DAP5-dependent translational control and breast cancer metastasis

肿瘤的发生、发展、侵袭和转移都与选择性mRNA有关 但是致癌翻译发生的大部分理解仍有待表征。 我们最近发现了一种新的帽依赖性mRNA翻译机制，建立了一种新的范式 对于翻译调控，因为它是帽依赖性的，但不涉及典型的前起始机制。 我们发现，约20%的使用eIF 4 E/eIF 4GI的mRNA不需要典型的eIF 4 E/eIF 4GI因子。 翻译起始复合物称为DAP 5/eIF 3d，其利用翻译的帽结合活性 起始因子eIF 3d而不是eIF 4 E和eIF 4GI同源物，DAP 5。我们发现DAP 5/eIF 3d对于 乳腺癌转移的动物模型，并与人类乳腺癌转移密切相关。这里 我们建议研究DAP 5/eIF 3d介导的mRNA翻译在乳腺癌发展中的作用， 转移我们将确定DAP 5/eIF 3d介导的mRNA翻译在肿瘤发展中的作用， 侵袭和转移，使用同基因小鼠乳腺癌模型，人异种移植乳腺 癌细胞系模型和异质患者来源的异种移植物模型，后两种模型进行了 在免疫受损的小鼠中。我们将描述DAP 5/eIF 3d与eIF 4GI/eIF 4 E启动的要求 癌细胞上皮间质转化（EMT）、间质组织浸润、血管生成、 内渗、外渗、迁移，防止由细胞脱离和迁移引起的凋亡， 和殖民化。其他研究将通过全基因组转录组学和翻译组学分析来表征， 与mRNA相比，由DAP 5/eIF 3d选择性翻译并为转移进展所需的mRNA 在动物模型中由eIF 4 E/eIF 4GI翻译。这些研究将进一步加深我们对DAP 5作用的理解。 选择性mRNA翻译驱动参与转移性肿瘤进展的特定致癌途径。我们 还将测试特异性DAP 5 mRNA翻译靶点在DAP 5介导的转移性肿瘤中的重要性。 进展最后，将进行研究以了解DAP 5/eIF 3d介导的细胞凋亡的机制。 选择性mRNA翻译研究将集中在通过甲基化修饰mRNA的特定形式的作用 我们称之为m6 A，因为我们已经找到了强有力的初步数据来支持它的重要性。

Cancer development, tumor formation, progression, invasion and metastasis all involve selective mRNA translation but much of the understanding by which oncogenic translation occurs remains to be characterized. We recently discovered a new mechanism of cap-dependent mRNA translation that established a new paradigm for translational regulation, in that it is cap-dependent but does not involve the canonical pre-initiation machinery. We showed that the canonical eIF4E/eIF4GIfactors are not required for approximately 20% of mRNAs that use the translation initiation complex known as DAP5/eIF3d, which utilizes the cap binding activity of translation initiation factor eIF3d rather than eIF4E and eIF4GI homolog, DAP5. We found that DAP5/eIF3d is essential for breast cancer metastasis in animal models and strongly associated with human breast cancer metastasis. Here we propose to study the role of DAP5/eIF3d-mediated mRNA translation in breast cancer development and metastasis. We will determine the roles of DAP5/eIF3d-mediated mRNA translation in tumor development, invasion and metastasis, using syngeneic mouse mammary cancer models, human xenotransplant breast cancer cell line models and a heterogeneous patient derived xenograft model, the latter two models carried out in immune impaired mice. We will characterize the requirement for DAP5/eIF3d versus eIF4GI/eIF4E initiation of translation on cancer cell epithelial to mesenchymal transition (EMT), stromal tissue invasion, vascular intravasation, extravasation, migration, prevention of apoptosis resulting from cell detachment and migration, and colonization. Other studies will characterize by genome-wide trancriptomic and translatomic analyses the mRNAs selectively translated by DAP5/eIF3d and required for progression to metastasis, compared to mRNAs translated by eIF4E/eIF4GI in animal models. These studies will further our understanding of the role of DAP5- selective mRNA translation in driving specific oncogenic pathways involved in metastatic tumor progression. We will also test the importance of specific DAP5 mRNA translation targets in DAP5-mediated metastatic tumor progression. Finally, studies will be carried out to understand the mechanism(s) for DAP5/eIF3d-mediated selective mRNA translation. Studies will focus on the role of a specific form of mRNA modification by methylation known as m6A because we have found strong preliminary data in support of its importance.