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: 8454513
• 负责人: BRIAN C LEWIS
• 金额: $ 31.87万
• 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/8454513
• 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.

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.在大多数PDAC标本和细胞系中发现了刺猬途径成分的水平升高。 SMAD4转录调节剂的丢失发生在大约一半的PDAC病例中，并且在较小的PDAC病例的较小子集中发生TGF？RII，BMPRII和ALK4受体激酶。然而，刺猬途径的确切作用和由TGF-激活的信号通路？ PDAC中的家庭配体尚不清楚。因此，该应用建议使用新型的小鼠建模系统和互补的细胞培养和体外研究，以系统地研究这些途径在胰腺癌中的作用。 先前的研究提供了有关刺猬配体在胰腺肿瘤发育过程中是否以自分泌和旁分泌方式起作用，还是仅是旁分泌方式的相互矛盾的数据。因此，AIM 1中的研究将使用新型小鼠模型直接比较Sonic Hedgehog（SHH）及其下游转录因子GLI1和GLI2的能力，以便在体内胰腺肿瘤发生过程中与活化的KRAS合作。将对在此目标中诱导的肿瘤产生的肿瘤样品和细胞系进行分析，以确定SHH是在癌细胞和反应性基质中还是仅在反应性基质中刺激信号传导。最后，将使用新型的显性抑制GLI3等位基因，将确定KRAS诱导的胰腺肿瘤发生中GLI转录活性的要求。 AIM 2中的研究将确定TGF-缺陷的相对贡献？和BMP信号传导至胰腺肿瘤发生。靶向Smad4，TGF？RII或BMPRII的shRNA将专门交付给体内胰腺上皮，并与确定激活的KRAS合作的能力。将进行源自诱导肿瘤的癌细胞系中的互补实验，以确定TGF-中的缺陷（或BMP信号传导是否会改变胰腺癌细胞的表型，以及TGF-（家庭配体影响胰腺癌细胞行为）。 AIM 3中的研究将确定刺猬和TGF-（信号传导在胰腺癌细胞中的层次层流以及这种串扰如何影响这些细胞的表型。最后，基因表达分析将用于识别刺猬和TGF-（tgf-（TGF-（TGF-）potigation progience prodiestr的基因的重要基因。在AIM 1和2中产生的癌细胞系，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。