The human glucocorticid receptor, its gene and actions

描述(申请人提供)：这项正在进行的资助的长期目标是了解糖皮质激素受体(GR)如何调节基因以影响白血病淋巴细胞的死亡。我们的发现为下一期的研究奠定了基础。糖皮质激素通过激活糖皮质激素受体，已经确定了几个标志性基因，它们的调节先于显性细胞凋亡的开始。具有高度意义的是观察到c-myc的转录抑制总是见于对糖皮质激素敏感的细胞(或通过激活蛋白激酶A而变得敏感)。我们已经开始进行基因阵列分析，以揭示最终发生凋亡事件之前的所有这些基因。我们已经从人急性淋巴细胞白血病CEM细胞系中开发出一套控制良好的克隆细胞系。比较这些克隆中表达的基因将使我们能够识别其调控与细胞凋亡的启动有关的基因。我们最近发现了两种药物干预措施，可以增强糖皮质激素诱导的细胞凋亡，这应该可以进一步完善这一基因集。基于这些发现，在下一个赠款期间，我们的研究将集中在四个具体目标上。我们将：1)通过基因芯片分析确定糖皮质激素诱导的CEM细胞死亡所需的表达改变的基因；2)测试这些基因之间的假设因果关系；3)获得糖皮质激素敏感细胞特有的蛋白质表达谱；4)测试GR主要的N端转录激活结构域在上述调控事件中的作用。为了进行这些实验，我们将结合分子和细胞生物学、基因组学、蛋白质组学和生物信息学的专业知识。由此产生的数据将检验一种假设，即一系列相互作用的基因产物负责糖皮质激素诱导的细胞凋亡。如果我们的假设是正确的，这项工作将导致在白血病细胞系统中发现该网络，为与其他淋巴系统(正常和恶性)进行详细比较奠定基础。这将为研究针对恶性肿瘤的新型干预措施开辟道路。

DESCRIPTION (provided by applicant): The long-term goal of this ongoing grant is understanding how the glucocorticoid receptor (GR) regulates genes to effect the death of leukemic lymphoid cells. Our findings have laid the groundwork for research in our next grant period. Glucocorticoids, through activation of the GR, have identified several landmark genes whose regulation by glucocorticoids precedes the onset of overt apoptosis. Of high significance is the observation that transcriptional repression of c-myc is invariably seen in cells sensitive to glucocorticoid (or rendered sensitive by activation of protein kinase A). We have begun gene array analysis to reveal all such genes antecedent to the eventual apoptotic events. We have developed a well-controlled set of clonal cell lines from the human acute lymphoblastic leukemia CEM cell line. Comparing the genes expressed in these clones will allow us to identify the genes whose regulation is specifically relevant to apoptotic onset. Our recent discovery of two pharmacological interventions that enhance glucocorticoid-evoked apoptosis should allow further refinement of this gene set. Based on these findings, in the next grant period our research will center on four specific aims. We will: 1) define by gene array analysis those genes whose altered expression is required for glucocorticoid-evoked CEM cell death; 2) test the hypothetical causal relationships between such genes; 3) obtain protein expression profiles unique to glucocorticoid-sensitive cells; and 4) test the role of the major, N-terminal transcription-activating domain of the GR in the above regulatory events. To carry out these experiments, we will combine expertise in molecular and cell biology, genomics, proteomics and bioinformatics. The resulting data will test the hypothesis that a network of interactive gene products is responsible for the glucocorticoid-evoked apoptosis. If our hypothesis is correct, this work will lead to the discovery of that network in a leukemic cell system, providing the foundation for detailed comparisons with other lymphoid systems, normal and malignant. This would open the way for studies of novel interventions against malignancies.