Elucidating the role of RNA splicing in the metastatic seeding and outgrowth of aggressive cancers.

项目摘要/摘要 转移是指播散性肿瘤细胞向远端组织和器官扩散的过程。 是癌症相关死亡的主要原因。为了完成转移级联，DTC必须能够 侵袭远端部位，启动肿瘤生长、增殖，并促进肿瘤微环境(TME)逃避 免疫监测和促进血管生成。阐明这些转移的新机制 DTC的表型可以确定转移的关键驱动因素，以及潜在的治疗脆弱性 可以更好地针对转移性肿瘤。我的论文研究集中在阐明以下机制： LncRNA Borg(BMP/OP反应基因)驱动乳腺癌(BC)转移。我的研究确定了 转移性BC细胞依赖Borg与E3相扑连接酶TRIM28的络合诱导乳房 肿瘤干细胞(BCSCs)在体外和体内都有扩增和自我更新的能力。这项工作将博格确立为 BCSCs的一个新的驱动因素，因此增加了我们对驱动积累的机制的理解 这些恶性细胞群中。我最近的初步数据表明Borg：TRIM28复合体 下调BC细胞中剪接因子的表达，从而影响BCSC的表型。有趣的是， 越来越多的证据表明，RNA剪接的失调，一种可以控制的复杂分子工具 细胞表型通过转录调控机制，促进多种肿瘤的发生 表型甚至转移复发。因此，在这项建议的F99部分，我要求澄清 Borg：TRIM28复合体失调RNA剪接操纵子驱动肿瘤转移和转移的机制 BC的BCSC表型。为了在我的论文中完成这项研究，我将(I)确定哪种剪接 Borg调控因子：TRIM28复合体在体外和体内驱动BC的转移表型，以及 (Ii)使用RNAseq和随后的验证来确定受 这些剪接因子的子集在表达Borg的细胞中。这项工作将确定RNA的新机制 剪接调控在BC细胞的转移表型中起关键作用。在本提案的K00阶段， 我计划与我的博士后导师密切合作，阐明RNA剪接在其中的作用机制 肿瘤细胞与TME的串扰，以促进免疫逃避和随后的转移生长。 具体地说，我计划阐明(I)肿瘤细胞中的选择性剪接如何驱动转移性TME的变化 促进免疫逃避，以及(Ii)替代剪接如何改变TME细胞，如T细胞和成纤维细胞， 有助于转移的生态位和随后的转移生长。我的当前和未来目标 研究旨在阐明失调的RNA剪接促进转移播种和转移的机制。 在侵袭性癌症中生长。我的博士后和博士后研究将为我提供专业知识 RNA剪接在癌症转移中的作用，并为我提供了必要的研究和专业技能 让我在一家领先的研究机构开始我的独立研究生涯。

Project Summary/Abstract Metastasis is the process in which disseminated tumor cells (DTCs) spread to distal tissues and organs, and it is the leading cause of cancer-related deaths. In order to complete the metastatic cascade, DTCs must be able to invade distal sites, initiate tumor growth, proliferate, and promote a tumor microenvironment (TME) to evade immune surveillance and promote angiogenesis. Elucidating novel mechanisms that underlie these metastatic phenotypes in DTCs can identify key drivers of metastasis, as well as potential therapeutic vulnerabilities which can better target metastatic tumors. My dissertation research focuses on elucidating the mechanisms in which the lncRNA BORG (BMP/OP-Responsive Gene) drives breast cancer (BC) metastasis. My studies determined that metastatic BC cells are reliant upon BORG complexing with E3 SUMO ligase TRIM28 to induce breast cancer stem cells (BCSCs) to expand and self-renew both in vitro and in vivo. This work establishes BORG as a novel driver of BCSCs, and therefore increases our understanding of the mechanisms driving the accumulation of these malignant cell populations. My recent preliminary data suggests BORG:TRIM28 complexes downregulate the expression of splicing factors in BC cells, which contributes to BCSC phenotypes. Interestingly, accumulating evidence indicates that dysregulation of RNA splicing, a complex molecular tool that can control cellular phenotypes through transcriptomic regulatory mechanisms, contributes to a variety of tumorigenic phenotypes and even metastatic relapse. Therefore, during the F99 portion of this proposal, I seek to elucidate the mechanism whereby BORG:TRIM28 complexes dysregulate RNA splicing operant in driving metastatic and BCSC phenotypes in BC. To complete this research during my dissertation, I will (i) determine which splicing factors dysregulated by BORG:TRIM28 complexes drive metastatic phenotypes in BC in vitro and in vivo, and (ii) use RNAseq and subsequent validation to determine the specific alternative splicing events affected by a subset of these splicing factors in BORG-expressing cells. This work will identify novel mechanisms of RNA splicing regulation that play key roles in metastatic phenotypes of BC cells. During the K00 phase of this proposal, I plan to work closely with my postdoctoral mentor to elucidate the mechanisms in which RNA splicing contributes to tumor cell crosstalk with the TME to promote immune evasion and subsequent metastatic outgrowth. Specifically, I plan to elucidate (i) how alternative splicing in tumor cells drive changes in the metastatic TME to promote immune evasion, and (ii) how alternative splicing changes in TME cells, such as T cells and fibroblasts, contribute to the metastatic niche and subsequent metastatic outgrowth. The current and future goals of my research are to elucidate mechanisms in which dysregulated RNA splicing contributes to metastatic seeding and outgrowth in aggressive cancers. My predoctoral and postdoctoral research will provide me with expertise in the role of RNA splicing in cancer metastasis, and provide me with essential research and professional skills to launch me into my independent research career at a leading research institute.