Identification of metastasis-related microRNAs in hepatocellular carcinoma

MicroRNAs (miRNAs) have been used as cancer-related biomarkers. Hepatocellular carcinoma (HCC) is an aggressive cancer with a dismal outcome largely due to metastasis and postsurgical recurrence. We investigated whether the expression of certain miRNAs are associated with HCC metastasis. We examined the miRNA expression profiles of 482 cancerous and noncancerous specimens from radical resection of 241 patients with HCC. Using a supervised algorithm and a clinically well-defined cohort of 131 cases, we built a unique 20-miRNA metastasis signature that could significantly predict (P < 0.001) primary HCC tissues with venous metastases from metastasis-free solitary tumors with 10-fold cross-validation. However, significant miRNAs could not be identified from the corresponding noncancerous hepatic tissues. A survival risk prediction analysis revealed that a majority of the metastasis-related miRNAs were associated with survival. Furthermore, the 20-miRNA tumor signature was validated in 110 additional cases as a significant independent predictor of survival (P = 0.009) and was significantly associated with both survival and relapse in 89 cases of early stage HCC (P = 0.022 and 0.002, respectively). These 20 miRNAs may provide a simple profiling method to assist in identifying patients with HCC who are likely to develop metastases/recurrence. In addition, functional analysis of these miRNAs may enhance our biological understanding of HCC metastasis.     

miRNAs 与肝细胞癌发生研究进展

MicroRNAs（miRNAs）是一类长度为21～25个核苷酸的非编码小分子 RNA,参与基因转录后调控。研究发现, miRNAs 的异常表达与疾病,尤其是恶性肿瘤的发生发展密切相关。 miRNAs 在不同癌症中水平不同。研究证明,miRNAs 可以作为肝细胞癌分类、预后和早期诊断的生物学标志,并有望成为体内治疗的新靶点。本文对各类 miRNAs 小分子与肝细胞癌发生的关系,及其在临床上的应用潜能等进行了介绍。     

Circulating microRNAs for the diagnosis of hepatocellular carcinoma

AimThere are no existing biomarkers that demonstrate very reliable performance in the diagnosis of hepatocellular carcinoma (HCC), especially in the early stage. Studies have shown that numerous aberrantly expressed circulating microRNAs (miRNAs) can be used as a diagnostic tool for HCC; however, these studies have produced inconsistent results.MethodsWe performed a meta-analysis to summarize the diagnostic accuracy of circulating miRNAs, alpha-fetoprotein (AFP), and AFP combined with miRNAs in differentiating HCC patients from non-HCC controls, healthy controls and chronic liver disease controls. We also evaluated the diagnostic accuracy of circulating miRNAs for early-stage HCC. Furthermore, we systematically reviewed the diagnostic effectiveness of single miRNAs and individual miRNA panels.ResultsCirculating miRNAs showed good diagnostic performance. Compared with single miRNAs, the diagnostic accuracy of miRNA panels was clearly better. The combination of AFP and miRNAs improved the diagnostic accuracy compared with the use of miRNAs or AFP alone. For early-stage HCC patients, circulating miRNAs exhibited relatively satisfactory diagnostic accuracy.ConclusionsCirculating miRNAs can be used as an early diagnostic marker of HCC. The combination of miRNAs and AFP has great potential as a novel strategy for the diagnosis of HCC.     

Viral hepatitis and hepatocellular carcinoma: From molecular pathways to the role of clinical surveillance and antiviral treatment

Hepatocellular carcinoma (HCC) is a global health challenge. Due to the high prevalence in low-income countries, hepatitis B virus (HBV) and hepatitis C virus infections remain the main risk factors for HCC occurrence, despite the increasing frequencies of non-viral etiologies. In addition, hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection. The molecular processes underlying HCC development are complex and various, either independent from liver disease etiology or etiology-related. The reciprocal interlinkage among non-viral and viral risk factors, the damaged cellular microenvironment, the dysregulation of the immune system and the alteration of gut-liver-axis are known to participate in liver cancer induction and progression. Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis. The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance, both through clinical-biochemical scores and periodic ultrasound assessment. This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.     

肝癌分子分型和相关信号通路的研究进展

肝细胞癌是一种原发于肝脏的恶性肿瘤,占原发性肝癌的85%~90%。随着高通量检测下一代测序(NGS)检测技术的不断发展,了解肝癌的分子分型和不同信号通路的调控机制,并针对靶点进行分子靶向治疗和免疫治疗,是目前肝癌领域的一大研究热点。该文综述其研究现状,归纳了肝癌发病中主要作用的信号通路,以期为肝癌的精准治疗与研究带来新的思路。     

RNAi抑制肝癌分子通路及靶向治疗

肝细胞肝癌(HCC)发生发展是由遗传学和表遗传学改变引起原癌基因激活和抑癌基因失活,相关信号传导通路活化以及增殖、凋亡平衡破坏,使肝细胞生长失控而致癌变,经启动、促进、演变的多阶段过程.RNA干扰(RNAinterference,RNAi)技术是由内源或外源性的双链RNA介导的,序列特异性地在mRNA水平上关闭相关基因表达转录的过程,属于转录后的基因沉默,是一项新兴的基因阻断技术.     

Genomics and signaling pathways in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of death among cirrhotic patients and has become a major health problem in developed countries. There is an elemental understanding of the genes and signaling pathways involved in the initiation and progression of this neoplasm. The current hypothesis of the HCC cell origin includes both somatic cells (hepatocytes) and stem cells/progenitor cells. Unlike that in other malignancies such as breast, brain, or hematopoietic cancers, the implication of cancer stem cells in HCC pathogenesis is not yet supported by consistent data. Analysis of somatic genetic alterations and gene expression profiles in HCC samples has provided relevant information on the genes involved in hepatocarcinogenesis, pinpointing a seminal molecular classification of the disease. Nonetheless, a comprehensive genomic analysis of HCC samples using high-resolution platforms in precisely annotated HCCs is clearly needed. Recent data have identified different signaling pathways in liver carcinogenesis (e.g., Wnt-betaCatenin, Hedgehog, tyrosine kinase receptor-related pathways), providing an important potential source of novel molecular targets for new therapies. This review summarizes the most relevant information regarding structural and functional alterations in HCC and describes some of the key signaling pathways implicated in hepatocarcinogenesis.     

Exosomal microRNAs as a potential therapeutic strategy in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the fifth most com-mon cancer and the second cause of cancer-related death worldwide. The incidence of HCC is constantly increasing in correlation with the rise in diabetes and obesity, arguing for an urgent need for new developments in the treatment of this lethal cancer. Exosomes are small double-membrane vesicles loaded with distinct cargos, particularly small non-coding RNAs called microRNAs, representative of each donor cell and secreted to affect the features of neighboring cells or recipient cells located further away, like in the case of metastasis. A better understanding of the role of exosomes with a microRNA signature in cancer pathogenesis gave rise to the concept of their use as a noninvasive diagnostic biomarker and in the treatment of cancer, including HCC. In this communication, we review recent works that demonstrate that hepatic stellate cells establish an epigenetic communication with liver cancer cells, which affects their pro-malignant features. If naturally secreted patient-derived exosomes show major limitations concerning their clinical use, bio-engineered exosome mimetics that incorporate controlled components and exhibit no protumoral properties could be promising carriers for the treatment of liver cancers, which is the organ preferentially targeted by systemic injection of exosomes.     

Specific molecular markers in hepatocellular carcinoma

BACKGROUND: The carcinogenesis of hepatocellular carcinoma (HCC) is a multi-factorial, multistep and complex process. Its prognosis is poor, and early diagnosis and monitoring metastasis of HCC is of the utmost importance. Circulating diagnostic and prognostic biomarkers could be used in proper postoperative treatment of patients at an early stage of HCC development. This review summarizes recent studies of the specific biomarkers in diagnosis and monitoring metastasis or postoperative recurrence of HCC. DATA SOURCES: An English-language literature search was conducted using MEDLINE (June 1998 to September 2006) on researches of some valuable specific biomarkers in diagnosis and monitoring metastasis or postoperative recurrence of HCC. RESULTS: Hepatoma tissues can synthesize various tumor-related proteins, polypeptides, and isoenzymes, such as alpha-fetoprotein (AFP), hepatoma-specific gamma-glutamyl transpeptidase (HS-GGT), etc, and then secrete into blood. The valuable early diagnostic and prognostic biomarkers could predict the development and metastases of HCC. Recent researches have confirmed that circulating hepatoma-specific AFP subfraction, transforming growth factor (TGF)-β1, HS-GGT, and free insulin-like growth factor (IGF)-Ⅱ may be more specific markers than total AFP level for early diagnosis for HCC. The circulating genetic markers such as AFP-mRNA, TGF-β1-mRNA, IGF-Ⅱ-mRNA, etc from peripheral blood mononuclear cells of HCC patients have been most extensively used in monitoring distal metastasis or postoperative recurrence of HCC. CONCLUSIONS: Hepatoma tissues synthesize and secrete valuable molecular markers into blood. The analyses of circulating hepatoma-specific biomarkers are usefulto early diagnosis of HCC or monitoring metastasis or postoperative recurrence of HCC.     

The molecular pathogenesis of hepatocellular carcinoma

SUMMARY. Some of the multiple factors involved in the molecular pathogenesis of hepatocellular carcinoma have been elucidated in recent years but no clear picture of how and in what sequence these factors interact at the molecular level has emerged yet. Transformation of hepatocytes to the malignant phenotype may occur irrespective of the aetiological agent through a pathway of chronic liver injury, regeneration and cirrhosis. The activation of cellular oncogenes, the inactivation of tumour suppressor genes and overexpression of certain growth factors contribute to the development of HCC. There is increasing evidence that the hepatitis B virus may play a direct role in the molecular pathogenesis of HCC. Aflatoxins have been shown to induce specific mutations of the p53 tumour suppressor gene thus providing a clue to how an environmental factor may contribute to tumour development at the molecular level.     

The prognostic molecular markers in hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) still remains dismal, although many advances in its clinical study have been made. It is important for tumor control to identify the factors that predispose patients to death. With new discoveries in cancer biology, the pathological and biological prognostic factors of HCC have been studied quite extensively. Analyzing molecular markers (biomarkers) with prognostic significance is a complementary method. A large number of molecular factors have been shown to associate with the invasiveness of HCC, and have potential prognostic significance. One important aspect is the analysis of molecular markers for the cellular malignancy phenotype. These include alterations in DNA ploidy, cellular proliferation markers (PCNA, Ki-67, Mcm2, MIB1, MIA, and CSE1L/CAS protein), nuclear morphology, the p53 gene and its related molecule MD M2, other cell cycle regulators (cyclin A, cyclin D, cyclin E, cdc2, p27, p73), oncogenes and their receptors (such as ras, c-myc, c-fms, HGF, c-met, and erb-B receptor family members), apoptosis related factors (Fas and FasL), as well as telomerase activity. Another important aspect is the analysis of molecular markers involved in the process of cancer invasion and metastasis. Adhesion molecules (E-cadherin, catenins, serum intercellular adhesion molecule-1, CD44 variants), proteinases involved in the degradation of extracellular matrix (MMP-2, MMP-9, uPA, uPAR, PAI), as well as other molecules have been regarded as biomarkers for the malignant phenotype of HCC, and are related to prognosis and therapeutic outcomes. Tumor angiogenesis is critical to both the growth and metastasis of cancers including HCC, and has drawn much attention in recent years. Many angiogenesis-related markers, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PD-ECGF), thrombospondin (TSP), angiogenin, pleiotrophin, and endostatin (ES) levels, as well as intratumor microvessel density (MVD) have been evaluated and found to be of prognostic significance. Body fluid (particularly blood and urinary) testing for biomarkers is easily accessible and useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum, and its genetic alterations in HCC are other important trends. More attention should be paid to these two areas in future. As the progress of the human genome project advances, so does a clearer understanding of tumor biology, and more and more new prognostic markers with high sensitivity and specificity will be found and used in clinical assays. However, the combination of some items, i.e., the pathological features and some biomarkers mentioned above, seems to be more practical for now.     

肝细胞癌分子影像诊断进展

肝细胞癌是高死亡率的恶性肿瘤之一,其早期诊断将直接影响治疗方案及预后。分子影像是目前最先进的诊断与评估手段,同时是肝细胞癌早期诊断研究的重要方向。介绍了分子影像的定义和意义、分子影像成像基本步骤,并论述了肝细胞癌成像的有关靶点及肝细胞癌分子影像未来的研究方向。     

Novel serum microRNAs panel on the diagnostic and prognostic implications of hepatocellular carcinoma

AIM To determine a panel of serum micro RNAs(mi RNAs) that could be used as novel biomarkers for diagnosis of hepatocellular carcinoma(HCC).METHODS We initially screened 9 out of 754 serum mi RNAs by Taq Man Low Density Array in two pooled samples respectively from 35 HCC and 35 normal controls, and then validated individually by RT-qP CR in another 114 patients and 114 controls arranged in two phases. The changes of the selected mi RNAs after operation and their prognostic value were examined.RESULTS miR-375, miR-10 a, miR-122 and miR-423 were found to be significantly higher in HCC than in controls(P 0.0001), and the area under the receiver-operating-characteristic curve for the 4-miR NA panel was 0.995(95%CI: 0.985-1). All the four mi RNAs were significantly reduced after surgical removal of the tumors(P 0.0001), while still higher than normal controls(at least P 0.05)CONCLUSION The four serum miR NAs(miR-375, miR-10 a, miR-122 and miR-423) could potentially serve as novel biomarkers for the diagnostic and prognostic of HCC.     

An update on the molecular genetics of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is associated with multiple risk factors and is believed to arise from preneoplastic lesions, usually in the background of cirrhosis. Extensive studies on HCC and its precursors have demonstrated complex and heterogeneous genetic or chromosomal abnormalities along the way from preneoplastic lesions to HCCs. These genetic abnormalities include loss of heterozygosity, microsatellite instability, gene alterations, and aberrant global gene expression profiles. Although some genetic alterations involving the p53 family, Rb family, and Wnt pathways are particularly important in the development of HCCs, the molecular pathogenesis of HCC differs with etiology in some extent. Recent studies using DNA microarray technique have identified some unique gene expression profiles in hepatitis B virus (HBV)- and hepatitis C virus (HCV)-associated HCCs. Gene expression profiling also allows people to distinguish HCCs from normal tissue or preneoplastic lesions and to evaluate metastatic or recurrent potentials. These unique genes or gene products associated with malignant transformation and recurrent or metastatic potentials may serve as molecular markers for early diagnosis, prediction of prognosis, and responsiveness to therapy. To date, information that has accumulated for the past several decades is still incomplete, and we still are faced with a great challenge in deciphering the molecular mechanisms of HCCs.     

The role of des-gamma-carboxyprothrombin expression in hepatocellular carcinoma

BACKGROUND/AIMS: Des-gamma-carboxyprothrombin (DCP), is a well-known tumor marker of hepatocellular carcinoma (HCC). On the other hand, some reports suggest that tissue expression of DCP is more useful as a prognostic factor than the serum DCP value. The aim of this study is to clarify the clinicopathological role of expression of DCP on HCC, especially when there is a low serum level of DCP. METHODOLOGY: Fifty-one patients with HCC who underwent curative hepatectomy were included in this study. Immunohistochemical staining was performed using anti-DCP monoclonal antibody, which was classified into 2 groups (strong and weak) by a pathologist. The immunohistochemical expression of tumor microvessel density (MVD) was evaluated using CD34 monoclonal antibody, and counted with specific staining of the capillary-like vessels in the tumor. The clinicopathological variables were compared between the strong and weak-staining groups. RESULTS: A strong DCP expression was recognized in 31 patients. DCP expression was associated with tumor size (p < 0.05) and portal vein infiltration (p < 0.01). In addition, serum DCP levels and alpha-fetoprotein levels tended to be higher in the strong group. In 16 patients whose serum DCP level was < 200mAU/ml, the recurrence-free survival rate was significantly lower in the strong group. No correlation was observed between DCP expression and MVD. CONCLUSIONS: DCP expression in HCC is useful for the prediction of early recurrence in patients with a low serum DCP level.