Polyamine Suppression By Antizyme inducing Analogs

描述(由申请人提供)： 这项工作的最终目标是开发一种药理方法 提高一种已知的肿瘤抑制蛋白、抗酶的水平，从而 减少人类癌症的发生和肿瘤的形成。多胺， 精胺和精胺，以及它们的二胺前体腐胺 哺乳动物细胞生长和存活所必需的脂肪族阳离子。癌 细胞需要更高水平的多胺和抑制剂，以防止 必需的多胺合成或细胞摄取可能会阻止促进 肿瘤形成阶段。正常细胞中的多胺稳态在很大程度上是 依赖于一种调节蛋白抗酶的活性，它是 在精胺或精胺升高时合成的。在……里面 反过来，这种小蛋白既介导了起始酶的快速降解 在多胺生物合成中，鸟氨酸脱羧酶和下调 多胺摄取系统。通过对癌基因转基因细胞进行工程使其超过 表达抗酶有可能抑制它们的转化表型 以及它们在动物体内形成肿瘤的能力。建议的具体目标 研究的结构是为了检验多胺类似物可以用于 不必要地刺激抗酶的产生，从而阻止 肿瘤形成的促进阶段。(1)腐胺模拟特定的 刺激转录的抗酶基因将被鉴定并 特色化的。(2)多胺类似物和低聚胺类化合物 抗酶信息在完整的哺乳动物细胞中的翻译将是 已确认身份。(3)选定的抗酶诱导类似物的潜力 增加和维持哺乳动物细胞中的抗酶水平将被评估。(4) 选定的类似物逆转转化的细胞表型的能力将 用H-ras基因转染的NIH3T3细胞进行检测。抗酶诱导研究 将使用大鼠肝脏(HTC)和仓鼠(CHO)细胞，并将涉及检测 Northern-Blot分析抗酶基因的表达，ODC酶检测抗酶活性 免疫印迹法检测抗酶蛋白。 这些研究将为进一步探索 作为动物化学预防手段的抗酶的化学诱导。

DESCRIPTION (provided by applicant): The eventual goal of this work is the development of a pharmacological method to elevate levels of a known, tumor-suppressing protein, antizyme, and thereby reduce cancer promotion and tumor formation in humans. The polyamines, spermidine and spermine, and their diamine precursor, putrescine, are aliphatic cations essential for mammalian cell growth and viability. Cancer cells require elevated levels of the polyamines, and inhibitors that prevent the requisite polyamine synthesis or cellular uptake can block the promotional stage of tumor formation. Polyamine homeostasis in normal cells is largely dependent upon the activity of a regulatory protein, antizyme, which is synthesized in response to elevations in either spermidine or spermine. In turn, this small protein mediates both rapid degradation of the initial enzyme in polyamine biosynthesis, ornithine decarboxylase, and down regulation of the polyamine uptake system. By engineering oncogene-transfected cells to over express antizyme it is possible to inhibit both their transformed phenotype and their tumor-forming ability in animals. The specific aims of the proposed study are structured to test the hypothesis that polyamine analogs can be used to gratuitously stimulate antizyme production, and thereby block the promotional phase of tumor formation. (1) Putrescine mimics that specifically stimulate transcription of the antizyme gene will be identified and characterized. (2) Polyamine analogs and oligoamines that specifically promote translation of the antizyme message in intact mammalian cells will be identified. (3) The potential of selected antizyme-inducing analogs to increase and sustain antizyme levels in mammalian cells will be evaluated. (4) The ability of selected analogs to reverse a transformed cell phenotype will be assessed using H-ras-transfected NIH 3T3 cells. Antizyme induction studies will use rat liver (HTC) and hamster (CHO) cells, and will involve detection of antizyme mRNA by northern-blot analysis, antizyme activity by ODC enzyme inhibition assays, and antizyme protein by immunodetection on western-blots. These studies will provide an essential foundation for further exploration of the chemical induction of antizyme as a means of chemoprevention in animals.