The identification of human hepatocellular carcinoma metastasis genes

人肝癌转移基因的鉴定

• 批准号: 10926086
• 负责人: Xin Wei Wang
• 金额: $ 28.65万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10926086
• 关键词: Alternative Splicing; Anti-Inflammatory Agents; Biological; CD44 gene; Cell Migration Inhibition function; Chronic; Cirrhosis; Clinical; Collagen; Data; Development; Disease; Early Diagnosis; Event; Expression Profiling; Follow-Up Studies; Gelatinase B; Gene Chips; Gene Expression; Gene Expression Profiling; Genes; Glycoproteins; Goals; Human; Immune; In Vitro; Incidence; Invaded; Lead; Liver; Liver neoplasms; Lymphocyte; Macrophage Colony-Stimulating Factor; Mediating; Metastatic Neoplasm to the Lung; MicroRNAs; Microarray Analysis; Molecular; Neoplasm Metastasis; Nonmetastatic; Nude Mice; Outcome; Patients; Peptides; Phenotype; Population; Primary carcinoma of the liver cells; Prognosis; Prognostic Marker; RNA Splicing; Recurrence; Role; Sampling; Small RNA; Specimen; System; T-Lymphocyte; Technology; Tumor Cell Invasion; Variant; Viral; cell growth; cytokine; diagnostic biomarker; extracellular; improved; intrahepatic; mortality; neutralizing antibody; novel marker; novel therapeutics; osteopontin; receptor; tool; transcriptome; tumor

We are using a microarray technology to perform global gene expression profiling of clinical specimens that are associated with human hepatocellular carcinoma metastasis and poor outcome. In a gene expression array-based comparison of primary liver tumors with or without accompanying intrahepatic metastasis, we found that osteopontin, a secreted multifunctional glycoprotein was a lead gene capable of differentiating this phenotype. Osteopontin, whose expression is elevated in many tumor types, was found at the leading edge of metastatic hepatocellular carcinoma and in vacularized regions of hepatocellular carcinoma, but was absent in normal liver. We also demonstrated that a neutralizing antibody to osteopontin could decrease lung metastases in nude mice and inhibit tumor cell invasion, highlighting an essential role of osteopontin in hepatocellular carcinoma metastasis. We have also observed a concordant elevated expression of osteopontin and matrix metalloproteinase-9 in primary metastatic hepatocellular carcinoma and using an in-vitro system, showed that matrix metalloproteinase-9 directs the cleavage of osteopontin into three specific fragments. A small 5-kilodalton osteopontin fragment could induce cellular invasion via CD44 receptors and could be effectively blocked by the addition of small peptides within the 5-kilodalton region of osteopontin. Furthermore, increased expression of a soluble osteopontin splice variant was associated with clinical hepatocellular carcinoma metastasis, enhanced cellular invasion and higher osteopontin 5-kilodalton levels. Thus, a distinct region of osteopontin was shown to be most essential for hepatocellular carcinoma cellular invasion and appeared to correlate with metastatic potential. Our data also suggests that an alternative splicing event occurs to promote extracellular cleavage of osteopontin by matrix metalloproteinase-9 to release an osteopontin 5-kilodalton fragment. The findings of this study may help to improve advanced stage HCC prognosis and suggests a utility of small peptides for novel therapies. Since hepatocellular carcinoma usually develops in an inflamed microenvironment due to chronic cirrhosis and/or viral mediated cirrhosis. In another study, we analyzed gene expression profiles of human hepatocellular carcinoma patients with or without metastasis. We have shown that a shift towards anti-inflammatory Th2 cytokines occurs in patient samples with metastasis. We demonstrated that colony stimulating factor 1 may be responsible for the unique signature present in the liver microenvironment of metastatic hepatocellular carcinoma patients. We have also recapitulated this shift in an enriched human lymphocyte population treated with colony stimulating factor 1 or osteopontin. Furthermore, we have shown that the Th2 cytokine shift observed in metastasis patients involves a T cell population. These results show that a significant alteration of immune related genes occurs in the liver microenvironment of patients with metastasis that seems to involve differential priming of lymphocytes possibly through the activity of stroma-produced colony stimulating factor 1 or tumor produced osteopontin. We have recently demonstrated that the expression levels of certain small RNAs, termed microRNAs, are altered in hepatocellular carcinoma metastasis. In a follow-up study, this 20-microRNA signature was validated and the role of a particular microRNA, let-7g in HCC progression, was determined. We confirmed the that the level of let-7g was significantly lower in metastatic compared to non-metastatic hepatocellular carcinoma and was predictive of poor survival. Functional studies indicated that let-7g could significantly inhibit cell migration and cell growth through targeting of soluble collagens. These results suggest that let-7g may suppress hepatocellular carcinoma metastasis through targeting collagen and that let-7g could be used as a tool to predict poor survival.

我们正在使用微阵列技术进行全球基因表达谱的临床标本，与人类肝细胞癌转移和预后不良。在一个基于基因表达阵列的原发性肝肿瘤伴或不伴肝内转移的比较中，我们发现骨桥蛋白，一种分泌的多功能糖蛋白是能够区分这种表型的主导基因。骨桥蛋白，其表达在许多肿瘤类型中升高，被发现在转移性肝细胞癌的前沿和肝细胞癌的血管化区域，但在正常肝脏中不存在。我们还证明了骨桥蛋白的中和抗体可以减少裸鼠肺转移和抑制肿瘤细胞的侵袭，突出了骨桥蛋白在肝细胞癌转移中的重要作用。我们还观察到骨桥蛋白和基质金属蛋白酶-9在原发性转移性肝细胞癌中的一致性表达升高，并使用体外系统显示基质金属蛋白酶-9指导骨桥蛋白裂解成三个特异性片段。一个小的5千道尔顿的骨桥蛋白片段可以通过CD 44受体诱导细胞侵袭，并且可以通过在骨桥蛋白的5千道尔顿区域内添加小肽来有效地阻断。此外，可溶性骨桥蛋白剪接变体的表达增加与肝细胞癌的临床转移、增强的细胞侵袭和更高的骨桥蛋白5千道尔顿水平相关。因此，骨桥蛋白的一个独特的区域被证明是最重要的肝细胞癌细胞的侵袭，并出现与转移的潜力。我们的数据还表明，选择性剪接事件的发生，以促进细胞外切割骨桥蛋白的基质金属蛋白酶-9释放骨桥蛋白5千道尔顿片段。这项研究的结果可能有助于改善晚期肝癌的预后，并建议小肽的新疗法的效用。由于肝细胞癌通常在慢性肝硬化和/或病毒介导的肝硬化引起的炎症微环境中发展。在另一项研究中，我们分析了有或无转移的人肝细胞癌患者的基因表达谱。我们已经表明，在转移患者样本中发生向抗炎性Th 2细胞因子的转变。我们证明了集落刺激因子1可能是转移性肝细胞癌患者肝脏微环境中存在的独特特征的原因。我们还概括了这一转变，在一个丰富的人淋巴细胞群体与集落刺激因子1或骨桥蛋白治疗。此外，我们已经表明，在转移患者中观察到的Th 2细胞因子转变涉及T细胞群。这些结果表明，免疫相关基因的显着改变发生在转移患者的肝脏微环境中，似乎涉及淋巴细胞的差异启动可能通过基质产生的集落刺激因子1或肿瘤产生的骨桥蛋白的活性。我们最近已经证明，某些小RNA的表达水平，称为microRNA，在肝细胞癌转移改变。在后续研究中，这种20-microRNA签名得到了验证，并确定了特定microRNA let-7 g在HCC进展中的作用。我们证实了let-7 g在转移性肝癌中的水平显著低于非转移性肝癌，并预测了较差的生存率。功能研究表明let-7 g可通过靶向可溶性胶原而显著抑制细胞迁移和细胞生长。这些结果表明let-7 g可能通过靶向胶原蛋白抑制肝癌转移，let-7 g可以作为预测生存率的工具。