Molecular signatures for liver cancer diagnosis and treatment stratification

我们正在使用基于最先进的微阵列技术的全球基因表达谱方法来分析与肝脏疾病不同阶段相关的临床标本。例如，通过比较具有不同程度发展为肝细胞癌风险的慢性肝病患者的肝脏样本，我们已经确定了一个独特的特征，可能有助于诊断早期发病的肝癌患者。几种血清蛋白已被确定为肝细胞癌早期或甲胎蛋白阴性的潜在诊断标志物。我们还开发了一种基于转移性原发性肝细胞癌标本mRNA基因表达的独特分子标记，用于预测肝细胞癌患者的预后和转移。我们最近在两个不同病因的独立队列中验证了该特征的预测能力。重要的是，我们发现这种分子标记可以识别那些复发风险最高的患者，即使是在早期疾病患者中。由于肝细胞癌通常存在于炎症肝脏，由于纤维化，肝硬化和/或慢性肝炎，我们还基于肝细胞癌患者肝脏微环境mRNA基因表达开发了一种独特的分子预后标记。我们发现，在转移性肝脏微环境中存在主要的体液细胞因子谱，并且向抗炎/免疫抑制反应的转变可能促进肝细胞癌的转移。因此，这些研究表明局部组织微环境在肝细胞癌转移中起重要作用。有趣的是，肿瘤的特征与肝脏微环境的特征主要不同。此外，我们使用分子谱法鉴定了5个可能作为早期肝癌生物标志物的基因，特别是那些甲胎蛋白阴性的基因。我们还探讨了小的非编码rna，称为microRNAs，在肝细胞癌转移和生存中的作用。我们发现某些microRNA表达变化与转移有关，甚至在早期疾病中也可以显著预测患者的生存和复发。这些微小rna可能提供一种简单的分析方法，以帮助识别可能发生转移的HCC患者。此外，对这些microrna的功能分析可以增强我们对肝细胞癌转移的生物学认识。为了进一步评估microRNA在肝脏中的作用，我们检查了男性和女性肝癌患者的microRNA表达模式、生存率和对干扰素的反应。我们发现microRNA-26的表达在男性和女性之间存在差异，并且在肿瘤组织中的表达高于非肿瘤组织。随着NFkB/IL6信号通路的激活，microRNA-26表达降低的肿瘤具有不同的转录组模式。microRNA-26低表达的患者生存率较低，对干扰素治疗的反应优于正常表达的患者。我们的发现非常富有成效，为个性化患者管理提供了有用的工具，也挑战了当前肿瘤进化的范式。显然，基因表达谱扩展了我们对肝癌发生的全局变化的认识，并为这种疾病的分子机制提供了许多见解。此外，这些研究无疑将有助于建立具有潜在诊断和预后价值的新标志物，以及直接临床干预的潜在治疗靶点。

We are using a global gene expression profiling approach based on state-of-the-art microarray technology to profile clinical specimens that are associated with different stages of liver diseases. For example, by comparing liver samples from chronic liver disease patients with varying degrees of risk for developing hepatocellular carcinoma, we have identified a unique signature that may be useful in diagnosing patients with early onset of liver cancer. Several serum proteins have been identified as potential diagnostic markers for hepatocellular carcinoma that are present at an early stage or in those negative for alpha-fetoprotein. We have also developed a unique molecular signature based on the mRNA gene expression of metastatic primary hepatocellular carcinoma specimens to predict prognosis and metastasis of hepatocellular carcinoma patients. We have recently validated the predictive capacity of this signature in two independent cohorts of differing etiology. Importantly, we found that this molecular signature could identify those patients who were most at risk for recurrence even in patients with early stage disease. Since hepatocellular carcinoma is usually present in inflamed liver, due to fibrosis, cirrhosis and/or chronic hepatitis, we also developed a unique molecular prognostic signature based on mRNA gene expression of the liver microenvironment of hepatocellular carcinoma patients. We found that a predominant humoral cytokine profile occurs in the metastatic liver microenvironment and that a shift toward anti-inflammatory/immune-suppressive responses may promote hepatocellular carcinoma metastases. These studies therefore suggest an important role of the local tissue microenvironment in hepatocellular carcinoma metastasis. Interestingly, the tumor signature is principally different from that of liver microenvironment. In addition, we have used molecular profiling to identify five genes that may serve as biomarkers for early onset of hepatocellular carcinoma, especially for those that are negative for alpha-fetoprotein. We have also explored the role of small non-coding RNAs, termed microRNAs, in hepatocellular carcinoma metastasis and survival. We found that certain microRNA expression changes are associated with metastasis and could significantly predict patient survival and relapse even in early stage disease. These microRNAs may provide a simple profiling method to assist in identifying HCC patients who are likely to develop metastases. In addition, functional analysis of these microRNAs may enhance our biological understanding of hepatocellular carcinoma metastasis. To further assess the role of microRNAs in the liver, we examined the microRNA expression patterns, survival and response to interferon in men and women with hepatocellular carcinoma. We found that the expression of microRNA-26 differed among men and women and was higher in tumor versus nontumor tissue. Tumors with reduced microRNA-26 expression had a distinct transcriptomic pattern with activation of the NFkB/IL6 signalling pathways. Patients with low microRNA-26 had poor survival and were better responders to interferon therapy than those with normal expression. Our findings have been extremely fruitful and offer useful tools for personalized patient management and also challenge the current paradigm of tumor evolution. Clearly, gene expression profiling has expanded our knowledge of the global changes that occur in liver cancer, and has provided numerous insights into the molecular mechanisms of this disease. In addition, these studies will undoubtedly contribute to the establishment of novel markers with potential diagnostic and prognostic value, as well as potential therapeutic targets for direct clinical intervention.