SIRT1 Regulates RNA Stability to Promote Breast Cancer

项目摘要 乳腺癌每年造成60多万妇女死亡。因此，有一个过度- 骑马需要更好地了解促进乳腺癌的机制，因为这些信息可能会 导致治疗这种疾病的新策略。最近，Cerione实验室发现了一种机制， 高度侵袭性形式的乳腺癌细胞产生含有促进癌细胞增殖的因子的分泌组， 存活和转移扩散。具体来说，研究人员表明，NAD +- 依赖性脱乙酰酶Sirtuin 1（SIRT 1）增加外泌体的形成和释放，外泌体是一类特定的 细胞外囊泡（EV），其来源于内吞/溶酶体内的多囊泡体（MVB） 贩运途径。这种效应是由于RNA结合蛋白IGF2BP2的乙酰化增加， 结合到编码ATP 6V1A的转录物的3 '非翻译区，ATP 6V1A是液泡膜的主要催化亚基。 ATP酶（v-ATP酶），维持溶酶体的适当pH和活性。乙酰化IGF2BP2招募了一个 外切核酸酶XRN2，其降解ATP 6V1A转录物，导致溶酶体活性受损。因此，在本发明中， 否则将被靶向并在溶酶体中降解的MVB被引导至细胞表面， 它们与质膜融合并释放它们的内容物，即，富含独特货物的外泌体， 可溶性水解酶，进入细胞外空间。分泌蛋白的这些组成部分被证明起作用 共同强烈促进乳腺癌细胞的侵袭力。是否有额外的记录 然后确定与ATP 6V1A转录物类似地由SIRT 1和IGF2BP 2调节。基于 在进行的全面RNA测序分析中，鉴定了14种转录本;其中4种， 编码可能在乳腺癌进展和/或外来体生物发生中起重要作用的蛋白质。 对于本申请的F99阶段，我计划确定这些成绩单的稳定性确实受到监管 通过SIRT1和IGF2BP2，并研究其水平的变化如何影响乳腺癌进展（Aim 1）。除了SIRT1在乳腺癌中发挥的肿瘤抑制作用外，其表达的减少也会导致乳腺癌的发生。 也与衰老密切相关，衰老是患癌症和其他疾病的主要风险因素。在 K00阶段的这个建议，我想调查衰老和癌症之间的相互作用。已经 最近表明，老化/衰老细胞的积累导致分泌组的产生， 增加癌细胞的生长。作为一名博士后实习生，我的计划是确定电动汽车 从老化/衰老细胞中提取的蛋白质有助于这种效果。此外，我亦有兴趣探讨 从癌细胞分泌的EV使细胞能够逃避衰老（Aim 2）。最终， 这项研究旨在了解衰老与癌症之间的关系，以帮助确定潜在的治疗方法。 为患者治疗。

Project Summary Breast cancer is responsible for the deaths of more than 600,000 women each year. Thus, there is an over- riding need to better understand the mechanisms that promote breast cancer, as this information can potentially lead to new strategies to treat the disease. Recently, the Cerione lab discovered a mechanism through which highly aggressive forms of breast cancer cells produce a secretome containing factors that promote cancer cell survival and metastatic spread. Specifically, the researchers showed that the decreased expression of the NAD+- dependent deacetylase Sirtuin 1 (SIRT1) increases the formation and release of exosomes, a specific class of extracellular vesicles (EVs) that are derived from multi-vesicular bodies (MVBs) within the endocytic/lysosomal trafficking pathway. This effect was due to the increased acetylation of the RNA binding protein, IGF2BP2, that binds to the 3' untranslated region of the transcript encoding ATP6V1A, a major catalytic subunit of the vacuolar ATPase (v-ATPase) that maintains the proper pH and activity of lysosomes. Acetylated IGF2BP2 recruits an exonuclease, XRN2, which degrades the ATP6V1A transcript, resulting in impaired lysosomal activity. Thus, MVBs that would otherwise be targeted and degraded in lysosomes are instead directed to the cell surface where they fuse with the plasma membrane and release their contents, i.e., exosomes enriched in unique cargo and soluble hydrolases, into the extracellular space. These components of the secretome were shown to work together to strongly promote the invasiveness of breast cancer cells. Whether there were additional transcripts that were regulated similarly to the ATP6V1A transcripts by SIRT1 and IGF2BP2 were then determined. Based on a comprehensive RNA sequencing analysis performed, fourteen transcripts were identified; four of which encode proteins that potentially play important roles in breast cancer progression and/or exosome biogenesis. For the F99 phase of this application, I plan to establish that the stability of these transcripts is indeed regulated by SIRT1 and IGF2BP2, and to investigate how changes in their levels impact breast cancer progression (Aim 1). In addition to the tumor suppressor role played by SIRT1 in breast cancer, reductions in its expression have also been heavily implicated in aging, a major risk factor for developing cancer, as well as other diseases. In the K00 phase of this proposal, I would like to investigate the interplay between aging and cancer. It has been recently shown that the accumulation of aged/senescent cells results in the production of a secretome that can increase the growth of cancer cells. My plan as a Post-doctoral trainee will be to determine whether the EVs from aged/senescent cells contribute to this effect. Furthermore, I am also interested in exploring whether the EVs secreted from cancer cells enable cells to evade undergoing senescence (Aim 2). Ultimately, the goal of this study is to understand the relationship between aging and cancer to help identify potential therapeutic treatment for patients.