METABOLIC AND MOLECULAR CONTROL OF MYELOPOIESIS

一种称为集落刺激因子的糖蛋白的持续存在 (CSF)是体外克隆生长所必需的 粒细胞-巨噬细胞祖细胞（CFU-GM）。脑脊液刺激释放 花生四烯酸是从膜磷脂中分离出来的， 然后转化为环氧化和脂氧合的产物。 抑制脂氧合酶，特别是合成 白三烯C和D（LTC和LTD）阻断CSF诱导的集落生长， 通过添加LTC或LTD，可以部分地反转该块。 急性非淋巴细胞白血病患者的CFU-GM （ANLL）表现出对高浓度的抑制作用的抗性 脂肪氧合酶抑制剂。这可能反映了从正常的 与肿瘤发生有关的调节机制。脂氧合酶的代谢 LTC和LTD的中间体依赖于谷胱甘肽还原酶，谷胱甘肽 S-转移酶和γ-谷氨酰转肽酶。其中两种基因 酶已经定位于染色体，这些染色体经常参与 与ANLL相关的细胞遗传学异常。 拟议研究的总体目标是进一步阐明 正常脑脊液中花生四烯酸和谷胱甘肽代谢的作用 刺激CFU-GM生长和白血病，通过1）确定 白三烯和谷胱甘肽代谢的特异性关键酶 正常和白血病骨髓细胞;和2）检查活性的变化 白血病细胞系被诱导 区分。 为了实现这一点，重组人CSF，半纯化骨髓 来自正常和白血病个体的祖细胞， 将使用表征的人白血病细胞系。酶 脂氧合酶途径将被选择性地抑制。抑制模式 的白血病细胞系将与正常和白血病骨进行比较 骨髓细胞酶的含量和活性被发现影响 将对正常和白血病集落形成进行定量，并与 增长模式。这些研究的结果将增进我们对以下方面的了解： 正常和肿瘤调节，并将有助于集中未来的研究 白血病细胞调节改变的分子遗传学。

Continuous presence of a glycoprotein termed colony stimulating factor (CSF) is necessary for the in vitro clonal growth of the committed granulocyte-macrophage progenitor cell (CFU-GM). CSF stimulates the release of arachidonic acid from membrane phospholipids, and arachidonic acid is then transformed to products of cyclooxygenation and lipoxygenation. Inhibition of lipoxygenase and specifically of the synthesis of leukotrienes C and D (LTC and LTD) blocks CSF-induced colony growth, and the block can be partially reversed by addition of LTC or LTD. CFU-GM from a subset of patients with acute non-lymphoblastic leukemia (ANLL) exhibit resistance to the inhibitory effects of high concentrations of lipoxygenase inhibitors. This may reflect a release from a normal regulatory mechanism related to oncogenesis. The metabolism of lipoxygenase intermediates to LTC and LTD depends on glutathione reductase, glutathione S-transferase and gamma-glutamyl transpeptidase. The genes for two of these enzymes have been localized to chromosomes that are frequently involved in cytogenetic abnormalities associated with ANLL. The overall objective of the proposed research is to further elucidate the role of arachidonic acid and glutathione metabolism in normal CSF stimulated CFU-GM growth and in leukemia by 1) determining the role of specific critical enzymes of leukotriene and glutathione metabolism in normal and leukemic myeloid cell; and 2) examining changes in the activity of those specific enzymes as leukemic cell lines are induced to differentiate. To accomplish this, recombinant human CSF, semi-purified bone marrow progenitor cells from normal and leukemic individuals, and well- characterized human leukemic cell lines will be used. Enzymes in the lipoxygenase pathway will be inhibited selectively. Patterns of inhibition of the leukemic cell lines will be compared with normal and leukemic bone marrow cells. The content and activity of enzymes which are found to impact on normal and leukemic colony formation will be quantitated and related to growth patterns. The results of these studies will enhance our knowledge of normal and neoplastic regulation and will serve to focus future studies on the molecular genetics of altered regulation in leukemic cells.