Role of Annexin-II in growth factor/co-carcinogenic effects of progastrin

膜联蛋白-II 在生长因子/前胃泌素的协同致癌作用中的作用

• 批准号: 7897648
• 负责人: Pomila Singh
• 金额: $ 29.92万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-10 至 2011-08-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7897648
• 关键词: ANXA2 gene; Abbreviations; Aberrant crypt foci; Acute; Adenomatous Polyps; Affinity; Antibodies; Apoptosis; Apoptotic; Applications Grants; Azoxymethane; Binding; Biochemical; Biological; Blood; Carcinoma; Cell Line; Cell membrane; Cells; Cellular Membrane; Cholecystokinin B Receptor; Chronic; Clathrin; Co-Immunoprecipitations; Colon Carcinoma; Colonic Neoplasms; Colonoscopy; Colorectal; Colorectal Cancer; Confocal Microscopy; Consent; Correlative Study; Data; Detection; Development; Disease; Distal; Early Endosome; Epithelial; Epithelial Cells; Excision; Fluorescence; Funding; Future; Gastrins; Gene Targeting; Genes; Genus Cola; Goals; Grant; Growth; Growth Factor; Human; Hyperplasia; Immunohistochemistry; Immunoprecipitation; In Situ; In Vitro; Intestines; Intracellular translocation; Investigation; Kinetics; Knockout Mice; Learning; Liver; Malignant neoplasm of pancreas; Measures; Mediating; Methods; Modeling; Mus; Operative Surgical Procedures; Organelles; PI3K/AKT; Pancreas; Pathway interactions; Patients; Peptides; Phosphorylation; Phosphotransferases; Pilot Projects; Proteins; Protocols documentation; RNA; Recombinants; Relative (related person); Reporting; Research Ethics Committees; Risk; Role; SRC gene; Sampling; Screening procedure; Serum; Serum-Free Culture Media; Signal Pathway; Signaling Molecule; Small Interfering RNA; Staging; Techniques; Time; Transgenic Mice; Transgenic Organisms; Up-Regulation; Western Blotting; Wild Type Mouse; adenoma; autocrine; base; big gastrin; cancer cell; carcinogenesis; clinically relevant; colon carcinogenesis; colonic crypt; crypt cell; extracellular; fatty acid-binding proteins; fetal; gastrin 17; in vitro Model; in vivo; mouse model; neoplastic; novel; overexpression; progastrin; receptor; research study; response; transcription factor; uptake

In the past funding period we confirmed our major hypothesis that progastrin peptides (PG) exert proliferative/anti-apoptotic/co-carcinogenic effects on intestinal/colonic epithelial cell lines, in vitro and in vivo, and increase the risk of colon carcinogenesis in response to azoxymethane (AOM). Additionally, we made the novel discovery that Annexin II (ANXII) functions as a high affinity receptor for PG and is required for mediating growth factor effects of PG on target cells. An important role of β-catenin, c-Src, PI3K/Akt, MAPK/ERK and NFkB in mediating growth factor effects of PG on normal and neoplastic intestinal epithelial cells was also identified. Based on these findings, the major hypothesis of our current grant proposal is that ANXII facilitates the activation of one or more of the above indicated kinases/transcription factors in response to PG. Experiments in Aims 1 and 2 will examine this hypothesis. In Aim 1, PG responsive cell lines, altered for ANX-II expression will be used, as an in vitro model of investigation. For the in vivo studies, we will either use transgenic mice over-expressing PG (Fabp-PG), before or after modulation of ANXII expression. We will either use ANX-II knock out mice, or use specific siRNA for down regulating ANXII expression. In preliminary studies co-localization of PG with ANXII in situ, in cells over-expressing autocrine PG or responsive to exogenous PG was observed. Therefore in Aim 2, pathways mediating intracellular translocation of ANXII/PG, in response to binding of PG to extracellular ANXII (and its functional significance) will be examined; fluorescence based detection techniques and biochemical analysis will be used. In Aim 3 the clinical relevance of our findings will be examined in a pilot correlative study with samples obtained from patients, consented at the time of colonoscopy or at the time of surgical resection of colonic tumors, at different stages of colon carcinogenesis. Our initial studies strongly implicate PG peptides in the progression of the colon cancer disease. Therefore, understanding the role of ANX-II and the various signaling molecules in mediating the actions of PG are clinically important goals. Data obtained from the above studies will facilitate the development of more effective strategies for targeting the actions of PG for preventative and treatment purposes.

在过去的资助期内，我们证实了我们的主要假设，即在体外和体内，前胃泌素肽（PG）对肠/结肠上皮细胞系具有增殖/抗凋亡/共致癌作用，并在偶氮甲烷（AOM）的作用下增加结肠癌发生的风险。此外，我们还发现了Annexin II （anxi）作为PG的高亲和力受体，并且是介导PG对靶细胞的生长因子作用所必需的。我们还发现β-catenin、c-Src、PI3K/Akt、MAPK/ERK和NFkB在介导PG对正常和肿瘤肠上皮细胞生长因子作用中的重要作用。基于这些发现，我们目前申请的主要假设是，焦虑症促进了一种或多种上述激酶/转录因子的激活，以响应PG。目标1和目标2的实验将检验这一假设。在Aim 1中，将使用改变了ax - ii表达的PG应答细胞系作为体外研究模型。在体内研究中，我们将使用过表达PG （Fabp-PG）的转基因小鼠，在调节anxi表达之前或之后。我们要么使用敲除anxi - ii的小鼠，要么使用特异性siRNA下调anxi的表达。在初步研究中，PG与anxi在原位共定位，在过度表达自分泌PG或对外源性PG有反应的细胞中被观察到。因此，在Aim 2中，将研究PG与细胞外焦虑症结合时介导焦虑症/PG细胞内易位的途径（及其功能意义）；将使用基于荧光的检测技术和生化分析。在Aim 3中，我们的研究结果的临床相关性将在一项试点相关研究中进行检验，该研究从患者身上获得样本，这些患者在结肠镜检查或结肠肿瘤手术切除时同意，处于结肠癌发生的不同阶段。我们的初步研究强烈地暗示PG肽在结肠癌疾病的进展中。因此，了解ax - ii和各种信号分子在介导PG作用中的作用是临床重要的目标。从上述研究中获得的数据将有助于制定更有效的策略，以针对PG的行动进行预防和治疗。