High Throughput Screening for SCAP Inhibitors as Pancreas Cancer Therapeutics

项目摘要 胰腺导管腺癌（PDAC）是美国第四大癌症死亡原因。 到2030年将成为癌症相关死亡的第二大原因。PDAC通常 在疾病过程的晚期诊断，此时治疗选择受到严重限制，导致总体 诊断后生存时间<12个月，5年生存率<10%。因此， 预防PDAC原发性和转移性肿瘤生长是迫切需要的。 PDAC肿瘤细胞具有极高的增殖性，因此对膜脂质有很高的必需需求。 然而，PDAC肿瘤微环境血管化不良，导致缺氧和营养有限 供应脂质合成是高度耗氧的，所以在缺氧环境中的肿瘤细胞是 面临着满足脂质需求的挑战。固醇调节元件结合蛋白（SREBP） 转录因子通过增加胆固醇、脂肪酸和胆固醇的合成和摄取来维持细胞脂质供应。 酸和甘油三酯。当脂质供应低时，SREBP被激活，并且SREBP裂解激活 蛋白（SCAP）是途径活性所必需的。因此，肿瘤应该需要SCAP来适应营养- 限制条件和提供膜结构所需的脂质。 迄今为止，SREBP通路已经涉及几种癌症的生长和进展， 包括结肠、前列腺、乳腺和胶质母细胞瘤。然而，SREBP在PDAC中的作用尚未得到证实。 考察使用多种人PDAC细胞系和小鼠肿瘤模型，我们证明了SCAP是 这是PDAC肿瘤发展和生长所必需的，使SCAP成为治疗的新靶点。 尽管在多种癌症中确定了对SREBP途径的要求，但没有有效的化学物质 抑制剂存在。为了鉴定新的候选疗法，我们开发了一种稳健的高通量测定法， SCAP抑制剂。在这里，我们建立在我们的初步研究，以确定有效的SCAP化学抑制剂， 胰腺癌的治疗 AIM 1.通过高通量筛选筛选SCAP抑制剂候选物。 AIM 2.验证SCAP抑制剂并进行初步SAR研究。 这些研究的总体目标是确定一系列有效的，化学上易处理的，经过验证的化合物 其在至少两个正交试验中以超过100倍浓度范围的剂量反应抑制SCAP。 针对癌症中脂质代谢的传统方法集中在抑制单一酶 胆固醇、类异戊二烯或脂肪酸合成所必需的。SREBPs直接调节30多个基因， 脂质代谢因此，抑制SCAP将协同阻断多种合成和摄取途径， 代表了一种靶向癌症脂质代谢的新方法。

PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of death due to cancer in the United States and will become the 2nd leading cause of cancer-related death by 2030. PDAC is typically diagnosed late in the disease process when therapeutic options are severely limited, resulting in an overall survival time of <12 months post-diagnosis and a 5-year survival rate of <10%. Therefore, new drugs that prevent PDAC primary and metastatic tumor growth are desperately needed. PDAC tumor cells are extremely proliferative and thus have a high requisite demand for membrane lipids. However, the PDAC tumor microenvironment is poorly vascularized, leading to hypoxia and limited nutrient supply. Lipid synthesis is highly oxygen-consumptive, so neoplastic cells in a hypoxic environment are challenged with meeting the demand for lipids. The sterol regulatory element-binding protein (SREBP) transcription factors maintain cellular lipid supply by increasing synthesis and uptake of cholesterol, fatty acids, and triglycerides. SREBPs are activated when lipid supply is low, and SREBP cleavage activating protein (SCAP) is required for pathway activity. Thus, tumors should require SCAP to adapt to nutrient- limiting conditions and supply lipid for membrane construction. To date, the SREBP pathway has been implicated in the growth and progression of several cancers, including colon, prostate, breast, and glioblastoma. However, the role of the SREBPs in PDAC has not been examined. Using multiple human PDAC cell lines and mouse tumor models, we demonstrated that SCAP is required for PDAC tumor development and growth, making SCAP a novel target for therapeutics. Despite the established requirement for the SREBP pathway in multiple cancers, no potent chemical inhibitor exists. To identify new candidate therapeutics, we developed a robust high throughput assay for SCAP inhibitors. Here, we build on our preliminary studies to identify potent SCAP chemical inhibitors for the treatment of pancreas cancer. AIM 1. To identify candidate SCAP inhibitors by high throughput screening. AIM 2. To validate SCAP inhibitors and conduct preliminary SAR studies. The overall goal of these studies is to identify a series of potent, chemically tractable, validated compounds that inhibit SCAP in at least two orthogonal assays with a dose-response over 100-fold concentration range. Traditional approaches to target lipid metabolism in cancer have focused on inhibition of a single enzyme required for cholesterol, isoprenoid or fatty acid synthesis. SREBPs directly regulate more than 30 genes of lipid metabolism. Thus, inhibiting SCAP will coordinately block multiple synthesis and uptake pathways and represents a novel approach to targeting lipid metabolism in cancer.