TUMOR PROMOTER MACROPHAGE DIFFERENTIATION AND APOPTOSIS

化学和辐射诱发的致癌作用是多阶段的 涉及肿瘤起始、促进和进展的过程。休伯曼医生 假设肿瘤启动子诱导的组织单核细胞分化 导致巨噬细胞池的不适当扩张，引起组织损伤， 炎症，从而有助于所需的克隆扩增， 在肿瘤促进过程中启动细胞。他正在调查 肿瘤促进剂诱导的髓样前体细胞巨噬细胞分化， 导致这种分化的信号转导系统。他的实验 将利用差异显示技术来识别基因 在人髓系HL-60白血病细胞变异体中差异表达， 对巨噬细胞分化敏感或抵抗。的功能 将通过检查以下因素的影响来确定所鉴定基因的作用： 反义介导的HL-60细胞中同源mRNA的抑制，以及 在适当的抗性细胞变体中过量表达有义cDNA。使用此 通过这种方法，Huberman博士已经分离出了一种编码新型激酶的基因， 它是由肿瘤促进剂佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）诱导的， HL-60细胞，在耐药细胞中不存在，对PMA介导的HL-60至关重要 分化 Huberman博士提出了旨在确定 这种激酶在信号转导途径中导致巨噬细胞 分化他建议建立激酶与其他蛋白质的关系。 分化的介质，表征这一生物学功能， 激酶，并研究激酶的目标和效应器使用两者 基因表达和蛋白质接触策略。此外，Huberman博士 提出了旨在分离和表征额外介质的实验 巨噬细胞分化的表达筛选和遗传 互补的方法。

Chemical- and radiation-induced carcinogenesis is a multistage process involving tumor initiation, promotion and progression. Dr. Huberman hypothesizes that tumor-promoter-induced differentiation of tissue monocytes results in an improper expansion of macrophage pools, causing tissue damage and inflammation and thereby contributing to the required clonal expansion of initiated cells during tumor promotion. He is investigating tumor-promoter-induced macrophage differentiation of myeloid precursors and the signal-transduction system that leads to this differentiation. His experiments will utilize the differential display technique to identify genes differentially expressed in human myeloid HL-60 leukemia cell variants that are either susceptible or resistant to macrophage differentiation. A functional role for the identified genes will be established by examining the effect of antisense-mediated inhibition of the cognate mRNA in HL-60 cells, as well as by over expressing sense cDNA in appropriate resistant cell variants. Using this approach, Dr. Huberman has already isolated a gene coding for a novel kinase, which is induced by the tumor promoter phorbol 12-myristate 13-acetate (PMA) in HL-60 cells, absent in resistant cells, and critical for PMA-mediated HL-60 differentiation. Dr. Huberman proposes experiments designed to determine the precise role of this kinase in the signal transduction pathway leading to macrophage differentiation. He proposes to establish the kinase's relationships to other mediators of differentiation, characterize the biological function of this kinase, and investigate the kinase's targets and effectors using both gene-expression and protein contact strategies. In addition, Dr. Huberman proposes experiments aimed at isolating and characterizing additional mediators of macrophage differentiation using an expression screen and genetic complementation approach.