Dissecting Hedgehog, TGF beta and BMP Signaling During Pancreatic Tumorigenesis

剖析胰腺肿瘤发生过程中的 Hedgehog、TGF beta 和 BMP 信号传导

• 批准号: 8254393
• 负责人: BRIAN C LEWIS
• 金额: $ 33.95万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-08 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8254393
• 关键词: Address; Alleles; American; BMPR2 gene; Biochemical; Biological; Biological Models; Cancer Etiology; Cancer cell line; Cell Culture Techniques; Cell Line; Cells; Cessation of life; Collection; Conflict (Psychology); Data; Defect; Development; Diagnosis; Disease; Disease Progression; Epithelial; Epithelial Cells; Epithelium; Erinaceidae; Event; Family; Frequencies; Gene Expression Profiling; Genes; Genetic; Genetic Transcription; Gli2 protein; In Vitro; KRAS2 gene; Lead; Lesion; Ligands; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Molecular; Mutation; Oncogenes; Pancreas; Pancreatic Ductal Adenocarcinoma; Pathogenesis; Pathway interactions; Phenotype; Phosphotransferases; Primary Cell Cultures; Public Health; Publishing; Relative (related person); Repressor Molecules; Role; Sampling; Signal Pathway; Signal Transduction; Specimen; Transforming Growth Factor beta; Tumor Cell Line; United States; Work; autocrine; bone morphogenetic protein receptors; bone morphogenic protein; cancer cell; cancer initiation; carcinogenesis; cell behavior; in vivo; mortality; mouse model; novel; novel therapeutics; pancreatic cancer cells; pancreatic neoplasm; pancreatic tumorigenesis; paracrine; postnatal; public health relevance; receptor; research study; small hairpin RNA; smoothened signaling pathway; statistics; transcription factor; tumor; tumor progression

DESCRIPTION (provided by applicant): Pancreatic cancer is a leading cause of cancer-related mortality in the United States, with an estimated 35,000 people dying from this disease in 2009. Activating mutations in the KRAS2 oncogene occur in >90% of pancreatic ductal adenocarcinomas (PDAC), the most common type of pancreatic cancer, and are believed to be initiating lesions in PDAC. Elevated levels of hedgehog pathway components are found in a majority of PDAC specimens and cell lines. Loss of the Smad4 transcriptional regulator occurs in approximately half of PDAC cases, and inactivation of the TGF?RII, BMPRII, and ALK4 receptor kinases that act upstream of Smad4 occurs in a smaller subset of PDAC cases. Yet, the precise roles of the hedgehog pathway and the signaling pathways activated by TGF-? family ligands in PDAC remain unclear. This application therefore proposes to use a novel mouse modeling system and complementary cell culture and in vitro studies to systematically investigate the roles of these pathways in pancreatic carcinogenesis. Prior studies have provided conflicting data on whether hedgehog ligands act in both autocrine and paracrine fashion, or only a paracrine manner, during pancreatic tumor development. Therefore, studies in Aim 1 will use novel mouse models to directly compare the ability of sonic hedgehog (Shh) and its downstream transcription factors Gli1 and Gli2 to cooperate with activated Kras during pancreatic tumorigenesis in vivo. Analyses of tumor samples and cell lines generated from the tumors induced in this Aim will be performed to determine whether Shh stimulates signaling in both the cancer cells and the reactive stroma, or only within the reactive stroma. Finally, using a novel dominant-repressor Gli3 allele, the requirement for Gli transcription activity in Kras-induced pancreatic tumorigenesis will be determined. The studies in Aim 2 will identify the relative contributions of defects in TGF-? and BMP signaling to pancreatic tumorigenesis. ShRNAs targeting Smad4, TGF?RII, or BMPRII will be delivered specifically to the pancreatic epithelium in vivo, and their ability to cooperate with activated Kras determined. Complementary experiments in cancer cell lines derived from the induced tumors will be performed to determine whether defects in TGF-( or BMP signaling alter the phenotypes of pancreatic cancer cells, and how TGF-( family ligands influence pancreatic cancer cell behavior. The studies in Aim 3 will determine whether there is cross-talk between the hedgehog and TGF-( signaling cascades in pancreatic cancer cells, and how this cross-talk influences the phenotypes of these cells. Finally, gene expression profiling will be used to identify important genes downstream of the hedgehog and TGF-( signaling cascades. The biological importance of these genes during pancreatic tumorigenesis will be validated using studies of the cancer cell lines generated in Aims 1 and 2, and the ability of these genes to cooperate with activated Kras during pancreatic tumorigenesis in vivo. PUBLIC HEALTH RELEVANCE: Pancreatic cancer claims the lives of 35,000 Americans annually; therefore understanding the mechanisms that contribute to the initiation and progression of this disease is of great significance. Through the use of novel mouse models for pancreatic cancer, this application seeks to understand how alterations in the hedgehog, transforming growth factor beta, and bone morphogenic protein signaling pathways contribute to pancreatic cancer initiation and progression. These studies will significantly enhance the understanding of pancreatic cancer, and may lead to the development of novel therapeutic strategies, thereby reducing the impact of this disease on public health.

描述（由申请人提供）：胰腺癌是美国癌症相关死亡率的主要原因，2009年估计有35，000人死于该疾病。KRAS 2癌基因的激活突变发生在>90%的胰腺导管腺癌（PDAC）（最常见的胰腺癌类型）中，并且被认为是PDAC中的起始病变。在大多数PDAC标本和细胞系中发现hedgehog途径组分水平升高。Smad 4转录调节因子的丢失发生在大约一半的PDAC病例中，TGF？RII、BMPRII和ALK 4受体激酶作用于Smad 4的上游，出现在PDAC病例的较小子集中。然而，刺猬通路和TGF-β激活的信号通路的确切作用？PDAC中的家族配体仍不清楚。因此，本申请提出使用新的小鼠建模系统和互补的细胞培养和体外研究来系统地研究这些途径在胰腺癌发生中的作用。 先前的研究提供了相互矛盾的数据，刺猬配体是否自分泌和旁分泌的方式，或仅旁分泌的方式，在胰腺肿瘤的发展。因此，目标1中的研究将使用新型小鼠模型直接比较音刺猬（Shh）及其下游转录因子Gli 1和Gli 2在体内胰腺肿瘤发生期间与活化的Kras合作的能力。将对肿瘤样品和由在该目的中诱导的肿瘤产生的细胞系进行分析，以确定Shh是否刺激癌细胞和反应性基质两者中的信号传导，或仅刺激反应性基质内的信号传导。最后，使用一种新的显性阻遏物Gli 3等位基因，将确定在Kras诱导的胰腺肿瘤发生中对Gli转录活性的需求。 目标2中的研究将确定TGF-β 1缺陷的相对贡献。和BMP信号传导到胰腺肿瘤发生。靶向Smad 4、TGF？RII或BMPRII将在体内特异性地递送至胰腺上皮，并且确定它们与活化的Kras合作的能力。将在源自诱导肿瘤的癌细胞系中进行补充实验以确定TGF-β或BMP信号传导的缺陷是否改变胰腺癌细胞的表型，以及TGF-β家族配体如何影响胰腺癌细胞行为。 目标3中的研究将确定胰腺癌细胞中hedgehog和TGF-β信号级联之间是否存在串扰，以及这种串扰如何影响这些细胞的表型。最后，基因表达谱将用于鉴定hedgehog和TGF-β信号级联下游的重要基因。这些基因在胰腺肿瘤发生过程中的生物学重要性将使用目的1和2中产生的癌细胞系的研究以及这些基因在体内胰腺肿瘤发生过程中与活化的Kras合作的能力来验证。 公共卫生关系：胰腺癌每年夺去35，000名美国人的生命;因此，了解导致这种疾病发生和发展的机制具有重要意义。通过使用胰腺癌的新型小鼠模型，本申请旨在了解刺猬，转化生长因子β和骨形态发生蛋白信号通路的改变如何有助于胰腺癌的发生和进展。这些研究将大大提高对胰腺癌的认识，并可能导致新的治疗策略的发展，从而减少这种疾病对公共卫生的影响。