ENOX2 as a biomarker for the diagnosis of pancreatic cancer

胰腺癌是一个重大的健康负担。80%的胰腺癌诊断为III / IV期，IV期患者的5年生存率低于1%，中位生存期~6个月，而诊断为局部疾病的患者的5年生存率高达25%。该项目将专注于开发一种有前景的前列腺癌生物标志物Enox2的检测方法。虽然很少在健康人的血浆中检测到，但Enox2在一系列恶性肿瘤的血浆中被检测到，包括乳腺癌、胰腺癌(1)、肾癌、胃癌和结肠癌。人们认为，Enox2蛋白在恶性肿瘤发生后不久就表达，因此在癌症发展的相对早期阶段就可以检测到。例如，在一项恶性间皮瘤的小型研究中，在诊断前4-10年的血清中可检测到Enox2(2)。有趣的是，Enox2已被证明存在于多种异构体中(3)，每种异构体似乎都针对特定的组织类型起源。这使得产生标准的Enox2免疫测定可能存在问题。然而，它也提供了一个机会，如果我们能够开发出区分和量化这些亚型的方法，就可以开发出针对亚型表达变化的肿瘤类型特异性检测，最终也可以为早期癌症提供组织起源测试。虽然标准免疫测定法不适合用于Enox2的测量，因为它们缺乏同型尺度的分辨率，质谱法（MS）为开发这种测定法提供了一个强有力的候选平台。我们之前已经证明，可以开发出能够区分和量化高度相似的蛋白质和剪接变体的检测方法(4)，而质谱技术的改进，包括分析的速度和灵敏度以及样品制备的自动化，意味着质谱有可能将这种检测方法带入临床环境。在这个项目中，学生将寻求与其他常见癌症类型相比，胰腺癌细胞系中Enox2亚型的特征，然后开发一种特异性和敏感的基于质谱的测定方法来确定其在血浆中的水平。随后将在一组胰腺癌样本和健康对照（包括I期、III期和IV期疾病个体）中进行该检测，以评估Enox2测量对胰腺癌检测的价值。

Pancreatic cancer is a significant health burden. 80% of pancreatic cancers are diagnosed at Stage III / IV. 5-year survival of patients diagnosed at Stage IV is less than 1%, with median survival ~6 months, compared with patients diagnosed with localised disease who have up to 25% 5-year survival rates. This project will focus on the development of assays for a promising cancer biomarker for use in prostate cancer, Enox2.While rarely detected in plasma from healthy individuals, Enox2 has been detected in plasma in a range of malignancies, including breast, pancreas (1), renal, gastric and colon cancers. It is thought that Enox2 proteins are expressed soon after the onset of malignancy and so are detectable at a relatively early stage of cancer development. For example, in a small study of malignant mesothelioma, Enox2 was detectable in the serum 4-10 years prior to diagnosis (2).Intriguingly, Enox2 has been shown to exist in multiple isoforms (3), with each isoform seemingly specific for a particular tissue type of origin. This makes generation of a standard Enox2 immunoassay potentially problematic. However, it also provides an opportunity in that, if we can develop methods which distinguish and quantify these isoforms, tumour type-specific assays which are robust to isoform expression changes can be developed, and ultimately could also provide a tissue-of-origin test for early-stage cancers.While standard immunoassays are therefore inappropriate for Enox2 measurements as they lack isoform-scale resolution, mass spectrometry (MS) provides a strong candidate platform for the development of such an assay. We have previously shown that assays can be developed which can distinguish between and quantify highly similar proteins and splice variants (4), and improvements in MS technology including speed and sensitivity of analysis and automation of sample preparation means that MS has the potential to carry such assays into a clinical setting.In this project, the student will seek to characterise the Enox2 isoforms in pancreatic cancer cell lines compared to other common cancer types, and then develop a specific and sensitive MS-based assay to determine its levels in plasma. This assay will subsequently be tested in a cohort of pancreatic cancer samples and healthy controls, including individuals with Stage I, III and IV disease to assess the value of Enox2 measurement for pancreatic cancer detection.