Novel relationships of splicing factors in temozolomide-resistant glioblastoma

替莫唑胺耐药胶质母细胞瘤中剪接因子的新关系

• 批准号: 10085005
• 负责人: Deanna Marie Tiek
• 金额: $ 8.66万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10085005
• 关键词: Address; Agonist; Alkylating Agents; Alternative Splicing; Apoptotic; Arginine; Back; Biology; Blood - brain barrier anatomy; Brain; Brain Glioblastoma; Brain Neoplasms; Cell model; Cell physiology; Cells; DNA; DNA Damage; DNA Repair; Diagnosis; Doctor of Philosophy; Drug resistance; Equilibrium; Event; FDA approved; Genes; Genetic Transcription; Glioblastoma; Goals; In Vitro; Knowledge; Lesion; Malignant Neoplasms; Mentorship; Methods; Methyltransferase; MicroRNAs; Modeling; Molecular; Nuclear Orphan Receptor; Operative Surgical Procedures; Organ; Paper; Pathway interactions; Patients; Phase; Phosphorylation; Phosphotransferases; Play; Porifera; Postdoctoral Fellow; Process; Production; Protein Isoforms; Proteins; RNA; RNA Splicing; RNA-Binding Protein EWS; RNA-Binding Proteins; Radiation therapy; Regulation; Research; Research Personnel; Research Project Grants; Research Technics; Resistance; Role; Serine; Signal Transduction; Testing; Therapeutic; Training; Transcript; Translating; Tubulin; Untranslated RNA; Work; Xenograft procedure; anticancer research; base; cell growth; cell motility; chemotherapy; circular RNA; combat; estrogen-related receptor; experience; gene product; improved; in silico; in vivo; inhibitor/antagonist; metabolic phenotype; neoplastic cell; new therapeutic target; novel; novel strategies; post-doctoral training; pre-doctoral; programs; receptor function; repaired; research study; response; success; temozolomide; therapeutic target; transcriptome; treatment strategy

Glioblastoma (GBM) is a devastating cancer, due to both our narrow understanding of its molecular drivers and limited therapeutic strategies. One potential mechanistic driver is alternative splicing. The brain contains the most alternatively spliced transcripts of any organ, and many splicing factors are upregulated between normal brain and GBM. While chemotherapeutic options are limited by the physical blood brain barrier (BBB), the DNA- damaging agent temozolomide (TMZ) is able to cross into the brain. However, most patients rapidly become resistant to TMZ and TMZ-resistant GBM is uniformly fatal. An initial goal of my PhD research was to establish novel TMZ-resistant cellular models in order to identify pathways that could be targeted for GBM treatment. My comprehensive characterization of the cell growth, motility, and metabolic phenotypes of my two new TMZ- resistant GBM models forms the basis for my initial first-author paper. During my dissertation research (Aim 1), I have conducted two complementary studies that identify novel approaches to targeting alternative splicing events in GBM. The first (Aim 1.1) is to target the alternatively spliced estrogen-related receptor beta (ERRβ). I have started to define with in silico and in vitro methods how the pro-apoptotic isoform of this gene, ERRβ2, is processed. I found that the serine/arginine (SR) rich splicing factor SRSF6 plays a role in ERRβ2 production and that inhibition of Cdc-like kinases (CLKs, which phosphorylate SR proteins) with TG-003 in combination with the ERRβ synthetic agonist DY-131 potently inhibits TMZ-resistant GBM cells in vitro and in intracranial xenografts. The second (Aim 1.2) is a broader study of splicing inhibition and regulation in TMZ-resistant GBM. I found that TMZ decreases the phosphorylation (p) of SR proteins in TMZ-sensitive, but not TMZ-resistant models. This is accompanied by mis-localization of pSR proteins, and increased baseline levels of DNA damage. In TMZ- resistant GBM cells, the RNA binding protein EWS also mis-localizes and forms aggregates that are stabilized by tubulin. My working hypothesis is that because of the increased DNA damage in TMZ-resistant GBM, the DNA damage response becomes reprogrammed which causes splicing factors (like EWS and pSR proteins) to be displaced from their normal cellular compartments and poised for aberrant aggregation. Also, that this new splicing factor/DNA damage repair axis can be therapeutically targeted with novel splicing inhibitors. During the postdoctoral training period (Aim 2), I will address a key gap in our understanding of the GBM transcriptome: the role of non-coding RNAs, specifically the noncanonical back-spliced or circular RNAs (circRNAs). I propose to define the circRNA landscape of GBM, to determine the regulatory functions and to propose potential therapeutic applications of these abundant and dynamic regulators of splicing and transcription. Together, my pre- and postdoctoral research experiences will have prepared me to balance both big picture ideas and focused studies of mechanism when I establish my own research program as an independent cancer researcher.

胶质母细胞瘤（GBM）是一种毁灭性的癌症，因为我们对其分子驱动因素的理解很狭隘