miR-214/199a/199a* cluster levels predict poor survival in hepatocellular carcinoma through interference with cell-cycle regulators

Structural basis of CDK3 activation by cyclin E1 and inhibition by dinaciclib

Cell cycle transitions are controlled by multiple cell cycle regulators, especially CDKs. Several CDKs, including CDK1-4 and CDK6, promote cell cycle progression directly. Among them, CDK3 is critically important because it triggers the transitions of G0 to G1 and G1 to S phase through binding to cyclin C and cyclin E1, respectively. In contrast to its highly related homologs, the molecular basis of CDK3 activation remains elusive due to the lack of structural information of CDK3, particularly in cyclin bound form. Here we report the crystal structure of CDK3 in complex with cyclin E1 at 2.25 Å resolution. CDK3 resembles CDK2 in that both adopt a similar fold and bind cyclin E1 in a similar way. The structural discrepancy between CDK3 and CDK2 may reflect their substrate specificity. Profiling a panel of CDK inhibitors reveals that dinaciclib inhibits CDK3-cyclin E1 potently and specifically. The structure of CDK3-cyclin E1 bound to dinaciclib reveals the inhibitory mechanism. The structural and biochemical results uncover the mechanism of CDK3 activation by cyclin E1 and lays a foundation for structural-based drug design.

A review on the role of cyclin dependent kinases in cancers

The Cyclin-dependent kinase (CDK) class of serine/threonine kinases has crucial roles in the regulation of cell cycle transition and is mainly involved in the pathogenesis of cancers. The expression of CDKs is controlled by a complex regulatory network comprised of genetic and epigenetic mechanisms, which are dysregulated during the progression of cancer. The abnormal activation of CDKs results in uncontrolled cancer cell proliferation and the induction of cancer stem cell characteristics. The levels of CDKs can be utilized to predict the prognosis and treatment response of cancer patients, and further understanding of the function and underlying mechanisms of CDKs in human tumors would pave the way for future cancer therapies that effectively target CDKs. Defects in the regulation of cell cycle and mutations in the genes coding cell-cycle regulatory proteins lead to unrestrained proliferation of cells leading to formation of tumors. A number of treatment modalities have been designed to combat dysregulation of cell cycle through affecting expression or activity of CDKs. However, effective application of these methods in the clinical settings requires recognition of the role of CDKs in the progression of each type of cancer, their partners, their interactions with signaling pathways and the effects of suppression of these kinases on malignant features. Thus, we designed this literature search to summarize these findings at cellular level, as well as in vivo and clinical levels.

Non-Coding RNAs in Hepatocellular Carcinoma

Liver cancer ranks as the fourth leading cause of cancer-related deaths. Despite extensive research efforts aiming to evaluate the biological mechanisms underlying hepatocellular carcinoma (HCC) development, little has been translated towards new diagnostic and treatment options for HCC patients. Historically, the focus has been centered on coding RNAs and their respective proteins. However, significant advances in sequencing and RNA detection technologies have shifted the research focus towards non-coding RNAs (ncRNA), as well as their impact on HCC development and progression. A number of studies reported complex post-transcriptional interactions between various ncRNA and coding RNA molecules. These interactions offer insights into the role of ncRNAs in both the known pathways leading to oncogenesis, such as dysregulation of p53, and lesser-known mechanisms, such as small nucleolar RNA methylation. Studies investigating these mechanisms have identified prevalent ncRNA changes in microRNAs, snoRNAs, and long non-coding RNAs that can both pre- and post-translationally regulate key factors in HCC progression. In this review, we present relevant publications describing ncRNAs to summarize the impact of different ncRNA species on liver cancer development and progression and to evaluate recent attempts at clinical translation.

MicroRNA-214 enriched exosomes from human cerebral endothelial cells (hCEC) sensitize hepatocellular carcinoma to anti-cancer drugs

Hepatocellular carcinoma (HCC) is the most common primary liver tumor worldwide. Current medical therapy for HCC has limited efficacy. The present study tests the hypothesis that human cerebral endothelial cell-derived exosomes carrying elevated miR-214 (hCEC-Exo-214) can amplify the efficacy of anti-cancer drugs on HCC cells. Treatment of HepG2 and Hep3B cells with hCEC-Exo-214 in combination with anti-cancer agents, oxaliplatin or sorafenib, significantly reduced cancer cell viability and invasion compared with monotherapy with either drug. Additionally, the therapeutic effect of the combination therapy was detected in primary tumor cells derived from patients with HCC. The ability of hCEC-Exo-214 in sensitizing HCC cells to anti-cancer drugs was specific, in that combination therapy did not affect the viability and invasion of human liver epithelial cells and non-cancer primary cells. Furthermore, compared to monotherapy with oxaliplatin and sorafenib, hCEC-Exo-214 in combination with either drug substantially reduced protein levels of P-glycoprotein (P-gp) and splicing factor 3B subunit 3 (SF3B3) in HCC cells. P-gp and SF3B3 are among miR-214 target genes and are known to mediate drug resistance and cancer cell proliferation, respectively. In conclusion, the present in vitro study provides evidence that hCEC-Exo-214 significantly enhances the anti-tumor efficacy of oxaliplatin and sorafenib on HCC cells.

Interstitial microRNA miR-214 attenuates inflammation and polycystic kidney disease progression

Renal cysts are the defining feature of autosomal dominant polycystic kidney disease (ADPKD); however, the substantial interstitial inflammation is an often-overlooked aspect of this disorder. Recent studies suggest that immune cells in the cyst microenvironment affect ADPKD progression. Here we report that microRNAs (miRNAs) are new molecular signals in this crosstalk. We found that miR-214 and its host long noncoding RNA Dnm3os are upregulated in orthologous ADPKD mouse models and cystic kidneys from humans with ADPKD. In situ hybridization revealed that interstitial cells in the cyst microenvironment are the primary source of miR-214. While genetic deletion of miR-214 does not affect kidney development or homeostasis, surprisingly, its inhibition in Pkd2- and Pkd1-mutant mice aggravates cyst growth. Mechanistically, the proinflammatory TLR4/IFN-γ/STAT1 pathways transactivate the miR-214 host gene. miR-214, in turn as a negative feedback loop, directly inhibits Tlr4. Accordingly, miR-214 deletion is associated with increased Tlr4 expression and enhanced pericystic macrophage accumulation. Thus, miR-214 upregulation is a compensatory protective response in the cyst microenvironment that restrains inflammation and cyst growth.

Cluster miRNAs and cancer: Diagnostic, prognostic and therapeutic opportunities

MiRNAs are class of noncoding RNA important for gene expression regulation in many plants, animals and viruses. MiRNA clusters contain a set of two or more miRNA encoding genes, transcribed together as polycistronic miRNAs. Currently, there are approximately 159 miRNA clusters reported in the human genome consisting of miRNAs ranging from two or more miRNA genes. A large proportion of clustered miRNAs resides in and around the fragile sites or cancer associated genomic hotspots and plays an important role in carcinogenesis. Altered expression of miRNA cluster can be pro-tumorigenic or anti-tumorigenic and can be targeted for clinical management of cancer. Over the past few years, manipulation of miRNA clusters expression is attempted for experimental purpose as well as for diagnostic, prognostic and therapeutic applications in cancer. Re-expression of miRNAs by epigenetic therapy, genome editing such as clustered regulatory interspaced short palindromic repeats (CRISPR) and miRNA mowers showed promising results in cancer therapy. In this review, we focused on the potential of miRNA clusters as a biomarker for diagnosis, prognosis, targeted therapy as well as strategies for modulating their expression in a therapeutic context. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Processing > Processing of Small RNAs RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.

The Effect of miR-98 and miR-214 on Apoptotic and Angiogenic Pathways in Hepatocellular Carcinoma HepG2 Cells

Hepatocellular carcinoma (HCC) is one of the foremost causes of cancer related morbidity worldwide. An increasing number of studies have confirmed that microRNAs play an important role in the development, progression and metastasis of HCC. From those important miRNAs are miR-98 and miR-214. This study were conducted to explore the effect of these two miRNAs on some apoptotic and angiogenic genes namely, BCL-2, survivin, CCND1, CDC2, P53 and P21, VEGF, Hif-1α, MMP-2, MMP-9, Ang-1, Ang-2, and FGF-1. miRNAs mimics and inhibitors transfection was used to investigate the role of both studied molecules in apoptosis and angiogenesis in HepG2 cells. QRT-PCR was used for Quantitative gene and miRNA expression analyses. The study revealed that miR-98 could serve as a pro-apoptotic factor through the upregulation of P53 gene expression levels. Besides, the anti-angiogenic effect of this miRNA was evident through the down regulation of Ang-1 and FGF-1 genes. Meanwhile, miR-214 showed a pro-apoptotic role and anti-angiogenic effects. These effects were verified through the significant down regulation of BCL-2, CDC2, VEGF, Ang-1 and MMP-2. These results introduced a possible positive role played by both miR-98 and miR-214 on some pro-apoptotic and anti-angiogenic genes.

Exosomal miR-214-5p Released from Glioblastoma Cells Modulates Inflammatory Response of Microglia after Lipopolysaccharide Stimulation through Targeting CXCR5

Methods:

The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was interrogated by luciferase reporter assay. Protein level was analyzed by Western blot.

Results:

We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214- 5p in this setting.

Conclusion:

Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia via exosomal transfer.

Construction of microRNA-messenger networks for human osteosarcoma

Osteosarcoma is the most common bone tumor in children and young adults. Although the microRNAs (miRNA) expression analyses of osteosarcoma have been performed previously, the construction of miRNA-messenger RNA (mRNA) networks for osteosarcoma is needed. This study aimed to identify osteosarcoma-related miRNAs through analyzing the microarray datasets and to construct the regulatory network of miRNA-mRNA for human osteosarcoma. The datasets were extracted from the Gene Expression Omnibus and the differentially expressed miRNAs were screened through the limma package in Bioconductor. Genes targeted by the differentially expressed miRNAs were screened out by using the Miranda, MirTarget2, PicTar, PITA, and TargetScan databases. The predicted target genes were further analyzed by Gene Ontology and pathway enrichment analysis and a regulatory network of differentially expressed miRNAs and their target osteosarcoma-associated genes was constructed. A total of 36 downregulated miRNAs and 182 upregulated miRNAs were identified in osteosarcoma samples compared with normal samples and 397 target genes for upregulated miRNAs and 222 target genes for downregulated miRNAs were obtained. The enriched pathways for target genes of differentially expressed miRNAs included transcriptional misregulation in cancer, the AMPK signaling pathway, and MAPK signaling pathway. In the regulatory network, has-miR-199a-5p targeted the highest number of genes and nemo-like kinase (NLK) was targeted by five miRNAs (hsa-miR-140-5p, hsa-miR-107, hsa-miR-324-5p, hsa-miR-199a-5p, and hsa-miR-28-5p). The has-miR-324-5p targets NLK, TGFB2, and PPARG. These miRNAs and their target genes may serve as potential therapeutic targets of osteosarcoma.

Integrated analysis of lncRNA-associated ceRNA network reveals potential biomarkers for the prognosis of hepatitis B virus-related hepatocellular carcinoma

Background

There is evidence that abnormal expression of lncRNAs is associated with hepatitis B virus (HBV) infection-induced hepatocellular carcinoma (HCC). However, the mechanisms remain not fully elucidated. The study aimed to identify novel lncRNAs and explore their underlying mechanisms based on the ceRNA hypothesis.

Methods

The RNA and miRNA expression profiling in 20 tumor and matched adjacent tissues from HBV–HCC patients were retrieved from the Gene Expression Omnibus database under accession numbers GSE77509 and GSE76903, respectively. Differentially expressed lncRNAs (DELs), miRNAs (DEMs), and genes (DEGs) were identified using the EdgeR package. Protein–protein interaction (PPI) network was constructed for DEGs followed by module analysis. The ceRNA network was constructed based on interaction relationships between miRNAs and mRNAs/lncRNAs. The functions of DEGs were predicted using DAVID and BinGO databases. The prognosis values (overall survival [OS] and recurrence-free survival [RFS]) of ceRNA network genes were determined using The Cancer Genome Atlas (TCGA) data with Cox regression analysis and Kaplan–Meier method.

Results

The present study screened 643 DELs, 83 DEMs, and 1,187 DEGs. PPI network analysis demonstrated that CDK1 and CCNE1 were hub genes and extracted in functionally related modules. E2F2, CDK1, and CCNE1 were significantly enriched into cell cycle pathway. FAM182B-miR-125b-5p-E2F2 and LINC00346-miR-10a-5p-CDK1/CCNE1 ceRNA axes were obtained by constructing the ceRNA network. Patients with high expressions of DELs and DEGs in the above ceRNA axes had poor OS, while patients with the high expression of DEMs possessed excellent OS. CDK1 was also an RFS-related biomarker, with its high expression predicting poor RFS. The upregulation of LINC00346 and CDK1 but the downregulation of miR-10a-5p in HCC was validated in other microarray datasets and TCGA database.

Conclusion

The LINC00346-miR-10a-5p-CDK1 axis may be an important mechanism for HBV-related HCC, and genes in this ceRNA axis may be potential prognostic biomarkers and therapeutic targets.

miR-214 regulates papillary thyroid carcinoma cell proliferation and metastasis by targeting PSMD10

MicroRNAs (miRNAs) have important effects on cancer occurrence and development by adjusting gene expression. The aim of the present study was to examine the role of miR-214 in papillary thyroid carcinoma cell proliferation and metastasis, and its molecular mechanisms. miR-214 was demonstrated to be markedly downregulated in papillary thyroid carcinoma tissues and cells compared with normal, and this was significantly associated with lymph node metastasis, tumor size and TNM stage. Upregulation of miR-214 significantly decreased cell proliferation, and promoted cell apoptosis and cell cycle arrest in papillary thyroid carcinoma cell lines in vitro. By contrast, downregulation of miR-214 resulted in the opposite effects. In addition, miR-214 mimics significantly decreased papillary thyroid carcinoma cell migration and invasion, which was correlated with decreased expression levels of matrix metallopeptidase (MMP)-2 and MMP-9. Restoration of miR-214 expression in papillary thyroid carcinoma cells decreased the activities associated with epithelial-mesenchymal transition (EMT). Furthermore, proteasome 26S subunit non-ATPase 10 (PSMD10) was predicted to be a target of miR-214. Experimental results demonstrated that miR-214 negatively regulated PSMD10 expression by targeting its 3′ untranslated region directly. Knockdown of PSMD10 reduced papillary thyroid carcinoma cell clone formation, migration and invasion, most likely by repressing glycogen synthase kinase (GSK)-3β/β-catenin and AKT signaling. Finally, a negative correlation was observed between the expression levels of miR-214 and PSMD10 in papillary thyroid carcinoma tissues. Taken together, these data suggested that miR-214 might be a candidate target for the treatment of papillary thyroid carcinoma.

PPARα Regulates the Proliferation of Human Glioma Cells through miR-214 and E2F2

Peroxisome proliferator-activated receptor α (PPARα) is a member of the nuclear hormone receptor superfamily and functions as a transcription factor. Previous work showed that PPARα plays multiple roles in lipid metabolism in tissues such as cardiac and skeletal muscle, liver, and adipose tissue. Recent studies have discovered additional roles for PPARα in cell proliferation and metabolism, as well as tumor progression. PPARα is aberrantly expressed in various cancers, and activated PPARα inhibits the proliferation of some tumor cells. However, there have been no studies of PPARα in human gliomas. Here, we show that PPARα is expressed at lower levels in anaplastic gliomas and glioblastoma multiforme (GBM) tissue compared with low-grade gliomas tissue, and low expression is associated with poor patient prognosis. PPARα activates transcription of dynamin-3 opposite strand (DNMO3os), which encodes a cluster of miR-214, miR-199a-3p, and miR-199a-5p microRNAs. Of these, miR-214 is transcribed at particularly high levels. PPARα-induced miR-214 expression causes downregulation of its target E2F2. Finally, miR-214 overexpression inhibits glioma cell growth in vitro and in vivo by inducing cell cycle arrest in G0/G1. Collectively, these data uncover a novel role for a PPARα-miR-214-E2F2 pathway in controlling glioma cell proliferation.

Expression of the Long Intergenic Non-Protein Coding RNA 665 (LINC00665) Gene and the Cell Cycle in Hepatocellular Carcinoma Using The Cancer Genome Atlas, the Gene Expression Omnibus, and Quantitative Real-Time Polymerase Chain Reaction

Background

Long non-coding RNAs (lncRNAs) have a role in physiological and pathological processes, including cancer. The aim of this study was to investigate the expression of the long intergenic non-protein coding RNA 665 (LINC00665) gene and the cell cycle in hepatocellular carcinoma (HCC) using database analysis including The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO), and quantitative real-time polymerase chain reaction (qPCR).

Material/Methods

Expression levels of LINC00665 were compared between human tissue samples of HCC and adjacent normal liver, clinicopathological correlations were made using TCGA and the GEO, and qPCR was performed to validate the findings. Other public databases were searched for other genes associated with LINC00665 expression, including The Atlas of Noncoding RNAs in Cancer (TANRIC), the Multi Experiment Matrix (MEM), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) networks.

Results

Overexpression of LINC00665 in patients with HCC was significantly associated with gender, tumor grade, stage, and tumor cell type. Overexpression of LINC00665 in patients with HCC was significantly associated with overall survival (OS) (HR=1.47795%; CI: 1.046–2.086). Bioinformatics analysis identified 469 related genes and further analysis supported a hypothesis that LINC00665 regulates pathways in the cell cycle to facilitate the development and progression of HCC through ten identified core genes: CDK1, BUB1B, BUB1, PLK1, CCNB2, CCNB1, CDC20, ESPL1, MAD2L1, and CCNA2.

Conclusions

Overexpression of the lncRNA, LINC00665 may be involved in the regulation of cell cycle pathways in HCC through ten identified hub genes.

Inhibition of ATG12-mediated autophagy by miR-214 enhances radiosensitivity in colorectal cancer

Radioresistance hampers success in the treatment of patients with advanced colorectal cancer (CRC). Improving our understanding of the underlying mechanisms of radioresistance could increase patients' response to irradiation (IR). MicroRNAs are a class of small RNAs involved in tumor therapy response to radiation. Here we found that miR-214 was markedly decreased in CRC cell lines and blood of CRC patients after IR exposure. Meanwhile, autophagy was enhanced in irradiated CRC cells. Mechanically, ATG12 was predicted and identified as a direct target of miR-214 by dual luciferase assay, qPCR, and Western blot. In vitro and in vivo experiments showed that miR-214 promoted radiosensitivity by inhibiting IR-induced autophagy. Restoration of ATG12 attenuated miR-214-mediated inhibition of cell growth and survival in response to IR. Importantly, miR-214 was highly expressed in radiosensitive CRC specimens and negatively correlated with plasma level of CEA. Moreover, ATG12 and LC3 expressions were increased in radioresistant CRC specimens. Our study elucidates that miR-214 promotes radiosensitivity by inhibition of ATG12-mediated autophagy in CRC. Importantly, miR-214 is a determinant of CRC irradiation response and may serve as a potential therapeutic target in CRC treatment.

Cluster of specified microRNAs in tissues and serum as biomarkers for early diagnosis of hepatocellular carcinoma

OBJECTIVE

Hepatocellular carcinoma (HCC) is a global public health concern that lacks efficient methods for early diagnosis. Accumulated evidence has revealed great potential using microRNAs (miRNAs) as noninvasive biomarkers in HCC detection.

METHODS

Serum miRNAs (miR21, miR122, miR-214, miR15b, and let-7f) were detected in 75 patients with HCC and 80 healthy controls (HC). In addition, 75 HCC tissues and paired normal adjacent tissues were also analyzed for comparison. Quantified by real-time quantitative RT-PCR was used to evaluate the expression of miRNAs.

RESULTS

We discovered significant up-regulation of miR-21 (P < 0.001) and miR-15b (P < 0.001) as well as a down-regulation of miR-122 (P = 0.01) in HCC tissues compared to adjacent non-tumor tissues. Additionally, miR-21 (P < 0.001) and miR-15b (P < 0.001) levels were upregulated in serum and miR-214 (P = 0.01) was decreased in HCC patients compared to that in healthy controls. Multivariate logistic regression analysis showed that serum miR-21 (OR = 1.68, P = 0.012) and miR-15b (OR = 1.736, P = 0.012) were independently associated with HCC whereas miR-214 (OR = 0.631, P = 0.006) was associated with a decreased risk of HCC. When we employed miR-(21 + 122 + 15b) classifier as biomarkers, we could discriminate HCC tissues from adjacent non-tumor tissues with an AUC of 0.885 (specificity: 89.7%; sensitivity: 73.1%). In serum, the cluster of miR-(21 + 214 + 15b) classifier (AUC = 0.887) had a sensitivity of 80.3% and a specificity of 87.0% for HCC diagnosis.

CONCLUSION

Our results suggest that these serum miRNAs may be useful markers for discriminating HCC patients from healthy controls. Combined determination of circulating miR-21, miR-122, miR-214, and miR-15b has great potential to serve as an accurate and noninvasive biomarker for the early HCC preliminary screening.

Thyroid hormone inhibits growth of hepatoma cells through induction of miR-214

Thyroid hormone (TH) plays a role in regulating the metabolic rate, heart functions, muscle control and maintenance of bones. 3,3′5-tri-iodo-L-thyronine (T₃) displays high affinity to nuclear thyroid hormone receptors (TRs), which mediate most TH actions. Recent studies have shown hypothyroidism in patients with an increased risk of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs), a class of non-protein-coding RNA, are suggested to control tumor growth by interacting with target genes. However, the clinical significance of T₃/TR-regulated miRNAs in tumors has yet to be established. In the current study, miRNA expression profile screening was performed using SYBR Green-Based qRT-PCR array in TR-overexpressing HepG2 cells. miR-214-3p, which is expressed at low levels in HCC, was stimulated upon T₃ application. The 3′UTR luciferase reporter assay confirmed that the proto-oncogene serine/threonine-protein kinase, PIM-1, is a miR-214-3p target. PIM-1 was decreased upon treatment with miR-214-3p or T₃ stimulation. PIM-1 was highly expressed in HCC, and the effect of PIM-1 on cell proliferation might be mediated by the inhibition of p21. Furthermore, the T₃-induced suppression of cell proliferation was partially rescued upon miR-214-3p knockdown. Our data demonstrate that T₃ induces miR-214-3p expression and suppresses cell proliferation through PIM-1, thus contributing to the inhibition of HCC tumor formation.

Prognostic value of microRNAs in hepatocellular carcinoma: a meta-analysis

Background

Numerous articles reported that dysregulated expression levels of miRNAs correlated with survival time of HCC patients. However, there has not been a comprehensive meta-analysis to evaluate the accurate prognostic value of miRNAs in HCC.

Design

Meta-analysis.

Materials and Methods

Studies, published in English, estimating expression levels of miRNAs with any survival curves in HCC were identified up until 15 April, 2017 by performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two independent authors. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

Results

54 relevant articles about 16 miRNAs, with 6464 patients, were ultimately included. HCC patients with high expression of tissue miR-9 (HR = 2.35, 95% CI = 1.46–3.76), miR-21 (HR = 1.76, 95% CI = 1.29–2.41), miR-34c (HR = 1.64, 95% CI = 1.05–2.57), miR-155 (HR = 2.84, 95% CI = 1.46–5.51), miR-221 (HR = 1.76, 95% CI = 1.02–3.04) or low expression of tissue miR-22 (HR = 2.29, 95% CI = 1.63–3.21), miR-29c (HR = 1.35, 95% CI = 1.10–1.65), miR-34a (HR = 1.84, 95% CI = 1.30–2.59), miR-199a (HR = 2.78, 95% CI = 1.89–4.08), miR-200a (HR = 2.64, 95% CI = 1.86–3.77), miR-203 (HR = 2.20, 95% CI = 1.61–3.00) have significantly poor OS (P < 0.05). Likewise, HCC patients with high expression of blood miR-21 (HR = 1.73, 95% CI = 1.07–2.80), miR-192 (HR = 2.42, 95% CI = 1.15–5.10), miR-224 (HR = 1.56, 95% CI = 1.14–2.12) or low expression of blood miR-148a (HR = 2.26, 95% CI = 1.11–4.59) have significantly short OS (P < 0.05).

Conclusions

In conclusion, tissue miR-9, miR-21, miR-22, miR-29c, miR-34a, miR-34c, miR-155, miR-199a, miR-200a, miR-203, miR-221 and blood miR-21, miR-148a, miR-192, miR-224 demonstrate significantly prognostic value. Among them, tissue miR-9, miR-22, miR-155, miR-199a, miR-200a, miR-203 and blood miR-148a, miR-192 are potential prognostic candidates for predicting OS in HCC.

Non-coding RNA in hepatocellular carcinoma: Mechanisms, biomarkers and therapeutic targets

The majority of the human genome is not translated into proteins but can be transcribed into RNA. Even though the resulting non-coding RNAs (ncRNAs) do not encode for proteins, they contribute to diseases such as cancer. Here, we review examples of the functions of ncRNAs in liver cancer and their potential use for the detection and treatment of liver cancer.

WITHDRAWN: Epigenetics in Chronic Liver Disease

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GTSE1 promotes cell migration and invasion by regulating EMT in hepatocellular carcinoma and is associated with poor prognosis

G2 and S phase-expressed-1 (GTSE1) regulates G1/S cell cycle transition. It was recently reported to be overexpressed in certain human cancers, but its significance and mechanism(s) in hepatocellular carcinoma (HCC) remain unknown. Here, we showed preferential GTSE1 upregulation in human HCC tissues and cell lines that positively correlated with Ki67. GTSE1 knockdown by short hairpin RNA resulted in deficient colony-forming ability and depleted capabilities of HCC cells to migrate and invade. Conversely, exogenous GTSE1 overexpression enhanced colony formation and stimulated HCC cell migration and invasion. Furthermore, GTSE1 silencing was associated with the downregulation of N-cadherin, β-catenin, and Snail, whereas GTSE1 overexpression caused the opposite effects. GTSE1 upregulated Snail via both transcription and protein degradation pathways. Additionally, GTSE1 modulated the sensitivity of HCC to 5-fluorouracil therapy. High GTSE1 correlates with chemo-resistance, while low GTSE1 increases drug sensitivity. Kaplan-Meier survival analysis indicated that high GTSE1 levels were significantly associated with poor overall survival. In conclusion, high expression of GTSE1 is commonly noted in HCC and is closely correlated with migration and invasion by epithelial-to-mesenchymal transition (EMT) modulation. Activated GTSE1 significantly interferes with chemotherapy efficacy and influences the probability of survival of patients with HCC. GTSE1 may thus represent a promising molecular target.

New Insights into the Epigenetics of Hepatocellular Carcinoma

Hepatocellular Carcinoma (HCC) is one of the most predominant malignancies with high fatality rate. This deadly cancer is rising at an alarming rate because it is quite resistant to radio- and chemotherapy. Different epigenetic mechanisms such as histone modifications, DNA methylation, chromatin remodeling, and expression of noncoding RNAs drive the cell proliferation, invasion, metastasis, initiation, progression, and development of HCC. These epigenetic alterations because of potential reversibility open way towards the development of biomarkers and therapeutics. The contribution of these epigenetic changes to HCC development has not been thoroughly explored yet. Further research on HCC epigenetics is necessary to better understand novel molecular-targeted HCC treatment and prevention. This review highlights latest research progress and current updates regarding epigenetics of HCC, biomarker discovery, and future preventive and therapeutic strategies to combat the increasing risk of HCC.

miR-1299 suppresses cell proliferation of hepatocellular carcinoma (HCC) by targeting CDK6

microRNA (miRNA) plays critical role in HCC initiation and development, many miRNAs have been reported to regulate HCC progression. In this study, we studied the role of miR-1299 in cell proliferation of HCC. We found miR-1299 was significantly downregulated in HCC cells and tissues. miR-1299 overexpression inhibited cell proliferation and arrested cell cycle in G0/G1 phase analyzed by MTT assay, soft agar assay, BrdU cell proliferation assay and cell cycle assay, while miR-1299 knockdown promoted cell proliferation and accelerated G1/S transition. Further analysis suggested the key regulator of G1/S transition, cyclin-dependent kinase 6 (CDK6) was the target of miR-1299, miR-1299 inhibited CDK6 expression and bound to the 3'UTR of CDK6. When double knockdown of miR-1299 and CDK6 promoted cell proliferation copied the phenotype caused by miR-1299 overexpression, suggesting miR-1299 inhibits cell proliferation by targeting CDK6. In summary, our data revealed miR-1299 inhibits cell proliferation, and might be a target for HCC therapy.