ACTIONS OF THE P53 TUMOR SUPPRESSOR PROTEINS

大多数最广泛和最令人沮丧的人类癌症， 包括肺癌、乳腺癌、结肠癌和肝癌， 显示p53肿瘤抑制蛋白产物的异常 基因 似乎也有可能，许多，如果不是大多数的家庭负担， 癌症的可能是遗传突变的结果， p53基因。 这项研究的主要目的是获得关于 正常和突变型p53肿瘤抑制蛋白的生物学， 正常形式抑制生长，而其突变形式允许或促进 恶性转化 在这个项目期间，我们将研究的假设，p53直接或 通过改变其他细胞因子的表达， 基因. 该方法将开始确定最 细胞基因产物（蛋白质及其mRNA）的直接变化， 正常的p53蛋白抑制生长， p53的形式允许恶性变化。 为此，我们将利用 本实验室开发的创新超高分辨率方法， 检测和定量细胞对几种新的mu-p53的反应 表达载体和温度敏感的p53突变体， Arnold Levine's Laboratory（普林斯顿） 某些构造允许 调节突变（转化）p53分子的高水平表达。 另一些则是转化突变体，改变它们的构象， 正常的生长抑制蛋白在较低的温度。 然后我们将 对与改变有关的情况进行充分的研究 基因表达来选择那些蛋白质和信息， 直接对p53起作用。 在这一点上，我们将进行分子 克隆那些最感兴趣的基因并研究它们的结构 和监管。 最后，我们预期使用表达载体， 研究p53反应基因产物的性质和功能， 培养细胞的恶性转化问题，以及 背景下，他们的潜在作用，作为生物学的重要决定因素， 人体内的癌细胞 我们的初步数据显示， 能够在本项目期间在这些方向上取得实质性进展 期

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.