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: 7659347
• 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 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7659347
• 关键词: ANXA2 gene; Address; Adenocarcinoma; Adenomatous Polyps; Affinity; Annexins; Apoptotic; Applications Grants; Azoxymethane; Binding; Biochemical; Blood; CCKBR gene; CD44 gene; Cell Line; Cell surface; Cells; Colon Carcinoma; Colonic Neoplasms; Colonoscopy; Consent; Correlative Study; Data; Detection; Development; Disease; Distal; Down-Regulation; Epithelial Cells; Excision; Fluorescence; Funding; Future; Genus Cola; Goals; Growth; Growth Factor; Human Resources; Hyperplasia; Immunofluorescence Immunologic; In Situ; In Vitro; Integral Membrane Protein; Intestines; Intracellular translocation; Investigation; Knockout Mice; LDL-Receptor Related Protein 1; Lesion; Location; Mediating; Minor; Nuclear; Operative Surgical Procedures; Pathway interactions; Patients; Peptides; Phosphorylation; Phosphotransferases; Postdoctoral Fellow; Relative (related person); Risk; Role; SRC gene; Sampling; Serum; Signal Pathway; Signaling Molecule; Small Interfering RNA; Specimen; Staging; Techniques; Time; Transgenic Mice; Work; abstracting; autocrine; base; clinically relevant; colon carcinogenesis; extracellular; in vitro Model; in vivo; knock-down; mouse model; neoplastic; novel; progastrin; public health relevance; receptor; research study; response; transcription factor

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.

在过去的资助期间，我们证实了我们的主要假设，即前胃泌素肽（PG）在体外和体内对肠/结肠上皮细胞系产生增殖/抗凋亡/共致癌作用，并增加了对氧化偶氮甲烷（AOM）的结肠致癌风险。此外，我们还发现膜联蛋白II（ANXII）作为PG的高亲和力受体发挥作用，并且是介导PG对靶细胞的生长因子效应所必需的。β-catenin、c-Src、PI 3 K/Akt、MAPK/ERK和NFkB在PG介导的生长因子对正常和肿瘤性肠上皮细胞的作用中起重要作用。基于这些发现，我们目前的拨款建议的主要假设是，ANXII促进一个或多个上述激酶/转录因子的激活，以响应PG。目标1和2的实验将检验这一假设。在目的1中，将使用针对ANX-II表达改变的PG应答细胞系作为体外研究模型。对于体内研究，我们将在调节ANXII表达之前或之后使用过表达PG（Fabp-PG）的转基因小鼠。我们将使用ANX-II敲除小鼠，或使用特异性siRNA下调ANXII表达。在初步研究中，观察到PG与ANXII原位共定位于过表达自分泌PG或对外源PG有反应的细胞中。因此，在目标2中，将检查响应于PG与细胞外ANXII的结合而介导ANXII/PG的细胞内易位的途径（及其功能意义）;将使用基于荧光的检测技术和生化分析。在目标3中，我们的研究结果的临床相关性将在一项初步相关性研究中进行检查，该研究使用从结肠镜检查时或结肠肿瘤手术切除时同意的患者中获得的样本，处于结肠癌发生的不同阶段。我们的初步研究强烈暗示PG肽在结肠癌疾病的进展。因此，了解ANX-II和各种信号分子在介导PG作用中的作用是临床上重要的目标。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的作用进行预防和治疗。