ZNF-Mediated Resistance to Imatinib Mesylate in Gastrointestinal Stromal Tumor

ZNF 介导的胃肠道间质瘤对甲磺酸伊马替尼的耐药性

• 批准号: 8241248
• 负责人: Lori Rink
• 金额: $ 10.1万
• 依托单位: FOX CHASE CANCER CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8241248
• 关键词: 70-kDa Ribosomal Protein S6 Kinases; Address; Adult; Advisory Committees; Affect; American Association of Cancer Research; American Society of Clinical Oncology; Award; Biological Assay; Biological Markers; Biopsy Specimen; Cancer Burden; Cell Line; Cells; Clinic; Clinical; Clinical Research; Combined Modality Therapy; Commit; Communities; Comprehensive Cancer Center; Dasatinib; Data; Developmental Therapeutics Program; Drug resistance; Exons; Faculty; Feedback; Fellowship; Fox Chase Cancer Center; Funding; Gastrointestinal Stromal Tumors; Genes; Goals; Human; Hypoxia; Imatinib mesylate; Immunoblotting; In Vitro; Kansas; Leadership; Light; Malignant Neoplasms; Measures; Mediating; Medical Oncology; Mentors; Modeling; Molecular Profiling; National Cancer Institute; Neoadjuvant Therapy; Oncogenic; PDGFRA gene; PI3K/AKT; Pathway interactions; Patients; Pharmaceutical Preparations; Phase II Clinical Trials; Philadelphia; Positioning Attribute; Proto-Oncogene Proteins c-akt; RNA Interference; RNA Splicing; Radiation Oncology; Radiation Therapy Oncology Group; Recurrence; Refractory; Reporting; Research; Research Infrastructure; Resistance; Role; Route; Sampling; Scientific Advances and Accomplishments; Serum; Signal Pathway; Signal Transduction; Small Interfering RNA; Stream; Surgical Oncology; Testing; Time; Training; Training Programs; Transactivation; Translating; Translational Research; Tumor Cell Line; Universities; Videoconferences; Videoconferencing; Work; Xenograft Model; anticancer research; base; career; cytotoxicity; experience; human ZNF45 protein; improved; in vivo; inhibitor/antagonist; interest; medical schools; meetings; member; molecular oncology; neoplastic cell; novel; novel strategies; overexpression; periostin; post-doctoral training; pre-clinical; prevent; professor; programs; prospective; research study; resistance mechanism; response; sarcoma; small molecule; sunitinib malate; tumor; tumor growth; tumor xenograft; tumorigenesis; working group

DESCRIPTION (provided by applicant): Imatinib mesylate (IM) has revolutionized the treatment of patients with gastrointestinal stromal tumors (GISTs); however, clinical resistance to IM has become a reality, despite the initial efficacy observed. Furthermore, very limited options exist for patients (~20%) that are refractory at the start of treatment. Using clinical pre treatment biopsy samples from a prospective neoadjuvant phase II trial (RTOG 0132), I identified a 32-gene signature that includes KRAB-ZNF 91 subfamily members that can predict response to IM. I subsequently demonstrated that many of these genes were not only predictive of IM response but mediated the drug's activity. In order to determine mechanistically how these ZNFs might be modulating response to IM, RNAi approaches were used to knockdown genes within the predictive signature (including 10 ZNFs) in GIST cells and expression profiling was performed using exon 1.0 ST arrays. This led to the finding that periostin, NEDD9 and TGF23, are universally downregulated following siRNA-mediated knockdown. This is intriguing because TGF23 is a known inducer of periostin and NEDD9, both of which have been reported as frequently overexpressed in a variety of human cancers and indicates that these ZNFs uncovered from these clinical studies may be a "master controller" over these pathways. Interestingly, hypoxia has been shown to upregulate expression of both NEDD9 and periostin (through the PI3K) leading to increased aggressiveness and enhanced survival of tumor cells. Therefore, it is possible that both periostin and NEDD9 are regulated in a similar mechanism by TGF2 and hypoxia, controlled by ZNFs, to modulate IM response in GIST cells. NEDD9 was also shown to be overexpressed and SRC hyper-activated in an IM-resistant GIST cell line, with knockdown of NEDD9 restoring IM sensitivity. I hypothesize that IM resistance in GISTs may be associated with hypoxia leading to the transactivation of TGF23 by ZNFs causing subsequent induction of periostin and/or NEDD9 and activation of the PI3-K or SRC pathways, respectively. The activation of these potential "rescue routes" occurs independent of KIT/PDGFRA signaling, thereby overcoming inhibiting activities of IM on pro- survival pathways. My preliminary data suggest that these ZNFs are responsible for regulating this pathway and overexpression of these genes is associated with clinical resistance of GIST patients to IM-based therapy. To test my hypothesis, I propose in Aim 1 to determine if expression of TGF23, NEDD9 and/or periostin in primary GIST samples correlate to IM response (both short and long-term) and ZNF expression. In Aim 2 I will investigate how these ZNFs affect TGF23, NEDD9 and periostin expression and ultimately response to IM. Aim 3 will establish whether targeting the hypoxia-induced TGF23-> periostin-> PI-3K/AKT and/or hypoxia- induced TGF23-> NEDD9-> SRC rescue pathway in vivo will abrogate resistance to IM. The central tenet of this proposal is that targeted agents will become potent when used in combinations that simultaneously block multiple oncogenic pathways, preventing the circumvention of parallel pathways that can act as "rescue routes" for these tumor cells. The proposed research will be accomplished at Fox Chase Cancer Center (FCCC) in Philadelphia, PA. FCCC is a comprehensive cancer center as designated by the National Cancer Institute, nationally recognized for its leadership in medical, radiation and surgical oncology. FCCC leadership is committed to providing the necessary infrastructure and support for me to successfully complete my proposed studies. I will be mentored by Drs. Margaret von Mehren (Professor & Director, Sarcoma Program), Andrew K. Godwin (Professor & Director of Molecular Oncology at the University of Kansas Medical School (KUMC), and Erica Golemis (Professor & Deputy Chief Scientific Officer at FCCC), esteemed faculty members at FCCC and KUMC and internationally recognized experts in the field of translational research and medical oncology. I will have the opportunity to interact and discuss my research in regular meetings of working groups including the Sarcoma Program, Translational Research Forum, Developmental Therapeutics and bi-monthly lab meetings attended by both Drs. von Mehren and Godwin (by videoconference). My primary goal is to obtain an independent academic career in cancer research. To help accomplish this goal, I have assembled an advisory committee consisting of my mentors and other FCCC faculty members (Drs. Maureen Murphy, Director of Postdoctoral Training Program and Edna Cukierman) in order to review my research progress and provide feedback. During the first two years of funding, I will continue to work closely with my mentors to address the research goals proposed in Aims 1 and 2. During this time I will transition into independence seeking out a tenure-track faculty position. In the last three years of funding, I wil continue the studies proposed in Aims 2 and 3 while establishing my independent research program. As part of my future research objectives, I am interested not only in mechanisms of resistance to novel biologics, such as IM, but in establishing models and challenging existing paradigms to rationally develop combination therapies in order to reduce the burden of cancer. I have already made significant scientific accomplishments in my short career and have established myself to be an important member of the GIST research community. I have authored 10 research articles and scholarly reviews. I have received a number of awards and training fellowships and was selected to orally present my work, the basis of this proposal, at both the AACR and ASCO meetings in 2009. PUBLIC HEALTH RELEVANCE: Despite initial efficacy of imatinib mesylate (IM) in most (~80%) gastrointestinal stromal tumor (GIST) patients, many experience primary/secondary drug resistance, limiting treatment options for these patients. This proposal seeks to identify mechanisms associated with resistance to IM and second line therapies, i.e., sunitinib malate, in GISTs and to subsequently evaluate potential targets and corresponding inhibitors for their ability to improve on current GIST treatment paradigms. This work will establish robust strategies to identify useful combinations in conjunction with predictive biomarkers that identify patients most likely to respond to a specific therapy.

描述（由申请人提供）：甲磺酸伊马替尼（IM）彻底改变了胃肠道间质瘤（GIST）患者的治疗；然而，尽管初步观察到了疗效，但 IM 的临床耐药性已成为现实。此外，对于治疗开始时难治的患者（~20%）来说，选择非常有限。使用临床预 通过对来自前瞻性新辅助 II 期试验 (RTOG 0132) 的治疗活检样本进行分析，我发现了一个 32 基因特征，其中包括可以预测 IM 反应的 KRAB-ZNF 91 亚家族成员。我随后证明，其中许多基因不仅可以预测 IM 反应，还可以介导药物的活性。为了从机制上确定这些 ZNF 如何调节 IM 反应，使用 RNAi 方法敲低 GIST 细胞中预测特征（包括 10 个 ZNF）内的基因，并使用外显子 1.0 ST 阵列进行表达谱分析。这导致发现骨膜素、NEDD9 和 TGF23 在 siRNA 介导的敲低后普遍下调。这很有趣，因为 TGF23 是骨膜素和 NEDD9 的已知诱导剂，据报道这两种物质在多种人类癌症中频繁过度表达，表明这些临床研究发现的 ZNF 可能是这些途径的“主控制器”。有趣的是，缺氧已被证明会上调 NEDD9 和骨膜蛋白（通过 PI3K）的表达，从而导致肿瘤细胞的侵袭性增加和存活率提高。因此，periostin 和 NEDD9 可能以相似的机制受到 TGF2 和缺氧的调节，并受 ZNF 控制，从而调节 GIST 细胞中的 IM 反应。 NEDD9 也被证明在 IM 抗性 GIST 细胞系中过度表达且 SRC 过度激活，敲低 NEDD9 可恢复 IM 敏感性。我推测 GIST 中的 IM 抵抗可能与缺氧有关，缺氧导致 ZNF 反式激活 TGF23，从而分别引起骨膜素和/或 NEDD9 的诱导以及 PI3-K 或 SRC 途径的激活。这些潜在“救援途径”的激活独立于KIT/PDGFRA信号传导而发生，从而克服了IM对促生存途径的抑制活性。我的初步数据表明，这些 ZNF 负责调节该通路，并且这些基因的过度表达与 GIST 患者对 IM 治疗的临床耐药性相关。 为了检验我的假设，我在目标 1 中建议确定原发性 GIST 样本中 TGF23、NEDD9 和/或骨膜素的表达是否与 IM 反应（短期和长期）和 ZNF 表达相关。在目标 2 中，我将研究这些 ZNF 如何影响 TGF23、NEDD9 和骨膜素表达以及最终对 IM 的反应。目标 3 将确定体内针对缺氧诱导的 TGF23-> 骨膜素-> PI-3K/AKT 和/或缺氧诱导的 TGF23-> NEDD9-> SRC 救援途径是否会消除对 IM 的耐药性。该提案的中心原则是，当靶向药物联合使用时，能够同时阻断多种致癌途径，从而防止绕过可充当这些肿瘤细胞“救援途径”的平行途径，从而变得有效。 拟议的研究将在宾夕法尼亚州费城的福克斯蔡斯癌症中心 (FCCC) 完成。 FCCC 是美国国家癌症研究所指定的综合性癌症中心，因其在肿瘤内科、放射科和外科肿瘤学领域的领先地位而获得全国认可。 FCCC 领导层致力于为我成功完成我拟议的学习提供必要的基础设施和支持。我将受到博士的指导。 Margaret von Mehren（肉瘤项目教授兼主任）、Andrew K. Godwin（堪萨斯大学医学院 (KUMC) 教授兼分子肿瘤学主任、Erica Golemis（FCCC 教授兼副首席科学官）、FCCC 和 KUMC 受人尊敬的教职人员以及转化研究和肿瘤医学领域的国际公认专家。我将邀请 有机会在工作组的定期会议上互动和讨论我的研究，包括肉瘤计划、转化研究论坛、发展治疗学以及由两位博士参加的双月实验室会议。冯·梅伦和戈德温（通过视频会议）。我的主要目标是在癌症研究领域获得独立的学术生涯。为了帮助实现这一目标，我组建了一个咨询委员会，由我的导师和其他 FCCC 教员（莫琳博士）组成。 博士后培训项目主任 Murphy 和 Edna Cukierman），以审查我的研究进展并提供反馈。在资助的前两年，我将继续与我的导师密切合作， 解决目标 1 和 2 中提出的研究目标。在此期间，我将过渡到独立，寻求终身教职。在过去三年的资助中，我将继续目标 2 和 3 中提出的研究，同时建立我的独立研究计划。作为我未来研究目标的一部分，我不仅对新型生物制剂（例如IM）的耐药机制感兴趣，而且对建立模型和挑战现有范例以合理开发联合疗法以减轻癌症负担感兴趣。 在我短暂的职业生涯中，我已经取得了重大的科学成就，并已成为 GIST 研究界的重要成员。我撰写了 10 篇研究文章和学术评论。我获得了许多奖项和培训奖学金，并被选中在 2009 年 AACR 和 ASCO 会议上口头介绍我的工作，这是本提案的基础。 公共卫生相关性：尽管甲磺酸伊马替尼 (IM) 对大多数 (~80%) 胃肠道间质瘤 (GIST) 患者具有初步疗效，但许多患者出现原发/继发耐药性，限制了这些患者的治疗选择。该提案旨在确定 GIST 中与 IM 和二线疗法（即苹果酸舒尼替尼）耐药相关的机制，并随后评估潜在靶点和相应抑制剂改善当前 GIST 治疗范例的能力。这项工作将建立强有力的策略，以识别与预测生物标志物相结合的有用组合，从而识别最有可能对特定治疗产生反应的患者。