Molecular Mechanisms of Gastrin Mediated Pathways in Gastric Cancer Cells

胃癌细胞胃泌素介导途径的分子机制

• 批准号: 8045809
• 负责人: BASABI RANA
• 金额: --
• 依托单位: EDWARD HINES JR VA HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8045809
• 关键词: Adenocarcinoma Cell; Adverse effects; Aging; Animal Model; Biological Assay; Cancer Cell Growth; Cancer Etiology; Carcinoma; Cause of Death; Cell Culture Techniques; Cell Line; Cell Proliferation; Cell physiology; Cessation of life; Cholecystokinin B Receptor; Clinical; Colorectal Cancer; Conditioned Culture Media; DNA; Data; Detection; Development; Disease; Disease Progression; Event; Excision; Future; Gastrins; Gastrointestinal Neoplasms; Gastrointestinal Physiology; Gastrointestinal tract structure; Gene Silencing; Glycine; Goals; Grant; Growth; Growth Factor; Helicobacter Infections; Immunoprecipitation; In Vitro; Ingestion; Injection of therapeutic agent; Interleukin-10; Investigation; JUN gene; Lead; Luciferases; MAP Kinase Gene; MAPK14 gene; MAPK8 gene; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of gastrointestinal tract; Mediating; Mediator of activation protein; Molecular; Mus; Neoplasm Metastasis; Operative Surgical Procedures; Pathway interactions; Patients; Pharmaceutical Preparations; Phosphotransferases; Procedures; Process; Proton Pump Inhibitors; Research; Research Design; Risk Factors; Role; Serum; Signal Pathway; Signal Transduction; Stomach; Stomach Carcinoma; Tail; Technology; Therapeutic; Transfection; United States; Veins; Veterans; Xenograft procedure; base; cancer cell; cell motility; cell type; combat; cytokine; design; drug development; effective therapy; gastrointestinal; in vivo; inhibitor/antagonist; malignant stomach neoplasm; member; migration; mixed lineage kinase 3; mortality; mouse model; neoplastic cell; overexpression; patient population; peptide hormone; progastrin; subcutaneous; tumor; tumor progression

DESCRIPTION (provided by applicant): Rationale: Gastric cancer is a leading cause of cancer death and ranks second in the overall cancer mortality worldwide. The GI (gastrointestinal) peptide hormone gastrin (both processed and unprocessed forms) is regarded as an important contributing factor towards the patho-physiology of GI malignancies. Studies with mice over-expressing the mature amidated form of gastrin were shown to produce invasive gastric carcinoma, which synergized with Helicobacter infection to promote carcinoma progression. These effects of gastrin pose a major clinical concern, since an increase in serum gastrin levels is a common side effect of the use of proton pump inhibitors (PPIs) or Helicobacter pylori infection. Thus the signaling pathways by which gastrin mediates cancer progression, though still poorly understood, represent an important target for the development of drugs to combat gastric cancer. The major focus of this proposal is to elucidate the signaling mechanism by which gastrin promotes tumor progression and metastasis in gastric cancer cells, and to target this signaling axis in mouse models of gastric cancer. Our recent studies indicated that: (i) treatment with amidated gastrin (G17) potently induces gastric cancer cell migration and invasion; (ii) G17-induced migration is associated with activation of all 3 MAPK pathways including ERK, p38 and JNK; (iii) G17 stimulation results in activation of the MAP3K member MLK3, which is an upstream activator of JNK, (iv) G17-induced migration operates via MLK3/JNK1 axis in vitro; (v) G17 activates the JNK downstream c-Jun via releasing some factor and (vi) conditioned media obtained from G17-treated gastric cancer cells showed increased IL-10 release by G17. Hypothesis: Based on these preliminary data we hypothesize that G17-induced gastric cancer cell growth (proliferation), migration and invasion operates through activation of MLK3/JNK1 signaling. Specific Objectives: To elucidate the signaling mechanism by which G17 induces gastric carcinoma progression, we propose the following 3 specific aims: (1) to determine whether G17-induced migration, invasion, EMT and growth involve the MLK3/JNK1 axis in vitro; (2) to elucidate the mechanism by which G17 activates MLK3/JNK1 axis and the role of cytokines in mediating this; (3) to determine the effect of hypergastrinemia on the progression of gastric cancer in vivo and the effect of inhibition of MLK3/JNK1 pathways, either by pharmacological inhibitors or via gene silencing on this progression. Procedures to be used: The proposed studies will be performed using a broad range of technical approaches, including migration, invasion and cell proliferation assays, Western analyses, DNA transfection, luciferase and kinase assays, immunoprecipitation, SiRNA technology, subcutaneous xenografts and tail vein injections. Significance of potential new findings: The fact that hypergastrinemia promotes tumor progression poses a major clinical concern in the setting of increased PPI use and H.pylori infection. No information is currently available regarding the involvement of MLK3/JNK axis in promoting gastric cancer growth and progression. The successful completion of these studies will determine whether this axis promotes gastrin-induced gastric carcinoma progression. The results from these studies can further promote the detailed investigation of the potential use of available MLK/JNK pathway inhibitors as safe, noninvasive drugs for the treatment of patients with gastric as well as other gastrin- dependent GI malignancies. PUBLIC HEALTH RELEVANCE: The proposed studies are of significant importance to the VA patient population, since GI cancer is prevalent among aging veterans. Surgical resection is the only form of therapy currently available to treat gastric or GI cancers, which is effective only if the tumor is detected early. The long-term focus of our studies is to develop a noninvasive form of curative therapy for treating VA patients with gastric or other GI malignancies. To achieve this goal, it is important to gain a better understanding of the molecular events that lead to the development and progression of these diseases. Since the GI peptide hormone gastrin is known to promote progression of gastric cancers, the studies described here will be focused on understanding the detailed mechanism by which gastrin mediates this function. These studies will be performed utilizing both cell culture (in vitro) and animal models of gastric cancer (in vivo). Once these mediators are identified, drugs that can target these mediators can be designed in the future, and utilized as safer, noninvasive therapeutic drugs for treating gastric cancer.

描述（由申请人提供）： 理由：胃癌是癌症死亡的主要原因，在全球癌症总死亡率中排名第二。胃肠道（胃肠）肽激素胃泌素（加工和未加工的形式）被认为是胃肠道恶性肿瘤的病理生理学的一个重要因素。对小鼠过表达成熟酰胺化形式的胃泌素的研究显示产生浸润性胃癌，其与螺杆菌感染协同促进癌进展。由于血清胃泌素水平升高是使用质子泵抑制剂（PPI）或幽门螺杆菌感染的常见副作用，因此胃泌素的这些作用引起了主要的临床关注。因此，胃泌素介导癌症进展的信号传导途径，尽管仍然知之甚少，但代表了开发对抗胃癌药物的重要目标。该提案的主要重点是阐明胃泌素促进胃癌细胞中肿瘤进展和转移的信号传导机制，并在胃癌小鼠模型中靶向该信号传导轴。我们最近的研究表明：（i）酰胺化胃泌素（G17）处理有效地诱导胃癌细胞的迁移和侵袭：（ii）G17诱导的迁移与ERK、p38和JNK三条MAPK通路的激活有关;（iii）G17刺激导致MAP 3 K成员MLK 3的活化，MLK 3是JNK的上游活化剂，（iv）G17诱导的迁移在体外通过MLK 3/JNK 1轴起作用;（v）G17通过释放一些因子激活JNK下游的c-Jun;和（vi）从G17处理的胃癌细胞获得的条件培养基显示G17增加的IL-10释放。假设：基于这些初步数据，我们假设G17诱导的胃癌细胞生长（增殖）、迁移和侵袭通过激活MLK 3/JNK 1信号传导而起作用。具体目标：为了阐明G17诱导胃癌进展的信号转导机制，我们提出了以下三个具体目标：（1）确定G17诱导的迁移、侵袭、EMT和生长是否涉及MLK 3/JNK 1轴;（2）阐明G17激活MLK 3/JNK 1轴的机制以及细胞因子在其中的作用;（3）确定高胃泌素血症对体内胃癌进展的影响以及通过药理学抑制剂或通过基因沉默抑制MLK 3/JNK 1途径对该进展的影响。拟采用的程序：将使用广泛的技术方法进行拟定研究，包括迁移、侵袭和细胞增殖试验、Western分析、DNA转染、荧光素酶和激酶试验、免疫沉淀、SiRNA技术、皮下异种移植和尾静脉注射。潜在新发现的意义：高胃泌素血症促进肿瘤进展的事实在PPI使用增加和幽门螺杆菌感染的情况下构成了一个主要的临床问题。目前没有关于MLK 3/JNK轴参与促进胃癌生长和进展的信息。这些研究的成功完成将确定该轴是否促进胃泌素诱导的胃癌进展。这些研究的结果可以进一步促进对现有MLK/JNK通路抑制剂作为安全、非侵入性药物用于治疗胃以及其他胃泌素依赖性GI恶性肿瘤患者的潜在用途的详细研究。 公共卫生相关性： 拟议的研究对VA患者人群具有重要意义，因为GI癌症在老年退伍军人中普遍存在。手术切除是目前治疗胃癌或GI癌的唯一形式，只有在早期发现肿瘤时才有效。我们研究的长期重点是开发一种非侵入性的治疗方法，用于治疗伴有胃或其他GI恶性肿瘤的VA患者。为了实现这一目标，重要的是更好地了解导致这些疾病发展和进展的分子事件。由于已知胃肠道肽激素胃泌素可促进胃癌的进展，因此本文所述的研究将侧重于了解胃泌素介导此功能的详细机制。这些研究将利用细胞培养（体外）和胃癌动物模型（体内）进行。一旦这些介质被确定，可以在未来设计出针对这些介质的药物，并作为更安全，非侵入性的治疗药物用于治疗胃癌。