Deciphering the functional role of recurrent PPP2R1A mutations on endometrial metastasis

破译PPP2R1A复发突变对子宫内膜转移的功能作用

基本信息

批准号：
10601651
负责人：
Terrance James Haanen
金额：
$ 4.08万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10601651
关键词：
3-Dimensional Biogenesis CRISPR/Cas technology Cancer Cell Growth Cancer cell line Carcinoma Cell Line Cell secretion Cells Cessation of life Communication Complement Complex Coupled Data Development Diagnosis Disease Disease Progression Distant Dominant-Negative Mutation Dose Limiting Endometrial Family Genes Genetic Transcription Greater sac of peritoneum Heterozygote Holoenzymes Immunocompromised Host Impairment In Vitro Injections Invaded Investigation Knock-in Ligands Link Luciferases Malignant Epithelial Cell Malignant Neoplasms Mediating Modeling Molecular Mus Mutation Nature Neoplasm Metastasis Nodule Pathway interactions Patients Phenotype Phosphoric Monoester Hydrolases Phosphorylation Process Protein Subunits Protein phosphatase Proteins Recurrence Regulation Role Serine Serous Signal Pathway Signal Transduction Site Testing Threonine Transfection Transforming Growth Factor beta Tumor Promotion Tumor Subtype Tumor Suppressor Proteins Tumorigenicity United States Uterine Cancer Uterine Corpus Carcinosarcoma Uterine Neoplasms Uterus WNT Signaling Pathway Work Xenograft Model beta catenin cancer cell cancer type disorder subtype effective therapy enhancing factor gain of function in vivo intraperitoneal leiomyosarcoma mutant neoplastic cell neutralizing antibody new therapeutic target notch protein overexpression permissiveness scaffold small hairpin RNA tumor tumor initiation tumor microenvironment tumorigenesis tumorigenic

项目摘要

Project Summary: Uterine serous carcinomas (USC), uterine carcinosarcomas (UCS), and leiomyosarcomas represent the most aggressive subtypes of uterine cancer and account for a disproportionate number of uterine cancer related deaths in the United States. The lethality of these high-grade uterine cancers is largely due to the propensity of these cancers to disseminate and metastasize, leaving patients with a lack of effective treatment options. Despite this, the molecular drivers of the metastatic potential of these disease subtypes remain incompletely understood. Previous work by our group and others have identified a recurrent mutational hotspot within the gene encoding for the A scaffolding subunit of the protein phosphatase 2A (PP2A), PPP2R1A. These mutations, P179R and S256F, occur exclusively within these high-grade subtypes of uterine cancer and are not found in any other cancer type. Protein phosphatase 2A (PP2A), is a family of serine/threonine phosphatases, where the active heterotrimeric form is comprised of the catalytic (C) subunit, the scaffolding (A) subunit, and a substrate directing regulatory (B) subunit. In aggregate, PP2A is considered a tumor suppressor protein, but certain heterotrimers have tumor promoting roles. We have shown that these mutations contribute to uterine cancer tumorigenesis by modulating PP2A function in a manner that impairs the formation of tumor suppressive heterotrimers, while leaving tumor promoting heterotrimeric complexes intact. My preliminary data show that the PP2A P179R and S256F mutations enhance tumor initiating capacity, and the ability to form 3D tumor spheres in vitro. Importantly, uterine cancer cells expressing these mutations also form intraperitoneal nodules at an increased rate in vivo, suggesting that these mutations may enhance the establishment of new tumor formation in the peritoneal cavity. Conditioned media from the mutant expressing uterine cancer cells promoted tumor sphere formation of WT expressing uterine cancer cell growth, indicating that the mutant cells may create a more permissive tumor microenvironment for tumor formation. Preliminary data suggests that the mutant cells have increased -catenin phosphorylation and WNT ligand expression. The working hypothesis of this proposal is that the recurrent mutants, P179R and S256F, enhance uterine cancer metastasis through increased WNT signaling and secretion of WNT ligands. To test this hypothesis, we will develop PP2A A knock-in xenograft models to determine how these recurrent mutants contribute to enhanced metastasis in vivo (Specific Aim 1). Second, mechanistic studies will explore the secreted factors from the mutant uterine cancer cells, exploring WNT ligands, coupled with secretome analysis. These studies will also explore the link between loss of PP2A and WNT mediated EMT (Specific Aim 2). This proposal aims to decipher the functional role of recurrent PP2A A𝛼 mutations on uterine cancer metastasis, which may identify a new therapeutic target(s) of high-grade uterine cancers.

项目摘要：子宫浆液性癌 (USC)、子宫癌肉瘤 (UCS) 和平滑肌肉瘤代表子宫癌最具侵袭性的亚型，并占子宫癌数量不成比例的在美国，这些高级别子宫癌的致死率主要是由于癌症相关的死亡。这些癌症有扩散和转移的倾向，导致患者缺乏有效的治疗尽管如此，这些疾病亚型转移潜力的分子驱动因素仍然存在。不完全理解。我们小组和其他人之前的工作已经确定了该基因内的一个反复发生的突变热点编码蛋白磷酸酶 2A (PP2A) 的 A 支架亚基，PPP2R1A。 P179R 和 S256F 仅出现在子宫癌的这些高级亚型中，并且在任何其他癌症类型。蛋白磷酸酶 2A (PP2A) 是丝氨酸/苏氨酸磷酸酶家族，其中活性异三聚体形式由催化 (C) 亚基、支架 (A) 亚基和底物组成总体而言，PP2A 被认为是一种肿瘤抑制蛋白，但也确实如此。我们已经证明这些突变会导致子宫癌。通过调节 PP2A 功能以损害肿瘤抑制细胞的形成来促进肿瘤发生异三聚体，同时保持促进异三聚体复合物完整的肿瘤。我的初步数据显示PP2A P179R和S256F突变增强了肿瘤启动能力，以及在体外形成 3D 肿瘤球的能力，重要的是，子宫癌细胞表达这些突变。在体内形成腹膜内结节的速度也增加，表明这些突变可能增强腹膜腔中新肿瘤形成的建立来自突变体表达的条件培养基。子宫癌细胞促进表达WT的子宫癌细胞生长的肿瘤球形成，表明突变细胞可能为肿瘤的初步形成创造了更宽松的肿瘤微环境。数据表明突变细胞的 β-连环蛋白磷酸化和 WNT 配体表达增加。该提案的工作假设是，反复突变体 P179R 和 S256F 增强子宫通过增加 WNT 信号传导和 WNT 配体分泌来促进癌症转移为了验证这一假设，我们进行了实验。将开发 PP2A A 敲入异种移植模型，以确定这些复发突变体如何促进增强体内转移（具体目标 1）。其次，机制研究将探索分泌因子。这些研究还将研究突变子宫癌细胞、探索 WNT 配体以及分泌蛋白组分析。探索 PP2A 丢失和 WNT 介导的 EMT 之间的联系（具体目标 2）。复发性 PP2A A𝛼 突变对子宫癌转移的功能作用，这可能会识别出新的高级别子宫癌的治疗靶点。