Targeting Tumor Initiating Cell in Undifferentiated Pleomorphic Sarcoma

靶向未分化多形性肉瘤中的肿瘤起始细胞

• 批准号: 9319633
• 负责人: Benjamin Aaron Alman
• 金额: $ 43.56万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9319633
• 关键词: Ablation; Adenoviruses; Aftercare; Alleles; Allografting; Alpha Cell; Antibodies; Automobile Driving; Biological Assay; CSPG4 gene; Cell Fraction; Cell surface; Cells; Characteristics; Chondroitin Sulfate Proteoglycan; Color; Data; Development; Diphtheria Toxin; Disease; Enterobacteria phage P1 Cre recombinase; Erinaceidae; Exhibits; Experimental Models; FLP recombinase; Gene Expression; Genetic Recombination; Growth; Human; Immune; Immunodeficient Mouse; Immunotherapy; In Situ; Individual; Infection; Intramuscular Injections; Label; Malignant Fibrous Histiocytoma; Mediating; Molecular Profiling; Mus; Mutant Strains Mice; Mutation; Neoplasm Metastasis; Oncogenes; Oncogenic; Outcome; Patients; Population; Proteins; Radiosurgery; Recurrence; Resistance; Role; Side; Signal Pathway; Soft tissue sarcoma; Stable Populations; TP53 gene; Tamoxifen; Testing; Time; Transgenic Mice; Transplantation; Tumor Initiators; Undifferentiated; Work; Xenograft procedure; base; chemotherapy; conventional therapy; daughter cell; effective therapy; innovation; insight; knock-down; mouse Cre recombinase; mouse model; neoplastic cell; notch protein; novel; novel strategies; novel therapeutic intervention; outcome forecast; prevent; public health relevance; sarcoma; self-renewal; small hairpin RNA; therapeutic target; tumor; tumor eradication; tumor growth; tumor progression

DESCRIPTION (provided by applicant): Undifferentiated pleomorphic sarcoma (UPS) is a soft tissue sarcoma, with one of the worst prognosis. We will build on our discovery that UPS contains a small subpopulation of tumor initiating cells (TICs) that are enhanced for the ability t form tumors when transplanted into immune-deficient mice. Our proof of principle data showed that therapeutically targeting signaling pathways activated in the TIC population inhibits growth in UPS tumors established as xenografts in mice. In our preliminary data, we identified the chondroitin sulfate proteoglycan, NG2, as expressed in the TIC subpopulation in human and mouse UPS tumors. Our hypothesis is that the TIC fraction in UPS is responsible for maintaining UPS self-renewal and tumor growth, and that therapeutically targeting the TIC fraction can be developed into an effective UPS treatment. We will test this hypothesis by answering the following questions: 1) Will the eradication of TICs cause the degeneration of UPS? We found that deletion of Ng2 expressing cells in mouse UPS tumors, by driving Diphtheria Toxin in tumors established as allografts, will cause degeneration of tumors. Using flippase to activate oncogenic alleles to drive UPS development in mice, and cre-recombinase to drive Diphtheria Toxin in Ng2 expressing, we will be able to delete the TIC population in tumors in-situ, and determine if this causes degeneration of UPS tumors, prevents recurrence, or inhibits metastatic capacity. 2) Are individual clones within the Ng2 expressing population stable over time and resistant to conventional therapies? Ng2 expressing cells could be composed of cells that survive long term in tumors, giving rise to daughter cells that maintain the tumor over time; or they may represent different cells, each having TIC characteristics at different points in time. To determine which is the case, we will use the Confetti allele to label Ng2 expressing cells in mouse UPS tumors with different colored fluorescent proteins labeling individual clones. How these cell populations behave as the tumors grow, with serial transplantation, and after treatment using conventional therapies will determine which one of these possibilities is the case. 3) Can targeting NG2 be used to treat UPS? To determine how targeting Ng2 expression regulates tumor growth and self-renewal, NG2 will be knocked-down with shRNA in human UPS tumors established as xenografts in immunodeficient mice and NG2 will be deleted in primary mouse UPS tumors initiated by Cre recombinase that drives expression of oncogenes and recombines conditional Ng2 null alleles. Immunotherapy to NG2 will be examined in a similar manner in UPS tumors established as xenografts in immunodeficient mice. In addition to proving important biologic insight into sarcomas, these data will determine if short or long term therapeutic targeting of the TIC population will be more effective in UPS treatment, and inform a novel approach to develop a therapy based on targeting the UPS TIC.

描述（由申请人提供）：未分化多形性肉瘤（UPS）是一种软组织肉瘤，是预后最差的一种。我们将基于我们的发现，即 UPS 含有一小部分肿瘤起始细胞 (TIC)，当移植到免疫缺陷小鼠体内时，这些细胞形成肿瘤的能力得到增强。我们的原理数据证明表明，治疗性靶向在 TIC 群体中激活的信号通路可抑制在小鼠异种移植物中建立的 UPS 肿瘤的生长。在我们的初步数据中，我们鉴定了硫酸软骨素蛋白多糖 NG2，它在人类和小鼠 UPS 肿瘤的 TIC 亚群中表达。我们的假设是，UPS 中的 TIC 部分负责维持 UPS 自我更新和肿瘤生长，并且针对 TIC 部分的治疗可以开发为有效的 UPS 治疗。我们将通过回答以下问题来检验这一假设： 1）消灭 TIC 是否会导致 UPS 退化？我们发现，在小鼠UPS肿瘤中删除Ng2表达细胞，通过在同种异体移植物建立的肿瘤中驱动白喉毒素，将导致肿瘤退化。使用翻转酶激活致癌等位基因以驱动小鼠中的UPS发育，并使用cre重组酶来驱动Ng2表达中的白喉毒素，我们将能够原位删除肿瘤中的TIC群体，并确定这是否会导致UPS肿瘤的退化，防止复发或抑制转移能力。 2) Ng2 表达群体中的各个克隆是否随时间稳定并且对常规疗法具有抵抗力？表达 Ng2 的细胞可能由在肿瘤中长期存活的细胞组成，产生子细胞，随着时间的推移维持肿瘤；或者它们可能代表不同的细胞，每个细胞在不同的时间点具有 TIC 特征。为了确定是哪种情况，我们将使用 Confetti 等位基因来标记小鼠 UPS 肿瘤中的 Ng2 表达细胞，并用不同颜色的荧光蛋白标记各个克隆。这些细胞群随着肿瘤生长、连续移植以及使用常规疗法治疗后的表现将决定是哪种可能性。 3）靶向NG2可以用来治疗UPS吗？为了确定靶向 Ng2 表达如何调节肿瘤生长和自我更新，将在免疫缺陷小鼠中作为异种移植物建立的人 UPS 肿瘤中用 shRNA 敲除 NG2，并在由 Cre 重组酶启动的原代小鼠 UPS 肿瘤中删除 NG2，Cre 重组酶驱动癌基因的表达并重组条件 Ng2 无效等位基因。 NG2 的免疫疗法将以类似的方式在免疫缺陷小鼠中作为异种移植物建立的 UPS 肿瘤中进行检查。除了证明对肉瘤的重要生物学见解外，这些数据还将确定针对 TIC 人群的短期或长期治疗目标在 UPS 治疗中是否更有效，并为开发基于 UPS TIC 的治疗方法提供新方法。