Molecular Analysis of Proliferative and Apoptotic Pathways in Soft Tissue Sarcoma

我们的工作假设是Rb、p53和PTEN的突变和表达改变，或者那些影响 参与这些途径的调控基因，为肿瘤的生长和 软组织肉瘤患者的攻击行为。这一假设将通过一个 综合方法，分析人类肿瘤样本并进行基因研究，包括 体外和体内模型的生成。目的1.明确Rb的临床和生物学意义 STS中增殖和基因组稳定性的失活。我们将描述RB突变，改变的模式 PRb和E2F1的表达，以及上游调控因子(Cyclin D，CDK4)的表达。我们还将评估MAD2 表达，一个E2F1转录靶点，当解除调控时，会导致染色体不稳定和 非整倍体。我们将评估RB失活的后果，确定上调和下调的目标 通过高通量研究。目的2.表征影响P53促细胞凋亡的分子变化 并明确其在STS中的临床意义。我们将对TP53进行系统的表征 采用突变和P53表达相结合的方法。我们将分析P53的调控事件 途径，重点是Hdm2和p14/Arf的表达。我们将以Bax为中心研究P53的凋亡信号 以及Bcl2、PUMA和NOXA，定义了它们对肿瘤进展的影响以及对特定的 治疗。将使用功能分析来评估P53失活的机制后果。 目的3.探讨STS中Pten途径抑制肿瘤的分子机制。我们会 建立检测PTEN突变和Pten表达改变的临床相关性。我们会调查的 下游事件的影响，如Akt、mTOR和elF4E的激活，因为它们参与 肉瘤发生与STS进展。此外，我们正在建立小鼠模型，以确定 Rb、P53和Pten的失活是肉瘤发生和发展所必需的。我们的 主要目标包括：i)评估Rb、P53和PTEN之间的功能串扰的基础 肿瘤抑制的途径；以及ii)将基础和医学研究成果转化为临床应用 学习。我们的最终翻译目标是在临床实践中通过将 生物标志物作为强有力的决策工具，更好地指导STS患者的管理。

It is our working hypothesis that mutations and altered expression of RB, p53, and PTEN, or those affecting regulatory genes involved in these pathways, produce a selective advantage for tumor growth and aggressive behavior in patients with soft tissue sarcomas (STS). This hypothesis will be tested by an integrated approach, analyzing human tumor samples and conducting genetic studies that include generation of in vitro and in vivo models. Aim 1. To define the clinical and biological implications of RB inactivation for proliferation and genomic stability in STS. We will characterize RB mutations, altered patterns of pRB and E2F1 expression, as well as upstream regulators (cyclin D, Cdk4). We will also assess Mad2 expression, an E2F1 transcriptional target that when deregulated causes chromosome instability and aneuploidy. We will assess the consequences of RB inactivation, identifying up- and down-regulated targets by high throughput studies. Aim 2. To characterize molecular alterations affecting the p53 pro-apoptotic response and define their clinical significance in STS. We will conduct a systematic characterization of TP53 mutations and p53 expression using a combination of methods. We will analyze regulatory events of the p53 pathway, focusing on Hdm2 and p14/Arf expression. We will study p53 apoptotic signaling, centering on Bax and Bcl-2, PUMA and NOXA, defining their impact on tumor progression and lack of response to particular treatments. The mechanistic consequences of p53 inactivation will be evaluated using functional assays. Aim 3. To determine the molecular mechanisms of tumor suppression by the Pten pathway in STS. We will establish the clinical relevance of detecting PTEN mutations and altered Pten expression. We will investigate the impact of downstream events, such as activation of Akt, mTOR and elF4E, as they participate in sarcomagenesis and STS progression. In addition, we are generating murine models to determine whether inactivation of Rb, p53 and Pten are required and cooperate for sarcoma development and progression. Our main objectives include: i) to assess the basis of the functional crosstalk between RB, p53, and PTEN pathways in tumor suppression; and ii) to translate basic and medical research findings into clinically applied studies. Our final translational goal is to produce a paradigm shift in clinical practice by incorporating biomarkers as robust decision tools to better guide the management of STS patients.