Investigating a hierarchical model for PI3K activation and inhibition in breast cancer by double PIK3CA mutations in cis

研究顺式 PIK3CA 双突变对乳腺癌 PI3K 激活和抑制的分层模型

基本信息

批准号：
10437283
负责人：
Neil Vasan
金额：
$ 26.3万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-13 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10437283
关键词：
Advisory Committees Alleles Amino Acids Binding Biochemical Biological Process Breast Breast Cancer Cell Breast Cancer Patient Breast Oncology Cell model Cell physiology Cells Clinic Clinical Clinical Trials Complex Double Effect Drug Targeting Environment Epigenetic Process Estrogen Receptors Estrogen receptor positive Family Generations Genetic Transcription Global Change Goals Growth Guanosine Triphosphate Histone-Lysine N-Methyltransferase Human Hyperactivity In Vitro Institution International Investigation Knock-in Lipid Binding Lipids MLL gene Malignant Neoplasms Mammary Neoplasms Measures Medicine Membrane Membrane Lipids Memorial Sloan-Kettering Cancer Center Mentors Mentorship Metastatic breast cancer Modeling Mutate Mutation Oncogene Activation Oncogenes PI3K/AKT PIK3CA gene Pathway interactions Patients Phase Phosphorylation Phosphotransferases Physiology Positioning Attribute Progression-Free Survivals Protein Biochemistry Protein Kinase Proteomics Proto-Oncogene Proteins c-akt Randomized Clinical Trials Receptor Activation Receptor Protein-Tyrosine Kinases Recombinants Recurrence Regulation Research Sampling Science Scientist Secure Services Signal Pathway Signal Transduction Testing Training Work alpelisib anticancer research base cancer cell candidate marker career career development experience experimental study genomic biomarker histone methyltransferase improved in vivo inhibitor/antagonist malignant breast neoplasm medical schools mouse model mutant novel overexpression phosphoproteomics pre-clinical reconstitution response response biomarker standard of care structural biology tenure track

项目摘要

PROJECT SUMMARY/ABSTRACT PIK3CA is the most frequently mutated oncogene in human cancer. PI3Kα inhibitors are a new standard of care in PIK3CA mutant ER+ metastatic breast cancer (ER+ MBC) and some patients have durable responses. In this proposal, I capitalize on our recent discovery of a novel mechanism of oncogene activation by double PIK3CA mutations. We have demonstrated that double PIK3CA mutations are frequent across all PIK3CA mutant cancers, occur at recurrent amino acid positions, and are in cis on the same allele. Double mutations activate PI3K signaling and growth more than single hotspot mutations in vitro and in vivo, and biochemically activate PI3K through disruption of p85 inhibition and increased membrane binding. Double mutations increase sensitivity to PI3Kα inhibition in cells and in PIK3CA mutant ER+ MBC patients. Our work has uncovered a hierarchical model for the activation and inhibition of PI3K based on mutation number (Vasan, et al. Science 2019). I will test the hypotheses that this hierarchical model extends to PI3K regulation, crosstalk with the estrogen receptor, and activation of novel AKT substrates. I will use recombinant double mutant PI3K complexes reconstituted with Ras and RTK to dissect the mechanisms of regulation (Aim 1.1) and the mechanisms of cellular generation of PIP3 (Aim 1.2). I will leverage knockin and overexpression cellular models to measure activation and inhibition of double mutant ER+ breast cancer (Aim 2.1) and modulation of ER-dependent transcription (Aim 2.2). These experiments will be performed in vitro, in vivo, in patient samples, and under PI3K inhibitor treatment. I will utilize unbiased phosphoproteomics on double mutant cells to credential new AKT protein kinase substrates (Aim 3.1) including the KMT family of histone lysine methyltransferases (Aim 3.2). Together these aims will validate our hierarchical model of oncogene activation by double PIK3CA mutants across a wide variety of cellular and biological processes and will lead to new strategies to inhibit PI3K including testing PI3Kα inhibitors in multiple PIK3CA mutant patients. I am an Assistant Attending with the Breast Medicine Service at Memorial Sloan Kettering Cancer Center (MSKCC), and I have outlined a 5-year career plan that builds upon my background studying structural biology and my clinical training in breast oncology. I have assembled an outstanding mentoring team of Dr. Lewis Cantley (primary mentor) and Dr. Maurizio Scaltriti (co-mentor). My advisory committee will include Dr. Neal Rosen, Dr. Ross Levine, and Dr. Komal Jhaveri. They are internationally renowned scientists in their respective fields who will provide me the mentorship and support to attain scientific independence. I will have access to unparalleled institutional support at MSKCC and Weill Cornell Medical College. Both institutions are at the leading edge of cancer research and are heavily invested in career development. Collectively, this training environment will enable me to achieve my goals of ultimately securing a tenure-track independent position.

项目概要/摘要 PIK3CA 是人类癌症中最常突变的癌基因，PI3Kα 抑制剂是治疗癌症的新标准。 PIK3CA 突变 ER+ 转移性乳腺癌 (ER+ MBC) 的护理，一些患者有持久的反应。在这个提案中，我利用了我们最近发现的一种通过双重激活癌基因的新机制我们已经证明，双重 PIK3CA 突变在所有 PIK3CA 中都很常见。突变癌症发生在重复的氨基酸位置，并且在同一等位基因上呈顺式双突变。在体外和体内以及生化方面比单个热点突变更能激活 PI3K 信号传导和生长通过破坏 p85 抑制和增加膜结合来激活 PI3K。我们的工作揭示了细胞和 PIK3CA 突变 ER+ MBC 患者对 PI3Kα 抑制的敏感性。基于突变数的 PI3K 激活和抑制的分层模型（Vasan 等人，Science） 2019）我将测试这种分层模型扩展到 PI3K 调节、与 PI3K 的串扰的假设。雌激素受体，以及新型 AKT 底物的激活我将使用重组双突变体 PI3K。用 Ras 和 RTK 重建复合物以剖析调节机制（目标 1.1）和 PIP3 的细胞生成机制（目标 1.2）我将利用敲入和过表达细胞。测量双突变 ER+ 乳腺癌激活和抑制（目标 2.1）以及调节的模型 ER 依赖性转录（目标 2.2）。这些实验将在体外、体内、患者体内进行。样品，并在 PI3K 抑制剂处理下，我将在双突变细胞上利用无偏磷酸蛋白质组学。证明新的 AKT 蛋白激酶底物（目标 3.1），包括组蛋白赖氨酸的 KMT 家族甲基转移酶（目标 3.2）。这些目标将共同验证我们的癌基因激活的分层模型。双 PIK3CA 突变体跨越多种细胞和生物过程，并将导致新的抑制 PI3K 的策略包括在多个 PIK3CA 突变患者中测试 PI3Kα 抑制剂。纪念斯隆凯特琳癌症中心 (MSKCC) 乳腺医学服务助理，我概述了一个 5 年的职业计划，该计划建立在我的结构生物学背景和我的我组建了刘易斯·坎特利 (Lewis Cantley) 博士的优秀指导团队进行乳腺肿瘤学临床培训。我的顾问委员会将包括 Neal Rosen 博士、Maurizio Scaltriti 博士（主要导师）和 Maurizio Scaltriti 博士（共同导师）。 Ross Levine 和 Komal Jhaveri 博士他们是各自领域的国际知名科学家。将为我提供指导和支持，以实现科学独立。 MSKCC 和威尔康奈尔医学院的机构支持这两所机构均处于领先地位。总的来说，这种培训环境将在癌症研究和职业发展方面投入大量资金。使我能够实现最终获得终身教职独立职位的目标。