Glycan control of stem cell-associated pathways in pancreatic cancer

胰腺癌中干细胞相关通路的聚糖控制

• 批准号: 8986782
• 负责人: Susan L Bellis
• 金额: $ 15.99万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8986782
• 关键词: Adopted; Apoptosis; Basic Science; Behavior; Biological Models; Cancer Patient; Cancer cell line; Cell Death; Cell Line; Cell Separation; Cell model; Cells; Cessation of life; Characteristics; Charge; Clinical; Clinical Treatment; Coupled; Data; Development; Diagnosis; Disease; Ductal; Ductal Epithelial Cell; Employee Strikes; Etiology; Event; Genetically Engineered Mouse; Goals; Growth; Harvest; Health; Human; Integrins; K-ras Oncogene; Knock-in; Knock-out; Knowledge; Link; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of pancreas; Modification; Molecular; Molecular Biology; Monitor; Mus; Neoplasm Metastasis; Neoplastic Cell Transformation; Oligosaccharides; Pancreas; Pancreatic Adenocarcinoma; Pancreatic Ductal Adenocarcinoma; Pathogenesis; Pathway interactions; Patient Care; Patients; Pharmaceutical Preparations; Phenotype; Physiological; Polysaccharides; Population; Primary Neoplasm; Property; Research; Resistance; Role; ST6Gal I; Sialic Acids; Signal Transduction; Sorting - Cell Movement; Staging; Stem cells; Surface; Testing; Therapeutic Intervention; Time; Tissues; Translating; Up-Regulation; Work; cancer cell; cancer initiation; cancer stem cell; cancer therapy; carcinogenesis; cell behavior; driving behavior; expectation; gemcitabine; glycosylation; glycosyltransferase; in vivo; innovation; knock-down; mouse model; neoplastic cell; novel; overexpression; pancreatic cancer cells; pancreatic neoplasm; receptor; response; self-renewal; stem; stemness; sugar; targeted treatment; therapeutic target; transcription factor; translational medicine; treatment response; tumor; tumor growth; tumor initiation; tumor progression; tumor xenograft; tumorigenesis

DESCRIPTION (provided by applicant): Abnormal surface glycosylation is a defining feature of a tumor cell, however the functional contribution of glycans to carcinogenesis has been largely ignored. One of the predominant tumor-associated changes is an increase in �6 sialic acid, a negatively-charged sugar added to selected receptors by the ST6Gal-I glycosyltransferase. In preliminary studies we find for the first time that ST6Gal-I is elevated in pancreatic cancer (PC), and that ST6Gal-I upregulation causes PC cells to acquire behaviors characteristic of "cancer stem cells" (CSCs), a stem-like cell population inherently metastatic, resistant to cell death, and insensitive to chemotherapeutic drugs. We have also made the landmark discovery that ST6Gal-I upregulation in PC cells induces expression of the CSC-associated transcription factor, Sox9. Sox9 induction is a pivotal initiating event in pancreatic ductal adenocarcinoma. The goals of this application are to establish a role for ST6Gal-I in: (i) CSC-like behaviors directed by a novel ST6Gal-I-NFkB-Sox9 signaling axis; (ii) PC pathogenesis in genetically engineered mice; and (iii) PC cell resistance to gemcitabine, a first-line PC treatment. To achieve these objectives we will employ unique cell model systems, spontaneous PC murine models with forced ST6Gal-I overexpression or deletion, and patient-derived primary tumor and tumor xenograft tissues. This research will extend fundamental knowledge of how sugars regulate tumor cell behavior, and also impact patient care by identifying ST6Gal-I as a marker for resistant cells and potential clinical target for restoring treatment response. AIM 1: ST6Gal-I signaling through Sox9 promotes stem-like PC behaviors that drive pathogenesis. Patient-derived primary PC cells, or PC cell lines with forced ST6Gal-I expression or knockdown, will be used to test the hypothesis that ST6Gal-I activity stimulates signaling through NFkB-Sox9 to promote CSC behaviors including self-renewal; tumor spheroid growth; and tumor-initiating potential. Co-expression of ST6Gal-I, activated NFkB and Sox9 will be examined in patient pancreatic adenocarcinoma tissues, and spontaneous PC murine models with pancreas-specific ST6Gal-I knockin or knockout will be utilized to establish a role for ST6Gal-I in PC development and progression. AIM 2: ST6Gal-I's contribution to chemoresistance and potential as a therapeutic target. Patient-derived PC cells or cell lines with forced ST6Gal-I expression or knockdown will be treated with gemcitabine to test the hypothesis that ST6Gal-I activity promotes chemoresistance. To show that ST6Gal-Iexpressing cells selectively survive gemcitabine treatment in vivo, ST6Gal-I expression will be quantified in patient-derived tumor xenografts harvested from mice treated with or without gemcitabine. Viable cells will be harvested from the gemcitabine-treated tumor xenografts to obtain an in vivo-selected chemoresistant population. These cells will then be subjected to ST6Gal-I knockdown, followed by gemcitabine treatment, to determine whether gemcitabine sensitivity can be restored in a cell population with known stable resistance.

描述(由申请人提供)：异常的表面糖基化是肿瘤细胞的一个决定性特征，然而，多糖在致癌过程中的功能贡献在很大程度上被忽视了。与肿瘤相关的主要变化之一是�6唾液酸的增加，ST6Gal-I糖基转移酶将一种带负电荷的糖添加到选定的受体上。在初步研究中，我们首次发现ST6Gal-I在 ST6Gal-I上调导致胰腺癌(PC)细胞获得“癌症干细胞”(CSCs)的行为特征，CSCs是一种干细胞群，具有固有的转移性，对细胞死亡具有抵抗力，对化疗药物不敏感。我们还取得了里程碑式的发现，即ST6Gal-I在PC细胞中上调诱导CSC相关转录因子Sox9的表达。SOX9的诱导是胰腺导管腺癌的关键启动事件。本申请的目标是确定ST6Gal-I在以下方面的作用：(I)由新的ST6Gal-I-NFkB-Sox9信号轴指导的类似CSC的行为；(Ii)基因工程小鼠的PC发病机制；以及(Iii)PC细胞对一线PC治疗药物吉西他滨的耐药性。为了实现这些目标，我们将使用独特的细胞模型系统，强制ST6Gal-I过度表达或缺失的自发PC小鼠模型，以及患者来源的原发肿瘤和肿瘤异种移植组织。这项研究将扩展糖如何调节肿瘤细胞行为的基础知识，并通过确定ST6Gal-I作为耐药细胞的标志和恢复治疗反应的潜在临床靶点来影响患者护理。目的1：ST6Gal-I信号通过Sox9促进干样PC行为，从而推动发病。患者来源的原代PC细胞，或强制表达或敲除ST6Gal-I的PC细胞系，将被用于测试ST6Gal-I活性通过NFkB-Sox9刺激信号以促进包括自我更新、肿瘤球体生长和肿瘤启动潜力在内的CSC行为的假设。将在患者胰腺癌组织中检测ST6Gal-I、激活的NFkB和Sox9的共同表达，并将利用具有胰腺特异性ST6Gal-I敲除或敲除的自发性PC小鼠模型来确定ST6Gal-I在PC的发生和发展中的作用。目的2：ST6Gal-I在化疗耐药中的作用及其作为治疗靶点的潜力。患者来源的PC细胞或ST6Gal-I被迫表达或被敲除的细胞系将被吉西他滨处理，以检验ST6Gal-I活性促进化疗耐药的假设。为了证明表达ST6Gal-I的细胞在体内选择性地存活于吉西他滨治疗中，我们将定量检测使用或不使用吉西他滨治疗的小鼠的患者来源的肿瘤移植瘤中ST6Gal-I的表达。活细胞将从吉西他滨治疗的肿瘤异种移植中获得，以获得体内选择的化疗耐药群体。然后对这些细胞进行ST6Gal-I基因敲除，然后进行吉西他滨治疗，以确定在已知具有稳定耐药性的细胞群体中是否可以恢复吉西他滨的敏感性。