尚未确定的成员活性降低可能是一种先前未被认识的机制的核心特征，该机制控制细胞对诸如类视黄醇和D3等环境刺激的反应性。
