REGULATION OF ATROPHY-INDUCED PROGENITOR CELLS IN THE GASTRIC CORPUS

胃体中萎缩诱导的祖细胞的调节

• 批准号: 10397061
• 负责人: Jason C Mills
• 金额: $ 38.25万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-11 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10397061
• 关键词: Acids; Acute; Applications Grants; Architecture; Atrophic; Autophagocytosis; Award; Bacteria; Binding; Biological Assay; CD44 gene; Cancer Patient; Carcinogens; Cause of Death; Cell Cycle; Cell Death; Cell Differentiation process; Cells; Chief Cell; Chronic; Coupled; Data; Differentiation and Growth; Diphtheria Toxin; Disease; Dose; Drug Screening; Enzymes; Fluorescence; Fundus; Gastric Metaplasia; Gastric Parietal Cells; Gene Expression Profile; Generations; Growth; Helicobacter pylori; Histology; Homeostasis; Human; Hyaluronic Acid; Image; Immunofluorescence Immunologic; Infection; Inflammation; Injections; Injury; Lysosomes; Malignant Neoplasms; Mediating; Metabolic Pathway; Metaplasia; Metformin; Methylnitrosourea; Mitotic; Modeling; Monitor; Mus; Mutation; Oncogenes; Organ; Organoids; Pathway interactions; Patient-Focused Outcomes; Patients; Pattern; Pharmaceutical Preparations; Phase; Population; Process; Proliferating; Proteins; Protocols documentation; Publishing; Recovery; Risk; Role; Route; Running; STAT3 gene; Selective Estrogen Receptor Modulators; Signal Pathway; Signal Transduction; Sirolimus; Smooth Pursuit; Solid; Stomach; Stomach Diseases; Tamoxifen; Testing; Time; Tissues; biobank; cancer risk; cell type; diphtheria toxin receptor; epithelial stem cell; experimental study; gastric corpus; gastric organoids; gastric tumorigenesis; gene discovery; human tissue; in vivo; in vivo evaluation; injury recovery; malignant stomach neoplasm; mouse model; novel; receptor; recruit; replication stress; response; spasmolytic polypeptide; stem; stem cell differentiation; stem cell expansion; stem cell genes; stem cell proliferation; stem cells; theories; transcriptome; transcriptome sequencing; tumor progression; tumorigenesis

PROJECT SUMMARY The epithelial stem cell of the stomach is poorly characterized, which is surprising given its role in many gastric diseases. High doses of the Selective Estrogen Receptor Modulator (SERM) tamoxifen (HD-Tam) kill parietal cells and causes a proliferative, metaplastic gastric response which follows the pattern seen in patients chronically infected with Helicobacter pylori, but in a more synchronous and controllable model, with the effect peaking at 3 days post injections. Published studies using HD-Tam show that this response is dependent on a ℗ERK→CD44→℗STAT3 signaling axis and combines proliferation both from expansion of the isthmal stem cell (iSC) and contribution from mature zymogenic cells which reprogram to re-enter the cell cycle, termed recruited stem cells (rSCs). While these proliferating populations are inseparable in their response to any metaplasia-causing agent, we recently discovered that highly specific diphtheria toxin (DT)-mediated parietal cell death induces iSC expansion but no metaplasia or rSC generation. These two models now allow us to specifically characterize iSCs and rSCs to determine their relative mechanisms of proliferation. Our Aims are: 1) Characterize mechanisms of iSC expansion/recovery and determine the specific role of CD44 in iSC expansion both in vivo and in human and murine gastric organoids (“gastroids”). We will also sort pure iSCs following DT and mixed iSCs+rSCs following HD-Tam and run RNA-Seq to characterize each population. 2) Examine new metabolic pathways governing each proliferative population using rapamycin and metformin, both of which are seen to decrease proliferation following HD-Tam. These drugs will be tested in vivo following HD-Tam and DT as well as in gastroids, along with a drug screen to identify other proteins involved in their signaling pathways. 3) We are now able to determine whether metaplastic rSC generation increases risk of gastric tumorigenesis over increased iSC proliferation alone. We will follow an established protocol using the carcinogen MNU to drive tumorigenesis in mice while treating with cycles of DT or HD-Tam while monitoring the entire course of tumorigenesis non-invasively with Near Infrared Fluorescence live imaging with novel probes found to track gastric cancer in vivo. We will track specific mutations and proteins necessary for this cancer progression and focus on any candidates found with our large biobank of human gastric cancer tissues. Our DT and HD-Tam models allow us to separate iSC and rSC proliferation in the stomach for the first time, finally allowing for detailed characterization of each population. Our experiments aim to use this opportunity to attribute our known proliferative axis more specifically to iSC and/or rSC expansion, define new metabolic pathways involved in governing proliferation in each population, and run unbiased screens to identify additional modulators of these pathways. Finally, our models allow us to test a new theory for how solid tissue cancers arise, investigating whether rounds of reprogramming and cell cycle re-entry of mature, post-mitotic cells (rSC generation) increase risk for tumorigenesis over increased iSC proliferation alone.

项目摘要 胃的上皮干细胞的特征很差，鉴于其在许多胃中的作用，这是令人惊讶的 疾病。高剂量的选择性雌激素受体调节器（SERM）他莫昔芬（HD-TAM）杀死顶叶 细胞并引起增殖，化生的胃反应，遵循患者的模式 长期被幽门螺杆菌感染，但在更同步和受控的模型中，其作用 注射后3天达到峰值。使用HD-TAM发表的研究表明，此反应取决于 ℗ERK→CD44→℗STAT3信号轴和组合增殖都来自地峡茎的膨胀 细胞（ISC）和成熟的酶原细胞的贡献，这些细胞重新进入细胞周期，称为称为细胞周期 招募的干细胞（RSC）。尽管这些扩散的人群在对任何 引起元素的剂，我们最近发现高度特异 细胞死亡会引起ISC扩展，但没有化生或RSC产生。这两个模型现在使我们能够 特别表征ISC和RSC，以确定它们的相对相对机制。 我们的目标是：1）表征ISC扩展/恢复的机制，并确定CD44的特定作用 在ISC膨胀中，体内以及人类和鼠胃癌（“胃肠道”）。我们还将排序 在HD-TAM之后DT和混合ISCS+RSC之后的ISC并运行RNA-Seq以表征每个种群。 2）检查使用雷帕霉素和二甲双胍的新的代谢途径，用于每个增殖种群， 两者都可以看到HD-TAM后降低增殖。这些药物将在体内进行测试 HD-TAM和DT以及胃肠道，以及药物筛选，以鉴定其他蛋白质 信号通路。 3）我们现在能够确定Metaplastic RSC生成是否增加 仅ISC增殖而增加的胃肿瘤发生。我们将遵循一个建立的协议 致癌物MNU在监测时用DT或HD-TAM的周期处理小鼠的肿瘤发生 肿瘤发生的整个过程无创，近红外荧光实时成像与新型 发现在体内追踪胃癌的问题。我们将跟踪特定的突变和蛋白质 癌症的进展和专注于我们大型人类胃癌组织的生物库发现的任何候选者。 我们的DT和HD-TAM模型使我们能够首次将ISC和RSC扩散分开， 最终允许对每个人群进行详细表征。我们的实验旨在利用这个机会 更具体地将我们已知的增殖轴归因于ISC和/或RSC扩展，定义新的代谢 每个人群中涉及的途径，并运行公正的屏幕以识别其他 这些途径的调节剂。最后，我们的模型使我们能够测试固体组织如何取消的新理论 出现，研究成熟，后有丝分裂细胞的重编程和细胞周期的回合（RSC）是否重新进入 产生）增加了仅增加ISC增殖而增加肿瘤发生的风险。