Hedgehog Palmitoylation as a Novel Target for Inhibiting Pancreatic Cancer

Hedgehog 棕榈酰化作为抑制胰腺癌的新靶点

• 批准号: 8089813
• 负责人: MARILYN D RESH
• 金额: $ 27.01万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8089813
• 关键词: Acyltransferase; Anchorage-Independent Growth; Biogenesis; Biological Assay; Cancer Cell Growth; Cancer Etiology; Carbon; Cessation of life; Enzymes; Erinaceidae; Fatty Acids; Funding; Goals; Growth; Human; In Vitro; Laboratories; Lead; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Molecular Target; Palmitates; Pharmaceutical Preparations; Proteins; Research; Screening procedure; Signal Transduction; System; antitumor agent; autocrine; base; cancer cell; high throughput screening; human migration; inhibitor/antagonist; matrigel; novel; palmitoylation; pancreatic cancer cells; pancreatic tumorigenesis; paracrine; research study; small hairpin RNA; small molecule; smoothened signaling pathway; statistics; therapeutic development; therapeutic target

DESCRIPTION (provided by applicant): Pancreatic cancer is the fourth leading cause of cancer-related deaths in the US. The goal of the research proposed in this R21 project is to identify and develop drugs that block the function of Sonic Hegehog (Shh), a key contributor to pancreatic tumorigenesis. Aberrant expression of Shh is implicated in the biogenesis of human pancreatic cancer. In order to signal correctly, Shh must be modified by attachment of the 16-carbon fatty acid palmitate to its N-terminus. We aim to exploit Shh palmitoylation as a potential Achilles heel by targeting Hhat (Hedgehog acyltransferase), the enzyme that catalyzes attachment of palmitate to Shh. Since palmitoylation is required for Shh function, Hhat inhibitors that block Shh palmitoylation could be developed into novel chemotherapeutics that will be efficacious in the treatment of pancreatic cancer. My laboratory has developed an in vitro Shh palmitoylation assay that is dependent on Hhat activity. The assay has been optimized for High Throughput Screening (HTS) to identify small molecule inhibitors of Hhat. We are nearing completion of the HTS (a total of 80,000 compounds) and estimate selection of 200-300 potential "hits" for secondary analysis. We now seek funding to identify the inhibitor hits that are the most effective in blocking Shh-driven pancreatic cancer cell growth. Aim 1) To perform secondary screening of the HTS "hits" to identify novel and effective small molecule inhibitors of Hhat-mediated Shh palmitoylation. Compounds that yielded >70% inhibition and a B-score >12 in the HTS assay will be analyzed in secondary HTS screens. The ability of these Hhat inhibitors to inhibit Shh palmitoylation in normal and pancreatic cancer cells will then be assessed. Aim 2) To identify Hhat inhibitors from the HTS that inhibit proliferation of pancreatic cancer cells. We have shown that shRNA mediated depletion of Hhat inhibits anchorage- dependent and independent growth of human pancreatic cancer cells and also blocks paracrine Shh signaling. These findings validate the choice of Hhat as a defined molecular and therapeutic target. Experiments in Aim 2 will assess the ability of the Hhat inhibitors from the HTS to inhibit proliferation, survival and migration of human pancreatic cancer cells. Three-dimensional Matrigel-based culture systems will be established and the effects of Hhat inhibitors on autocrine and paracrine Shh signaling will be determined. The most effective inhibitors will be developed into lead compounds for further therapeutic development. PUBLIC HEALTH RELEVANCE: Hedgehog signaling has been shown to drive the growth of human pancreatic cancers. The proposed studies will help us develop small molecule inhibitors that block the functioning of Hedgehog proteins in cancer cells. These compounds could potentially be clinically useful as anti-tumor agents to treat human pancreatic cancer.

描述（由申请人提供）：胰腺癌是美国癌症相关死亡的第四大原因。 R21 项目中提出的研究目标是识别和开发阻断 Sonic Hegehog (Shh) 功能的药物，Sonic Hegehog (Shh) 是胰腺肿瘤发生的关键因素。 Shh 的异常表达与人类胰腺癌的生物发生有关。为了正确发出信号，Shh 必须通过在其 N 末端连接 16 碳脂肪酸棕榈酸酯进行修饰。我们的目标是通过针对 Hhat（Hedgehog 酰基转移酶）（一种催化棕榈酸酯与 Shh 附着的酶）来利用 Shh 棕榈酰化作为潜在的致命弱点。由于Shh功能需要棕榈酰化，因此阻断Shh棕榈酰化的Hhat抑制剂可以开发成新型化疗药物，有效治疗胰腺癌。我的实验室开发了一种依赖于 Hhat 活性的体外 Shh 棕榈酰化测定法。该测定已针对高通量筛选 (HTS) 进行了优化，以鉴定 Hhat 的小分子抑制剂。我们即将完成 HTS（总共 80,000 种化合物），并估计选择 200-300 种潜在“命中”进行二次分析。我们现在寻求资金来确定最有效阻止 Shh 驱动的胰腺癌细胞生长的抑制剂。目标 1) 对 HTS“命中”进行二次筛选，以鉴定 Hhat 介导的 Shh 棕榈酰化的新颖且有效的小分子抑制剂。在 HTS 测定中产生 >70% 抑制且 B 分数 >12 的化合物将在二次 HTS 筛选中进行分析。然后将评估这些 Hhat 抑制剂抑制正常细胞和胰腺癌细胞中的 Shh 棕榈酰化的能力。目标 2) 从 HTS 中鉴定出抑制胰腺癌细胞增殖的 Hhat 抑制剂。我们已经证明，shRNA 介导的 Hhat 消耗会抑制人胰腺癌细胞的锚定依赖性和独立生长，并且还阻断旁分泌 Shh 信号传导。这些发现证实了选择 Hhat 作为明确的分子和治疗靶点。目标 2 中的实验将评估 HTS 的 Hhat 抑制剂抑制人胰腺癌细胞增殖、存活和迁移的能力。将建立基于基质胶的三维培养系统，并确定 Hhat 抑制剂对自分泌和旁分泌 Shh 信号传导的影响。最有效的抑制剂将被开发成先导化合物，用于进一步的治疗开发。 公共健康相关性：Hedgehog 信号传导已被证明可促进人类胰腺癌的生长。拟议的研究将帮助我们开发小分子抑制剂，阻止癌细胞中刺猬蛋白的功能。这些化合物可能在临床上用作治疗人类胰腺癌的抗肿瘤剂。