PU.1 Is Identified as a Novel Metastasis Suppressor in Hepatocellular Carcinoma Regulating the miR-615-5p/IGF2 Axis

Invasion and metastasis is the major cause of tumor recurrence, difficulty for cure and low survival rate. Excavating key transcription factors, which can regulate tumor invasion and metastasis, are crucial to the development of therapeutic strategies for cancers. PU.1 is a master hematopoietic transcription factor and a vital regulator in life. Here, we report that, compared to adjacent non-cancerous tissues, expression of PU.1 mRNA in metastatic hepatocellular carcinoma (HCC), but not primary HCC, was significantly down-regulated. In addition, levels of PU.1 mRNA in metastatic hepatoma cell lines MHCC97L and MHCC97H were much lower than in non-metastatic Hep3B cells. Transwell invasion assays after PU.1 siRNA transfection showed that the invasion of hepatoma cell lines was increased markedly by PU.1 knockdown. Oppositely, overexpression of PU.1 suppressed the invasion of these cells. However, knockdown and overexpression of PU.1 did not influence proliferation. Finally, we tried to explore the potential mechanism of PU.1 suppressing hepatoma cell invasion. ChIP-qPCR analysis showed that PU.1 exhibited a high binding capacity with miR-615-5p promoter sequence. Overexpression of PU.1 caused a dramatic increase of pri-, pre- and mature miR-615-5p, as well as a marked decrease of miR-615-5p target gene IGF2. These data indicate that PU.1 inhibits invasion of human HCC through promoting miR-615-5p and suppressing IGF2. These findings improve our understanding of PU.1 regulatory roles and provided a potential target for metastatic HCC diagnosis and therapy.

Abrogating the interplay between IGF2BP1, 2 and 3 and IGF1R by let-7i arrests hepatocellular carcinoma growth

IGF2BP 1, 2 and 3 control the fate of many transcripts. Immunoprecipitation studies demonstrated the IGF2BPs to bind to IGF1R mRNA, and our laboratory has recently shown them to post-transcriptionally regulate IGF1R. This study sought to identify a microRNA regulating the IGF2BPs and consequently IGF1R. All three IGF2BPs were among the top-ranked predicted targets of let-7i. Let-7i was downregulated in HCC tissues, and transfection of HuH-7 with let-7i inhibited malignant cell behaviors and decreased IGF2BPs transcripts. Direct binding of let-7i to IGF2BP2 and IGF2BP3 3'UTRs was confirmed, and the effect of let-7i caused a decrease in the IGF2BPs' target gene, the IGF1R. IGF1R mRNA was inversely correlated with let-7i in HCC tissues and was reduced upon let-7i transfection into HuH-7. Reporter assays validated IGF1R as a target of let-7i. Therefore, let-7i may control HCC tumorigenesis by regulating IGF1R directly and indirectly by interrupting the interplay between IGF1R and the IGF2BPs.

CDX2 inhibits pancreatic adenocarcinoma cell proliferation via promoting tumor suppressor miR-615-5p

CDX2 has recently been identified as a prognostic marker for pancreatic adenocarcinoma. However, the role and mechanism of CDX2 in progression of pancreatic adenocarcinoma are still elusive. In this study, we observed that CDX2 expression was much lower in mouse pancreatic adenocarcinoma tissues and pancreatic cancer cells. A network integrated by ChIPBase platform hinted that miR-615-5p, a most newly discovered tumor suppressor, was probably bound by CDX2 in the promoter region. Chromatin immunoprecipitation (ChIP)-qPCR assay showed that CDX2 exhibited a high capacity of binding to miR-615-5p promoter region compared to the negative control. Real-time PCR and western blotting analyses revealed that CDX2 overexpression caused inflation of miR-615-5p and depression of insulin-like growth factor 2 (IGF2), a direct target of miR-615-5p. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and EdU approaches showed that CDX2 overexpression markedly suppressed pancreatic adenocarcinoma cell proliferation. CDX2 small interfering RNA (siRNA) transfection showed an opposite effect on gene expression and cell proliferation to that of CDX2 overexpression. Collectively, CDX2 inhibited pancreatic adenocarcinoma cell proliferation via promoting tumor suppressor miR-615-5p. Our findings suggested a potential molecular target for pancreatic adenocarcinoma therapy.

Pigment epithelium-derived factor and matrix metalloproteinase-9 in liver cirrhosis

BACKGROUND/AIM

The aim of this study was to assess the role of serum pigment epithelium-derived factor (PEDF) and matrix metalloproteinase-9 (MMP-9) in progression of liver cirrhosis and development of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Serum levels of PEDF and MMP-9 were tested in 212 patients with liver cirrhosis and in a control group of 30 healthy volunteers. HCC was diagnosed in 45 of the 212 patients studied (21%).

RESULTS

Serum PEDF and MMP-9 were higher in the study group than that in the control group (P < 0.001). In patients with alcoholic or mixed (alcoholic and viral hepatitis-related) cirrhosis, serum PEDF was higher than that in other patients (13970.2 ± 13406.9 ng/ml vs. 8563.5 ± 9602.7 ng/ml, P = 0.008). In patients with viral hepatitis-related cirrhosis, significantly higher PEDF levels were recorded in those with HCC (13429.1 ± 12045.8) than that in patients without HCC (6660.1 ± 7927.1; P = 0.04). There was a trend for higher serum MMP-9 in patients with HCC (5778.7 ± 12426.6 vs. 1389.8 ± 1944.7 in those without HCC; P = 0.07). Significant negative correlation between serum MMP-9 and serum alpha-fetoprotein in patients with HCC was observed (r = -0.54; P = 0.04).

CONCLUSION

Serum PEDF and MMP-9 could be auxiliary markers in diagnosis of HCC, especially in patients with low alpha-fetoprotein level. Alcohol consumption can affect serum PEDF.

A polymeric nanoparticle formulation of curcumin in combination with sorafenib synergistically inhibits tumor growth and metastasis in an orthotopic model of human hepatocellular carcinoma

Curcumin, a yellow polyphenol extracted from the rhizome of turmeric root (Curcuma longa) has potent anti-cancer properties in many types of tumors with ability to reverse multidrug resistance of cancer cells. However, widespread clinical application of this agent in cancer and other diseases has been limited due to its poor aqueous solubility. The recent findings of polymeric nanoparticle formulation of curcumin (NFC) have shown the potential for circumventing the problem of poor solubility, however evidences for NFC's anti-cancer and reverse multidrug resistance properties are lacking. Here we provide models of human hepatocellular carcinoma (HCC), the most common form of primary liver cancer, in vitro and in vivo to evaluate the efficacy of NFC alone and in combination with sorafenib, a kinase inhibitor approved for treatment of HCC. Results showed that NFC not only inhibited the proliferation and invasion of HCC cell lines in vitro, but also drastically suppressed primary tumor growth and lung metastases in vivo. Moreover, in combination with sorafenib, NFC induced HCC cell apoptosis and cell cycle arrest. Mechanistically, NFC and sorafenib synergistically down-regulated the expression of MMP9 via NF-κB/p65 signaling pathway. Furthermore, the combination therapy significantly decreased the population of CD133-positive HCC cells, which have been reported as cancer initiating cells in HCC. Taken together, NanoCurcumin provides an opportunity to expand the clinical repertoire of this agent. Additional studies utilizing a combination of NanoCurcumin and sorafenib in HCC are needed for further clinical development.

miR-615-5p prevents proliferation and migration through negatively regulating serine hydromethyltransferase 2 (SHMT2) in hepatocellular carcinoma

It has been reported that miR-615-5p was upregulated in hepatocellular carcinoma (HCC) preventing both growth and migration. However, the underlying mechanism by which miR-615-5p played a role in HCC remains unknown. Here, in our present study, to investigate the mechanism of miR-615-5p, bioinformatic prediction and luciferase reporter assay were employed to ascertain the downstream target of miR-615-5p finding that the serine hydromethyltransferase 2 (SHMT2) was the direct downstream target. Knockdown or overexpression of miR-615-5p can lead to increasing or decreasing expression of SHMT2 in HCC cells. Besides, knockdown or overexpression of SHMT2 can suppress or promote both proliferation and migration of HCC cells, indicating that miR-615-5p can directly and negatively regulate the SHMT2 in HCC cells. In addition, to understand the clinicopathological significance of SHMT2 expression in HCC, immunohistochemistry was performed. It was found that SHMT2 expression was significantly associated with poor prognosis and TNM stage. Together, our results for the first time showed that miR-615-5p prevents proliferation and migration through negatively regulating SHMT2 in HCC.

A c-Myc/miR-17-5p feedback loop regulates metastasis and invasion of hepatocellular carcinoma

The molecular mechanisms that control metastasis of hepatocellular cancer (HCC) are still poorly understood. It has been determined that microRNA (miRNA) expression has tissue and cell specific, and decreased expression of specific miRNA could induce tumor genesis or metastasis. In this study, we identified that miR-17-5p was expressed lower in high metastatic capability HCC cell lines HCCLM3 and MHCC97H than low metastatic HCC cell line HepG2 by real-time (RT)-PCR. Restoration of miR-17-5p could significantly repress the invasiveness and metastasis of MHCC97H cell line. Furthermore, we validated c-Myc as a downstream and functional target of miR-17-5p using luciferase reporter assay. Immunohistochemical assay revealed that the expression of c-Myc protein levels was significantly increased in cancerous tissues compared with para-tumor tissues. After clinical data analysis, we observed that the higher level of c-Myc was significantly associated with a reduced overall survival (p = 0.0209). Consistent with previous research, we also demonstrated that c-Myc could upregulate the expression of miR-17-5p. Taken together, our data indicated that there is a regulatory feedback loop between miR-17-5p and c-Myc, in which miR-17-5p could suppress some of the distinguishing features, invasion, and metastasis, of oncogenic c-Myc in HCC cells, and meanwhile, miR-17-5p is upregulated by c-Myc role as a transcription factor, although further studies are still needed.

miR-17 is involved in Japanese Flounder (Paralichthys olivaceus) development by targeting the Cdc42 mRNA

The expression patterns of 197 miRNAs during Japanese flounder metamorphic development were recently analyzed. miR-17 was differentially expressed during the metamorphic period of the Japanese flounder; however, the role of miR-17 in Japanese flounder development has remained elusive to date. Bioinformatics analysis showed that Cdc42 was a putative target of miR-17. Cdc42 is a gene related to cell adhesion, migration, polarity, cytokinesis, growth, actin cytoskeleton, microtubule dynamics and transcription factor activity; thus, Cdc42 may contribute to metamorphic development. In our study, overexpression of miR-17 in FEC cells suppressed Cdc42 expression. The luciferase reporter assay confirmed that Cdc42 was the target of miR-17. The Cdc42 cDNA from the Japanese flounder was cloned and characterized for the first time. The expression of miR-17 was found to be negatively correlated with Cdc42 mRNA expression during temporal development and in the tissues of adult Japanese flounders. These results indicated that the decrease in miR-17 contributed to the up-regulation of Cdc42 during Japanese flounder metamorphosis. Cdc42 gene expression was down-regulated by thyroid hormone during Japanese flounder metamorphosis, whereas miR-17 was significantly up-regulated by thyroid hormone during these stages. These results indicated that miR-17 was a negative regulator of Cdc42.

Transcriptional activation of the IGF-II/IGF-1R axis and inhibition of IGFBP-3 by miR-155 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is characterized by the aberrant expression of a number of genes that govern crucial signaling pathways. The insulin-like growth factor (IGF) axis is important in this context, and the precise regulation of expression of members of this axis is known to be lost in HCC. miR-155 is a well-established oncogene in numerous types of cancer. However, to the best of our knowledge, its effect on the regulation of the IGF axis has not been investigated to date. The present study aimed to elucidate the interactions between miR-155 and key components of the IGF axis, in addition to examining its effect on HCC development. Reverse transcription-quantitative polymerase chain reaction was used to measure the expression of miR-155 in HCC and cirrhotic tissues, in addition to HCC cell lines. Furthermore, the effect of the induction of miR-155 expression on the expression of three members of the IGF axis [IGF II, IGF type-1 receptor (IGF-1R) and IGF-binding protein 3 (IGFBP-3)], was analyzed. Finally, the effect of miR-155 on HCC cell proliferation, migration and clonogenicity was also examined. Quantification of the expression of miR-155 demonstrated that it is upregulated in HCC. Induction of the expression of miR-155 in HCC cell lines led to the upregulation of IGF-II and IGF-IR, and the downregulation of IGFBP-3. In addition, the proliferation, migration and clonogenicity of HCC was increased following induction of miR-155 expression. miR-155 is an oncomiR, which upregulates the oncogenes, IGF-II and IGF-IR, and downregulates the tumor suppressor, IGFBP-3, thereby resulting in increased HCC cell carcinogenicity. Therefore, miR-155 may be a therapeutic target in HCC.

The Hox cluster microRNA miR-615: a case study of intronic microRNA evolution

BACKGROUND

Introns represent a potentially rich source of existing transcription for the evolution of novel microRNAs (miRNAs). Within the Hox gene clusters, a miRNA gene, miR-615, is located within the intron of the Hoxc5 gene. This miRNA has a restricted phylogenetic distribution, providing an opportunity to examine the origin and evolution of a new miRNA within the intron of a developmentally-important homeobox gene.

RESULTS

Alignment and structural analyses show that the sequence is highly conserved across eutherian mammals and absent in non-mammalian tetrapods. Marsupials possess a similar sequence which we predict will not be efficiently processed as a miRNA. Our analyses suggest that transcription of HOXC5 in humans is accompanied by expression of miR-615 in all cases, but that the miRNA can also be transcribed independently of its host gene through the use of an intragenic promoter. We present scenarios for the evolution of miR-615 through intronic exaptation, and speculate on the acquisition of independent transcriptional regulation. Target prediction and transcriptomic analyses suggest that the dominant product of miR-615 is involved in the regulation of growth and a range of developmental processes.

CONCLUSIONS

The miR-615 gene evolved within the intron of Hoxc5 in the ancestor of placental mammals. Using miR-615 as a case study, we propose a model by which a functional miRNA can emerge within an intron gradually, by selection on secondary structure followed by evolution of an independent miRNA promoter. The location within a Hox gene intron is of particular interest as the miRNA is specific to placental mammals, is co-expressed with its host gene and may share complementary functions.

IMP2/p62 induces genomic instability and an aggressive hepatocellular carcinoma phenotype

Hepatocellular carcinoma (HCC) represents the third leading cause of cancer-related deaths and commonly develops in inflammatory environments. The IGF2 mRNA-binding protein IMP2-2/IGF2BP2-2/p62 was originally identified as an autoantigen in HCC. Aim of this study was to investigate a potential pathophysiological role of p62 in hepatocarcinogenesis. Human HCC tissue showed overexpression of IMP2, which strongly correlated with the fetal markers AFP and DLK1/Pref-1/FA-1 and was particularly elevated in tumors with stem-like features and hypervascularization. Molecular classification of IMP2-overexpressing tumors revealed an aggressive phenotype. Livers of mice overexpressing the IMP2 splice variant p62 highly expressed the stem cell marker DLK1 and secreted DLK1 into the blood. p62 was oncogenic: diethylnitrosamine (DEN)-treated p62 transgenic mice exhibited a higher tumor incidence and multiplicity than wild types. Tumors of transgenics showed a more aggressive and stem-like phenotype and displayed more oncogenic chromosomal aberrations determined with aCGH analysis. DEN-treated p62 transgenic mice exhibited distinct signs of inflammation, such as inflammatory cytokine expression and oxidative stress markers, that is, thiobarbituric acid-reactive substance (TBARS) levels. Reactive oxygen species (ROS) production was elevated in HepG2 cells, which either overexpressed p62 or were treated with DLK1. p62 induced this ROS production by a DLK1-dependent induction and activation of the small Rho-GTPase RAC1, activating NADPH oxidase and being overexpressed in human HCC. Our data indicate that p62/IMP2 promotes hepatocarcinogenesis by an amplification of inflammation.

Function and clinical potential of microRNAs in hepatocellular carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs involved in the initiation and progression of several types of human cancer, including hepatocellular carcinoma (HCC), which is one of the most common types of cancer and the third leading cause of cancer-related mortality worldwide. Mounting evidence has demonstrated that miRNAs play a vital role in HCC, hepatitis, alcoholic liver disease, liver cell development and the metabolic functions of the liver. The aim of the present review was to summarize the most recent findings on the functions of miRNAs in the liver and discuss their potential roles in the diagnosis, prognosis and treatment of HCC.

MicroRNAs: Emerging Novel Clinical Biomarkers for Hepatocellular Carcinomas

The discovery of small non-coding RNAs known as microRNAs has refined our view of the complexity of gene expression regulation. In hepatocellular carcinoma (HCC), the fifth most frequent cancer and the third leading cause of cancer death worldwide, dysregulation of microRNAs has been implicated in all aspects of hepatocarcinogenesis. In addition, alterations of microRNA expression have also been reported in non-cancerous liver diseases including chronic hepatitis and liver cirrhosis. MicroRNAs have been proposed as clinically useful diagnostic biomarkers to differentiate HCC from different liver pathologies and healthy controls. Unique patterns of microRNA expression have also been implicated as biomarkers for prognosis as well as to predict and monitor therapeutic responses in HCC. Since dysregulation has been detected in various specimens including primary liver cancer tissues, serum, plasma, and urine, microRNAs represent novel non-invasive markers for HCC screening and predicting therapeutic responses. However, despite a significant number of studies, a consensus on which microRNA panels, sample types, and methodologies for microRNA expression analysis have to be used has not yet been established. This review focuses on potential values, benefits, and limitations of microRNAs as new clinical markers for diagnosis, prognosis, prediction, and therapeutic monitoring in HCC.

The Circulating IGF System in Hepatocellular Carcinoma: The Impact of Liver Status and Treatment

BACKGROUND

Previous studies have demonstrated an elevated IGF-II mRNA expression and protein levels in tumors and blood from patients with hepatocellular carcinoma (HCC), hereby suggesting a role of IGF-II as a pathogenic marker of HCC. We hypothesized that in HCC, an increased IGF-II secretion would translate into an elevated circulating IGF bioactivity, which would normalize following treatment.

METHODS

Patients with HCC (n=39) were studied before and after radio-frequency ablation and/or transarterial chemo-embolization. Baseline data were compared to healthy subjects (n=150) and patients with liver cirrhosis (n=41). Serum levels of IGF ligands and IGF binding proteins (IGFBPs) were determined using gold standard methods as well as novel assays and compared to liver function tests and HCC treatment status.

RESULTS

At baseline, HCC patients differed from cirrhosis patients and healthy controls regarding IGF-I (29 [23-37] vs. 12 [7-19] vs. 109 [103-116] μg/l), IGF-II (254 [224-288] vs. 118 [102-137] vs. 545 [525-566] μg/l) and IGF bioactivity (0.53 [0.41-0.68] vs. 0.29 [0.24-0.34] vs. 1.43 [1.33-1.53] μg/l) (mean [95% confidence interval], all age-adjusted P<0.001). All variables but IGFBP-2 were strongly associated with liver status (MELD score), and accordingly, differences were either attenuated or disappeared when adjusted for MELD score. There was no effect of treatment on any IGF variables.

CONCLUSIONS

The marked differences in IGF and IGFBP levels between patients with HCC, liver cirrhosis and healthy subjects are mainly explained by variations in liver status. Therefore, this study questions the clinical utility of circulating IGF variables as markers of HCC.

MicroRNAs dysregulation in hepatocellular carcinoma: Insights in genomic medicine

Hepatocellular carcinoma (HCC) is the leading primary liver cancer and its clinical outcome is still poor. MicroRNAs (miRNAs) have demonstrated an interesting potential to regulate gene expression at post-transcriptional level. Current findings suggest that miRNAs deregulation in cancer is caused by genetic and/or epigenetic, transcriptional and post-transcriptional modifications resulting in abnormal expression and hallmarks of malignant transformation: aberrant cell growth, cell death, differentiation, angiogenesis, invasion and metástasis. The important role of miRNAs in the development and progression of HCC has increased the efforts to understand and develop mechanisms of control overt this single-stranded RNAs. Several studies have analyzed tumoral response to the regulation and control of deregulated miRNAs with good results in vitro and in vivo, proving that targeting aberrant expression of miRNAs is a powerful anticancer therapeutic. Identification of up and/or down regulated miRNAs related to HCC has led to the discovery of new potential application for detection of their presence in the affected organism. MiRNAs represent a relevant new target for diagnosis, prognosis and treatment in a wide variety of pathologic entities, including HCC. This manuscript intends to summarize current knowledge regarding miRNAs and their role in HCC development.

High IGF2 expression is associated with poor clinical outcome in human ovarian cancer

Ovarian cancer is one of the most common types of cancer in females and is the leading cause of death among gynaecological cancers in women worldwide. In the present study, we identified insulin-like growth factor 2 (IGF2) as a differentially expressed gene between cancerous and non-cancerous ovarian tissues. IGF2 was frequently increased in the human ovarian cancers when compared to the frequency in the non-cancerous ovarian tissues both at the mRNA (30/35) and protein level (61/72). The mean level of IGF2 in the tumor tissues was markedly higher than that in the non-cancerous tissues (nearly 3-fold change) (P=0.000). There was a significant correlation of IGF2 expression with histological grade (P=0.047). Kaplan-Meier analysis indicated that the ovarian cancer patients with high IGF2 expression showed a poorer prognosis both in regards to overall survival (OS) and progression-free survival (PFS) (n=1,648, P=0.000). Further analysis revealed that high expression of IGF2 was an unfavorable factor for the prognosis of the ovarian cancer patients at clinical stage I + II, stage III, histological grade 2, grade 3 or those treated with chemotherapy containing platin and Taxol. Our data provide evidence that IGF2 expression is frequently increased in ovarian cancer tissues, and high expression of IGF2 may be a significant prognostic factor for poor survival in ovarian cancer patients.

MiRNA-615-5p functions as a tumor suppressor in pancreatic ductal adenocarcinoma by targeting AKT2

Background

Aberrant microRNA (miRNA) expression is associated with tumor development. This study aimed to elucidate the role of miR-615-5p in the development of pancreatic ductal adenocarcinoma (PDAC).

Methods

Locked nucleic acid in situ hybridization (LNA-ISH) was performed to compare miR-615-5p expression in patients between PDAC and matched adjacent normal tissues. Effects of miR-615-5p overexpression on cell proliferation, apoptosis, colony formation, migration, and invasion were determined in the pancreatic cancer cell lines PANC-1 and MIA PaCa-2. Effects of miR-615-5p on AKT2 were examined by dual-luciferase reporter assay. Lentivirus expressing miR-615 was used to create stable overexpression cell lines, which were subsequently used in mouse xenograft and metastasis models to assess tumor growth, apoptosis and metastasis.

Results

miR-615-5p expression was significantly lower in PDAC than in adjacent normal tissues. Low levels of miR-615-5p were independently associated with poor prognosis (HR: 2.243, 95% CI: 1.190-4.227, P=0.013). AKT2 protein expression was inversely correlated with miR-615-5p expression (r=-0.3, P=0.003). miR-615-5p directly targeted the 3’-untranslated region of AKT2 mRNA and repressed its expression. miR-615-5p overexpression inhibited pancreatic cancer cell proliferation, migration, and invasion in vitro, and tumor growth and metastasis in vivo. Furthermore, miR-615-5p overexpression also induced pancreatic cancer cell apoptosis both in vitro and in vivo.

Conclusions

These results show that miR-615-5p inhibits pancreatic cancer cell proliferation, migration, and invasion by targeting AKT2. The data implicate miR-615-5p in the prognosis and treatment of PDAC.

miRNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Despite improvements in HCC therapy, the prognosis for HCC patients remains poor due to a high incidence of recurrence. An improved understanding of the pathogenesis of HCC development would facilitate the development of more effective outcomes for the diagnosis and treatment of HCC at earlier stages. miRNA are small, endogenous, non-coding, ssRNA that are 21-30 nucleotides in length and modulate the expression of various target genes at the post-transcriptional and translational levels. Aberrant expression of miRNA is common in various human malignancies and modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNA and HCC, several studies have demonstrated that the aberrant expression of specific miRNA can be detected in HCC cells and tissues. However, little is known about the mechanisms of miRNA-related cell proliferation and development. In this review, we summarize the central and potential roles of miRNA in the pathogenesis of HCC and elucidate new possibilities that may be useful as diagnostic and prognostic markers, as well as novel therapeutic targets in HCC.

Targeting the insulin-like growth factor pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Only 30%-40% of the patients with HCC are eligible for curative treatments, which include surgical resection as the first option, liver transplantation and percutaneous ablation. Unfortunately, there is a high frequency of tumor recurrence after surgical resection and most HCC seem resistant to conventional chemotherapy and radiotherapy. Sorafenib, a multi-tyrosine kinase inhibitor, is the only chemotherapeutic option for patients with advanced hepatocellular carcinoma. Patients treated with Sorafenib have a significant increase in overall survival of about three months. Therefore, there is an urgent need to develop alternative treatments. Due to its role in cell growth and development, the insulin-like growth factor system is commonly deregulated in many cancers. Indeed, the insulin-like growth factor (IGF) axis has recently emerged as a potential target for hepatocellular carcinoma treatment. To this aim, several inhibitors of the pathway have been developed such as monoclonal antibodies, small molecules, antisense oligonucleotides or small interfering RNAs. However recent studies suggest that, unlike most tumors, HCC development requires increased signaling through insulin growth factor II rather than insulin growth factor I. This may have great implications in the future treatment of HCC. This review summarizes the role of the IGF axis in liver carcinogenesis and the current status of the strategies designed to target the IGF-I signaling pathway for hepatocellular carcinoma treatment.

The role of microRNAs in the control of innate immune response in cancer

Ligands for receptors of natural killer (NK) cells and CD8(+) cytotoxic T lymphocytes (CTL), such as the inhibitory nonclassical HLA-G, the activating stress-induced major histocompatibility complex class I-related antigens MICA and MICB, and/or the UL16-binding proteins (ULBPs), are often aberrantly expressed upon viral infection and neoplastic transformation, thereby preventing virus-infected or malignant-transformed cells from elimination by immune effector cells. Recently, it has been shown that ligands of both NK and CD8(+) T cells are regulated by a number of cellular and/or viral microRNAs (miRs). These miRs are involved in shaping the antiviral and/or antitumoral immune responses as well as neoplastic growth properties. This review summarizes the expression pattern and function of miRs directed against selected NK and T cell receptor ligands, their putative role in shaping immune surveillance and tumorigenicity, and their clinical relevance. In addition, the potential role of RNA-binding proteins in the post-transcriptional gene regulation of these ligands will be discussed.

Delivery and targeting of miRNAs for treating liver fibrosis

Liver fibrosis is a pathological condition originating from liver damage that leads to excess accumulation of extracellular matrix (ECM) proteins in the liver. Viral infection, chronic injury, local inflammatory responses and oxidative stress are the major factors contributing to the onset and progression of liver fibrosis. Multiple cell types and various growth factors and inflammatory cytokines are involved in the induction and progression of this disease. Various strategies currently being tried to attenuate liver fibrosis include the inhibition of HSC activation or induction of their apoptosis, reduction of collagen production and deposition, decrease in inflammation, and liver transplantation. Liver fibrosis treatment approaches are mainly based on small drug molecules, antibodies, oligonucleotides (ODNs), siRNA and miRNAs. MicroRNAs (miRNA or miR) are endogenous noncoding RNA of ~22 nucleotides that regulate gene expression at post transcription level. There are several miRNAs having aberrant expressions and play a key role in the pathogenesis of liver fibrosis. Single miRNA can target multiple mRNAs, and we can predict its targets based on seed region pairing, thermodynamic stability of pairing and species conservation. For in vivo delivery, we need some additional chemical modification in their structure, and suitable delivery systems like micelles, liposomes and conjugation with targeting or stabilizing the moiety. Here, we discuss the role of miRNAs in fibrogenesis and current approaches of utilizing these miRNAs for treating liver fibrosis.

The genetic and epigenetic alterations in human hepatocellular carcinoma: a recent update

Hepatocellular carcinoma (HCC) is one of the most frequent human malignancies worldwide with very poor prognosis. It is generally accepted that the progression of HCC is a long-term process with accumulation of multiple genetic and epigenetic alterations, which further lead to the activation of critical oncogenes or inactivation of tumor suppressor genes. HCC is characterized with multiple cancer hallmarks including their ability to proliferate, anti-apoptosis, invade, metastasis, as well as the emerging features such as stem cell properties and energy metabolic switch. The irreversible alterations at genetic level could be detected as early as in the pre-neoplastic stages and accumulate during cancer progression. Thus, they might account for the cancer initiating steps and further malignant transformation. In addition to genetic alterations, epigenetic alterations can affect the cancer transcriptome more extensively. Alterations in DNA methylation, histone modification, miRNAs, RNA editing, and lncRNAs might result in disrupted gene regulation networks and substantially contribute to HCC progression. In this review, the genetic and epigenetic alterations which significantly contribute to the malignant capabilities of HCC will be updated and summarized in detail. Further characterization of those critical molecular events might better elucidate the pathogenesis of HCC and provide novel therapeutic targets for treatment of this deadly disease.

Association of IGF1R polymorphisms with the development of HBV-related hepatocellular carcinoma

Although the involvement of insulin-like signaling in cancer has been well documented in various types of cancers, the association between the genetic variants in the insulin-like signaling and the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains unclear. In this study, a total of 498 individuals including 173 HBV related cirrhosis patients, 171 HBV-related HCC patients, and 154 healthy controls were enrolled. Sixteen single nucleotide polymorphisms (SNPs) in IGF1, IGF2, IGF1R and IGF2R have been genotyped by employing SNaPshot assays. We found A/A genotype at rs3743251 of IGF1R was negatively associated with HBV related HCC [odds ratio (OR) = 0.38, 95% confidence interval (CI) = 0.20-0.72, P = 0.037]; A/G genotype decreased the risk of portal vein thrombosis (OR = 0.38, 95%CI = 0.18-0.82, P = 0.01). These results indicate that rs3743251 polymorphism in IGF1R is associated with the susceptibility of HBV-related HCC.

The genetic and epigenetic alterations in human hepatocellular carcinoma: a recent update

Hepatocellular carcinoma (HCC) is one of the most frequent human malignancies worldwide with very poor prognosis. It is generally accepted that the progression of HCC is a long-term process with accumulation of multiple genetic and epigenetic alterations, which further lead to the activation of critical oncogenes or inactivation of tumor suppressor genes. HCC is characterized with multiple cancer hallmarks including their ability to proliferate, anti-apoptosis, invade, metastasis, as well as the emerging features such as stem cell properties and energy metabolic switch. The irreversible alterations at genetic level could be detected as early as in the pre-neoplastic stages and accumulate during cancer progression. Thus, they might account for the cancer initiating steps and further malignant transformation. In addition to genetic alterations, epigenetic alterations can affect the cancer transcriptome more extensively. Alterations in DNA methylation, histone modification, miRNAs, RNA editing, and lncRNAs might result in disrupted gene regulation networks and substantially contribute to HCC progression. In this review, the genetic and epigenetic alterations which significantly contribute to the malignant capabilities of HCC will be updated and summarized in detail. Further characterization of those critical molecular events might better elucidate the pathogenesis of HCC and provide novel therapeutic targets for treatment of this deadly disease.

miR-615-5p is epigenetically inactivated and functions as a tumor suppressor in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly invasive cancer with a poor prognosis. Although microRNA (miRNA) transcripts have a crucial role in carcinogenesis and development, little information is known regarding the aberrant DNA methylation of miRNAs in PDAC. Using methylated DNA immunoprecipitation-chip analysis, we found that miR-615-5p was hypermethylated in its putative promoter region, which silenced its expression in PDAC cell lines. In addition, the overexpression of miR-615-5p in pancreatic cancer cells suppressed cell proliferation, migration and invasion. Insulin-like growth factor 2 (IGF2) is an imprinted gene, and its abnormal expression contributes to tumor growth. Here, we identified IGF2 as a target of miR-615-5p using a luciferase reporter assay. IGF2 upregulation in PDAC tissues was not correlated with a loss of imprinting but was inversely correlated with miR-615-5p downregulation. In addition, miR-615-5p suppressed pancreatic cancer cell proliferation, migration and invasion by directly targeting IGF2, and this effect could be reversed by co-transfection with IGF2. Furthermore, the stable overexpression of miR-615-5p inhibited tumor growth in vivo and was correlated with IGF2 expression. Using RNA sequencing, we further identified miR-615-5p as potentially targeting other genes, such as the proto-oncogene JUNB, and interfering with the insulin signaling pathway. Taken together, our results demonstrate that miR-615-5p was abnormally downregulated in PDAC cells due to promoter hypermethylation, which limited its inhibition of IGF2 and other target genes, thereby contributing to tumor growth, invasion and migration. These data demonstrate a novel and important role of miR-615-5p as a tumor suppressor in PDAC.

MicroRNA expression might predict prognosis of epithelial hepatoblastoma

Hepatoblastoma (HB) is the most common primary liver cancer in childhood. The fetal and mixed embryonal/fetal epithelial subtypes of HB differ not only in grade of differentiation but probably also in prognosis. We aimed to determine microRNA (miRNA) expression patterns of the main subtypes of epithelial HBs to reveal differences and relate them to survival. We studied 20 cases of epithelial HB, subtyped as pure fetal (n = 12) or embryonal/fetal (n = 8). Tissues were sampled according to subtype to arrive at 15 purely fetal and eight purely embryonal samples (n = 8) and 15 samples of non-tumorous surrounding liver (SL). Relative expression of miR-17-5p, miR-18a, miR-21, miR-34a, miR-96, miR-122, miR-181a, miR-195, miR-210, miR-214, miR-221, miR-222, miR-223, and miR-224 was determined by TaqMan MicroRNA Assays applying miR-140 as reference. A higher level of miR-18a (p < 0.01) was found in embryonal samples than in fetal samples. Lower miR-17-5p, miR-195, miR-210, miR-214, and higher miR-221 levels were detected in fetal samples (p < 0.02) in comparison with SL samples, whereas a lower miR-122 level was observed in embryonal samples (p < 0.003). Histological subtype did not correlate with survival; however, high miR-21, low miR-222, and low miR-224 levels proved to be independently prognostic for HB with significantly increased overall survival (p < 0.03). The fetal and embryonal components of epithelial HB, as well as SL, revealed different miRNA expression patterns. Furthermore, miR-21, miR-222, and miR-224 levels predict overall survival of HB patients regardless of epithelial subtype.

Abnormal expression of insulin-like growth factor-I receptor in hepatoma tissue and its inhibition to promote apoptosis of tumor cells

Abnormal signaling of insulin-like growth factor I receptor (IGF-IR) is associated with hepatocellular carcinoma, but the underlying molecular mechanisms remain largely unknown. The objective of this study was to investigate IGF-IR's role as a signaling molecule, its pathological alteration in hepatoma tissues, and its effect on hepatoma cell proliferation when inhibited. As measured by immunohistochemical analysis, the incidence of hepatic IGF-IR expression in cancerous tissue was 80.0 % (24 of 30), which was significantly higher (P < 0.05) than 43.3 % (13 of 30) occurrence in the surrounding tissue and the nondetectable (0 of 30) frequency in the distal cancerous tissue. Hepatoma IGF-IR expression was correlated to the differentiation degree and not to the number or size of tumors, HBV infection, and AFP level. The in vitro IGF-IR expression in hepatoma cells was down-regulated significantly by picropodophyllin, a specific kinase inhibitor, in a time- and dose-dependent manner. Cell proliferation was inhibited through typical mechanisms of promoting apoptosis and cell cycle arrest (G2/M phase). Up-regulation of IGF-IR in hepatocarcinogenesis suggests that the down-regulation of IGF-IR expression could be a specific molecular target for hepatoma cell proliferation.

IGF2 and cancer

Insulin-like growth factor 2 (IGF2) is a 7.5  kDa mitogenic peptide hormone expressed by liver and many other tissues. It is three times more abundant in serum than IGF1, but our understanding of its physiological and pathological roles has lagged behind that of IGF1. Expression of the IGF2 gene is strictly regulated. Over-expression occurs in many cancers and is associated with a poor prognosis. Elevated serum IGF2 is also associated with increased risk of developing various cancers including colorectal, breast, prostate and lung. There is established clinical utility for IGF2 measurement in the diagnosis of non-islet cell tumour hypoglycaemia, a condition characterised by a molar IGF2:IGF1 ratio >10. Recent advances in understanding of the pathophysiology of IGF2 in cancer have suggested much novel clinical utility for its measurement. Measurement of IGF2 in blood and genetic and epigenetic tests of the IGF2 gene may help assess cancer risk and prognosis. Further studies will determine whether these tests enter clinical practice. New therapeutic approaches are being developed to target IGF2 action. This review provides a clinical perspective on IGF2 and an update on recent research findings.

The regulation of Hox gene expression during animal development

Hox genes encode a family of transcriptional regulators that elicit distinct developmental programmes along the head-to-tail axis of animals. The specific regional functions of individual Hox genes largely reflect their restricted expression patterns, the disruption of which can lead to developmental defects and disease. Here, we examine the spectrum of molecular mechanisms controlling Hox gene expression in model vertebrates and invertebrates and find that a diverse range of mechanisms, including nuclear dynamics, RNA processing, microRNA and translational regulation, all concur to control Hox gene outputs. We propose that this complex multi-tiered regulation might contribute to the robustness of Hox expression during development.

Advances in research of epigenetic regulation in liver fibrosis

Liver fibrosis is a pathological repair process in response to chronic injury caused by various etiologies in the liver. Imbalance between the expression of pro-fibrosis genes and anti-fibrosis genes play a pivotal role in hepatic fibrosis. The important path of reversing liver fibrosis is the early diagnosis and effective treatment. Epigenetic modifications have been considered an initial event in the development of hepatic fibrosis. Epigenetic regulatory mechanisms in liver fibrosis are intricate, including DNA methylation, histone modification, and microRNAs (miRNAs). Recently, many researchers have studied the effect of fibrosis-related gene expression at the epigenetic level on hepatic stellate cell activation and myofibroblast differentiation in hepatic fibrosis. This review discusses the epigenetic regulation in liver fibrosis, with an aim to provide new insights into the early non-invasive diagnosis, condition assessment and targeted therapy of this disease.

Downregulation of microRNA-100 correlates with tumor progression and poor prognosis in hepatocellular carcinoma

Increasing evidence suggests that dysregulation of microRNAs is correlated with malignant transformation and tumor development. miR-100, a potential tumor suppressor, is downregulated by many human cancers. However, the expression and functions of miR-100 in hepatocellular carcinoma (HCC) are still unclear. The aim of this study was to detect the expression of miR-100 in HCC tissues and investigate its clinicopathological and prognostic significance. Also, the effects of miR-100 on growth and apoptosis of HCC cells and its potential molecular mechanisms were analyzed. Results showed that the expression level of miR-100 in HCC tissues was significantly lower than that in matched non-cancerous liver tissues. Also, low-miR-100 expression was observed to be significantly correlated with higher tumor grade, higher incidence of lymph node metastasis, advanced TNM stage and higher incidence of tumor recurrence in HCC patients. Multivariate survival analyses suggested that low-miR-100 expression was an independent prognostic factor for HCC patients (HR = 1.66, 95 % CI 1.32-2.82, P = 0.019). In addition, we found that upregulation of miR-100 could inhibit growth and increase apoptosis of HCC cells by downregulating polo-like kinase 1 (plk1). In HCC tissues, miR-100 expression was inversely correlated with the expression of plk1 protein (r = -0.418; P = 0.029). Therefore, downregulation of miR-100 was correlated with progressive pathological feature and poor prognosis in HCC patients, and miR-100 could function as a tumor suppressor by targeting plk1. miR-100 may serve as a prognostic marker and molecular therapeutic target in HCC.

Paracrine activation of hepatic stellate cells in platelet-derived growth factor C transgenic mice: evidence for stromal induction of hepatocellular carcinoma

Cirrhosis is the primary risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes to carcinogenesis are poorly understood. Using a mouse model that recapitulates many aspects of the pathophysiology of human liver disease, we explored the mechanisms by which changes in the liver microenvironment induce dysplasia and HCC. Hepatic expression of platelet-derived growth factor C (PDGF-C) induces progressive fibrosis, chronic inflammation, neoangiogenesis and sinusoidal congestion, as well as global changes in gene expression. Using reporter mice, immunofluorescence, immunohistochemistry and liver cell isolation, we demonstrate that receptors for PDGF-CC are localized on hepatic stellate cells (HSCs), which proliferate, and transform into myofibroblast-like cells that deposit extracellular matrix and lead to production of growth factors and cytokines. We demonstrate induction of cytokine genes at 2 months, and stromal cell-derived hepatocyte growth factors that coincide with the onset of dysplasia at 4 months. Our results support a paracrine signaling model wherein hepatocyte-derived PDGF-C stimulates widespread HSC activation throughout the liver leading to chronic inflammation, liver injury and architectural changes. These complex changes to the liver microenvironment precede the development of HCC. Further, increased PDGF-CC levels were observed in livers of patients with nonalcoholic fatty steatohepatitis and correlate with the stage of disease, suggesting a role for this growth factor in chronic liver disease in humans. PDGF-C transgenic mice provide a unique model for the in vivo study of tumor-stromal interactions in the liver.

Association between insulin-like growth factor-2 expression and prognosis after transcatheter arterial chemoembolization and octreotide in patients with hepatocellular carcinoma

OBJECTIVE

To investigate the association between the change of IGF-2 level in serum after transcatheter arterial chemoembolization (TACE) and hepatocellular carcinoma (HCC) progression, especially in relation to metastasis.

METHODS

IGF-2 in serum was measured by quantitative sandwich enzyme-linked immunosorbent assay before, 3 days and 4 weeks after TACE in 60 patients with HCC. The occurrence of HCC metastasis was also evaluated, 3 months after TACE.

RESULTS

(1) The average serum level of IGF-2 in the 60 patients with HCC was 136.5 ± 87.3 pg/ml; (2) A tendency for increase was observed with heterogenous uptake of octreotide and portal vein thrombosis. Metastatic foci were found in 37/38 patients in the group with IGF-2 increasing (97.0%), in contrast to 3/22 (13.6%) patients with IGF-2 decrease.

CONCLUSION

The increase of IGF-2 level in serum appears to be associated with the occurrence of metastatic HCC after TACE and chemotherapy.

Clinical implications of microRNAs in liver cancer stem cells

The prognosis of patients diagnosed with hepatocellular carcinoma (HCC) is often dismal, mainly due to late presentation, high recurrence rate, and frequent resistance to chemotherapy and radiotherapy. Accumulating evidence on the differential microRNA (miRNA) expression patterns between non-tumor and HCC tissues or between liver cancer stem cells (CSCs) and non-CSC subsets and the significant clinical implications of these differences suggest that miRNAs are a promising, non-invasive marker for the prognosis and diagnosis of the disease. This perspective article summarizes the current knowledge of miRNAs in liver CSCs and highlights the need for further investigations of the role of miRNAs in regulating liver CSC subsets for possible future clinical applications.

Repression of miR-17-5p with elevated expression of E2F-1 and c-MYC in non-metastatic hepatocellular carcinoma and enhancement of cell growth upon reversing this expression pattern

E2F-1, c-MYC, and miR-17-5p is a triad of two regulatory loops: a negative and a positive loop, where c-MYC induces the expression of E2F-1 that induces the expression of miR-17-5p which in turn reverses the expression of E2F-1 to close the loop. In this study, we investigated this triad for the first time in hepatocellular carcinoma (HCC), where miR-17-5p showed a significant down-regulation in 23 non-metastatic HCC biopsies compared to 10 healthy tissues; however, E2F-1 and c-MYC transcripts were markedly elevated. Forced over-expression of miR-17-5p in HuH-7 cells resulted in enhanced cell proliferation, growth, migration and clonogenicity with concomitant inhibition of E2F-1 and c-MYC transcripts expressions, while antagomirs of miR-17-5p reversed these events. In conclusion, this study revealed a unique pattern of expression for miR-17-5p in non-metastatic HCC patients in contrast to metastatic HCC patients. In addition we show that miR-17-5p is the key player among the triad that tumor growth and spread.

MicroRNAs in hepatocellular carcinoma: regulation, function, and clinical implications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and the third cause of cancer-related death. Poor understanding of the mechanisms underlying the pathogenesis of HCC makes it difficult to be diagnosed and treated at early stage. MicroRNAs (miRNAs), a class of noncoding single-stranded RNAs of ~22 nucleotides in length, posttranscriptionally regulate gene expression by base pairing with the 3' untranslated regions (3'UTRs) of target messenger RNAs (mRNAs). Aberrant expression of miRNAs is found in many if not all cancers, and many deregulated miRNAs have been proved to play crucial roles in the initiation and progression of cancers by regulating the expression of various oncogenes or tumor suppressor genes. In this Paper, we will summarize the regulations and functions of miRNAs aberrantly expressed in HCC and discuss the potential application of miRNAs as diagnostic and prognostic biomarkers of HCC and their potential roles in the intervention of HCC.

Insulin resistance and cancer: the role of insulin and IGFs

Insulin, IGF1, and IGF2 are the most studied insulin-like peptides (ILPs). These are evolutionary conserved factors well known as key regulators of energy metabolism and growth, with crucial roles in insulin resistance-related metabolic disorders such as obesity, diseases like type 2 diabetes mellitus, as well as associated immune deregulations. A growing body of evidence suggests that insulin and IGF1 receptors mediate their effects on regulating cell proliferation, differentiation, apoptosis, glucose transport, and energy metabolism by signaling downstream through insulin receptor substrate molecules and thus play a pivotal role in cell fate determination. Despite the emerging evidence from epidemiological studies on the possible relationship between insulin resistance and cancer, our understanding on the cellular and molecular mechanisms that might account for this relationship remains incompletely understood. The involvement of IGFs in carcinogenesis is attributed to their role in linking high energy intake, increased cell proliferation, and suppression of apoptosis to cancer risks, which has been proposed as the key mechanism bridging insulin resistance and cancer. The present review summarizes and discusses evidence highlighting recent advances in our understanding on the role of ILPs as the link between insulin resistance and cancer and between immune deregulation and cancer in obesity, as well as those areas where there remains a paucity of data. It is anticipated that issues discussed in this paper will also recover new therapeutic targets that can assist in diagnostic screening and novel approaches to controlling tumor development.

Association between expression of key insulin-like growth factor signaling molecules and malignant transformation of hepatocytes

AIM: To investigate the dynamic expression of key insulin-like growth factor (IGF) signaling IGF-Ⅱ and IGF-Ⅰreceptor (IGF-IR) during malignant transformation of rat hepatocytes.

METHODS: Hepatoma was induced in male Sprague-Dawley rats with 2-fluorenylacetamide (2-FAA). Morphological changes of the liver were observed, and dynamic changes in the levels of IGF-Ⅱ and IGF-1R in the liver and serum were quantitatively analyzed. The expression and distribution of IGF-Ⅱ and IGF-1R proteins were analyzed by immunohistochemistry. Serum IGF-1R and IGF-II levels were detected by ELISA. Expression of IGF-Ⅱ and IGF-IR mRNAs in the liver was detected by nested RT-PCR and confirmed by DNA sequencing.

RESULTS: After induction with 2-FAA, rat hepatocytes showed granule-like degeneration, atypical hyperplasia, and malignant transformation, and hepatic total RNA, IGF-1R, and IGF-Ⅱ levels significantly increased. The levels of IGF-Ⅱ in the liver (F = 48.1, P < 0.01) and serum (F = 13.2, P < 0.01) were significantly higher in the hepatoma group than in any of other groups. There was a positive relationship (r = 0.97, t = 5.97, P < 0.01) between liver IGF-II (nmol/mg wet liver) and serum IGF-Ⅱ (nmol/L). Similar results were also obtained for IGF-IR in the liver and serum, and IGF-IR expression in the hepatoma group was significantly higher (P < 0.01) than that in any of other groups.

CONCLUSION: IGF-1R and IGF-Ⅱ may participate in hepatocyte canceration. Overexpression of IGF-1R and IGF-Ⅱ might be useful molecular markers for early diagnosis and prognosis of hepatocellular carcinoma.

Serum IGFBP-3 is a more effective predictor than IGF-1 and IGF-2 for the development of hepatocellular carcinoma in patients with chronic HCV infection

Hepatocellular carcinoma (HCC) contributes to 14.8% of all cancer mortality in Egypt, which has a high prevalence of hepatitis C virus (HCV). We have previously shown alterations in the insulin-like growth factor-1 (IGF-1) receptor signalling pathway during experimental hepatocarcinogenesis. The aim of this study was to determine whether serum levels of IGF-1, IGF-2 and IGFBP-3 can be used to discriminate between HCC and the stages of hepatic dysfunction in patients with liver cirrhosis assessed by the Child-Pugh (CP) score, and to correlate these levels with HCC stages. We recruited 241 subjects to the present study; 79 with liver cirrhosis, 62 with HCV-induced HCC and 100 age-matched controls. Results showed that serum levels of IGF-1, IGF-2 and IGFBP-3 were reduced significantly in cirrhosis and HCC patients in comparison to the controls, and that this reduction negatively correlated with the CP scores. However, only IGFBP-3 levels showed significant negative correlation with α-fetoprotein levels. The reduction in IGF-1 and IGFBP-3 but not IGF-2 levels was significant in HCC in comparison to patients with cirrhosis. None of the parameters significantly correlated with the HCC stage. IGFBP-3 levels discriminated between cirrhosis and HCC at a sensitivity of 87%, a specificity of 80% and a cut-off value of <682.6 ng/ml. In conclusion, although our results showed that serum IGF-1, IGF-2 and IGFBP-3 are reduced with the progression of hepatic dysfunction, only IGFBP-3 may be considered as the most promising serological marker for the prediction of the development of HCC in the chronic HCV patients with liver cirrhosis.