Novel Roles of LY6K in Glioblastoma Tumorigenicity

LY6K 在胶质母细胞瘤致瘤性中的新作用

• 批准号: 9751625
• 负责人: Namratha G Sastry
• 金额: $ 3.67万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9751625
• 关键词: Behavior; Biological Assay; Biological Models; Biology; Cell Differentiation process; Cells; Characteristics; Clinical; Combined Modality Therapy; Complex; DNA Methylation; Data; Epidermal Growth Factor Receptor; Family; Frequencies; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic Heterogeneity; Genomics; Glioblastoma; Glioma; Head and neck structure; Heterogeneity; Human; Immune; In Vitro; Inherited; Knowledge; Lead; Lung; Lymphocyte Function; Lymphocyte Suppression; Lymphocyte antigen; MAPK1 gene; MAPK3 gene; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of brain; Malignant neoplasm of esophagus; Malignant neoplasm of lung; Measures; Mediating; Mesenchymal; Methylation; Molecular; Normal Cell; Nude Mice; Oncogenes; Oncogenic; Pathology; Pathway interactions; Patients; Pattern; Phenotype; Population; Proteins; Radiation; Radiation therapy; Radioresistance; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Resistance; Role; Sampling; Signal Pathway; Signal Transduction; Specimen; Squamous Cell; Testing; Tumorigenicity; Up-Regulation; Xenograft Model; base; behavior in vitro; cancer cell; cancer testis antigen; cell growth; clinically relevant; differential expression; experimental study; glioma cell line; improved; in vivo; in vivo Model; insight; knock-down; malignant breast neoplasm; member; molecular subtypes; novel; outcome forecast; promoter; protein K; reproductive; small hairpin RNA; stem; stem-like cell; tumor; tumor growth; tumorigenesis; tumorigenic

PROJECT SUMMARY Glioblastoma (GBM) is the most malignant brain cancer, with extremely poor prognosis in patients. Distinct molecular subtypes, characterized as proneural (PN), classical, and mesenchymal (MES), as well as inherited heterogeneity render GBM tumors resistant to current therapies. In addition to the genetic heterogeneity arising from the differentiated cells, GBM tumors also contain a small population of glioma-initiating or stem-like cancer cells (GSCs). Gene expression profiling studies from our lab showed that patient-derived GSCs can also be classified into subtypes phenotypically similar to GBM. We found over three thousand genes that are differentially expressed between PN and MES-like GSCs. Among these, Lymphocyte Antigen Complex 6, Locus K (LY6K) was one of the top differentially expressed genes. LY6K is a GPI-anchored protein from the LY6 family. Various members of the LY6 family have been implicated in human cancers, including breast, esophageal, and lung cancers. In our preliminary studies, we tested the roles of LY6K upregulation in GBM tumorigenesis and started to examine the underlying mechanism of LY6K action. We found that 1) high levels of LY6K expression correlates with poor prognosis of patients with GBM; 2) suppression of LY6K expression in MES-like GSCs significantly reduced tumorigenic behaviors in vitro and in vivo; 3) LY6K and EGFR-ERK signaling both become activated in irradiated PN-like GSCs which otherwise have undetectable levels of both; 4) suppression of LY6K expression decreases ERK1/2 activation, which is likely a downstream effect of EGFR signaling. Thus, we hypothesize that high levels of LY6K in GSCs promotes GBM tumorigenesis. Moreover, based our radiation data, we hypothesize that LY6K may function by enhancing EGFR signaling and subsequent ERK activation, thus promoting radioresistance. To test these hypotheses, we have developed two specific aims. The first aim examines the function of LY6K as an oncogene in GSCs. We will perform in vitro and in vivo tumorigenicity assays to determine whether modulation of LY6K expression in GSCs regulates tumorigenicity. We will also examine the mechanism of LY6K expression in GSCs and GBM clinical samples by examining LY6K promoter methylation. Secondly, we will investigate the relationship between LY6K and EGFR signaling, as it pertains to radioresistance. To determine whether LY6K modulates EGFR signaling, we propose to modify the expression of LY6K in GSCs and measure the resulting changes in pERK. Subsequently, we will determine which specific domains within LY6K are responsible for EGFR signal enhancement, via domain-deletion experiments. The insight gained from these aims will further our understanding the function LY6K in EGFR signaling as well as GBM tumorigenicity.

项目摘要 胶质母细胞瘤（GBM）是最恶性的脑癌，患者预后极差。不同 分子亚型，特征为前神经（PN），经典，和间质（MES），以及遗传 异质性使得GBM肿瘤对当前疗法具有抗性。除了遗传异质性 从分化的细胞中，GBM肿瘤还包含一小部分神经胶质瘤起始或干细胞样癌 细胞（GSC）。我们实验室的基因表达谱研究表明，患者来源的GSC也可以是 分为表型上与GBM相似的亚型。我们发现了三千多个基因， 在PN和MES样GSC之间表达。其中，淋巴细胞抗原复合物6，基因座K（LY 6 K） 是差异表达最多的基因之一。LY 6 K是来自LY 6家族的GPI锚定蛋白。各种 LY 6家族的成员与人类癌症有关，包括乳腺癌、食管癌和肺癌 癌的在我们的初步研究中，我们测试了LY 6 K上调在GBM肿瘤发生中的作用，并开始研究LY 6 K在GBM肿瘤发生中的作用。 研究LY 6 K作用的潜在机制。我们发现1）高水平的LY 6 K表达与 GBM患者预后不良; 2）抑制MES样GSC中LY 6 K的表达， 降低体外和体内的致瘤行为; 3）LY 6 K和EGFR-ERK信号传导均被激活， 照射的PN样GSC，否则两者的水平都检测不到; 4）抑制LY 6 K表达 降低ERK 1/2活化，这可能是EGFR信号传导的下游效应。因此，我们假设， GSC中高水平的LY 6 K促进GBM肿瘤发生。此外，根据我们的辐射数据，我们假设 LY 6 K可能通过增强EGFR信号传导和随后的ERK激活发挥作用，从而促进 抗辐射性为了验证这些假设，我们制定了两个具体目标。第一个目标是审查 LY 6 K作为癌基因在GSC中的功能。我们将进行体外和体内致瘤性试验，以确定 GSC中LY 6 K表达的调节是否调节致瘤性。我们亦会研究有关机制 通过检查LY 6 K启动子甲基化，在GSC和GBM临床样品中检测LY 6 K表达。其次我们 将研究LY 6 K和EGFR信号传导之间的关系，因为它涉及辐射抗性。到 为了确定LY 6 K是否调节EGFR信号传导，我们建议在GSC中修饰LY 6 K的表达， 并测量pERK的变化。随后，我们将确定哪些特定域中 LY 6 K通过结构域缺失实验负责EGFR信号增强。从以下方面获得的见解 这些目标将进一步加深我们对LY 6 K在EGFR信号传导以及GBM致瘤性中的功能的理解。