Role of Heparan Sulfate-Degrading Sulfatases in Pancreatic Adenocarcinomas

硫酸乙酰肝素降解硫酸酯酶在胰腺腺癌中的作用

• 批准号: 7128287
• 负责人: STEVEN D ROSEN
• 金额: $ 11.67万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7128287
• 关键词: adenocarcinoma; cell line; enzymes; heparan sulfate; human; motivation; neoplasm /cancer; proteins; reduction; role; stem cells; sulfatases; sulfation

DESCRIPTION (provided by applicant): Pancreatic adenocarcinoma is one of the most deadly malignancies in human for which there are very limited treatment options. There is great interest in the possible role of embryonic signaling pathways in the initiation and progression of this cancer and others. Among these pathways is canonical Wnt signaling, which is involved in the proliferation and self-renewal of stem/progenitor cells and has been speculated to have a similar role in cancer stem cells. The presence of activated beta-catenin in pancreatic tumor samples suggests that 30-40% of these tumors manifest Wnt signaling. Moreover, Matthias Hebrok and colleagues at UCSF have discovered that active Wnt signaling is required for the growth of several pancreatic adenocarcinoma cell lines in vitro. Our exploratory R21 project proposes to investigate the role of two novel sulfatases, called HSulf-1 and HSulf-2, in Wnt signaling within pancreatic adenocarcinomas and their contributions to the growth and tumorigenicity of these cancer cells. The Sulfs are extracellular enzymes which act on heparan sulfate proteoglycans (HSPGs) to remove a specific sulfation modification (glucosamine-6-O-sulfation). One known biological activity of the Sulfs is to modulate the interaction of Wnt ligands with HSPGs and to potentiate the ability of the Wnts to activate their signal transduction receptors. Our preliminary studies have found the expression of SULF1 or SULF2 transcripts in 23 of 24 pancreatic adenocarcinoma cell lines and the presence of Sulf-1 or Sulf-2 protein in 4/4 of these cell lines and 3/5 of pancreatic tumor samples. Expression of a dominant negative form (enzymatically-inactive mutant) of either Sulf-1 or Sulf-2 in 3 out of 4 of these lines resulted a reduction in Wnt signaling. Furthermore, co-culturing the same three cell lines in the presence of inactive Sulf protein produced a parallel reduction in Wnt signaling and cell growth in vitro. The proposed research will employ lentivirus-transduced shRNA expression to silence one or both Sulfs in representative pancreatic adenocarcinoma cell lines. Our Aims are: 1) To determine the effects of Sulf silencing on the growth and Wnt signaling of these cells in vitro; and 2) To determine the effects of Sulf silencing on the ability of the cells to form tumors in nude mice. Positive results from these studies should stimulate considerable interest in the Sulfs as possible targets (for small molecules or function-blocking antibodies) for the treatment of pancreatic adenocarcinoma in humans.

描述（由申请人提供）：胰腺癌是人类最致命的恶性肿瘤之一，其治疗选择非常有限。人们对胚胎信号通路在这种癌症和其他癌症的发生和进展中可能发挥的作用非常感兴趣。这些途径中包括经典的 Wnt 信号传导，它参与干细胞/祖细胞的增殖和自我更新，并推测在癌症干细胞中具有类似的作用。胰腺肿瘤样本中存在活化的 β-连环蛋白，表明这些肿瘤中有 30-40% 表现出 Wnt 信号传导。此外，加州大学旧金山分校的 Matthias Hebrok 及其同事发现，几种胰腺腺癌细胞系的体外生长需要活跃的 Wnt 信号传导。我们的探索性 R21 项目旨在研究两种新型硫酸酯酶（HSulf-1 和 HSulf-2）在胰腺癌 Wnt 信号传导中的作用及其对这些癌细胞生长和致瘤性的贡献。 Sulf 是细胞外酶，作用于硫酸乙酰肝素蛋白聚糖 (HSPG)，以去除特定的硫酸化修饰（葡萄糖胺-6-O-硫酸化）。 Sulf 的一种已知生物活性是调节 Wnt 配体与 HSPG 的相互作用并增强 Wnt 激活其信号转导受体的能力。我们的初步研究发现，24 个胰腺腺癌细胞系中有 23 个细胞系表达 SULF1 或 SULF2 转录本，其中 4/4 的细胞系和 3/5 的胰腺肿瘤样本中存在 Sulf-1 或 Sulf-2 蛋白。其中 4 个品系中有 3 个品系中 Sulf-1 或 Sulf-2 的显性失活形式（酶促失活突变体）的表达导致 Wnt 信号传导减少。此外，在无活性的 Sulf 蛋白存在下共培养相同的三种细胞系，导致 Wnt 信号传导和体外细胞生长平行减少。拟议的研究将采用慢病毒转导的 shRNA 表达来沉默代表性胰腺癌细胞系中的一个或两个 Sulf。我们的目标是： 1) 确定 Sulf 沉默对这些细胞体外生长和 Wnt 信号传导的影响； 2)确定Sulf沉默对裸鼠细胞形成肿瘤能力的影响。这些研究的积极结果应该会激发人们对 Sulfs 作为治疗人类胰腺腺癌的可能靶点（小分子或功能阻断抗体）的极大兴趣。