Markers for HCV-related HCC: plasma profiling, targeted strategies and validation

描述(申请人提供)：据报道，世界范围内肝细胞癌的发病率呈上升趋势，这与丙型肝炎病毒在人群中的高流行率有关。迫切需要更好的肝癌诊断手段。我们先前的研究为潜在肝病的病因和肝细胞癌基因/蛋白表达模式的差异之间的关联提供了证据。他们还提供了对蛋白质亚型的新见解，这些亚型在肝细胞癌的发展中具有潜在的重要意义。我们最近开发了一种全面和定量分析复杂样本蛋白质组的方法，并已将该方法应用于肝脏和血浆。这种方法基于对完整蛋白质的广泛分离，在肝脏中鉴定了大约9000种蛋白质，鉴定的可信度很高，包括细胞因子、趋化因子和受体等低丰度蛋白质。基于光谱计数的丰度分数被归因于每一种被识别的蛋白质。计算的丰度分数似乎是蛋白质丰度的一个很好的估计。在血浆中，鉴定了大量生物标志物浓度范围(pg/ml)内的低丰度蛋白质，并在肝组织和血浆中鉴定了疾病阶段(纤维化和早期肝癌)的特异性蛋白质。有趣的是，在组织中观察到的丰度变化与在血浆中观察到的选择性蛋白丰度变化之间没有相关性，这些变化随着疾病的阶段而变化。总之，这种方法在蛋白质组学方面达到了以前没有报道过的针对哺乳动物组织和血浆等复杂生物混合物的深度，允许识别与疾病相关的蛋白质变化，并表明基于组织的发现研究和基于血浆的发现研究可能会导致不同的结果。这项建议的目的是利用该方法来鉴定可用于早期检测和诊断的丙型肝炎病毒相关肝细胞癌的蛋白质生物标志物。我们将应用这种方法来鉴定最近进展为肝细胞癌的丙型肝炎病毒相关性肝硬变患者和无肝细胞癌的丙型肝炎病毒相关性肝硬化症患者的血浆中表达水平不同的蛋白质及其异构体。在这项研究的发现部分确定的最有希望的候选者将被确定为验证的目标。我们将确定这些蛋白质生物标记物单独和联合检测肝细胞癌早期的敏感性和特异性。公共卫生相关性：据报道，世界范围内肝细胞癌的发病率呈上升趋势，这与人群中丙型肝炎病毒感染的高流行率有关。迫切需要更好的肝癌诊断手段。这项建议的目的是开发一套强大的肝细胞癌生物标志物，可用于早期检测和诊断。

DESCRIPTION (provided by applicant): A trend of increasing rates of hepatocellular carcinoma (HCC) has been reported worldwide, that is related to the high prevalence of hepatitis C virus (HCV) infection in the population. Better means for HCC diagnosis are urgently needed. Our prior studies provided evidence for an association between the etiology of the underlying liver disease and differences in patterns of gene/protein expression in HCC. They also offered new insights into protein isoforms that are potentially important in the development of HCC. We recently developed a method to comprehensively and quantitatively profile the proteome of a complex sample and we have applied this method to the liver and to plasma. This method, based on extensive fractionation of intact proteins, resulted in the identification of approximately 9,000 proteins in the liver, identified with high confidence and including low-abundance proteins such as cytokines, chemokines and receptors. An abundance score based on spectral counts was attributed to each identified protein. The calculated abundance scores appeared to be a good estimate of protein abundance. In the plasma, numerous low-abundance proteins in the biomarker concentration range (pg/ml) were identified and proteins specific to disease stage (fibrosis and early HCC) were identified in liver tissue as well as in plasma. Interestingly, there was no correlation between the abundance changes observed in the tissues and the abundance changes observed in the plasma for selective proteins changing with disease stage. In conclusion, this method reached a depth in proteomic profiling not previously reported for complex biological mixtures such as mammalian tissue and plasma, allowed for the identification of protein changes associated with disease and suggested that tissue-based discovery and plasma-based discovery studies may lead to different results. The purpose of this proposal is to utilize this method for the identification of protein biomarkers for HCV-related HCC that could be used for early detection and diagnosis. We will apply this approach to identify proteins and their isoforms that differ in expression levels between plasma obtained from patients with HCV-related cirrhosis that have recently progressed to HCC and patients with HCV-related cirrhosis with no HCC. The most promising candidates identified in the discovery component of this research will be targeted for validation. We will establish the sensitivity and specificity of these protein biomarkers individually and in combination, for detecting HCC early. PUBLIC HEALTH RELEVANCE: A trend of increasing rates of hepatocellular carcinoma (HCC) has been reported worldwide, that is related to the high prevalence of hepatitis C virus (HCV) infection in the population. Better means for HCC diagnosis are urgently needed. The purpose of this proposal is the development of a robust set of biomarkers for HCC that could be used for early detection and diagnosis.