Molecular signatures for liver cancer diagnosis and treatment stratification

我们正在使用一种基于最先进的微阵列技术的全球基因表达谱分析方法来分析与肝脏疾病不同阶段相关的临床标本。例如，通过比较来自具有不同程度的肝细胞癌发生风险的慢性肝病患者的肝脏样本，我们已经确定了一种独特的特征，该特征可能有助于诊断早期肝癌患者。几种血清蛋白已被确定为肝细胞癌的潜在诊断标志物，这些标志物存在于早期阶段或甲胎蛋白阴性者中。我们还开发了一种基于转移性原发性肝细胞癌标本的mRNA基因表达的独特分子标记，以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签名的预测能力。 重要的是，我们发现这种分子特征可以识别那些即使在早期疾病患者中也最有复发风险的患者。 由于肝细胞癌通常存在于发炎的肝脏中，由于纤维化，肝硬化和/或慢性肝炎，我们还开发了基于肝细胞癌患者肝脏微环境的mRNA基因表达的独特分子预后特征。 我们发现，一个主要的体液细胞因子发生在转移性肝微环境中，并向抗炎/免疫抑制反应的转变可能会促进肝细胞癌转移。 因此，这些研究表明局部组织微环境在肝细胞癌转移中的重要作用。 有趣的是，肿瘤特征主要不同于肝脏微环境。 此外，我们已经使用分子分析来确定五个基因，可能作为早期肝细胞癌的生物标志物，特别是对于那些甲胎蛋白阴性。我们还探讨了小的非编码RNA，称为microRNA，在肝细胞癌转移和生存的作用。 我们发现某些microRNA表达变化与转移相关，即使在早期疾病中也可以显着预测患者的生存和复发。 这些microRNA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，这些microRNA的功能分析可能会提高我们对肝细胞癌转移的生物学理解。 为了进一步评估microRNA在肝脏中的作用，我们研究了男性和女性肝细胞癌患者的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。 microRNA-26表达降低的肿瘤具有不同的转录组模式，并激活了NF κ B/IL 6信号传导途径。 microRNA-26低表达的患者生存率低，对干扰素治疗的反应优于正常表达的患者。我们最近使用了一种整合的方法来识别HCC驱动基因，定义为拷贝数与基因表达和癌症进展相关的基因。通过对来自76例B型肝炎病毒感染患者的HCC样本进行高分辨率、基于阵列的比较基因组杂交和转录组分析，我们发现了与染色体8 p丢失和预后不良相关的10个基因标记。 在2个独立的HCC队列和乳腺癌队列中验证了该特征。 体外和体内功能研究表明，10个基因签名中的三个基因产物具有肿瘤抑制特性。 因此，我们的综合方法已经确定了可能有助于HCC诊断、预后和开发新的治疗策略以提高HCC患者生存率的驱动基因。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，也挑战了当前肿瘤演变的范式。显然，基因表达谱扩展了我们对肝癌发生的全球变化的了解，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型标志物，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. We have recently used an integrative approach to identify HCC driver genes, defined as genes whose copy numbers are associated with gene expression and cancer progression. Through a combination of data from high-resolution, arraybased comparative genomic hybridization and transcriptome analysis of HCC samples from 76 patients with hepatitis B virus infection, we found a 10-gene signature associated with chromosome 8p loss and poor outcome. The signature was validated in 2 independent HCC cohorts and breast cancer cohorts. Functional in vitro and in vivo studies demonstrated that three gene products among the 10-gene signature have tumor suppressive properties. Thus our integrative approach has identified driver genes that may assist in HCC diagnosis, prognosis andthe development of new therapeutic strategies to improve HCC patient survival.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.