ENOX2 as a biomarker for the diagnosis of pancreatic cancer

胰腺癌是一个重大的健康负担。80%的胰腺癌是在III/IV期确诊的。IV期确诊的患者的5年生存率不到1%，中位生存期为6个月，而被诊断为局限性疾病的患者的5年生存率高达25%。该项目将专注于开发一种有前景的用于前列腺癌的癌症生物标记物Enox2的分析方法。虽然在健康人的血浆中很少检测到Enox2，但在包括乳腺癌、胰腺癌(1)、肾癌、胃癌和结肠癌在内的一系列恶性肿瘤的血浆中都检测到Enox2。据认为，Enox2蛋白在肿瘤发生后不久就会表达，因此在癌症发展的相对早期阶段就可以检测到。例如，在一项对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]。因此，Enox2已被证明以多种亚型存在(3)，每种亚型似乎针对特定的起源组织类型。这使得标准的Enox2免疫分析的产生存在潜在的问题。然而，这也提供了一个机会，因为如果我们能够开发出区分和量化这些异构体的方法，就可以开发出对异构体表达变化有强大抵抗力的肿瘤类型特异性分析，最终也可以为早期癌症提供组织起源测试。尽管标准免疫分析因此不适合Enox2的测量，因为它们缺乏异构体尺度分辨率，但质谱学(MS)为这种分析的发展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定量高度相似的蛋白质和剪接变体的分析方法(4)，而MS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MS有可能将这种分析方法应用到临床环境中。在这个项目中，学生将寻求与其他常见癌症类型相比，表征胰腺癌细胞株中的Enox2亚型，然后开发一种基于MS的特异性和灵敏的分析方法，以确定其在血浆中的水平。这项检测随后将在一组胰腺癌样本和健康对照中进行测试，包括I、III和IV期疾病患者，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.