ACTIONS OF THE P53 TUMOR SUPPRESSOR PROTEINS

大多数最普遍和最令人沮丧的人类癌症， 包括肺癌、乳腺癌、结肠癌和肝癌，现在已知 P53抑癌基因蛋白产物的异常显示 吉恩。似乎也很可能有许多，如果不是大多数家庭敏感的话 可能是遗传突变导致癌症的结果 P53基因。这项研究的主要目的是获得关于 正常和突变型p53抑癌蛋白的生物学研究 正常形式抑制生长，而其突变形式允许或促进 恶变。 在这个项目期间，我们将检验这样的假设：P53直接或 通过改变其他细胞的表达间接发挥作用 基因。该方法将从识别大多数 细胞基因产物(蛋白质及其mRNAs)的即时变化 发生在正常的P53蛋白抑制生长时，以及几个突变体 各种形式的p53允许恶变。为此，我们将利用 本实验室开发的创新超高分辨率方法 检测和量化对几种新的突变型p53的细胞反应 表达载体和温度敏感型P53突变体 阿诺德·莱文实验室(普林斯顿)。某些构造允许 调控突变(转化)的p53分子的高水平表达。 其他人正在改造突变体，这些突变体改变了它们的构象，成为 正常生长-在较低温度下抑制蛋白质。到时候我们会的 对与变更相关的情况进行充分的研究 基因表达，选择出现最多的蛋白质和信息 对P53有直接反应。在这一点上，我们将进行分子 克隆最感兴趣的基因并研究其结构 和监管。最后，我们预计将使用表达载体来 研究P53反应基因产物的性质和功能 关于培养细胞的恶性转化问题，以及在 它们作为生物的重要决定因素的潜在作用的背景 人类体内的癌细胞。我们的初步数据表明我们应该 能够在此项目期间在这些方向上取得实质性进展 句号。

The majority of the most widespread and discouraging of human cancers, including carcinoma of the lung, breast, colon and liver, are now known to display abnormalities in the protein products of the p53 tumor suppressor gene. It also seems likely that many if not most familial susceptibilities to cancers may turn out to be the consequence of inherited mutations in the p53 gene. The broad aim of this research is to gain new information about the biology of normal and mutant p53 tumor suppressor proteins, as its normal forms inhibit growth and as its mutant forms allow or promote malignant transformation. In this project period we will examine the hypothesis that p53 directly or indirectly exerts actions by altering the expression of other cellular genes. The approach will begin with the identification of the most immediate changes in cellular gene products (proteins and their mRNAs) that occur as the normal p53 protein inhibits growth, and as several mutant forms of p53 allow malignant change. To these ends we will utilize innovative ultra-high resolution methods developed in this laboratory to detect and quantify the cellular responses to several novel mutant-p53 expression vectors and temperature-sensitive p53 mutants developed in Arnold Levine's Laboratory (Princeton). Some constructs allow the regulated high-level expression of mutant (transforming) p53 molecules. Others are transforming mutants that shift their conformation to become normal growth-suppressing proteins at lower temperatures. We will then conduct sufficient studies on the circumstances associated with altered gene expression to select those proteins and messages that appear most directly responsive to p53. At that point we will undertake the molecular cloning of those that have the highest interest and study their structure and regulation. Finally, we anticipate the use of expression vectors to study the nature and functions of p53-responsive gene products, as related to the problem of malignant transformation in cultured cells, and in the context of their potential role as important determinants in the biology of cancer cells in humans. Our preliminary data indicates that we should be able to make substantial progress in these directions during this project period.