MECHANISM OF 1-25-D3 ANTI-PROLIFERATIVE ACTION IN CML

RWLeu-4在最近建立的费城染色体阳性 (Ph1)细胞系分离自处于慢性炎症“急变期”的患者， 骨髓性白血病（CML）。用la，25（OH）2 Vitami处理RWLeu-4 D3（1，25-D3）、佛波醇酯（PMA）或DMSO导致这些细胞停止 增殖并分化成具有表型的细胞， 单核细胞的功能和细胞表面抗原特征 和/或巨噬细胞。我们最近得到了这种细胞的一种变体 命名为RD 3的细胞系，其对抗增殖作用具有抗性 1，25-D3，但仍然诱导分化，以响应这些 剂.使用野生型和抗性细胞，我们将 探讨1，25-D_3抗肿瘤细胞增殖作用的机制。 这些CML细胞。我们建议对1，25-D_3受体的特性在bc 使用DNA-纤维素洗脱图谱的RWLeu-4和RD 3细胞，部分 肽图谱和DNA-纤维素结合图谱。如果差异 发现，我们将进一步表征编码受体的基因 使用分子克隆技术。如果没有发现差异， 将研究其他信号传导系统的变化，如蛋白质 激酶C和其他蛋白激酶，磷脂酰肌醇代谢 干扰素、环核苷酸的产生和 磷脂，细胞膜的含量。利用差异， RWLeu-4和RD 3中响应于1，25-D3的基因表达， 处理和未处理的cDNA的差异杂交 rwleu 4和rd 3细胞，我们将研究特异性的因素， 调节增殖本身。通过这样做，我们希望进一步 了解阻止CML细胞正常成熟的过程 并开始阐明调节细胞增殖的因子。 此外，这些研究将增进我们对 作用机制 的1，25-Da的一般，和调节增殖和成熟， 特别是造血细胞。

RWLeu-4 in a recently established, Philadelphia chromosome positive (Ph1) cell line isolated from a patient in the "blast phase" of chronic myelogenous leukemia (CML). Treatment of RWLeu-4 with la,25(OH)2 Vitami D3 (1,25-D3), phorbol esters (PMA), or DMSO causes these cells to cease proliferating and to differentiate into cells with phenotypic, functional, and cell surface antigenic characteristics of monocytes and/or macrophages. We have recently derived a variant of this cell line, designated RD3, that in resistant to the anti-proliferative effect of 1,25-D3 but in still induced to differentiate in response to these agents. Using both the wild type and the resistant cells, we will investigate the mechanism of anti-proliferative action of 1,25-D3 on these CML cells. We propose to characterize the 1,25-D3 receptors in bc RWLeu-4 and RD3 cells using DNA-cellulose elution profiles, partial peptide maps, and DNA-cellulose binding profiles. If differences are found, we will further characterize the genes coding for the receptors using molecular cloning techniques. If no differences are found we will examine changes in other signal trasduction systems such as protein kinase C and other protein kinases, phosphatidylinositol metabolism interferon, cyclic nucleotide production and changes in the phospholipid, content of the cell membrane. Exploiting differences in gene expression in RWLeu-4 and RD3 in response to 1,25-D3 as detected by differential hybridization of cDNA's made from treated and untreated rwleu4 and rd3 cells, we will investigate the factors specific for the regulation of proliferation per se. By doing so, we hope to further understand the processes that prevent normal maturation of cells in CML and begin to elucidate the factors that regulate cellular proliferation. Furthermore these studies will enhance our understanding of the mechanism of action of 1,25-Da in general, and regulation of proliferation and maturation in hematopoietic cells in specific.