CHARACTERIZATION OF ACUTE MYELOGENOUS LEUKEMIA STEM CELL

该项目涉及白血病集落形成细胞的研究 急性髓性白血病（AML）患者中的L-CFC。 在 本研究的一个方面，L-CFC表达的细胞表面抗原 将在AML患者中使用一组骨髓特异性 单克隆抗体和补体介导的细胞毒性。 患者将 在随后的复发中进行连续检查，以确定L-CFC是否 表型随时间稳定。 这些研究的结果将 可以与一系列旨在检查感应强度的实验进行比较， 使用已知影响骨髓的各种试剂使L-CFC成熟 细胞分化 待测试的试剂包括重组γ-氨基丁酸。 干扰素、1，25二羟维生素D3和顺式维甲酸。 变化 将检查表面抗原、增殖潜力和形态学 在L-CFC暴露于最佳浓度的成熟诱导 剂. 这些研究旨在检查AML中的L-CFC是否 响应于分化剂，并确定是否响应 表现为与正常骨髓细胞生成相似的细胞变化 (i.e.,表达更分化的细胞表型和减少 在细胞增殖中）。 另一个方面是将两者的细胞表面抗原性展示关联起来， 具有癌基因表达的正常和白血病骨髓细胞。 表达 将研究三种骨髓相关细胞癌基因（c-onc）： N-ras、c-myc和c-fos。 将通过以下方法定量癌基因表达： 探针与从正常骨髓提取的c-onc RNA的杂交 亚群（单核细胞和中性粒细胞）和白血病母细胞 来自AML患者的人群。 癌基因蛋白表达 将使用抗血清通过免疫荧光研究测定产品， 癌基因蛋白，并通过放射性标记的免疫沉淀研究， 细胞裂解物。 这些研究的目的是将 癌基因与髓样细胞表面抗原的模式在正常和 恶性细胞，以确定是否有关系， 分化状态。 结果将进一步加深我们对白血病的认识 细胞生物学在AML，并针对澄清成熟的 发生在骨髓性白血病中的缺陷。 通过确定 L-CFC群体的成熟能力，替代方法 包括免疫疗法和成熟诱导疗法在内的治疗， 结果.

This project involves the study of the leukemia-colony forming cell population (L-CFC) in patients with acute myelogenous leukemia (AML). In one aspect of this study, the cell surface antigens expressed by the L-CFC will be examined in patients with AML using a panel of myeloid-specific monoclonal antibodies and complement-mediated cytotoxicity. Patients will be examined serially on subsequent relapses to determine whether the L-CFC phenotype is stable with time. The findings from these studies will then be compared to a series of experiments designed to examine the inducibility to maturation of the L-CFC using various agents known to effect myeloid cell differentiation. The agents to be tested include recombinant gamma interferon, 1,25 dihydroxyvitamin D3, and cis-retinoic acid. Changes in surface antigens, proliferative potential, and morphology will be examined in the L-CFC exposed to optimal concentrations of the maturation-inducing agents. The studies are designed to examine whether the L-CFC in AML is responsive to agents of differentiation, and to determine whether response is manifested in cellular changes similar to those of normal myelopoiesis (i.e., expression of a more differentiated cell phenotype and a reduction in cellular proliferation). Another aspect is to correlate the cell surface antigenic display of both normal and leukemic myeloid cells with oncogene expression. The expression of three myeloid-associated cellular oncogenes (c-onc) will be studied: N-ras, c-myc and c-fos. Oncogene expression will be quantified by hybridization of probes to c-onc RNA extracted from normal myeloid subpopulations (monocytes and neutrophils) and from leukemia blast cell populations from patients with AML. Expression of oncogene protein products will be determined by immunofluorescence studies using antisera to the oncogene proteins, and by immunoprecipitation studies of radiolabelled cell lysates. The aim of these studies is to correlate the expression of oncogenes with patterns of myeloid cell-surface antigens on normal and malignant cells to determine whether there is a relationship with differentiation status. Results will further our understanding of leukemia cell biology in AML, and are directed towards clarifying the maturational defect that occurs in myelogenous leukemia. By determining the maturational capabilities of the L-CFC population, alternative approaches to therapy, including immunotherapy and maturation-inducing therapy, may result.