miRNA in hepatocellular carcinoma.

bs_bs_banner

Hepatology Research 2014

doi: 10.1111/hepr.12386

Review Article

miRNA in hepatocellular carcinoma Asahiro Morishita and Tsutomu Masaki Department of Gastroenterology and Neurology, Kagawa University School of Medicine, Kagawa, Japan

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

INTRODUCTION

M

IRNA ARE SMALL, interfering, non-coding RNA that are 21–30 nucleotides in length, and it has been predicted that there are approximately 1000 of these sequences in the human genome.1 Each miRNA negatively regulates its target genes by binding to multiple mRNA. Binding between miRNA and mRNA triggers the RNA-mediated RNAi pathway, in which the mRNA transcripts are cleaved by an miRNA-associated RNA-induced silencing complex (miRISC).2 In most animals, single-stranded miRNA act by binding to imperfectly complementary sites within the 3′untranslated regions of their target mRNA, inhibiting translation or initiating degradation via the miRISC.3 Recruitment of the miRISC can modulate the expression of targeted protein-coding genes.4,5 Surprisingly, each

Correspondence: Profesor Tsutomu Masaki, Department of Gastroenterology and Neurology, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki-cho, Kida-gun, Kagawa 761-0793, Japan. Email: [email protected] Received 27 June 2014; revision 27 June 2014; accepted 1 July 2014.

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. Key words: diagnostic and prognostic markers, hepatocellular carcinoma, miRNA, therapeutic target

miRNA can promote the targeting and modulation of more than 200 mRNA.6,7 In humans, a total of 2000 miRNA have been discovered.8 Although their importance is recognized in regulating protein-coding gene expression, the precise functions of miRNA remain elusive. It is now apparent that miRNA play an important role in human carcinogenesis.6,9–12 In addition, the expression of miRNA is generally downregulated in tumor tissues compared with normal tissues, indicating that a subset of miRNA act as tumor suppressors. Therefore, the discovery of miRNA has expanded our knowledge of post-transcriptional gene regulation during cancer development. Interestingly, more than half of all genes that encode miRNA are located at fragile sites or in cancer-associated regions of the genome,13 suggesting that miRNA may serve as diagnostic markers or therapeutic targets. The first report of altered miRNA expression in cancer involved a frequent chromosomal deletion and two miRNA, miRNA-15 (miR-15) and miRNA-16 (miR-16), thought to target B-cell lymphoma 2 (BCL-2), which is the anti-apoptotic factor in chronic lymphocytic leukemia.14 Recent reports have shown that miRNA are associated with the

© 2014 The Authors. 1 Hepatology Research published by Wiley Publishing Asia Pty Ltd on behalf of The Japan Society of Hepatology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

2

A. Morishita and T. Masaki


pathogenesis of various types of cancers,9–12 and these findings have increased our understanding of epigenetic modification during oncogenesis.2 Several studies have recently reported a relationship between miRNA and hepatocellular carcinoma (HCC).12,15–18 Among several miRNA implicated in HCC, including miR-21, miR-221 and miR-222, the aberrant levels of miRNA expressions were upregulated.12,16,17 However, other miRNA, including miR-122a, miR-145, miR-199a and miR-223, were decreased in HCC compared to normal tissues.15,19 Surprisingly, Huang et al. have shown that, among aberrant miRNA in HCC, miR338 affects several clinical features, such as tumor size, tumor–node–metastasis classification, vascular invasion and intrahepatic metastasis.18 These studies suggest that

the modulation of miRNA may play an important role in the progression of HCC.

BIOGENESIS AND REGULATION OF miRNA

S

EVERAL STEPS ARE involved in the biogenesis of miRNA: transcription, cleavage, export, further cleavage, strand selection and interaction with mRNA (Fig. 1).20 The genes encoding miRNA are primarily transcribed by RNA polymerase II into initial transcripts that are then processed through the canonical pathway or the “mirtron” pathway to form primary miRNA transcripts (pri-miRNA) that include one or more hairpin structures.21 These pri-miRNA are capped at the 5′-end and polyadenylated at the 3′-end22 and then

Cytoplasm

Nucleus Translational repression

Genome DNA

mRNA degradation

Pol II RISC AGO

RISC formation

Transcription

AGO

Mature miRNA

Pri-miRNA Unwinding

AAAAA

m7G

Degradation

miRNA duplex Clevage Clevage

Pre-miRNA Exportin 5

Drosha

DGCR8

Export TRBP

Dicer

Figure 1 Steps in biogenesis of miRNA. The primary miRNA (pri-miRNA) is transcribed from genome DNA mainly by RNA polymerase II (Pol II). The Drosha–DGCR8 complex cleaves and splices pri-miRNA into hairpin-like miRNA precursors called pre-miRNA. These pre-miRNA are exported from the nucleus to the cytoplasm in an Exportin-5-Ran-guanosine-5′-triphosphate (GTP)-dependent manner. In the cytoplasm, Dicer and TRBP cleaves hairpin structure of pre-miRNA into mature miRNA. The processed miRNA are then loaded onto the RNA-induced silencing complex (RISC) with Argonaute (Ago2) and are guided to their mRNA targets for translational repression or mRNA degradation.

© 2014 The Authors. Hepatology Research published by Wiley Publishing Asia Pty Ltd on behalf of The Japan Society of Hepatology


cleaved into approximately 70-nucleotide (nt) hairpinstructured precursors (pre-miRNA) with a 5′-phosphate and a 3′-2-nt overhang by a multiprotein complex that includes an RNase III enzyme named Drosha and a dsRNA-binding domain protein (dsRBD) named DGCR8/Pasha.23 Subsequently, exportin-5 translocates pre-miRNA from the nucleus to the cytoplasm through a Ran-guanine-triphosphate (GTP)-dependent mechanism.24 These translocated pre-miRNA are cleaved by a second RNase III endonuclease named Dicer and the dsRBD proteins TRBP/PACT.25 Finally, one strand of the pre-miRNA interacts with the Argonaute (AGO) protein and is degraded in the RNA-induced silencing complex that modulates mRNA degradation and translational repression.26 In addition to the canonical miRNA pathway, some miRNA are processed into miRNA-like molecules in a Microprocessor-independent manner, including certain snoRNA,27 tRNA28 and endogenous shRNA.29 Furthermore, more than 1 million Drosophila smallRNA sequences were recently generated using 454 pyrosequencing, and these sequences identified 14 short introns with predicted hairpin structures.30 These short introns were named “mirtrons” after analyzing their characteristics. Primary mirtron precursors include mirtronic introns and flanking exonic sequences that typically lack the lower stem (∼11 bp) that is found in miRNA, which mediates their recognition and cleavage via the Pasha (DGCR8)/Drosha complex.31 The “AG” splice acceptor of a typical mirtron adopts a 2-nt 3′-overhang for these hairpins, allowing mirtronsto enter the miRNA-processing pathway without Droshamediated cleavage.32 miRNA regulate various biological processes by modulating specific mRNA, and their expression is tightly regulated in normal cells.29,33 Each miRNA can potentially be controlled independently at the transcriptional level by various regulators or at the epigenetic level via DNA methylation.33–35 Interestingly, the regulatory elements that control protein-coding genes, such as CpG islands, TATA boxes, transcription factor II B recognition sites, initiator elements and histone modifications, are also found in the promoters of miRNA genes,36 indicating that the transcription factors are similar between protein-coding genes and miRNA. Therefore, the expression of various processing components is simultaneously regulated to modulate the activity of mature miRNA. In addition, miRNA can also autoregulate their own transcription by controlling various transcription factors in positive or negative feedback loops. The miR-200

miRNA profiles for the treatment of HCC 3

family of miRNA plays an important role by inhibiting the expression of zinc finger E-box-binding homeobox 1 (ZEB1) and survival of motor neuron proteininteracting protein 1 (SIP1), which act as transcriptional repressors in epithelial cells, to regulate the epithelial to mesenchymal transition; however, ZEB1 and SIP1 also suppress the miR-200 family, including miR-200a and miR-200b, by binding their promoter regions.37 This result indicates that miRNA and their target molecules are tightly regulated by each other at the transcription level. Moreover, miRNA are also regulated by epigenetic processes, such as DNA methylation and specific histone deacetylation. Seventeen of the 313 human miRNA were upregulated more than threefold after treatment with the chromatin-modifying drugs 5-aza2′-deoxycytidine and 4-phenylbutyric acid. Among these miRNA, miR-127 was highly upregulated after treatment.38 In addition, inhibiting histone deacetylases rapidly downregulated 22 miRNA and upregulated five miRNA.39 Furthermore, miRNA expression is also controlled at the post-transcriptional level. A large fraction of miRNA genes are post-transcriptionally regulated, including those of the Let-7 family.40 Individual miRNA expression processed from the same pri-miRNA is occasionally different at the mature miRNA level.41 Initially during post-transcriptional regulation, miRNA are processed by Microprocessor, which consists of Drosha and the dsRNA-binding protein DGCR8 in the nucleus.23 A loss of Drosha or DGCR8 function leads to a decrease in pre-miRNA and mature miRNA.23 In the cytoplasm, pre-miRNA that are exported from the nucleus in a Ran/GTP/Exportin-5-mediated event are further regulated by the RNase III enzyme Dicer to become mature RNA.40

MIRNA EXPRESSION AND HCC DEVELOPMENT

M

IRNA HAVE BEEN reported to influence the critical functions of cellular differentiation, proliferation, apoptosis, invasion and metastasis.42 The miRNA expression profiles in tumors are different from those in normal tissues and also vary according to the type of tumor. Interestingly, the direct targets of miRNA are also protein-coding genes of the cell cycle, apoptosis and metastasis in HCC.43 Recently, microarray analysis has revealed that a subset of miRNA are up- and downregulated during the development of HCC.44 Reductions in the expression of miRNA are frequently


4


observed in HCC, and the targets of these downregulated miRNA may be putative oncogenes. Conversely, some of the upregulated miRNA act as oncogenic miRNA in HCC and may be targets of tumor suppressor genes. miRNA are associated with various chronic liver diseases, such as alcoholic liver disease,45 non-alcoholic steatohepatitis (NASH)46–48 and viral hepatitis.49–51 In addition to these chronic diseases, miRNA are also involved in the development of HCC. In alcoholic liver disease, miR-217 induces ethanol-induced fat accumulation in hepatocytes by inhibiting the expression of SIRT1.45 The miRNA miR-126, miR-27b, miR-182, miR-183, miR-199, miR-200a, miR-214 and miR-322 were downregulated in alcohol-related HCC.51,52 The observed reduction in miR-27 in alcoholic steatohepatitis was the result of epigenetic events that occurred in response to alcohol.53 The development and exacerbation of NASH, both of which are also associated with miRNA, increase the risk of HCC. A recent study indicated that miRNA play a critical role in activating hepatic stellate cells (HSC) during the development of NASH.54 Free cholesterol was observed to accumulate due to an enhancement of both sterol regulatory elementbinding protein-2 (SREBP2) and miR-33a signaling via the inhibition of peroxisome proliferator-activated receptor-γ signaling together with HSC activation and disruption of the SREBP2-mediated cholesterolfeedback system in HSC.54 The upregulation of miR-21, which downregulates the expression of tumor suppressor phosphatase and tensin homolog (PTEN), is induced by unsaturated fatty acids in hepatocytes.46 In addition, miR-155 suppresses another tumor suppressor gene, CCAAT-enhancer-binding protein-β, and has been also shown to be upregulated in mice fed a choline-deficient amino acid-defined diet.47,48 Viral hepatitis, such as that caused by the hepatitis B virus (HBV) and hepatitis C virus (HCV), is the most frequent cause of HCC and cirrhosis.55 The 5-year cumulative risk of hepatocarcinogenesis with liver cirrhosis ranges 5–30%.55 Among HBV cases, only two miRNA, miR-210 and miR-199-3p, were observed to affect HBV gene expression and replication in an experimental model. In contrast, many cellular miRNA indirectly regulate the HBV life cycle by affecting virusrelevant cellular proteins.56 Ura et al. examined the expression of 188 miRNA in HCC and adjacent normal tissues obtained from 12 HBV positive and 14 HCV positive patients. In these groups, the expression of six miRNA was decreased in HBV patients, and that of 13


miRNA was reduced in HCV patients.57 These data suggest that there are distinct patterns in the miRNA profiles between HBV and HCV infection. Several reports demonstrated that miR-96 or miR-26 were significantly upregulated in HBV-related HCC tissues.52,58 Takazawa et al. reported comprehensive miRNA profiles using sequencing methods that provided more than 314 000 reliable reads from HCC tissue and more than 268 000 reliable reads from adjacent normal liver. Bioinformatic-based analysis revealed several miRNA altered in HCC, including miR-122, miR-21 and miR34a.59 Therefore, further studies that characterize the miRNA associated with HBV-related HCC may yield a novel therapeutic tool for HCC patients with HBV infection. In addition, miR-196 plays an important role through the inhibition of Bach1 (a basic leucine zipper mammalian transcriptional repressor) and upregulation of hemeoxygenase 1 in HCV-related HCC.60 Diaz et al. also demonstrated 18 miRNA among 2226 human miRNA that were exclusively expressed in HCV-related HCC.61 One of these 18 miRNA has been associated with networks that include p53, PTEN and retinoic acid and is involved in the pathogenesis of HCC.62,63 These data suggest that miRNA pathways are essential to the development of HCC during HCV infection.

CLINICAL SIGNIFICANCE OF MIRNA IN HCC Single nucleotide polymorphisms of miRNA and the risk of HCC

S

INGLE NUCLEOTIDE POLYMORPHISMS in miRNA and their targets have been associated with an increased risk of HCC. Because miRNA must closely recognize binding sites in their target genes, a variation in even 1 nt may produce dramatic changes in the post-transcriptional regulation of target genes. Polymorphisms in miR-101-1/rs7536540,64 miR-101-2/ rs12375841,64 miR-34b/c/rs493872365 and miR-106b25-cluster/rs99988566 are positively associated with an increased risk of HCC. In contrast, miR-371–373/ rs385950167 and miR-149c/rs229283268 are negatively involved in HCC risk. However, conflicting results were obtained from several studies, such as with miR-499a/ rs374644468–70 and miR-196a-2/rs11614913.68,71–73

miRNA as biomarkers for HCC miRNA can be characterized as prognostic or diagnostic markers. Downregulation of the miRNA miR-let-7g,74 miR-22,75 miR-26,58 miR-29,76 miR-99a,77 miR-122,78




Table 1 Downregulated miRNA in hepatocellular carcinoma miRNA

Targets

Mechanisms

References

let-7a let-7b let-7c let-7d let-7f-1 let-7g miR-1 miR-7 miR-10a miR-10b miR-15a/16 miR-21 miR-26a miR-29a miR-29b miR-29c miR-34a miR-99a miR-100 miR-101 miR-122 miR-124 miR-125a miR-125b

Caspase-3, STAT3 HMGA2 Bcl-xL, c-Myc

Apoptosis, proliferation Apoptosis, proliferation Apoptosis, proliferation, cell growth Apoptosis, proliferation Apoptosis, proliferation Apoptosis, metastasis Proliferation

50,83,84

miR-139 miR-139-5p miR-140-5p miR-141 miR-145 miR-148a miR-152 miR-195 miR-198 miR-199a-3p miR-199a-5p miR-199b miR-200a miR-200b miR-200c miR-203 miR-214 miR-219-5p miR-222 miR-223 miR-224 miR-363-3p miR-375 miR-376a miR-429 miR-449 miR-450a miR-520b/e miR-612 miR-637 miR-1271

Bcl-xL, c-Myc, COLIA2, p16 ET-1 PIK3CD EphA4

85 51,86,87 50 50 74,88,89 90 91 92 93 94 52

CDK6, IL-6, cyclin D2, E1, E2 SPARC MMP-2 SIRT1 c-Met, CCL22 PLK1, IGF-1R PLK1 EZH2, EED, Mcl-1, Fos, Bcl-w, ADAM17, Wnt1 PIK3CA MMP11, VEGF-A,SIRT7 Mcl-1, Bcl-w, SUV39H1, SIRT7 ROCK2, c-Fos

Cell cycle Proliferation Invasion

95–97 98 99 100

Metastasis

101,102 77,103

Carcinogenesis Apoptosis, DNA methylation Apoptosis, proliferation, angiogenesis Proliferation Proliferation, metastasis, metabolism Proliferation, metastasis, angiogenesis, apoptosis, histone modification Metastasis

103 104–106 107–110 111 112,113 51,113–117

51,118,119 51

TGFβR1, FIF9, DMMT1 DLC-1 IRS1/2, IGF-1R, β-catenin c-Met, HRIP, E-cadherin, c-Myc DNMT1, GSTP1, CDH1 cyclin D1, CDK6, E2F3, LATS2

120,121 122 81,123 124–127 128

Cell cycle, tumorigenesis, apoptosis

129,130 17

mTOR, PAK4, caveolin-2 DDR1, ATG7 HDAC4

Drug resistance, cell growth Invasion, autophagy Proliferation, invasion, apoptosis Proliferation, metastasis

131–133 134,135 136 137 51 52

Surviving HDGF, β-catenin GPC3

Proliferation Cell growth, angiogenesis, metastasis Proliferation

STMN1

Proliferation

138 139–141 142 52 16 143

c-Myc ATG7, AEG-1 PIK3R1 Rab18 c-Met DNMT3a NIK, MEKK2, cyclin D1 AKT2 STAT activation GLP3

127

Autophagy Apoptosis, proliferation

144,145 146 147

Proliferation, apoptosis Proliferation Cell growth, proliferation

148 149 150,151 152 153 93


6


miR-124,79 miR-139,80 miR-14581 and miR-199b82 has been implicated in cell proliferation, apoptosis, angiogenesis, recurrence, shorter disease-free survival and poor prognosis (Table 1). In contrast, upregulation of miR-10b,154 miR-17-5p,155 miR-21,156 miR-135a,157 miR-155,158 miR-182,159 miR-221156 and miR-222118,156 has been associated with metastasis, angiogenesis and poor prognosis (Table 2). In addition, miRNA profiling


classified HCC into three main clusters.189 These results indicate the potential value of miRNA detection for the prediction of survival in HCC. Furthermore, Yamamoto et al. reported that miR-500 was increased in the sera of HCC patients and decreased after surgical treatment.196 In addition, other miRNA, such as miR-25, miR-375 and let-7f, can be used to distinguish HCC from normal control tissue.197 Interestingly, extracellular miRNA are

Table 2 Upregulated miRNA in hepatocellular carcinoma miRNA

Targets

Mechanisms

References

miR-10a miR-17-5p miR-18a miR-21 miR-22 miR-23a miR-26a miR-30d miR-100 miR-106b miR-130b miR-135a miR-143 miR-151 miR-155 miR-181b miR-182 miR-183 miR-186 miR-200 miR-210 miR-216a miR-216a/217 miR-221 miR-221/222 miR-224 miR-301a miR-373 miR-423 miR-485-3p miR-490-3p miR-494 miR-495 miR-517a miR-519d miR-550a miR-590-5p miR-615-5p miR-657 miR-664 miR-1323

EphA4; CADM1 p38 pathway ER1a PTEN; RHOB; PDCD4 Era, IL-1a PGC-1a, G6PC IL-6, CyclinD2, E2 GNAI2 PLK1 APC TP53INP1 FOXM1, MTSS1 FNDC3B FAK, RhoGDIA SOCS1, DKK1, APC, PTEN TIMP3 MTSS1 AKAP12 AKAP12 NRF2 pathway VMP1 TSLC1 PTEN, SMAD7 p27, p57, Arnt, CDK inhibitors p27, DDIT4 Atg5, Smad4, autophagy, API-5 Gax PPP6C p21/waf1 MAT1, LIN28B ERCIC3 MCC MAT1, LIN28B

EMT, metastasis Migration Proliferation Metastasis, drug resistance Carcinogenesis Gluconeogenesis Tumor growth, metastasis Invasion, metastasis Carcinogenesis Proliferation Cell growth, self-renewal Metastasis Metastasis Migration Proliferation; tumorigenesis Tumorigenesis, metastasis Metastasis Carcinogenesis Carcinogenesis Carcinogenesis Metastasis Carcinogenesis EMT, drug resistance Apoptosis, proliferation, angiogenesis Tumorigenesis Tumorigenesis, autophagy Metastasis Cell cycle Cell growth Cell growth, EMT EMT Tumorigenesis Tumorigenesis, metastasis Tumorigenesis, metastasis Proliferation, invasion, apoptosis Proliferation, invasion, metastasis Metastasis, proliferation Proliferation, migration Proliferation Tumorigenesis, metastasis Proliferation

92,154

p21, PTEN, AKT3, TIMP2 CPEB4 TGF-β RII IGF-II TLE1, NF-κB MAT1, LIN28B

160 49 12,48 161 162 96,97 163 17 164 165 157 166 167,168 48,169,170 171 159 172 172 173 174 175 176 177–179 180 181,182 183 184 185 186 187 188 186 189 190 191 192 193 194 186 195



stable in circulation, indicating that miRNA may serve as useful diagnostic markers for HCC.

miRNA as targets for HCC treatment Because miRNA function as oncogenes or tumor suppressors, alterations in these miRNA influence the malignant phenotypes of HCC cells. In tumor tissues, miRNA associated with tumor suppressors are downregulated during tumorigenesis, tumor development and metastasis. These miRNA may be potential therapeutic targets, and strategies for miRNA replacement therapies have been developed using miR-26a,95 miR122198 and miR-124111 in a HCC mouse model. In contrast, inhibition of miR-221 lengthened survival, reduced the nodule number and retarded tumor development.177,199 Furthermore, no toxicity was observed when miRNA-targeted therapy was used to treat HCC in a mice model. miRNA have been also shown to affect the sensitivity of tumors to anticancer drugs. Several reports have indicated that miRNA profiles are dramatically altered following metformin treatment for various cancers: gastric cancer,200 esophageal cancer201 and HCC.202 Interestingly, overexpression of miR-21203 and miR-181b171 induced resistance to interferon–5fluorouracil combination therapy and doxorubicin treatment in HCC. In contrast, Bai et al. demonstrated that restoring expression of the tumor suppressive miR122 makes HCC cells more sensitive to sorafenib via the downregulation of multidrug resistance genes.

CONCLUSION

M

IRNA ARE BEING considered as new biomarkers and potential therapeutic targets for HCC. To date, many miRNA have been identified as regulators of various target genes during HCC development. In addition, although miRNA-based therapy is not currently used in the clinic, its innovative applications are growing in various fields. However, the details regarding targetable miRNA and the mechanisms of miRNAinduced anticancer effects remain unclear. Further analyses and new technology for miRNA research will elucidate novel concepts in the pathogenesis of HCC. Consequently, analyzing miRNA profiles and their signaling pathways offers deeper insights into the treatment options for HCC.

REFERENCES 1 Zamore PD, Haley B. Ribo-gnome: the big world of small RNAs. Science 2005; 309: 1519–24.


2 Suzuki H, Maruyama R, Yamamoto E, Kai M. Epigenetic alteration and microRNA dysregulation in cancer. Front Genet 2013; 4: 258. 3 Masaki T. MicroRNA and hepatocellular carcinoma. Hepatol Res 2009; 39: 751–2. 4 Davis-Dusenbery BN, Hata A. MicroRNA in cancer: the involvement of aberrant MicroRNA biogenesis regulatory pathways. Genes Cancer 2010; 1: 1100–14. 5 Farazi TA, Hoell JI, Morozov P, Tuschl T. MicroRNAs in human cancer. Adv Exp Med Biol 2013; 774: 1–20. 6 Bartel DP. MicroRNAs: genomics, biogenesis, mechanism, and function. Cell 2004; 116: 281–97. 7 Krek A, Grun D, Poy MN et al. Combinatorial microRNA target predictions. Nat Genet 2005; 37: 495–500. 8 Griffiths-Jones S. miRBase: microRNA sequences and annotation. Curr Protoc Bioinformatics 2010; Chapter 12: Unit 12 9: 1–0. 9 Michael MZ, SM OC, van Holst Pellekaan NG, Young GP, James RJ. Reduced accumulation of specific microRNAs in colorectal neoplasia. Mol Cancer Res 2003; 1: 882– 91. 10 Lee EJ, Gusev Y, Jiang J et al. Expression profiling identifies microRNA signature in pancreatic cancer. Int J Cancer 2007; 120: 1046–54. 11 Takamizawa J, Konishi H, Yanagisawa K et al. Reduced expression of the let-7 microRNAs in human lung cancers in association with shortened postoperative survival. Cancer Res 2004; 64: 3753–6. 12 Meng F, Henson R, Wehbe-Janek H, Ghoshal K, Jacob ST, Patel T. MicroRNA-21 regulates expression of the PTEN tumor suppressor gene in human hepatocellular cancer. Gastroenterology 2007; 133: 647–58. 13 Calin GA, Sevignani C, Dumitru CD et al. Human microRNA genes are frequently located at fragile sites and genomic regions involved in cancers. Proc Natl Acad Sci U S A 2004; 101: 2999–3004. 14 Calin GA, Dumitru CD, Shimizu M et al. Frequent deletions and down-regulation of micro- RNA genes miR15 and miR16 at 13q14 in chronic lymphocytic leukemia. Proc Natl Acad Sci U S A 2002; 99: 15524–9. 15 Gramantieri L, Ferracin M, Fornari F et al. Cyclin G1 is a target of miR-122a, a microRNA frequently downregulated in human hepatocellular carcinoma. Cancer Res 2007; 67: 6092–9. 16 Wong QW, Lung RW, Law PT et al. MicroRNA-223 is commonly repressed in hepatocellular carcinoma and potentiates expression of Stathmin1. Gastroenterology 2008; 135: 257–69. 17 Varnholt H, Drebber U, Schulze F et al. MicroRNA gene expression profile of hepatitis C virus-associated hepatocellular carcinoma. Hepatology 2008; 47: 1223–32. 18 Huang XH, Wang Q, Chen JS et al. Bead-based microarray analysis of microRNA expression in hepatocellular carcinoma: miR-338 is downregulated. Hepatol Res 2009; 39: 786–94.


8


19 Murakami Y, Yasuda T, Saigo K et al. Comprehensive analysis of microRNA expression patterns in hepatocellular carcinoma and non-tumorous tissues. Oncogene 2006; 25: 2537–45. 20 Wang XW, Heegaard NH, Micro OH. RNAs in liver disease. Gastroenterology 2012; 142: 1431–43. 21 Kim VN, Han J, Siomi MC. Biogenesis of small RNAs in animals. Nat Rev Mol Cell Biol 2009; 10: 126–39. 22 Cai X, Hagedorn CH, Cullen BR. Human microRNAs are processed from capped, polyadenylated transcripts that can also function as mRNAs. RNA 2004; 10: 1957– 66. 23 Gregory RI, Yan KP, Amuthan G et al. The Microprocessor complex mediates the genesis of microRNAs. Nature 2004; 432: 235–40. 24 Okada C, Yamashita E, Lee SJ et al. A high-resolution structure of the pre-microRNA nuclear export machinery. Science 2009; 326: 1275–9. 25 Chendrimada TP, Gregory RI, Kumaraswamy E et al. TRBP recruits the Dicer complex to Ago2 for microRNA processing and gene silencing. Nature 2005; 436: 740–4. 26 Kim Y, Kim VN. MicroRNA factory: RISC assembly from precursor microRNAs. Mol Cell 2012; 46: 384–6. 27 Ender C, Krek A, Friedlander MR et al. A human snoRNA with microRNA-like functions. Mol Cell 2008; 32: 519– 28. 28 Cole C, Sobala A, Lu C et al. Filtering of deep sequencing data reveals the existence of abundant Dicer-dependent small RNAs derived from tRNAs. RNA 2009; 15: 2147– 60. 29 Babiarz JE, Ruby JG, Wang Y, Bartel DP, Blelloch R. Mouse ES cells express endogenous shRNAs, siRNAs, and other Microprocessor-independent, Dicer-dependent small RNAs. Genes Dev 2008; 22: 2773–85. 30 Ruby JG, Jan CH, Bartel DP. Intronic microRNA precursors that bypass Drosha processing. Nature 2007; 448: 83–6. 31 Han J, Lee Y, Yeom KH et al. Molecular basis for the recognition of primary microRNAs by the DroshaDGCR8 complex. Cell 2006; 125: 887–901. 32 Okamura K, Hagen JW, Duan H, Tyler DM, Lai EC. The mirtron pathway generates microRNA-class regulatory RNAs in Drosophila. Cell 2007; 130: 89–100. 33 Dews M, Homayouni A, Yu D et al. Augmentation of tumor angiogenesis by a Myc-activated microRNA cluster. Nat Genet 2006; 38: 1060–5. 34 Lujambio A, Calin GA, Villanueva A et al. A microRNA DNA methylation signature for human cancer metastasis. Proc Natl Acad Sci U S A 2008; 105: 13556–61. 35 He L, He X, Lim LP et al. A microRNA component of the p53 tumour suppressor network. Nature 2007; 447: 1130–4. 36 Corcoran DL, Pandit KV, Gordon B, Bhattacharjee A, Kaminski N, Benos PV. Features of mammalian microRNA promoters emerge from polymerase II


37

38

39

40

41

42 43

44

45

46

47

48

49

50

51

chromatin immunoprecipitation data. PLoS ONE 2009; 4: e5279. Bracken CP, Gregory PA, Kolesnikoff N et al. A doublenegative feedback loop between ZEB1-SIP1 and the microRNA-200 family regulates epithelial-mesenchymal transition. Cancer Res 2008; 68: 7846–54. Saito Y, Liang G, Egger G et al. Specific activation of microRNA-127 with downregulation of the protooncogene BCL6 by chromatin-modifying drugs in human cancer cells. Cancer Cell 2006; 9: 435–43. Scott GK, Mattie MD, Berger CE, Benz SC, Benz CC. Rapid alteration of microRNA levels by histone deacetylase inhibition. Cancer Res 2006; 66: 1277–81. Thomson JM, Newman M, Parker JS, Morin-Kensicki EM, Wright T, Hammond SM. Extensive post-transcriptional regulation of microRNAs and its implications for cancer. Genes Dev 2006; 20: 2202–7. Mineno J, Okamoto S, Ando T et al. The expression profile of microRNAs in mouse embryos. Nucleic Acids Res 2006; 34: 1765–71. Hanahan D, Weinberg RA. Hallmarks of cancer: the next generation. Cell 2011; 144: 646–74. Liu WR, Shi YH, Peng YF, Fan J. Epigenetics of hepatocellular carcinoma: a new horizon. Chin Med J (Engl) 2012; 125: 2349–60. Sun J, Lu H, Wang X, Jin H. MicroRNAs in hepatocellular carcinoma: regulation, function, and clinical implications. ScientificWorldJournal 2013; 2013: 924206. Yin H, Hu M, Zhang R, Shen Z, Flatow L, You M. MicroRNA-217 promotes ethanol-induced fat accumulation in hepatocytes by down-regulating SIRT1. J Biol Chem 2012; 287: 9817–26. Vinciguerra M, Sgroi A, Veyrat-Durebex C, Rubbia-Brandt L, Buhler LH, Foti M. Unsaturated fatty acids inhibit the expression of tumor suppressor phosphatase and tensin homolog (PTEN) via microRNA-21 up-regulation in hepatocytes. Hepatology 2009; 49: 1176–84. O’Connell RM, Rao DS, Chaudhuri AA et al. Sustained expression of microRNA-155 in hematopoietic stem cells causes a myeloproliferative disorder. J Exp Med 2008; 205: 585–94. Wang B, Majumder S, Nuovo G et al. Role of microRNA155 at early stages of hepatocarcinogenesis induced by choline-deficient and amino acid-defined diet in C57BL/6 mice. Hepatology 2009; 50: 1152–61. Liu WH, Yeh SH, Lu CC et al. MicroRNA-18a prevents estrogen receptor-alpha expression, promoting proliferation of hepatocellular carcinoma cells. Gastroenterology 2009; 136: 683–93. Wang Z, Lin S, Li JJ et al. MYC protein inhibits transcription of the microRNA cluster MC-let-7a-1∼let-7d via noncanonical E-box. J Biol Chem 2011; 286: 39703– 14. Au SL, Wong CC, Lee JM et al. Enhancer of zeste homolog 2 epigenetically silences multiple tumor suppressor



52

53

54

55 56

57

58

59

60

61

62

63

64

65

66

microRNAs to promote liver cancer metastasis. Hepatology 2012; 56: 622–31. Ladeiro Y, Couchy G, Balabaud C et al. MicroRNA profiling in hepatocellular tumors is associated with clinical features and oncogene/tumor suppressor gene mutations. Hepatology 2008; 47: 1955–63. Choudhury M, Shukla SD. Surrogate alcohols and their metabolites modify histone H3 acetylation: involvement of histone acetyl transferase and histone deacetylase. Alcohol Clin Exp Res 2008; 32: 829–39. Tomita K, Teratani T, Suzuki T et al. Free cholesterol accumulation in hepatic stellate cells: mechanism of liver fibrosis aggravation in nonalcoholic steatohepatitis in mice. Hepatology 2014; 59: 154–69. El-Serag HB. Epidemiology of viral hepatitis and hepatocellular carcinoma. Gastroenterology 2012; 142: 1264–73. Liu WH, Yeh SH, Chen PJ. Role of microRNAs in hepatitis B virus replication and pathogenesis. Biochim Biophys Acta 2011; 1809: 678–85. Ura S, Honda M, Yamashita T et al. Differential microRNA expression between hepatitis B and hepatitis C leading disease progression to hepatocellular carcinoma. Hepatology 2009; 49: 1098–112. Ji J, Shi J, Budhu A et al. MicroRNA expression, survival, and response to interferon in liver cancer. N Engl J Med 2009; 361: 1437–47. Mizuguchi Y, Mishima T, Yokomuro S et al. Sequencing and bioinformatics-based analyses of the microRNA transcriptome in hepatitis B-related hepatocellular carcinoma. PLoS ONE 2011; 6: e15304. Hou W, Tian Q, Zheng J, Bonkovsky HL. MicroRNA-196 represses Bach1 protein and hepatitis C virus gene expression in human hepatoma cells expressing hepatitis C viral proteins. Hepatology 2010; 51: 1494–504. Diaz G, Melis M, Tice A et al. Identification of microRNAs specifically expressed in hepatitis C virus-associated hepatocellular carcinoma. Int J Cancer 2013; 133: 816–24. Chen JS, Wang Q, Fu XH et al. Involvement of PI3K/ PTEN/AKT/mTOR pathway in invasion and metastasis in hepatocellular carcinoma: association with MMP-9. Hepatol Res 2009; 39: 177–86. Hsu HC, Tseng HJ, Lai PL, Lee PH, Peng SY. Expression of p53 gene in 184 unifocal hepatocellular carcinomas: association with tumor growth and invasiveness. Cancer Res 1993; 53: 4691–4. Bae JS, Kim JH, Pasaje CF et al. Association study of genetic variations in microRNAs with the risk of hepatitis B-related liver diseases. Dig Liver Dis 2012; 44: 849– 54. Xu Y, Liu L, Liu J et al. A potentially functional polymorphism in the promoter region of miR-34b/c is associated with an increased risk for primary hepatocellular carcinoma. Int J Cancer 2011; 128: 412–7. Liu Y, Zhang Y, Wen J et al. A genetic variant in the promoter region of miR-106b-25 cluster and risk of HBV


67

68

69

70

71

72

73

74

75

76

77

78

79

infection and hepatocellular carcinoma. PLoS ONE 2012; 7: e32230. Kwak MS, Lee DH, Cho Y et al. Association of polymorphism in pri-microRNAs-371-372-373 with the occurrence of hepatocellular carcinoma in hepatitis B virus infected patients. PLoS ONE 2012; 7: e41983. Kim WH, Min KT, Jeon YJ et al. Association study of microRNA polymorphisms with hepatocellular carcinoma in Korean population. Gene 2012; 504: 92–7. Akkiz H, Bayram S, Bekar A, Akgollu E, Uskudar O. Genetic variation in the microRNA-499 gene and hepatocellular carcinoma risk in a Turkish population: lack of any association in a case-control study. Asian Pac J Cancer Prev 2011; 12: 3107–12. Xiang Y, Fan S, Cao J, Huang S, Zhang LP. Association of the microRNA-499 variants with susceptibility to hepatocellular carcinoma in a Chinese population. Mol Biol Rep 2012; 39: 7019–23. Guo J, Jin M, Zhang M, Chen K. A genetic variant in miR-196a2 increased digestive system cancer risks: a meta-analysis of 15 case-control studies. PLoS ONE 2012; 7: e30585. Li XD, Li ZG, Song XX, Liu CF. A variant in microRNA196a2 is associated with susceptibility to hepatocellular carcinoma in Chinese patients with cirrhosis. Pathology 2010; 42: 669–73. Akkiz H, Bayram S, Bekar A, Akgollu E, Ulger Y. A functional polymorphism in pre-microRNA-196a-2 contributes to the susceptibility of hepatocellular carcinoma in a Turkish population: a case-control study. J Viral Hepat 2011; 18: e399–407. Ji J, Zhao L, Budhu A et al. Let-7g targets collagen type I alpha2 and inhibits cell migration in hepatocellular carcinoma. J Hepatol 2010; 52: 690–7. Zhang J, Yang Y, Yang T et al. microRNA-22, downregulated in hepatocellular carcinoma and correlated with prognosis, suppresses cell proliferation and tumourigenicity. Br J Cancer 2010; 103: 1215–20. Xiong Y, Fang JH, Yun JP et al. Effects of microRNA-29 on apoptosis, tumorigenicity, and prognosis of hepatocellular carcinoma. Hepatology 2010; 51: 836–45. Li D, Liu X, Lin L et al. MicroRNA-99a inhibits hepatocellular carcinoma growth and correlates with prognosis of patients with hepatocellular carcinoma. J Biol Chem 2011; 286: 36677–85. Coulouarn C, Factor VM, Andersen JB, Durkin ME, Thorgeirsson SS. Loss of miR-122 expression in liver cancer correlates with suppression of the hepatic phenotype and gain of metastatic properties. Oncogene 2009; 28: 3526–36. Zheng F, Liao YJ, Cai MY et al. The putative tumour suppressor microRNA-124 modulates hepatocellular carcinoma cell aggressiveness by repressing ROCK2 and EZH2. Gut 2012; 61: 278–89.


10


80 Wong CC, Wong CM, Tung EK et al. The microRNA miR139 suppresses metastasis and progression of hepatocellular carcinoma by down-regulating Rho-kinase 2. Gastroenterology 2011; 140: 322–31. 81 Jia Y, Liu H, Zhuang Q et al. Tumorigenicity of cancer stem-like cells derived from hepatocarcinoma is regulated by microRNA-145. Oncol Rep 2012; 27: 1865– 72. 82 Wang C, Song B, Song W et al. Underexpressed microRNA-199b-5p targets hypoxia-inducible factor1alpha in hepatocellular carcinoma and predicts prognosis of hepatocellular carcinoma patients. J Gastroenterol Hepatol 2011; 26: 1630–7. 83 Wang Y, Lu Y, Toh ST et al. Lethal-7 is down-regulated by the hepatitis B virus x protein and targets signal transducer and activator of transcription 3. J Hepatol 2010; 53: 57–66. 84 Tsang WP, Kwok TT. Let-7a microRNA suppresses therapeutics-induced cancer cell death by targeting caspase-3. Apoptosis 2008; 13: 1215–22. 85 Di Fazio P, Montalbano R, Neureiter D et al. Downregulation of HMGA2 by the pan-deacetylase inhibitor panobinostat is dependent on hsa-let-7b expression in liver cancer cell lines. Exp Cell Res 2012; 318: 1832–43. 86 Zhu XM, Wu LJ, Xu J, Yang R, Wu FS. Let-7c microRNA expression and clinical significance in hepatocellular carcinoma. J Int Med Res 2011; 39: 2323–9. 87 Shah YM, Morimura K, Yang Q, Tanabe T, Takagi M, Gonzalez FJ. Peroxisome proliferator-activated receptor alpha regulates a microRNA-mediated signaling cascade responsible for hepatocellular proliferation. Mol Cell Biol 2007; 27: 4238–47. 88 Shimizu S, Takehara T, Hikita H et al. The let-7 family of microRNAs inhibits Bcl-xL expression and potentiates sorafenib-induced apoptosis in human hepatocellular carcinoma. J Hepatol 2010; 52: 698–704. 89 Lan FF, Wang H, Chen YC et al. Hsa-let-7g inhibits proliferation of hepatocellular carcinoma cells by downregulation of c-Myc and upregulation of p16(INK4A). Int J Cancer 2011; 128: 319–31. 90 Li D, Yang P, Li H et al. MicroRNA-1 inhibits proliferation of hepatocarcinoma cells by targeting endothelin-1. Life Sci 2012; 91: 440–7. 91 Fang Y, Xue JL, Shen Q, Chen J, Tian L. MicroRNA-7 inhibits tumor growth and metastasis by targeting the phosphoinositide 3-kinase/Akt pathway in hepatocellular carcinoma. Hepatology 2012; 55: 1852–62. 92 Yan Y, Luo YC, Wan HY et al. MicroRNA-10a is involved in the metastatic process by regulating Eph tyrosine kinase receptor A4-mediated epithelial-mesenchymal transition and adhesion in hepatoma cells. Hepatology 2013; 57: 667–77. 93 Maurel M, Jalvy S, Ladeiro Y et al. A functional screening identifies five microRNAs controlling glypican-3: role of


94

95

96

97

98

99

100

101

102

103

104

105

106

107

miR-1271 down-regulation in hepatocellular carcinoma. Hepatology 2013; 57: 195–204. Wang Y, Jiang L, Ji X, Yang B, Zhang Y, Fu XD. Hepatitis B viral RNA directly mediates down-regulation of the tumor suppressor microRNA miR-15a/miR-16-1 in hepatocytes. J Biol Chem 2013; 288: 18484–93. Zhu Y, Lu Y, Zhang Q et al. MicroRNA-26a/b and their host genes cooperate to inhibit the G1/S transition by activating the pRb protein. Nucleic Acids Res 2012; 40: 4615–25. Yang X, Liang L, Zhang XF et al. MicroRNA-26a suppresses tumor growth and metastasis of human hepatocellular carcinoma by targeting interleukin-6-Stat3 pathway. Hepatology 2013; 58: 158–70. Kota J, Chivukula RR, O’Donnell KA et al. Therapeutic microRNA delivery suppresses tumorigenesis in a murine liver cancer model. Cell 2009; 137: 1005–17. Zhu XC, Dong QZ, Zhang XF et al. microRNA-29a suppresses cell proliferation by targeting SPARC in hepatocellular carcinoma. Int J Mol Med 2012; 30: 1321–6. Fang JH, Zhou HC, Zeng C et al. MicroRNA-29b suppresses tumor angiogenesis, invasion, and metastasis by regulating matrix metalloproteinase 2 expression. Hepatology 2011; 54: 1729–40. Bae HJ, Noh JH, Kim JK et al. MicroRNA-29c functions as a tumor suppressor by direct targeting oncogenic SIRT1 in hepatocellular carcinoma. Oncogene 2014; 33: 2557–67. Li N, Fu H, Tie Y et al. miR-34a inhibits migration and invasion by down-regulation of c-Met expression in human hepatocellular carcinoma cells. Cancer Lett 2009; 275: 44–53. Yang P, Li QJ, Feng Y et al. TGF-beta-miR-34a-CCL22 signaling-induced Treg cell recruitment promotes venous metastases of HBV-positive hepatocellular carcinoma. Cancer Cell 2012; 22: 291–303. Petrelli A, Perra A, Schernhuber K et al. Sequential analysis of multistage hepatocarcinogenesis reveals that miR100 and PLK1 dysregulation is an early event maintained along tumor progression. Oncogene 2012; 31: 4517–26. Wang L, Zhang X, Jia LT et al. c-Myc-mediated epigenetic silencing of MicroRNA-101 contributes to dysregulation of multiple pathways in hepatocellular carcinoma. Hepatology 2014; 59: 1850–63. Su H, Yang JR, Xu T et al. MicroRNA-101, down-regulated in hepatocellular carcinoma, promotes apoptosis and suppresses tumorigenicity. Cancer Res 2009; 69: 1135– 42. Li S, Fu H, Wang Y et al. MicroRNA-101 regulates expression of the v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) oncogene in human hepatocellular carcinoma. Hepatology 2009; 49: 1194–202. Lin CJ, Gong HY, Tseng HC, Wang WL, Wu JL. miR-122 targets an anti-apoptotic gene, Bcl-w, in human hepatocellular carcinoma cell lines. Biochem Biophys Res Commun 2008; 375: 315–20.



108 Kong G, Zhang J, Zhang S, Shan C, Ye L, Zhang X. Upregulated microRNA-29a by hepatitis B virus X protein enhances hepatoma cell migration by targeting PTEN in cell culture model. PLoS ONE 2011; 6: e19518. 109 Reddi HV, Madde P, Milosevic D et al. The putative PAX8/ PPARgamma fusion oncoprotein exhibits partial tumor suppressor activity through up-regulation of micro-RNA122 and dominant-negative PPARgamma activity. Genes Cancer 2011; 2: 46–55. 110 Xu J, Zhu X, Wu L et al. MicroRNA-122 suppresses cell proliferation and induces cell apoptosis in hepatocellular carcinoma by directly targeting Wnt/beta-catenin pathway. Liver Int 2012; 32: 752–60. 111 Lang Q, Ling C. MiR-124 suppresses cell proliferation in hepatocellular carcinoma by targeting PIK3CA. Biochem Biophys Res Commun 2012; 426: 247–52. 112 Bi Q, Tang S, Xia L et al. Ectopic expression of MiR-125a inhibits the proliferation and metastasis of hepatocellular carcinoma by targeting MMP11 and VEGF. PLoS ONE 2012; 7: e40169. 113 Kim JK, Noh JH, Jung KH et al. Sirtuin7 oncogenic potential in human hepatocellular carcinoma and its regulation by the tumor suppressors MiR-125a-5p and MiR-125b. Hepatology 2013; 57: 1055–67. 114 Zhao A, Zeng Q, Xie X et al. MicroRNA-125b induces cancer cell apoptosis through suppression of Bcl-2 expression. J Genet Genomics 2012; 39: 29–35. 115 Alpini G, Glaser SS, Zhang JP et al. Regulation of placenta growth factor by microRNA-125b in hepatocellular cancer. J Hepatol 2011; 55: 1339–45. 116 Liang L, Wong CM, Ying Q et al. MicroRNA-125b suppressesed human liver cancer cell proliferation and metastasis by directly targeting oncogene LIN28B2. Hepatology 2010; 52: 1731–40. 117 Fan DN, Tsang FH, Tam AH et al. Histone lysine methyltransferase, suppressor of variegation 3-9 homolog 1, promotes hepatocellular carcinoma progression and is negatively regulated by microRNA-125b. Hepatology 2013; 57: 637–47. 118 Wong QW, Ching AK, Chan AW et al. MiR-222 overexpression confers cell migratory advantages in hepatocellular carcinoma through enhancing AKT signaling. Clin Cancer Res 2010; 16: 867–75. 119 Fan Q, He M, Deng X et al. Derepression of c-Fos caused by microRNA-139 down-regulation contributes to the metastasis of human hepatocellular carcinoma. Cell Biochem Funct 2013; 31: 319–24. 120 Yang H, Fang F, Chang R, Yang L. MicroRNA-140-5p suppresses tumor growth and metastasis by targeting transforming growth factor beta receptor 1 and fibroblast growth factor 9 in hepatocellular carcinoma. Hepatology 2013; 58: 205–17. 121 Takata A, Otsuka M, Yoshikawa T et al. MicroRNA-140 acts as a liver tumor suppressor by controlling NF-kappaB


122

123

124

125

126

127

128

129

130

131

132

133

134

135

activity by directly targeting DNA methyltransferase 1 (Dnmt1) expression. Hepatology 2013; 57: 162–70. Banaudha K, Kaliszewski M, Korolnek T et al. MicroRNA silencing of tumor suppressor DLC-1 promotes efficient hepatitis C virus replication in primary human hepatocytes. Hepatology 2011; 53: 53–61. Law PT, Ching AK, Chan AW et al. MiR-145 modulates multiple components of the insulin-like growth factor pathway in hepatocellular carcinoma. Carcinogenesis 2012; 33: 1134–41. Gailhouste L, Gomez-Santos L, Hagiwara K et al. miR148a plays a pivotal role in the liver by promoting the hepatospecific phenotype and suppressing the invasiveness of transformed cells. Hepatology 2013; 58: 1153–65. Xu X, Fan Z, Kang L et al. Hepatitis B virus X protein represses miRNA-148a to enhance tumorigenesis. J Clin Invest 2013; 123: 630–45. Zhang JP, Zeng C, Xu L, Gong J, Fang JH, Zhuang SM. MicroRNA-148a suppresses the epithelial-mesenchymal transition and metastasis of hepatoma cells by targeting Met/Snail signaling. Oncogene 2013; [Epub ahead of print]. Han H, Sun D, Li W et al. A c-Myc-MicroRNA functional feedback loop affects hepatocarcinogenesis. Hepatology 2013; 57: 2378–89. Huang J, Wang Y, Guo Y, Sun S. Down-regulated microRNA-152 induces aberrant DNA methylation in hepatitis B virus-related hepatocellular carcinoma by targeting DNA methyltransferase 1. Hepatology 2010; 52: 60–70. Xu T, Zhu Y, Xiong Y, Ge YY, Yun JP, Zhuang SM. MicroRNA-195 suppresses tumorigenicity and regulates G1/S transition of human hepatocellular carcinoma cells. Hepatology 2009; 50: 113–21. Yang X, Yu J, Yin J, Xiang Q, Tang H, Lei X. MiR-195 regulates cell apoptosis of human hepatocellular carcinoma cells by targeting LATS2. Pharmazie 2012; 67: 645–51. Fornari F, Milazzo M, Chieco P et al. MiR-199a-3p regulates mTOR and c-Met to influence the doxorubicin sensitivity of human hepatocarcinoma cells. Cancer Res 2010; 70: 5184–93. Hou J, Lin L, Zhou W et al. Identification of miRNomes in human liver and hepatocellular carcinoma reveals miR199a/b-3p as therapeutic target for hepatocellular carcinoma. Cancer Cell 2011; 19: 232–43. Shatseva T, Lee DY, Deng Z, Yang BB. MicroRNA miR199a-3p regulates cell proliferation and survival by targeting caveolin-2. J Cell Sci 2011; 124: 2826–36. Shen Q, Cicinnati VR, Zhang X et al. Role of microRNA199a-5p and discoidin domain receptor 1 in human hepatocellular carcinoma invasion. Mol Cancer 2010; 9: 227. Xu N, Zhang J, Shen C et al. Cisplatin-induced downregulation of miR-199a-5p increases drug resistance


12

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150


by activating autophagy in HCC cell. Biochem Biophys Res Commun 2012; 423: 826–31. Gao P, Wong CC, Tung EK, Lee JM, Wong CM, Ng IO. Deregulation of microRNA expression occurs early and accumulates in early stages of HBV-associated multistep hepatocarcinogenesis. J Hepatol 2011; 54: 1177–84. Yuan JH, Yang F, Chen BF et al. The histone deacetylase 4/SP1/microrna-200a regulatory network contributes to aberrant histone acetylation in hepatocellular carcinoma. Hepatology 2011; 54: 2025–35. Wei W, Wanjun L, Hui S, Dongyue C, Xinjun Y, Jisheng Z. miR-203 inhibits proliferation of HCC cells by targeting survivin. Cell Biochem Funct 2013; 31: 82–5. Shih TC, Tien YJ, Wen CJ et al. MicroRNA-214 downregulation contributes to tumor angiogenesis by inducing secretion of the hepatoma-derived growth factor in human hepatoma. J Hepatol 2012; 57: 584–91. Wang X, Chen J, Li F et al. MiR-214 inhibits cell growth in hepatocellular carcinoma through suppression of betacatenin. Biochem Biophys Res Commun 2012; 428: 525–31. Xia H, Ooi LL, Hui KM. MiR-214 targets beta-catenin pathway to suppress invasion, stem-like traits and recurrence of human hepatocellular carcinoma. PLoS ONE 2012; 7: e44206. Huang N, Lin J, Ruan J et al. MiR-219-5p inhibits hepatocellular carcinoma cell proliferation by targeting glypican-3. FEBS Lett 2012; 586: 884–91. Guichard C, Amaddeo G, Imbeaud S et al. Integrated analysis of somatic mutations and focal copy-number changes identifies key genes and pathways in hepatocellular carcinoma. Nat Genet 2012; 44: 694–8. Chang Y, Yan W, He X et al. miR-375 inhibits autophagy and reduces viability of hepatocellular carcinoma cells under hypoxic conditions. Gastroenterology 2012; 143: 177–87. He XX, Chang Y, Meng FY et al. MicroRNA-375 targets AEG-1 in hepatocellular carcinoma and suppresses liver cancer cell growth in vitro and in vivo. Oncogene 2012; 31: 3357–69. Zheng Y, Yin L, Chen H et al. miR-376a suppresses proliferation and induces apoptosis in hepatocellular carcinoma. FEBS Lett 2012; 586: 2396–403. You X, Liu F, Zhang T, Li Y, Ye L, Zhang X. Hepatitis B virus X protein upregulates oncogene Rab18 to result in the dysregulation of lipogenesis and proliferation of hepatoma cells. Carcinogenesis 2013; 34: 1644–52. Buurman R, Gurlevik E, Schaffer V et al. Histone deacetylases activate hepatocyte growth factor signaling by repressing microRNA-449 in hepatocellular carcinoma cells. Gastroenterology 2012; 143: 811–20. e1-15. Weng Z, Wang D, Zhao W et al. microRNA-450a targets DNA methyltransferase 3a in hepatocellular carcinoma. Exp Ther Med 2011; 2: 951–5. Zhang W, Kong G, Zhang J, Wang T, Ye L, Zhang X. MicroRNA-520b inhibits growth of hepatoma cells by


151

152

153

154

155

156

157

158

159

160

161

162

targeting MEKK2 and cyclin D1. PLoS ONE 2012; 7: e31450. Zhang S, Shan C, Kong G, Du Y, Ye L, Zhang X. MicroRNA-520e suppresses growth of hepatoma cells by targeting the NF-kappaB-inducing kinase (NIK). Oncogene 2012; 31: 3607–20. Tao ZH, Wan JL, Zeng LY et al. miR-612 suppresses the invasive-metastatic cascade in hepatocellular carcinoma. J Exp Med 2013; 210: 789–803. Zhang JF, He ML, Fu WM et al. Primate-specific microRNA-637 inhibits tumorigenesis in hepatocellular carcinoma by disrupting signal transducer and activator of transcription 3 signaling. Hepatology 2011; 54: 2137– 48. Li QJ, Zhou L, Yang F et al. MicroRNA-10b promotes migration and invasion through CADM1 in human hepatocellular carcinoma cells. Tumour Biol 2012; 33: 1455– 65. Chen L, Jiang M, Yuan W, Tang H. miR-17-5p as a novel prognostic marker for hepatocellular carcinoma. J Invest Surg 2012; 25: 156–61. Karakatsanis A, Papaconstantinou I, Gazouli M, Lyberopoulou A, Polymeneas G, Voros D. Expression of microRNAs, miR-21, miR-31, miR-122, miR-145, miR146a, miR-200c, miR-221, miR-222, and miR-223 in patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma and its prognostic significance. Mol Carcinog 2013; 52: 297–303. Liu S, Guo W, Shi J et al. MicroRNA-135a contributes to the development of portal vein tumor thrombus by promoting metastasis in hepatocellular carcinoma. J Hepatol 2012; 56: 389–96. Han ZB, Chen HY, Fan JW, Wu JY, Tang HM, Peng ZH. Up-regulation of microRNA-155 promotes cancer cell invasion and predicts poor survival of hepatocellular carcinoma following liver transplantation. J Cancer Res Clin Oncol 2012; 138: 153–61. Wang J, Li J, Shen J, Wang C, Yang L, Zhang X. MicroRNA182 downregulates metastasis suppressor 1 and contributes to metastasis of hepatocellular carcinoma. BMC Cancer 2012; 12: 227. Yang F, Yin Y, Wang F et al. miR-17-5p Promotes migration of human hepatocellular carcinoma cells through the p38 mitogen-activated protein kinase-heat shock protein 27 pathway. Hepatology 2010; 51: 1614– 23. Jiang R, Deng L, Zhao L et al. miR-22 promotes HBVrelated hepatocellular carcinoma development in males. Clin Cancer Res 2011; 17: 5593–603. Wang B, Hsu SH, Frankel W, Ghoshal K, Jacob ST. Stat3-mediated activation of microRNA-23a suppresses gluconeogenesis in hepatocellular carcinoma by down-regulating glucose-6-phosphatase and peroxisome proliferator-activated receptor gamma, coactivator 1 alpha. Hepatology 2012; 56: 186–97.



163 Yao J, Liang L, Huang S et al. MicroRNA-30d promotes tumor invasion and metastasis by targeting Galphai2 in hepatocellular carcinoma. Hepatology 2010; 51: 846–56. 164 Shen G, Jia H, Tai Q, Li Y, Chen D. miR-106b downregulates adenomatous polyposis coli and promotes cell proliferation in human hepatocellular carcinoma. Carcinogenesis 2013; 34: 211–9. 165 Ma S, Tang KH, Chan YP et al. miR-130b Promotes CD133(+) liver tumor-initiating cell growth and selfrenewal via tumor protein 53-induced nuclear protein 1. Cell Stem Cell 2010; 7: 694–707. 166 Zhang X, Liu S, Hu T, Liu S, He Y, Up-regulated SS. microRNA-143 transcribed by nuclear factor kappa B enhances hepatocarcinoma metastasis by repressing fibronectin expression. Hepatology 2009; 50: 490–9. 167 Luedde T. MicroRNA-151 and its hosting gene FAK (focal adhesion kinase) regulate tumor cell migration and spreading of hepatocellular carcinoma. Hepatology 2010; 52: 1164–6. 168 Ding J, Huang S, Wu S et al. Gain of miR-151 on chromosome 8q24.3 facilitates tumour cell migration and spreading through downregulating RhoGDIA. Nat Cell Biol 2010; 12: 390–9. 169 Zhang Y, Wei W, Cheng N et al. Hepatitis C virus-induced up-regulation of microRNA-155 promotes hepatocarcinogenesis by activating Wnt signaling. Hepatology 2012; 56: 1631–40. 170 Yan XL, Jia YL, Chen L et al. Hepatocellular carcinoma-associated mesenchymal stem cells promote hepatocarcinoma progression: role of the S100A4miR155-SOCS1-MMP9 axis. Hepatology 2013; 57: 2274– 86. 171 Wang B, Hsu SH, Majumder S et al. TGFbeta-mediated upregulation of hepatic miR-181b promotes hepatocarcinogenesis by targeting TIMP3. Oncogene 2010; 29: 1787–97. 172 Goeppert B, Schmezer P, Dutruel C et al. Downregulation of tumor suppressor A kinase anchor protein 12 in human hepatocarcinogenesis by epigenetic mechanisms. Hepatology 2010; 52: 2023–33. 173 Petrelli A, Perra A, Cora D et al. MicroRNA/gene profiling unveils early molecular changes and nuclear factor erythroid related factor 2 (NRF2) activation in a rat model recapitulating human hepatocellular carcinoma (HCC). Hepatology 2014; 59: 228–41. 174 Ying Q, Liang L, Guo W et al. Hypoxia-inducible microRNA-210 augments the metastatic potential of tumor cells by targeting vacuole membrane protein 1 in hepatocellular carcinoma. Hepatology 2011; 54: 2064–75. 175 Chen PJ, Yeh SH, Liu WH et al. Androgen pathway stimulates microRNA-216a transcription to suppress the tumor suppressor in lung cancer-1 gene in early hepatocarcinogenesis. Hepatology 2012; 56: 632–43. 176 Xia H, Ooi LL, Hui KM. MicroRNA-216a/217-induced epithelial-mesenchymal transition targets PTEN and


177

178

179

180

181

182

183

184

185

186

187

188

189

190

SMAD7 to promote drug resistance and recurrence of liver cancer. Hepatology 2013; 58: 629–41. Callegari E, Elamin BK, Giannone F et al. Liver tumorigenicity promoted by microRNA-221 in a mouse transgenic model. Hepatology 2012; 56: 1025–33. Yuan Q, Loya K, Rani B et al. MicroRNA-221 overexpression accelerates hepatocyte proliferation during liver regeneration. Hepatology 2013; 57: 299–310. Gramantieri L, Fornari F, Ferracin M et al. MicroRNA-221 targets Bmf in hepatocellular carcinoma and correlates with tumor multifocality. Clin Cancer Res 2009; 15: 5073–81. Pineau P, Volinia S, McJunkin K et al. miR-221 overexpression contributes to liver tumorigenesis. Proc Natl Acad Sci U S A 2010; 107: 264–9. Lan SH, Wu SY, Zuchini R et al. Autophagy suppresses tumorigenesis of hepatitis B virus-associated hepatocellular carcinoma through degradation of microRNA-224. Hepatology 2014; 59: 505–17. Scisciani C, Vossio S, Guerrieri F et al. Transcriptional regulation of miR-224 upregulated in human HCCs by NFkappaB inflammatory pathways. J Hepatol 2012; 56: 855–61. Zhou P, Jiang W, Wu L, Chang R, Wu K, Wang Z. miR301a is a candidate oncogene that targets the homeobox gene Gax in human hepatocellular carcinoma. Dig Dis Sci 2012; 57: 1171–80. Wu N, Liu X, Xu X et al. MicroRNA-373, a new regulator of protein phosphatase 6, functions as an oncogene in hepatocellular carcinoma. FEBS J 2011; 278: 2044–54. Lin J, Huang S, Wu S et al. MicroRNA-423 promotes cell growth and regulates G(1)/S transition by targeting p21Cip1/Waf1 in hepatocellular carcinoma. Carcinogenesis 2011; 32: 1641–7. Yang H, Cho ME, Li TW et al. MicroRNAs regulate methionine adenosyltransferase 1A expression in hepatocellular carcinoma. J Clin Invest 2013; 123: 285–98. Zhang LY, Liu M, Li X, Tang H. miR-490-3p modulates cell growth and epithelial to mesenchymal transition of hepatocellular carcinoma cells by targeting endoplasmic reticulum-Golgi intermediate compartment protein 3 (ERGIC3). J Biol Chem 2013; 288: 4035–47. Lim L, Balakrishnan A, Huskey N et al. MicroRNA-494 within an oncogenic microRNA megacluster regulates G1/S transition in liver tumorigenesis through suppression of mutated in colorectal cancer. Hepatology 2014; 59: 202–15. Toffanin S, Hoshida Y, Lachenmayer A et al. MicroRNAbased classification of hepatocellular carcinoma and oncogenic role of miR-517a. Gastroenterology 2011; 140: 1618–28. e16. Fornari F, Milazzo M, Chieco P et al. In hepatocellular carcinoma miR-519d is up-regulated by p53 and DNA hypomethylation and targets CDKN1A/p21, PTEN, AKT3 and TIMP2. J Pathol 2012; 227: 275–85.


14


191 Tian Q, Liang L, Ding J et al. MicroRNA-550a acts as a pro-metastatic gene and directly targets cytoplasmic polyadenylation element-binding protein 4 in hepatocellular carcinoma. PLoS ONE 2012; 7: e48958. 192 Jiang X, Xiang G, Wang Y et al. MicroRNA-590-5p regulates proliferation and invasion in human hepatocellular carcinoma cells by targeting TGF-beta RII. Mol Cells 2012; 33: 545–51. 193 El Tayebi HM, Hosny KA, Esmat G, Breuhahn K, Abdelaziz AI. miR-615-5p is restrictedly expressed in cirrhotic and cancerous liver tissues and its overexpression alleviates the tumorigenic effects in hepatocellular carcinoma. FEBS Lett 2012; 586: 3309–16. 194 Zhang L, Yang L, Liu X et al. MicroRNA-657 promotes tumorigenesis in hepatocellular carcinoma by targeting transducin-like enhancer protein 1 through nuclear factor kappa B pathways. Hepatology 2013; 57: 1919–30. 195 Law PT, Qin H, Ching AK et al. Deep sequencing of small RNA transcriptome reveals novel non-coding RNAs in hepatocellular carcinoma. J Hepatol 2013; 58: 1165– 73. 196 Yamamoto Y, Kosaka N, Tanaka M et al. MicroRNA-500 as a potential diagnostic marker for hepatocellular carcinoma. Biomarkers 2009; 14: 529–38.


197 Li LM, Hu ZB, Zhou ZX et al. Serum microRNA profiles serve as novel biomarkers for HBV infection and diagnosis of HBV-positive hepatocarcinoma. Cancer Res 2010; 70: 9798–807. 198 Tsai WC, Hsu PW, Lai TC et al. MicroRNA-122, a tumor suppressor microRNA that regulates intrahepatic metastasis of hepatocellular carcinoma. Hepatology 2009; 49: 1571–82. 199 Park JK, Kogure T, Nuovo GJ et al. miR-221 silencing blocks hepatocellular carcinoma and promotes survival. Cancer Res 2011; 71: 7608–16. 200 Kato K, Gong J, Iwama H et al. The antidiabetic drug metformin inhibits gastric cancer cell proliferation in vitro and in vivo. Mol Cancer Ther 2012; 11: 549–60. 201 Kobayashi M, Kato K, Iwama H et al. Antitumor effect of metformin in esophageal cancer: in vitro study. Int J Oncol 2013; 42: 517–24. 202 Miyoshi H, Kato K, Iwama H et al. Effect of the antidiabetic drug metformin in hepatocellular carcinoma in vitro and in vivo. Int J Oncol 2014; 45: 322–32. 203 Tomimaru Y, Eguchi H, Nagano H et al. MicroRNA-21 induces resistance to the anti-tumour effect of interferonalpha/5-fluorouracil in hepatocellular carcinoma cells. Br J Cancer 2010; 103: 1617–26.


MiRNA-22 inhibits oncogene galectin-1 in hepatocellular carcinoma.

MiRNA-192 [corrected] and miRNA-204 Directly Suppress lncRNA HOTTIP and Interrupt GLS1-Mediated Glutaminolysis in Hepatocellular Carcinoma.

miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in human hepatocellular carcinoma.

Separate roles of different miRNA in the proliferation and migration of hepatocellular carcinoma.

MiRNA-211 suppresses cell proliferation, migration and invasion by targeting SPARC in human hepatocellular carcinoma.

Circulating miRNA-122, miRNA-199a, and miRNA-16 as Biomarkers for Early Detection of Hepatocellular Carcinoma in Egyptian Patients with Chronic Hepatitis C Virus Infection.

Analysis of miRNA expression patterns in human and mouse hepatocellular carcinoma cells.

miRNA-708 functions as a tumour suppressor in hepatocellular carcinoma by targeting SMAD3.

MiRNA-99a directly regulates AGO2 through translational repression in hepatocellular carcinoma.

107 contribute to HBx-induced hepatocellular carcinoma progression through suppression of maspin.

Downregulation of miRNA-638 promotes angiogenesis and growth of hepatocellular carcinoma by targeting VEGF.

Elevated CXCL1 increases hepatocellular carcinoma aggressiveness and is inhibited by miRNA-200a.

miRNA-135a promotes hepatocellular carcinoma cell migration and invasion by targeting forkhead box O1.

Advances in hepatocellular carcinoma: Nonalcoholic steatohepatitis-related hepatocellular carcinoma.

Hepatocellular carcinoma in Karachi.

Hepatocellular carcinoma in children.

Hepatocellular carcinoma.

Hepatocellular carcinoma.

Hepatocellular carcinoma.

Hepatocellular Carcinoma.

Hepatocellular carcinoma.

Hepatocellular carcinoma: genome-scale metabolic models for hepatocellular carcinoma.

Correction: fMiRNA-192 and miRNA-204 Directly Suppress lncRNA HOTTIP and Interrupt GLS1-Mediated Glutaminolysis in Hepatocellular Carcinoma.

Feasibility of global miRNA analysis from fine-needle biopsy FFPE material in patients with hepatocellular carcinoma treated with sorafenib.