MOLECULAR SENSITIZATION OF P210BCR-ABL POSTIVIE CELLS TO THERAPY--CML

细胞A belson（c-abl）基因的P145产物已被证明是 介导G1/S期细胞周期进程和凋亡的抑制 当在细胞中过表达或当细胞暴露于 遗传毒性应激作为放射疗法和化学疗法。而反观 P145 c-abl的异常对应物P210 crabl的存在， 与生长因子非依赖性生长的表型相关， 锚定非依赖性生长，凋亡拯救和遗传不稳定性， 慢性粒细胞白血病（CML）。为了研究 这两种蛋白在AB 1结构域中具有结构相似性， 但在骨髓细胞中却有相反的作用， bcrabl和c-abl蛋白的关键底物，我们修饰了 骨髓性白血病细胞系，使P210 crab的表达， 蛋白质受四环素的细胞外浓度调节。 我们已经证明，P210 c-abl/p145 c-abl蛋白的比例，以及p210 c-abl/p145 c-abl蛋白的比例， 在缺乏IL 3的情况下，这些细胞的生长依赖于 四环素浓度我们将使用该细胞系来测试bcrabl 蛋白质与应激激活蛋白激酶（SAP）途径相互作用 如果c-ABL的底物或磷酸化位点与c-ABL相同， abl或bcrabl蛋白相同或不同，以及哪些底物或 修饰或底物的位点与 P210 crabl转化。由于已知c-abl促进细胞凋亡， 对遗传毒性应激的反应，并且已知bcrabl可从 凋亡，我们建议使用这种细胞系也研究，如果 对化疗和干扰素治疗的敏感性不同， P210 bcrabl/P145 c-abl比值变化。我们将使用肽转录 选择性中断P210 bcrabl与其相互作用的单元 底物而不影响P145 c-abl激酶，以区分 P210 bcrabl和P145 c-abl的作用，并逆转转化的 CML细胞的表型。我们将使用这些产生的信息 设计CML治疗新方法的研究，包括 用于抑制P210的肽模拟化合物的设计和测试 bcrabl作用于P210 bcrabl阳性细胞。

The P145 product of the cellular A belson (c-abl) gene has been shown to mediate inhibition of cell cycle progression and apoptosis at the Gl/S interface when over-expressed in cells or when cells are exposed to genotoxic stress as radiation therapy and chemotherapy. In contrast, the presence of the abnormal counterpart of P145c-abl, the P210crabl, is associated with the phenotypes of growth factor independent growth, anchorage independent growth, apoptosis rescue and genetic instability in chronic myelogenous leukemia (CML). In order to study the interaction of these two proteins which have structural similarities in the abl domain, but have such opposing effects in the myeloid cells, and to identify the key substrates of bcrabl and c-abl proteins, we have modified a myelogenous leukemia cell line so that the expression of the P210crabl protein is regulated by the extracellular concentration of tetracycline. We have shown that the ration of the P210crabl/p145c-abl proteins, and the growth of these cells, in the absence of IL3, is dependent on the tetracycline concentration. We will use this cell line to test if bcrabl proteins interact with the Stress Activated Protein Kinase (SAP) pathway as does the c-abl, if the substrates or sites of phosphorylation of the c- abl or bcrabl proteins are the same or different, and which substrates or sites of modifications or substrates are associated with the emergence of P210crabl transformation. Since c-abl is known to promote apoptosis in response to genotoxic stress, and the bcrabl is known to rescue from apoptosis, we are proposing to use this cell line to also study if the sensitivity to chemotherapy and interferon therapy is different as the ratio of P210 bcrabl/P145c-abl changes. We will use peptide transcription units which selective interrupt the interaction of P210 bcrabl with it substrates without affecting the P145c-abl kinase to discriminate between effects of P210 bcrabl and P145c-abl, and to reverse the transformed phenotype of the CML cell. We will use the information generated by these studies to design new approaches to the therapy of CML, including the design and testing of peptidomimetic compounds for the inhibition of P210 bcrabl action in P210 bcrabl positive cells.