Identifying lincRNAs that Mediate PI 3 Kinase Dependent Breast Cancer

PI 3-K信号轴在包括乳腺癌在内的许多癌症的发生和发展过程中都起着至关重要的作用 癌症，通过促进癌细胞的存活和生长。PIK3CA基因的体细胞致癌突变 编码PI3-K的催化亚单位，在很大比例的癌症患者中观察到。很多事情都是众所周知的 关于PI3-K通路在信号和信号水平促进肿瘤的机制 转录机制。然而，目前还没有关于大基因间隔区功能重要性的信息 非编码RNA(LincRNA)在调节与恶性肿瘤相关的PIK3CA表型中的作用这是一项新的 应用程序响应关于“识别用于癌症早期检测的非编码RNA目标”的FOA。vbl.使用 两种不同的计算和实验方法，我们已经确定了一组核心的lincRNAs，它们是 乳腺癌临床标本中PIK3CA的激活。这是第一次 PI3-K通路激活和lincRNAs之间的任何已知联系。我们发现了lincRNAs的一个子集 其在乳腺癌细胞系中的表达受PI 3-K的直接调控，并与PIK3CA相关 乳腺肿瘤中的基因签名。这一发现为这一提议奠定了基础，其假设是 在乳腺癌细胞和组织中，lincRNAs由致癌的PIK3CA调控，而这些 在体内外，lincRNAs均能促进PIK3CA介导的细胞转化。 在目标1中，我们建议验证和鉴定其表达受PIK3CA调控的lincRNAs 乳腺癌细胞和组织。我们将确定乳腺癌中与PIK3CA突变相关的lincRNAs 作为TCGA的一部分进行了全面的分子图谱分析，并将这些与 从我们的实验筛选中，我们已经从表达致癌PIK3CA的乳腺上皮细胞中鉴定出，AS 以及从与PIK3CA基因相关的乳腺肿瘤数据集计算注释的那些 签名。我们已经制定了优先排序策略，并将验证和描述其 PIK3CA显著正向和负向调控基因的表达。我们将评估lincRNA的表达 在含有致癌PIK3CA突变的乳腺癌细胞系中。在目标2中，我们将确定 在我们的初始筛查中发现的lincRNA和从Aim 1中出现的lincRNA对表型的贡献 相关的依赖PIK3CA的恶性肿瘤。我们将在含有致癌基因的细胞中敲除特定的lincRNA PIK3CA，并测定其对细胞转化和生长的锚定独立性的影响。 我们将利用原位技术评估乳腺癌组织芯片中lincRNA的表达。 杂交探针，并评价lincRNAs在促进体内肿瘤生长中的需求 异种移植物。最终，我们的研究将提供新的分子见解，将PIK3CA癌症表型与 LincRNAs，从而为将lincRNAs作为一种新的肿瘤发生机制提供了理论基础 癌症。他们还将倡导使用特定的lincRNAs作为早期癌症检测的新生物标记物。

The PI 3-K signaling axis is critical for both the initiation and progression of many cancers, including breast cancer, by promoting cancer cell survival and growth. Somatic oncogenic mutations in PIK3CA, the gene that encodes the catalytic subunit of PI 3-K, are observed in a large proportion of cancer patients. Much is known concerning the mechanisms by which the PI 3-K pathway promotes malignancy at the level of signaling and transcriptional mechanisms. However, there is no information on the functional importance of large intergenic non-coding RNAs (lincRNA) in mediating PIK3CA phenotypes associated with malignancy. This new application responds to the FOA on 'Identifying Non-coding RNA targets for Early Detection of Cancer'. Using two distinct computational and experimental approaches, we have identified a core set of lincRNAs that are associated with PIK3CA activation in human breast cancer clinical samples. This represents for the first time any identified link between PI 3-K pathway activation and lincRNAs. We have discovered a subset of lincRNAs whose expression is directly regulated by PI 3-K in breast cancer cell lines, and also associated with a PIK3CA gene signature in breast tumors. This finding formulates the basis for this proposal with the hypothesis that lincRNAs are regulated by oncogenic PIK3CA in breast cancer cells and tissues, and that in turn these lincRNAs promote PIK3CA-mediated cellular transformation both in vitro and in vivo. In Aim 1, we propose to validate and characterize lincRNAs whose expression is regulated by PIK3CA in breast cancer cells and tissues. We will identify lincRNAs associated with PIK3CA mutation in breast cancers that underwent comprehensive molecular profiling as part of TCGA, and compare these with the lincRNAs that we have identified from our experimental screen from breast epithelial cells expressing oncogenic PIK3CA, as well as those computationally annotated from a breast tumor data set associated with a PIK3CA gene signature. We have devised a prioritization strategy and will validate and characterize lincRNAs whose expression is significantly positively and negatively regulated by PIK3CA. We will evaluate lincRNA expression in breast cancer cell lines that harbor oncogenic PIK3CA mutations. In Aim 2, we will determine the contribution of lincRNAs identified in our initial screens and those emerging from Aim 1 to phenotypes associated PIK3CA-dependent malignancy. We will knock down specific lincRNAs in cells harboring oncogenic PIK3CA and determine the consequence on cellular transformation and anchorage independence of growth. We will evaluate lincRNA expression in tissue microarrays from breast cancer samples using in situ hybridization probes, and evaluate the requirement of lincRNAs in promoting tumor growth in vivo using xenografts. Ultimately, our studies will provide new molecular insights linking PIK3CA cancer phenotypes to lincRNAs and thus provide a rationale for the inclusion of lincRNAs as a novel mechanism of tumorigenesis in cancer. They will also advocate for the use of specific lincRNAs as novel biomarkers for early cancer detection.