POSTTRANSCRIPTIONAL REGULATION OF TRANSFORMING GROWTH FACTOR-BETA 1

转化生长因子-BETA 1 的转录后调控

• 批准号: 3838365
• 负责人: L M WAKEFIELD
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3838365
• 关键词: MCF7 cell; cell type; complementary DNA; gene induction /repression; genetic manipulation; genetic regulation; genetic translation; hormone regulation /control mechanism; human tissue; messenger RNA; pharmacogenetics; polysomes; posttranscriptional RNA processing; protein biosynthesis; retinoids; steroid hormone; tamoxifen; tissue /cell culture; transfection; transforming growth factors; vitamin analog

In many cell types there is a large discrepancy between the measured levels of TGF-Beta 1 mRNA and protein. Furthermore, many members of the steroid hormone superfamily, including the clinically significant antiestrogens and certain novel synthetic progestins, appear to increase TGF-Beta 1 protein production without any concomitant change in mRNA levels. This suggests that translational or post-translational mechanisms may play an important role in the regulation of TGF-Beta 1 production. We have performed polysome analyses on a number of cell types and have shown that both the initial recruitment and subsequent translation of the TGF- Beta 1 mRNA may be inefficient. In certain cells such as the breast adenocarcinoma line MCF-7, there is evidence that a low abundance of small TGF-Beta 1 mRNA transcript may be preferentially translated. To investigate these phenomena further, expression constructs have been made in which various portions of the 5' and 3' UTRs of the TGF-Beta 1 cDNA have been deleted. These constructs are being used for in vitro transcription/translation and in the generation of stable trans- fectants, in order to identify regions of the TGF-Beta 1 mRNA that are responsible for the translational regulation, particularly in response to steroid hormone superfamily members. Preliminary experiments indicate that the 3' UTR may be critical for efficient mRNA translation. The production of TGF-Beta 1 by cell lines in vitro in response to steroid hormones varies dramatically with culture conditions. The methodology is being developed to allow measurement of circulating TGF-Betas in the plasma of human subjects with breast cancer, before and after treatment with the antiestrogen tamoxifen and a synthetic retinoid, to determine whether TGF- Betas are induced by these agents in vivo as well as in vitro. An understanding of the mechanisms whereby steroids and related compounds regulate the production of the TGF-Beta family of growth inhibitors may allow the rational design of more potent pharmacological agents for use in chemoprevention or chemotherapy of cancer.

在许多细胞类型中，所测量的 TGF-β 1 mRNA和蛋白水平。 此外，许多成员国 类固醇激素超家族，包括具有临床意义的 抗雌激素和某些新的合成孕激素，似乎增加 TGF-β 1蛋白产生，而mRNA无任何伴随变化 程度. 这表明，翻译或翻译后机制 可能在调节TGF-β 1的产生中起重要作用。 我们 已经对许多细胞类型进行了多核糖体分析， 无论是最初的招聘和随后的翻译的TGF- β 1 mRNA可能是低效的。 在某些细胞中，如乳腺 腺癌细胞系MCF-7，有证据表明，低丰度的小 TGF-β 1 mRNA转录物可能优先翻译。 到 进一步研究这些现象，已经制备了表达构建体， 其中TGF-β 1 cDNA的5 ′和3 ′ UTR的不同部分 已被删除。 这些构建体被用于体外 转录/翻译和稳定转染子的产生中， 为了确定TGF-β 1 mRNA的区域， 对于翻译调节，特别是对类固醇的反应， 激素超家族成员。 初步实验表明，3' UTR可能是高效mRNA翻译的关键。 生产 TGF-β 1通过细胞系在体外对类固醇激素的反应而变化 与培养条件有很大关系。 正在制定方法 以允许测量人血浆中的循环TGF-β 乳腺癌受试者，在用 抗雌激素他莫昔芬和合成类维生素A，以确定是否TGF- 这些试剂在体内和体外诱导β。 一个 了解类固醇和相关化合物 调节TGF-β家族生长抑制剂的产生， 允许合理设计更有效的药理学试剂用于 癌症的化学预防或化学疗法。