Role of TTK/Mps-1 upregulation by Ral GTPase activation in pancreatic oncogenesis

Ral GTPase 激活上调 TTK/Mps-1 在胰腺肿瘤发生中的作用

• 批准号: 8398164
• 负责人: Jeran K Stratford
• 金额: $ 2.94万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 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 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8398164
• 关键词: Adenocarcinoma; Adenocarcinoma Cell; Agar; Amino Acid Sequence; Anchorage-Independent Growth; Antineoplastic Agents; Attention; Basic Science; Binding; Biological Assay; Catalytic Domain; Cell Line; Cell Survival; Cells; Characteristics; Clinical Trials; Data; Dependency; Disease; Ductal; Evaluation; Family; Frequencies; Gene Targeting; Genes; Growth; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; In Vitro; KRAS2 gene; MEKs; Malignant Neoplasms; Malignant neoplasm of pancreas; Measures; Mediating; Messenger RNA; Metastatic Lesion; Modeling; Molecular; Monomeric GTP-Binding Proteins; Mutation; Neoplasm Metastasis; Oncogenes; Paclitaxel; Pancreas; Pancreatic Ductal Adenocarcinoma; Pathway interactions; Patients; Peptide Sequence Determination; Phase; Phosphatidylinositols; Phosphorylation; Phosphotransferases; Post-Translational Protein Processing; Primary Neoplasm; Process; Property; Protein Isoforms; Protein Kinase; Protein Tyrosine Kinase; Proto-Oncogene Proteins c-akt; RNA Interference; Ras Inhibitor; Regulation; Role; Sampling; Signal Pathway; Signal Transduction; Structure; T-Cell Immunologic Specificity; TTK Protein Kinase; Techniques; Therapeutic; Tissues; Transcript; Translational Research; Ubiquitination; Up-Regulation; Validation; Xenograft procedure; cancer therapy; clinical application; drug discovery; human FRAP1 protein; in vivo; inhibitor/antagonist; interest; mRNA Expression; matrigel; mouse model; mutant; neoplastic cell; novel; overexpression; protein expression; protein protein interaction; ral Guanine Nucleotide Exchange Factor; ras Guanine Nucleotide Exchange Factors; small hairpin RNA; success; therapeutic development; therapeutic target; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): Pancreatic cancer is a deadly disease with few therapeutic options available. While success has been made in signal transduction-targeted therapies for some cancers, no significant targeted therapies have been identified for pancreatic cancer. The oncogene KRAS is activated by mutation in ~100% of pancreatic cancer ductal adenocarcinomas (PDAC). However, efforts to develop direct inhibitors of K-Ras have been disappointing. Therefore, focus has shifted to inhibiting the effector signaling cascades activated downstream of K-Ras. The canonical K-Ras effector pathways, Raf-MEK-ERK and PI3K-AKT-mTOR have received the most attention with >40 inhibitors of these two pathways currently under evaluation in clinical trials. However, recent studies investigating KRAS dependency and synthetic lethality argue that other effectors are key to K-Ras regulated transformation. The Ral guanine-nucleotide exchange factor (RalGEF)-Ral pathway is a non-canonical K-Ras effector pathway that have recently been validated for its importance in K-Ras-mediated oncogenesis. RalGEF activates the RalA and RalB Ras-like small GTPases. RalA regulates PDAC anchorage-independent growth in vitro and tumorigenesis in vivo, whereas RalB regulates invasion in vitro and metastasis in vivo. Transcription factor activation is a key consequence of Ral effector signaling. Therefore, we hypothesize that gene array profiling will identify key gene targets of Ral signaling, providing therapeutically useful avenues for drug discovery. Recently I performed gene array analyses and identified the gene encoding the dual specificity protein kinase TTK (also called Mps-1) as a transcript regulated by both RalA and RalB in PDAC. I also identified TTK mRNA overexpression in PDAC primary tumors and metastatic lesions compared to normal pancreas tissue. Furthermore, my preliminary studies have validated the requirement for TTK expression in PDAC anchorage-independent growth and Matrigel invasion in vitro. Thus, TTK may be an attractive and tractable target for anti-Ral and Ras drug discovery. In Aim 1, I will further validate the role of TTK in PDAC oncogenesis by using orthotopic tumor mouse models that better model the invasive and metastatic disease of the patient. In Aim 2, I will establish the importance of specific Ral effector signaling pathways for TTK expression and PDAC growth. RalBP1/RLIP76 and the Sec5 and Exo84 exocyst components are the best- characterized Ral effectors and I will determine if Ral mutants that differentially uncouple Ral from these effectors can rescue impaired TTK expression due to endogenous Ral silencing. Finally, Aim 3 studies will utilize missense and truncation mutants of TTK to investigate the requirement for kinase and non-kinase sequences in TTK function in PDAC anchorage-independent growth and invasion through Matrigel. Taken together, these studies will require me to master an array of experimental techniques, while preparing me to do both basic and translational research. PUBLIC HEALTH RELEVANCE: Pancreatic cancer is a deadly disease with few therapeutic options. Ral GTPases have a validated role in pancreatic cancer oncogenesis downstream of the oncogene KRAS. TTK/Mps1 is a protein kinase regulated by Ral signaling and represents a novel anti-Ral therapeutic target for blocking Ras signaling in pancreatic cancer drug discovery.

描述（由申请人提供）：胰腺癌是一种致命疾病，几乎没有治疗选择。尽管在某些癌症的信号转导目标疗法中取得了成功，但尚未确定胰腺癌的明显靶向疗法。在约100％的胰腺癌导管腺癌（PDAC）中，突变激活了癌基因KRAS。但是，开发K-RAS直接抑制剂的努力令人失望。因此，焦点已转移到抑制效应子信号级联激活 K-Ras的下游。规范的K-RAS效应途径，RAF-MEK-ERK和PI3K-AKT-MTOR在临床试验中目前正在评估的这两种途径中受到了最大的关注。但是，最近研究KRAS依赖性和合成致死性的研究表明，其他效应子是K-RAS调节转化的关键。 RAL鸟嘌呤核苷酸交换因子（RALGEF）-RAR途径是一种非典型的K-RAS效应途径，最近因其在K-RAS介导的肿瘤发生中的重要性而得到了验证。 Ralgef激活Rala和Ralb Ras样小GTPase。 RALA在体外调节PDAC锚定非依赖性生长和体内肿瘤发生，而Ralb则在体外调节侵袭和体内转移。转录因子激活是RAL效应子信号传导的关键结果。因此，我们假设基因阵列分析将确定RAL信号的关键基因靶标，从而为药物发现提供治疗上有用的途径。最近，我进行了基因阵列分析，并确定了编码双重特异性蛋白激酶TTK（也称为MPS-1）的基因作为PDAC中RALA和RALB调控的转录本。我还确定了与正常胰腺组织相比，PDAC原发性肿瘤和转移性病变中的TTK mRNA过表达。此外，我的初步研究已经验证了PDAC锚定非依赖性生长和体外矩阵侵袭中TTK表达的需求。因此，TTK可能是抗ras和RAS药物发现的有吸引力且可进行的靶标。在AIM 1中，我将通过使用原位肿瘤小鼠模型来进一步验证TTK在PDAC肿瘤发生中的作用，从而更好地模拟患者的侵入性和转移性疾病。在AIM 2中，我将确定特定RAL效应子信号通路对TTK表达和PDAC生长的重要性。 RALBP1/RLIP76以及SEC5和EXO84外囊剂组件是最具特征的RAL效应子，我将确定由于内源性ral ral ral ral ral ral ral ral ral ral ral ral ral ral ral ral ral ral ral sance降低了RAL与这些效应子的差异是否会产生差异。最后，AIM 3研究将利用TTK的错义和截断突变体来研究PDAC锚定非依赖性生长和通过Matrigel的TTK功能中激酶和非激酶序列的需求。综上所述，这些研究将要求我掌握一系列实验技术，同时准备进行基础研究和转化研究。 公共卫生相关性：胰腺癌是一种致命的疾病，几乎没有治疗选择。 RAL GTPases在癌基因KRAS下游的胰腺癌肿瘤发生中具有验证作用。 TTK/MPS1是一种受RAL信号传导调控的蛋白激酶，代表了一种新型的抗和抗和抗治疗靶标，用于阻断胰腺癌药物发现中的RAS信号传导。