Role of Nuclear Tyrosine Rak in Breast Cancer

描述（由申请方提供）：酪氨酸激酶是调节蛋白 在细胞生长和分化中起着重要作用。 初步 工作中，酪氨酸激酶在乳腺癌细胞系中的表达， 与正常样乳腺细胞相比， 展示分析 核酪氨酸激酶Rak表达下调与否 在几种乳腺癌细胞系中表达。 此外，腺病毒 早期基因E1A，已知可抑制乳腺癌细胞的生长 lines，上调Rak表达。 Rak在乳腺中的表达增强 癌细胞具有生长抑制活性，这是通过 集落形成效率 令人惊讶的是，很少有人知道 细胞中的Rak及其作用机制。 这项提案将考验 假设Rak抑制肿瘤细胞生长， Rak在乳腺癌中起作用。 首先，Rak表达对 肿瘤细胞生长将在体外通过细胞计数、殖民地 形成测定和软琼脂测定，并在体内测试。 二是 Rak对乳腺癌细胞凋亡敏感性及对乳腺癌细胞增殖的影响 将研究细胞周期。 Rak临界域的贡献 将通过缺失和突变分析来研究其功能。 第三、 Rak在不同级别和转移性乳腺癌中的表达 将通过免疫组织化学分析来确定电位。 这些研究 将描述Rak在细胞生长中的作用及其作用机制。 从科学的角度来看，确定Rak的作用机制将 这将极大地提高我们对细胞生长是如何调节的理解。 从 从临床角度来看，Rak可能是一个有用的预后标志物， 治疗剂。 此外，确定Rak在肿瘤生长中的作用将使 我们可以更好地定制酪氨酸激酶抑制剂用于 临床试验

DESCRIPTION (provided by applicant): Tyrosine kinases are regulatory proteins that play a central role in cell growth and differentiation. In preliminary work, the expression of tyrosine kinases in breast cancer cell lines was compared to normal-like breast cells using a tyrosine kinase differential display assay. The nuclear tyrosine kinase Rak was downregulated or not expressed in several breast cancer cell lines. Furthermore, the adenovirus early gene E1A, which is known to inhibit the growth of breast cancer cell lines, upregulated Rak expression. Enhanced expression of Rak in breast cancer cells had a growth suppressing activity as measured by a decrease in colony formation efficiency. Surprisingly, little is known about the role of Rak in cells and its mechanism of action. This proposal will test the hypothesis that Rak inhibits tumor cell growth, and that loss of expression of Rak plays a role in breast cancer. First, the effect of Rak expression on tumor cell growth will be assessed in vitro by cell counts, the colony formation assay and the soft agar assay, and tested in vivo. Second, the effect of Rak on the sensitivity of breast cancer cells to apoptosis and on the cell cycle will be studied. The contribution of critical domains of Rak to its function will be studied by deletion and mutation analysis. Third, expression of Rak in breast cancers of various grades and metastatic potentials will be determined by immunohistochemical analysis. These studies will delineate the role of Rak in cell growth and its mechanism of action. From a scientific standpoint, determining Rak's mechanism of action will significantly enhance our understanding of how cell growth is regulated. From a clinical standpoint, Rak may be a useful prognostic marker, and a gene therapy agent. Furthermore, identifying Rak's role in tumor growth will allow us to better tailor the specificity of tyrosine kinase inhibitors used in clinical trials.