MicroRNA-657 promotes tumorigenesis in hepatocellular carcinoma by targeting transducin-like enhancer protein 1 through nuclear factor kappa B pathways

Phenethyl isothiocyanate inhibits metastasis potential of non-small cell lung cancer cells through FTO mediated TLE1 m6A modification

N6-methyladenosine (m6A) modification is a prevalent RNA epigenetic modification, which plays a crucial role in tumor progression including metastasis. Isothiocyanates (ITCs) are natural compounds and inhibit the tumorigenesis of various cancers. Our previous studies show that ITCs inhibit the proliferation and metastasis of non-small cell lung cancer (NSCLC) cells, and have synergistic effects with chemotherapy drugs. In this study, we investigated the molecular mechanisms underlying the inhibitory effects of ITCs on cancer cell metastasis. We showed that phenethyl isothiocyanate (PEITC) dose-dependently inhibited the cell viability of both NSCLC cell lines H1299 and H226 with IC50 values of 17.6 and 15.2 μM, respectively. Furthermore, PEITC dose-dependently inhibited the invasion and migration of H1299 and H226 cells. We demonstrated that PEITC treatment dose-dependently increased m6A methylation levels and inhibited the expression of the m6A demethylase fat mass and obesity-associated protein (FTO) in H1299 and H226 cells. Knockdown of FTO significantly increased m6A methylation in H1299 and H226 cells, impaired their abilities of invasion and migration in vitro, and enhanced the inhibition of PEITC on tumor growth in vivo. Overexpression of FTO promoted the migration of NSCLC cells, and also mitigated the inhibitory effect of PEITC on migration of NSCLC cells. Furthermore, we found that FTO regulated the mRNA m6A modification of a transcriptional co-repressor Transducin-Like Enhancer of split-1 (TLE1) and further affected its stability and expression. TCGA database analysis revealed TLE1 was upregulated in NSCLC tissues compared to normal tissues, which might be correlated with the metastasis status. Moreover, we showed that PEITC suppressed the migration of NSCLC cells by inhibiting TLE1 expression and downstream Akt/NF-κB pathway. This study reveals a novel mechanism underlying ITC's inhibitory effect on metastasis of lung cancer cells, and provided valuable information for developing new therapeutics for lung cancer by targeting m6A methylation.

Emerging role of MicroRNA-Based theranostics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), with its high mortality and short survival rate, continues to be one of the deadliest malignancies despite relentless efforts and several technological advances. The poor prognosis of HCC and the few available treatments are to blame for the low survival rate, which emphasizes the importance of creating new, effective diagnostic markers and innovative therapy strategies. In-depth research is being done on the potent biomarker miRNAs, a special class of non-coding RNA and has shown encouraging results in the early identification and treatment of HCC in order to find more viable and successful therapeutics for the disease. It is beyond dispute that miRNAs control cell differentiation, proliferation, and survival and, depending on the genes they target, can either promote tumorigenesis or suppress it. Given the vital role miRNAs play in the biological system and their potential to serve as ground-breaking treatments for HCC, more study is required to fully examine their theranostic potential.

Upregulation of long intergenic non-coding RNA LINC00326 inhibits non-small cell lung carcinoma progression by blocking Wnt/β-catenin pathway through modulating the miR-657/dickkopf WNT signaling pathway inhibitor 2 axis

BACKGROUND

Long intergenic non-coding RNA 326 (LINC00326) modulates hepatocarcinogenic lipid metabolism. However, the ability of LINC00326 to modulate the highly aggressive non-small cell lung carcinoma (NSCLC) is unknown. Here, LINC00326 in NSCLC was investigated, together with its effects on tumor malignancy and the underlying mechanisms of action.

METHODS

LINC00326 levels in tumor tissues and cell lines were measured by Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and RNA fluorescence in situ hybridization (FISH). Proliferation and apoptosis were assessed in cell lines by Cell Counting Kit-8 (CCK-8), EdU staining assays and flow cytometry, respectively, and tumor growth was measured in mouse models. Possible microRNA targets of LINC00326 were predicted by bioinformatics and verified by RNA pull-down and immunoprecipitation and luciferase reporter assays. Western blotting was used to evaluate the expression of Wnt/β-catenin-associated proteins.

RESULTS

LINC00326 was downregulated in tumor tissues and cell lines. Knockdown of LINC00326 stimulated NSCLC cell proliferation and suppressed apoptosis in vitro, as well as enhancing xenograft tumor growth. LINC00326 sponged miR-657, and dickkopf WNT signaling pathway inhibitor 2 (DKK2) was found to be directly targeted by miR-657, with LINC00326 positively regulating its expression through sponging miR-657. The actions of LINC00326 knockdown on proliferation and apoptosis were reversed by stimulation of the miR-657/DKK2 axis. Furthermore, overexpression of miR-657 mitigated DKK2 inhibition on Wnt/β-catenin signaling.

CONCLUSIONS

LINC00326/miR-657/DKK2 axis signaling blocked tumor-associated functions in NSCLC cells through the targeting Wnt/β-catenin pathway. This suggests that this pathway could be a target for NSCLC treatment.

Roles of transducin-like enhancer of split (TLE) family proteins in tumorigenesis and immune regulation

Mammalian transducin-like enhancer of split family proteins (TLEs) are homologous to Drosophila Groucho (Gro) and are essential transcriptional repressors. Seven TLE family members, TLE1-7, have been identified to date. These proteins do not bind DNA directly; instead, they bind a set of transcription factors and thereby inhibit target gene expression. Loss of TLEs in mice usually leads to defective early development; however, TLE functions in developmentally mature cells are unclear. Recent studies have revealed that TLEs are dysregulated in certain human cancer types and may function as oncogenes or tumor suppressors in different contexts. TLE levels also affect the efficacy of cancer treatments and the development of drug resistance. In addition, TLEs play critical roles in the development and function of immune cells, including macrophages and lymphocytes. In this review, we provide updates on the expression, function, and mechanism of TLEs; discuss the roles played by TLEs in tumorigenesis and the inflammatory response; and elaborate on several TLE-associated signaling pathways, including the Notch, Wnt, and MAPK pathways. Finally, we discuss potential strategies for targeting TLEs in cancer therapy.

miR-657 Targets SRCIN1 via the Slug Pathway to Promote NSCLC Tumor Growth and EMT Induction

Background

MicroRNA- (miR-) 657 has been shown to regulate immunological and inflammatory activity, and it has also been defined to be dysregulated in both non-small-cell lung cancer (NSCLC) and hepatocellular carcinoma. The mechanistic role whereby miR-657 influences NSCLC progression, however, has yet to be clarified.

Methods

miR-657 and SRCIN1 expression levels were assessed via qPCR in the cell lines and tissues of NSCLC. Besides, correlations between the levels of miR-657 and NSCLC patient pathological characteristics were examined, and the Kaplan-Meier approach was employed for the evaluation of the prognostic utility of miR-657 in these patients. Moreover, the Pearson correlation analyses and dual-luciferase reporter assessments were used for detecting interactive relationships between miR-657 and SRCIN1. In addition, CCK-8, EdU, and Transwell assessments were employed for the appraisal of the ability of miR-657/SRCIN1 to regulate NSCLC cell proliferation and invasion. Western blotting was employed for the assessment of the levels of NSCLC cell proteins associated with the epithelial-mesenchymal transition (EMT) that were influenced by miR-657. The nude mice xenograft tumor model is established to observe the effect of miR-657 on NSCLC growth in vivo.

Results

NSCLC patient tissues and cell lines exhibited upregulated miR-657 expression that was closely related to tumor differentiation, lymphoid metastasis, and TNM stage. High levels of miR-657 were predictive of a poorer NSCLC patient prognosis, and overexpressing miR-657 resulted in the more rapid growth of NCI-H1650 and A549 cells, with a concomitant increase in their invasion. In addition, miR-657 overexpression raised the levels of Slug, N-cadherin, and Vimentin in these two cell lines while promoting E-cadherin downregulation. Dual-luciferase reporter assays confirmed that miR-657 was capable of binding to the SRCIN1 gene, and SRCIN1 expression levels were negatively associated with those of miR-657, indicating that it acts as a negative regulator of this gene. Knocking down SRCIN1 was capable to reverse the influences of miR-657 inhibitor treatment on NSCLC cell behavior. Finally, in vivo studies showed that miR-657 promoted NSCLC cell growth.

Conclusion

The obtained findings illuminate that miR-657 can promote the growth of tumors and the induction of the EMT in NSCLC cells by targeting SRCIN1 expression and modulating Slug pathway activation, highlighting this pathway as a promising therapeutic target in cases suffering from NSCLC.

miR‑4730 suppresses the progression of liver cancer by targeting the high mobility group A1 pathway

As liver cancer (LC) is the sixth most commonly diagnosed malignancy, it is necessary to elucidate the molecular mechanisms responsible for LC progression. MicroRNAs (miRNAs/miRs) play crucial roles in tumor progression by regulating target gene expression. The present study assessed miRNA-4730 expression and function in LC. The effects of miR-4730 overexpression were examined in LC cell lines, and the target genes of miR-4730 were evaluated using microarray analysis and TargetScan data. In addition, the association between miR-4730 expression in tissue samples and the prognosis of 70 patients with LC was evaluated. miR-4730 expression was suppressed in LC tissues and cell lines. miR-4730 overexpression suppressed cell proliferation and cell cycle progression and promoted apoptosis. High mobility group A1 (HMGA1) was revealed as the direct target of miR-4730 using luciferase reporter assay, and the inhibition of downstream integrin-linked kinase (ILK) expression and Akt or glycogen synthase kinase 3β (GSK3β) phosphorylation was confirmed. The lower expression of miR-4730 in tissue samples was significantly associated with a worse recurrence-free survival of patients with LC. On the whole, miR-4730 suppressed tumor progression by directly targeting HMGA1 and inhibiting the ILK/Akt/GSK3β pathway. miR-4730 thus has potential for use as a prognostic marker and may prove to be a therapeutic target for miRNA-based therapies.

miRNAs inspirations in hepatocellular carcinoma: Detrimental and favorable aspects of key performers

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. HCC initiation, progression, and therapy failure are all influenced by various variables, including microRNAs (miRNAs). miRNAs are short non-coding RNA sequences that modulate target mRNA expression by deteriorating or repressing translation. miRNAs play an imperative role in HCC pathogenesis by triggering the induction of cancer stem cells (CSCs) and their proliferation, while also delaying apoptosis, sustaining the cell cycle, and inspiring angiogenesis, invasion, and metastasis. Additionally, miRNAs modulate crucial HCC-related molecular pathways such as the p53 pathway, the Wnt/β-catenin pathway, VEGFR2, and PTEN/PI3K/AKT pathway. Consequently, the goal of this review was to give an up-to-date overview of oncogenic and tumor suppressor (TS) miRNAs, as well as their potential significance in HCC pathogenesis and treatment responses, highlighting their underpinning molecular pathways in HCC initiation and progression. Similarly, the biological importance and clinical application of miRNAs in HCC are summarized.

MicroRNA hsa-miR-657 promotes retinoblastoma malignancy by inhibiting peroxisome proliferator-activated receptor alpha expression

Retinoblastoma is a familial inherited embryonic neuroretinal malignancy with a low survival rate and poor prognosis. Our study aimed to evaluate the potential interaction between microRNA miR-657 and the peroxisome proliferator-activated receptor alpha (PPARA) in retinoblastoma. Expression of miR-657 and PPARA was analyzed in retinoblastoma tissues and cells using RT-qPCR. Cell proliferation, apoptosis, and migration were measured in retinoblastoma cell lines, and xenografting experiments were performed using nude mice. Our study showed that miR-657 expression was markedly increased, whereas that of PPARA was markedly decreased in retinoblastoma. Additionally, PPARA knockdown enhanced the development of retinoblastoma. miR-657 enhanced the retinoblastoma tumorigenesis by directly inhibiting PPARA expression, suggesting that PPARA targeting by miR-657 facilitates retinoblastoma development by enhancing cell growth. This study provides novel insights into the miR-657- and PPARA-mediated mechanisms underlying retinoblastoma progression and suggests that the interaction between miR-657 and PPARA may serve as an effective target for therapeutic intervention.

miR-221-3p regulates hepatocellular carcinoma cell proliferation, migration and invasion via targeting LIFR

INTRODUCTION AND OBJECTIVES

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancers in the world. This study aims to investigate the mechanism by which miR-221-3p regulates HCC cell proliferation, migration and invasion, so as to provide a new idea for targeted therapy towards HCC.

MATERIALS AND METHODS

Expression quantification data including mature miRNA and mRNA were accessed from TCGA-LIHC dataset, and matched clinical information was obtained as well, which helped identify the miRNA of interest. Thereafter, effect of the miRNA on HCC cell biological functions was assessed with a series of in vitro experiments, such as qRT-PCR, MTT, wound healing assay and Transwell. To gain more insight into the mechanism of the miRNA in HCC, bioinformatics method was conducted to predict downstream target gene. The potential targeting relationship between the miRNA and the predicted mRNA was validated by dual-luciferase reporter assay. Western blot was performed to test protein expression.

RESULTS

MiR-221-3p identified by differential expression analysis was found to be significantly elevated in HCC tissue. Overexpressing miR-221-3p noticeably enhanced HCC cell proliferative, migratory and invasive abilities. Leukemia inhibitory factor receptor (LIFR), confirmed as a downstream target of miR-221-3p in HCC by dual-luciferase reporter assay, was poorly expressed in HCC tissue and cells. Additionally, the expression of LIFR was decreased following the targeted binding between miR-221-3p and LIFR 3'-UTR, while increasing the expression of LIFR attenuated the promoting effect of miR-221-3p on HCC cells.

CONCLUSION

MiR-221-3p is an oncogene in HCC cells, and it exerts its role in HCC cell viability and motility via targeting LIFR.

The Crosstalk Between Regulatory Non-Coding RNAs and Nuclear Factor Kappa B in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal type of malignancies that possesses great loss of life safety to human beings worldwide. However, few effective means of curing HCC exist and its specific molecular basis is still far from being fully elucidated. Activation of nuclear factor kappa B (NF-κB), which is often observed in HCC, is considered to play a significant part in hepatocarcinogenesis and development. The emergence of regulatory non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), is a defining advance in cancer biology, and related research in this branch has yielded many diagnostic and therapeutic opportunities. Recent studies have suggested that regulatory ncRNAs act as inhibitors or activators in the initiation and progression of HCC by targeting components of NF-κB signaling or regulating NF-κB activity. In this review, we attach importance to the role and function of regulatory ncRNAs in NF-κB signaling of HCC and NF-κB-associated chemoresistance in HCC, then propose future research directions and challenges of regulatory ncRNAs mediated-regulation of NF-κB pathway in HCC.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Gene of the month: TLE 1

TLE 1 is the human homologue belonging to a family of four genes and is located on chromosome 9q21. It consists of 19 exons. Although it does not bind directly to DNA, it acts as a repressor of several signalling pathways via transcription factors. TLE1 protein has several physiological roles in embryogenesis, haematopoiesis, general differentiation, and both neuronal and eye development. Much attention was focused on its expression in the tumour cell nuclei of synovial sarcoma (SS). However, several other soft tissue tumours that do and do not share morphological similarity with SS also display nuclear immunoreactivity for TLE1; hence, caution in interpretation is advocated.

Construct a circRNA/miRNA/mRNA regulatory network to explore potential pathogenesis and therapy options of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most representative subtype of renal cancer. CircRNA acts as a kind of ceRNA to play a role in regulating microRNA (miRNA) in many cancers. However, the potential pathogenesis role of the regulatory network among circRNA/miRNA/mRNA is not clear and has not been fully explored. CircRNA expression profile data were obtained from GEO datasets, and the differentially expressed circRNAs (DECs) were identified through utilizing R package (Limma) firstly. Secondly, miRNAs that were regulated by these circRNAs were predicted by using Cancer-specific circRNA database and Circular RNA Interactome. Thirdly, some related genes were identified by intersecting targeted genes, which was predicted by a web tool (miRWalk) and differentially expressed genes, which was obtained from TCGA datasets. Function enrichment was analyzed, and a PPI network was constructed by Cytoscape software and DAVID web set. Subsequently, ten hub-genes were screened from the network, and the overall survival time in patients of ccRCC with abnormal expression of these hub-genes were completed by GEPIA web set. In the last, a circRNA/miRNA/mRNA regulatory network was constructed, and potential compounds and drug which may have the function of anti ccRCC were forecasted by taking advantage of CMap and PharmGKB datasets. Six DECs (hsa_circ_0029340, hsa_circ_0039238, hsa_circ_0031594, hsa_circ_0084927, hsa_circ_0035442, hsa_circ_0025135) were obtained and six miRNAs (miR-1205, miR-657, miR-587, miR-637, miR-1278, miR-548p) which are regulated by three circRNAs (hsa_circ_0084927, hsa_circ_0035442, hsa_circ_0025135) were also predicted. Then 497 overlapped genes regulated by these six miRNAs above had been predicted, and function enrichment analysis revealed these genes are mainly linked with some regulation functions of cancers. Ten hub-genes (PTGER3, ADCY2, APLN, CXCL5, GRM4, MCHR1, NPY5R, CXCR4, ACKR3, MTNR1B) have been screened from a PPI network. PTGER3, ADCY2, CXCL5, GRM4 and APLN were identified to have a significant effect on the overall survival time of patients with ccRCC. Furthermore, one compound (josamycin) and four kinds of drugs (capecitabine, hmg-coa reductase inhibitors, ace Inhibitors and bevacizumab) were confirmed as potential therapeutic options for ccRCC by CMap analysis and pharmacogenomics analysis. This study implies the potential pathogenesis of the regulatory network among circRNA/miRNA/mRNA and provides some potential therapeutic options for ccRCC.

MiR-126 Regulates Properties of SOX9+ Liver Progenitor Cells during Liver Repair by Targeting Hoxb6

Liver progenitor cells (LPCs) have a remarkable contribution to the hepatocytes and ductal cells when normal hepatocyte proliferation is severely impaired. As a biomarker for LPCs, Sry-box 9 (Sox9) plays critical roles in liver homeostasis and repair in response to injury. However, the regulation mechanism of Sox9 in liver physiological and pathological state remains unknown. In this study, we found that miR-126 positively regulated the expression of Sox9, the proliferation and differentiation of SOX9⁺ LPCs by suppressing the translation of homeobox b6 (Hoxb6). As a transcription factor, HOXB6 directly binds to the promoter of Sox9 to inhibit Sox9 expression, resulting in the destruction of the properties of SOX9⁺ LPCs in CCl₄-induced liver injury. These findings revealed the role of miR-126 in regulating SOX9⁺ LPCs fate by targeting Hoxb6 in liver injury repair. Our findings suggest the potential role of miR-126 as a nucleic acid therapy drug target for liver failure.

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miR-126 promotes Sox9 expression and maintains SOX9⁺ LPCs in adult mouse livers

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HOXB6 suppresses properties of SOX9⁺ LPCs in chronic liver injury model

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HOXB6 negatively regulates Sox9 trans-activity

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miR-126 regulates properties of SOX9⁺ LPCs by targeting Hoxb6

MicroRNA Signatures in Blood or Bone Marrow Distinguish Subtypes of Pediatric Acute Lymphoblastic Leukemia

OncomiRs are microRNAs that are associated with early onset of specific cancers. To identify microRNAs involved in pediatric acute lymphoblastic leukemia (ALL) subtypes T-ALL and B-ALL, peripheral blood and bone marrow samples were independently subjected to microarray analysis using two different high-fidelity array platforms. The unique and common gene signatures from both arrays were validated by TaqMan individual assays in 100 pediatric ALL samples. Survival studies were carried out in the test set and validation set with 50 randomly selected samples in each set. MicroRNA expression profile revealed characteristic signatures for distinguishing T and B lineages and identified 51 novel microRNAs in pediatric ALL. Interestingly, the present study also revealed endogenous similarities and differences between blood and bone marrow within each ALL subtype. When Cox regression analysis was carried out with these identified microRNAs, 11 of them exhibited expression levels significantly correlated with survival. Validation of some of the common and relevant microRNAs from both arrays showed that their targets are involved in key oncogenic signaling pathways. Thus, this study suggests that microRNAs have the potential to become important diagnostic tools for identification and monitoring clinical outcomes in ALL patients.

Transducin-Like Enhancer of Split-1 Inhibits Malignant Behaviors in vitro and Predicts a Better Prognosis in Pancreatic Ductal Adenocarcinoma

Background: Transducin-like enhancer of split-1 (TLE1), a member of the Groucho/TLE family of transcriptional corepressors, has been reported to be involved in the tumorigenesis of various cancers and function as a clinical prognostic indicator. However, the mechanisms and prognostic significance of TLE1 in pancreatic ductal adenocarcinoma (PDAC) have not been elucidated. Methods: In this study, western blot analyses and real-time polymerase chain reaction (RT-PCR) were employed to evaluate the expression of TLE1 and related proteins in PDAC cell lines. Wound healing, transwell migration and invasion, and Cell Counting Kit-8 (CCK-8) assays were used to determine cell line-specific differences in metastasis and proliferation. Flow cytometry was performed for cell cycle detection. RNA sequencing and bioinformatics were undertaken to explore the molecular mechanisms and potential targeted molecules of TLE1. TLE1 expression in tumor and para-tumor tissues was evaluated by tissue microarray-based immunohistochemistry using a semiquantitative method (H-score) in 262 patients with radical PDAC resection. Correlation, Kaplan-Meier survival, univariate, and multivariate analyses were also performed. Results: Our findings showed that TLE1 expression was common in PDAC cell lines. Upregulation of TLE1 inhibited PDAC cell migration, invasion, and proliferation in vitro by delaying the G0/G1 transition. Immunohistochemistry revealed that TLE1 was specifically expressed in the nucleus and at higher levels in tumor tissues compared with para-tumor tissues. Generally, high TLE1 expression was associated with no vascular invasion. In univariate analyses, high TLE1 expression was associated with longer disease-specific survival (DSS) in all patients and in 16 patient subgroups. In multivariate analyses, TLE1 expression was independently associated with DSS in all patients and four patient subgroups. Conclusion: In conclusion, these results suggest that TLE1 has an inhibitory role in PDAC progression and is a favorable prognostic indicator for patients with resectable PDAC.

MicroRNA-212-3p inhibits the Proliferation and Invasion of Human Hepatocellular Carcinoma Cells by Suppressing CTGF expression

MicroRNA-212-3p inhibits several human cancers but its effects on hepatocellular carcinoma (HCC) remain unclear. In this study, we show that miR-212-3p is down-regulated in HCC cell lines and tissues, and correlates with vascular invasion (p = 0.001), and the absence of capsule formation (p = 0.009). We found that miR-212-3p influenced the epithelial to mesenchymal transition (EMT) of HCCLM3 and Huh7 cells. Mechanistically, miR-212-3p repressed cell invasion through the suppression of connective tissue growth factor (CTGF). We therefore validate the anti-HCC effects of miR-212-3p through its ability to suppress CTGF and subsequent EMT.

Deletion of miR-126a Promotes Hepatic Aging and Inflammation in a Mouse Model of Cholestasis

MicroRNAs (miRNAs) act as regulators of aging at the tissue or organism level or as regulators of cellular senescence. Targeted deletion of miR-126 in mice causes partial embryonic lethality, but its biological function in the liver is still largely unknown. Here, we deleted miR-126a, using the CRISPR/Cas9 system in vitro and in vivo. miR-126a was reduced in the aging livers, and disruption of miR-126a in bone mesenchymal stem cells (BMSCs) induced age-associated telomere shortening, DNA damage responses, and proinflammatory cytokines. Moreover, disruption of miR-126a in mice caused hepatocyte senescence, inflammation, and metabolism deficiency. In addition, disruption of miR-126a via BMSC transplantation aggravated the severity of liver defects induced by cholestasis compared with that in the functional miR-126a BMSC group. Mechanistically, we identified versican (VCAN) as a novel direct miR-126a-5p target that induces telomere shortening, BMSC senescence, and nuclear factor κB (NF-κB) pathway activation. This study identified aging-related reduced expression of miR-126a and promotion of its target VCAN as a key mechanism in the regulation of hepatic metabolic function during aging and hepatic damage by inducing NF-κB pathway activation, DNA repair function disorder, and telomere attrition. The findings indicate that miR-126a may be a drug target for the treatment of hepatic failure.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

TLE1 as an indicator of adverse prognosis in pediatric acute lymphoblastic leukemia

PURPOSE

Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children, and despite the high rate of cure (over 80%) it still has a big impact on morbidity and mortality. The Transducin-like enhancer of split 1 (TLE1), a transcriptional corepressor, has been described as dysregulated and recently emerged as a tumor marker in several cancer types, including hematologic malignancies.

METHODS

In the present study TLE1 gene expression was evaluated by RT-qPCR. A total of 60 consecutive pathological ALL samples and 8 normal bone marrow samples were included. Associations between TLE1 levels and clinicopathological features were estimated using Mann-Whitney tests.

RESULTS

TLE1 mRNA levels were significantly diminished in ALL samples when compared to normal counterparts (fold change -1.45, p-value 0.039). Lower TLE1 expression levels were associated with poorer prognostic features such as age at diagnosis (<1 or >9 years-old), absence of the Common Acute Lymphoblastic Leukemia Antigen (CALLA) and high white cell count. Considering immunophenotype, decreased expression of TLE1 was only evident for T-cell ALL, what was validated using gene expression profiling data available in public repositories. No associations with event or overall survival were observed. However, TLE1 expression was statistically different between patients who achieved complete clinical remission (CCR) from those that relapsed or died.

CONCLUSION

These data are of particular interest and give support for a plausible role of TLE1 as a tumor suppressor in T-cell ALL. Moreover, the prognostic value of this corepressor may assist ALL treatment stratification and suggest the need of alternative regimens.

Small but Heavy Role: MicroRNAs in Hepatocellular Carcinoma Progression

Hepatocellular carcinoma (HCC), which accounts for 85-90% of primary liver cancer, is the fifth most common malignant tumor and the third leading cause of cancer-related deaths worldwide, but the pathological mechanism of HCC is still not fully elucidated. miRNAs are evolutionarily endogenous small noncoding RNAs that negatively regulate gene expression via posttranscriptional inhibition or target mRNA degradation in several diseases, especially human cancer. Therefore, discovering the roles of miRNAs is appealing to scientific researchers. Emerging evidence has shown that the aberrant expressions of numerous miRNAs are involved in many HCC biological processes. In hepatocarcinogenesis, miRNAs with dysregulated expression can exert their function as oncogenes or tumor suppressors depending on their cellular target during the cell cycle, and in tumor development, differentiation, apoptosis, angiogenesis, metastasis, and progression of the tumor microenvironment. In this review, we summarize current findings on miRNAs and assess their functions to explore the molecular mechanisms of tumor progression in HCC.

microRNA-501-3p suppresses metastasis and progression of hepatocellular carcinoma through targeting LIN7A

Increasing numbers of evidences have demonstrated that microRNAs (miRNAs) are implicated in metastasis and progression of hepatocellular carcinoma (HCC). However, their detailed expression levels and actual functions in HCCs have not been fully clarified yet. Results from our recent study revealed that some miRNAs were particularly related to metastasis of HCCs. As one of these newly found miRNAs, miR-501-3p showed to highly involve into metastatic process of HCCs. Here we reported that the expression of miR-501-3p was decreased in both metastatic HCC cell lines and tissue samples from HCC patients with recurrence and metastasis. Downregulation of miR-501-3p correlated with tumor progression and poor prognosis in the HCC patients. Results of functional analyses revealed that overexpression of miR-501-3p in HCCLM3 cancer cells inhibited their proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT), while miR-501-3p loss in PLC/PRF/5 cancer cells facilitated all these cellular activities. In addition, Lin-7 homolog A (LIN7A) was directly targeted by miR-501-3p to mediate the suppression effects on metastasis in HCC cells. miR-501-3p suppresses metastasis and progression of HCCs through targeting LIN7A. This finding suggests that miR-501-3p could be used as a potential prognostic predictor as well as a potential therapeutic tool for HCC therapies.

Liver regeneration microenvironment of hepatocellular carcinoma for prevention and therapy

Research on liver cancer prevention and treatment has mainly focused on the liver cancer cells themselves. Currently, liver cancers are no longer viewed as only collections of genetically altered cells but as aberrant organs with a plastic stroma, matrix, and vasculature. Improving the microenvironment of the liver to promote liver regeneration and repair by affecting immune function, inflammation and vasculature can regulate the dynamic imbalance between normal liver regeneration and repair and abnormal liver regeneration, thus improving the microenvironment of liver regeneration for the prevention and treatment of liver cancer. This review addresses the basic theory of the liver regeneration microenvironment, including the latest findings on immunity, inflammation and vasculature. Attention is given to the potential design of molecular targets in the microenvironment of hepatocellular carcinoma (HCC). In an effort to improve the liver regeneration microenvironment of HCC, researchers have extensively utilized the enhancement of immunity, anti-inflammation and the vasculature niche, which are discussed in detail in this review. In addition, the authors summarize the latest pro-fibrotic transition characteristics of the vascular niche and review potential cell therapies for liver disease.

Mir-452-3p: A Potential Tumor Promoter That Targets the CPEB3/EGFR Axis in Human Hepatocellular Carcinoma

Purpose:

We proposed to investigate the effects of miR-452-3p on the proliferation and mobility of hepatocellular carcinoma (HCC) cells by targeting cytoplasmic polyadenylation element binding protein 3/estimated glomerular filtration rate (CPEB3/EGFR) axis.

Methods:

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-452-3p expression in 84 pairs of HCC tissues and adjacent tissues. Luciferase reporter assay was employed to examine the relationship between miR-452-3p and CPEB3. Microculture tetrazolium (MTT) assay, colony formation assay, flow cytometry detection, wound healing assay, and transwell assay were used to detect cell proliferation, cycle arrest, apoptosis, and mobility, respectively, in HCC, HepG2, and Huh-7. Western blot was used to detect protein expression levels in EGFR signaling pathway. Kaplan-Meier survival analysis was conducted to analyze the correlation between the miR-452-3p and CPEB3 expression levels and the survival of patients with HCC.

Results:

MiRNA-452-3p was found significantly upregulated in 84 human HCC sample tissues and cells in comparison with adjacent tissues and normal liver epithelial cells (P < .01). Luciferase reporter assay demonstrated that CPEB3 was a direct target of miR-452-3p. Overexpression of miR-452-3p promoted cell proliferation and mobility and suppressed apoptosis. MiR-452-3p enhanced EGFR and phosphorylated AKT (pAKT) expression but inhibited p21 expression level.

Conclusion:

MiR-452-3p promoted HCC cell proliferation and mobility by directly targeting the CPEB3/EGFR axis.

Disease relevant modifications of the methylome and transcriptome by particulate matter (PM2.5) from biomass combustion

Exposure to particulate matter (PM) is recognized as a major health hazard, but molecular responses are still insufficiently described. We analyzed the epigenetic impact of ambient PM_2.5 from biomass combustion on the methylome of primary human bronchial epithelial BEAS-2B cells using the Illumina HumanMethylation450 BeadChip. The transcriptome was determined by the Affymetrix HG-U133 Plus 2.0 Array. PM_2.5 induced genome wide alterations of the DNA methylation pattern, including differentially methylated CpGs in the promoter region associated with CpG islands. Gene ontology analysis revealed that differentially methylated genes were significantly clustered in pathways associated with the extracellular matrix, cellular adhesion, function of GTPases, and responses to extracellular stimuli, or were involved in ion binding and shuttling. Differential methylations also affected tandem repeats. Additionally, 45 different miRNA CpG loci showed differential DNA methylation, most of them proximal to their promoter. These miRNAs are functionally relevant for lung cancer, inflammation, asthma, and other PM-associated diseases. Correlation of the methylome and transcriptome demonstrated a clear bias toward transcriptional activation by hypomethylation. Genes that exhibited both differential methylation and expression were functionally linked to cytokine and immune responses, cellular motility, angiogenesis, inflammation, wound healing, cell growth, differentiation and development, or responses to exogenous matter. Disease ontology of differentially methylated and expressed genes indicated their prominent role in lung cancer and their participation in dominant cancer related signaling pathways. Thus, in lung epithelial cells, PM_2.5 alters the methylome of genes and noncoding transcripts or elements that might be relevant for PM- and lung-associated diseases.

Noncoding RNAs Regulating NF-κB Signaling

As transcription factors that regulate expression of a variety of genes essential for diverse physiological and pathological processes, nuclear factor kappa B (NF-κB) family molecules play important roles in the development and progression of malignant tumor, and constitutive activation of NF-κB has been evidenced in various types of tumor tissues. Underlying its pathologic role, deregulated expression and/or transactivating activity of NF-κB usually involves multiple layers of molecular mechanisms. Noncoding RNAs, including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are known to modulate expression and biological functions of regulatory proteins in a variety of cancer contexts. In this chapter, the regulatory role of miRNAs and lncRNAs in NF-κB signaling in malignant diseases will be discussed.

Clinicopathologic and Prognostic Significance of Transducin-Like Enhancer of Split 1 Protein Expression in Invasive Breast Cancer

Purpose

Transducin-like enhancer of split 1 (TLE1) is a member of the TLE family of transcriptional co-repressors that control the transcription of a wide range of genes. We investigated the prognostic significance of TLE1 protein expression in breast cancers by using immunohistochemistry and explored the relationship of TLE1 with clinicopathological parameters.

Methods

Immunohistochemistry was performed on 456 cases of breast cancer tiled on tissue microarrays. The relationship between TLE1 expression in normal breast specimens and ductal carcinoma in situ (DCIS) was also analyzed.

Results

TLE1 was highly expressed in 57 of 456 (12.5%) carcinoma samples. TLE1 was more frequently expressed in DCIS and invasive breast cancers than in normal breast tissue (p=0.002). High expression of TLE1 significantly correlated with negative lymph node (LN) metastasis (p=0.007), high histologic grade (p<0.001), estrogen receptor negativity (p<0.001), progesterone receptor negativity (p<0.001), human epidermal growth factor receptor 2 (HER2) positivity (p<0.001), and high Ki-67 proliferation index (p<0.001). Based on intrinsic subtypes, high TLE1 expression was strongly associated with HER2+ and triple-negative breast cancers (TNBC) (p<0.001). Survival analysis demonstrated no significant association between TLE1 expression and disease-free survival (DFS) (p=0.167) or overall survival (OS) (p=0.286). In subgroup analyses, no correlation was found between TLE1 expression and DFS or OS according to LN status or intrinsic subtype.

Conclusion

High TLE1 expression is significantly associated with the HER2+ and TNBC subtypes. This is the first study documenting immunohistochemical expression of TLE1 in invasive breast cancer and its association with clinicopathological parameters, prognosis, and intrinsic subtype.

TLE1 function and therapeutic potential in cancer

Groucho (Gro)/Transducin-like enhancer of split (TLE) family proteins act as co-repressors of many transcription factors, and are involved in key signaling pathways. TLE1 negatively regulates inflammation and has potential roles in various diseases, including cancer. Previous studies suggest TLE1 could be used as a diagnostic marker and is a possible therapeutic target in various malignancies. It is therefore important to elucidate the mechanisms underlying TLE1 function during cancer initiation and metastasis. In this review, we highlight the functions of TLE1 in cancer and explore targeted approaches for cancer diagnosis and treatment. In particular, we discuss the TLE1 function in pancreatic cancer.

Mechanisms for microRNAs in pathogenesis of hepatocellular carcinoma and challenges in their clinical application

Hepatocellular carcinoma (HCC) is one of the most deadly tumors worldwide, and it seriously endangers the health of people in China. Hepatocarcinogenesis is an extremely complex process that involves many risk factors. MicroRNAs (miRNAs) are a group of small, short and non-coding RNAs, and approximately one-third of human genes are regulated by miRNAs, which play important roles in tumor cell proliferation, cell cycle and apoptosis as well as tumor invasion, metastasis, and angiogenesis. Numerous studies have shown that miRNAs have a close relationship with hepatocarcinogenesis. In addition, miRNAs play a significant role in the diagnosis and therapy of HCC. In this review, we discuss the recent advances in the understanding of signaling pathways that are related to miRNAs in hepatocarcinogenesis, and the challenges faced in the clinical application of miRNAs.

Upregulated in Hepatitis B virus-associated hepatocellular carcinoma cells, miR-331-3p promotes proliferation of hepatocellular carcinoma cells by targeting ING5

Hepatitis B virus (HBV) is a major risk factor for development and progression of hepatocellular carcinoma (HCC). It has been reported that viral infection can interfere with cellular microRNA (miRNA) expression and participate in the pathogenesis of oncogenicity. Our miRNAs array data indicated that miR-331-3p expression in HCC cell lines increased, but the relationship between miR-331-3p expression and HBV activity is unclear. Here, we observed elevated expression of miR-331-3p in different HCC cell lines expressing HBV. HBV, especially HBx, promotes miR-331-3p expression by enhancing its promoter activity. Using a miRNA target prediction database miRBase, we identified ING5 to be a novel target gene of miR-331-3p. miR-331-3p could inhibit ING5 expression by directly targeting its 3′-untranslated region (3′-UTR). As predicted, HBV was confirmed to repress ING5 at both mRNA and protein levels by promoting miR-331-3p expression. Our result indicated that miR-331-3p expression promotes proliferation of SMMC7721 cells by inhibiting ING5. ING5 overexpression promoted cell apoptosis in HCC cell lines. We also found ING5 expression was decreased in tumor tissue of HCC patient with HBV infection compared to its expression in para-carcinoma tissues. Conclusion: These results showed that miR-331-3p is upregulated by HBV and promotes proliferation of HCC cells though repression of ING5 expression. These data provide new insights for understanding the mechanisms of HBV-related HCC pathogenesis.

Prognostic and Clinicopathological Significance of Transducer-Like Enhancer of Split 1 Expression in Gastric Cancer

PURPOSE

Transducer-like enhancer of split 1 (TLE1) is a member of the Groucho/TLE family of transcriptional co-repressors that regulate the transcriptional activity of numerous genes. TLE1 is involved in the tumorigenesis of various tumors. We investigated the prognostic significance of TLE1 expression and its association with clinicopathological parameters in gastric cancer (GC) patients.

MATERIALS AND METHODS

Immunohistochemical analysis of six tissue microarrays was performed to examine TLE1 expression using 291 surgically resected GC specimens from the Soonchunhyang University Cheonan Hospital between July 2006 and December 2009.

RESULTS

In the non-neoplastic gastric mucosa, TLE1 expression was negative. In GC, 121 patients (41.6%) were positive for TLE1. The expression of TLE1 was significantly associated with male gender (P=0.021), less frequent lymphatic (P=0.017) or perineural invasion (P=0.029), intestinal type according to the Lauren classification (P=0.024), good histologic grade (P<0.001), early pathologic T-stage (P=0.012), and early American Joint Committee on Cancer stage (P=0.022). In the Kaplan-Meier analysis, the TLE1 expression was significantly associated with longer disease-free (P=0.022) and overall (P=0.001) survival rates.

CONCLUSIONS

We suggested that TLE1 expression is a good prognostic indicator in GCs.

Tle1 tumor suppressor negatively regulates inflammation in vivo and modulates NF-κB inflammatory pathway

Tle1 (transducin-like enhancer of split 1) is a corepressor that interacts with a variety of DNA-binding transcription factors and has been implicated in many cellular functions; however, physiological studies are limited. Tle1-deficient (Tle1(Δ/Δ)) mice, although grossly normal at birth, exhibit skin defects, lung hypoplasia, severe runting, poor body condition, and early mortality. Tle1(Δ/Δ) mice display a chronic inflammatory phenotype with increased expression of inflammatory cytokines and chemokines in the skin, lung, and intestine and increased circulatory IL-6 and G-CSF, along with a hematopoietic shift toward granulocyte macrophage progenitor and myeloid cells. Tle1(Δ/Δ) macrophages produce increased inflammatory cytokines in response to Toll-like receptor (TLR) agonists and lipopolysaccharides (LPS), and Tle1(Δ/Δ) mice display an enhanced inflammatory response to ear skin 12-O-tetradecanoylphorbol-13-acetate treatment. Loss of Tle1 not only results in increased phosphorylation and activation of proinflammatory NF-κB but also results in decreased Hes1 (hairy and enhancer of split-1), a negative regulator of inflammation in macrophages. Furthermore, Tle1(Δ/Δ) mice exhibit accelerated growth of B6-F10 melanoma xenografts. Our work provides the first in vivo evidence, to our knowledge, that TLE1 is a major counterregulator of inflammation with potential roles in a variety of inflammatory diseases and in cancer progression.

Role of microRNAs in inflammation-associated liver cancer

Liver cancer, primarily hepatocellular carcinoma (HCC), is a major cause of cancer-related death worldwide. HCC is a suitable model of inflammation-induced cancer because more than 90% of HCC cases are caused by liver damage and chronic inflammation. Several inflammatory response pathways, such as NF-κB and JAK/STAT3 signaling pathways, play roles in the crosstalk between inflammation and HCC. MicroRNAs (miRNAs) are evolutionarily conserved, short endogenous, non-coding single-stranded RNAs that are involved in various biological and pathological processes by regulating gene expression and protein translation. Evidence showed that miRNAs play a pivotal role in hepatitis virus infection and serve as promoters or inhibitors of inflammatory response. Aberrant miRNA was observed during liver inflammation and HCC. Many dysregulated miRNAs modulate the initiation and progression of inflammation-induced HCC. This review summarizes the role and functions of miRNAs in inflammation-associated HCC, as well as the designed therapeutics targeting miRNAs to treat liver inflammation and HCC.

tRFs: miRNAs in disguise

tRFs and tiRNAs are two new classes of regulatory non-coding small RNAs that are derived from the cleavage of pre-existing tRNAs. tRFs are 18-22 nt long and are classified into the tRF-5, tRF-3, and tRF-1 series. Here, we discuss in detail the regulatory roles of tRFs in translation, viral infections, and carcinogenesis. Moreover, we have reviewed the association of tRFs with Argonaute proteins, including their potential to function as miRNAs. Interestingly, few miRNAs are generated from pre-existing tRNAs. Hence, tRNAs generate similar-sized tRFs and miRNAs, leading to misannotations due to cross mapping of tRFs and tRNA-derived miRNAs during deep sequencing data analysis. Therefore, it is important to catalogue the overlapping sequences between tRNA-derived miRNAs and tRFs. We have catalogued the miRNAs that overlap with tRFs sequences in humans using miRBase. We identified 20 tRNA-derived miRNAs that share sequences with tRFs. Of the 20 miRNAs, 5 miRNAs (miR-3182, miR-4521, miR-1260a, miR-1260b, and miR-7977) showed significant prediction scores. Furthermore, we have identified a lysine degradation pathway as a common regulatory pathway for miR-1260a, miR-1260b, and miR-3182 by using DIANA-mirPath.

MicroRNAs dysregulation in hepatocellular carcinoma: Insights in genomic medicine

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

miRNA in hepatocellular carcinoma

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

Expression of glypican 3 enriches hepatocellular carcinoma development-related genes and associates with carcinogenesis in cirrhotic livers

Glypican-3 (GPC3) protein expression was determined by immunohistochemical analysis from 29 normal livers, 80 cirrhotic livers sample taken near hepatocellular carcinoma (HCC), and 87 cirrhotic livers without HCC. The levels for miR-657 and HCC-related gene mRNAs were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Also, a published microarray dataset was used for gene set enrichment analysis (GSEA) to investigate the relationship between GPC3- and HCC-related gene signatures. Kaplan-Meier analysis was used to evaluate the relationship between GPC3 and HCC recurrence. GPC3 protein expression was not detected in any of the 29 (0%) normal livers, but was detected in 32 of 87 (37%) cirrhotic livers without HCC, and 51 of 80 (64%) cirrhotic liver samples taken near HCC sites (P < 0.001). The GPC3-positive rate in cirrhotic livers of viral origin was 68% (27/40), which was significantly higher than for non-viral cirrhotic livers (11%, 5/47) (P < 0.001). Also, GPC3 expression positively correlated with mRNA expression of HCC-related genes in the qRT-PCR and GSEA evaluations. Furthermore, HCC recurrence in cirrhotic liver samples taken near HCC sites was significantly higher in the GPC3-positive group than the GPC3-negative group (Log-rank P = 0.02, HR = 3.26; 95% CI = 1.20-10.29). This study demonstrated that highly expression of GPC3 could enrich HCC-related genes' mRNA expression and positive associate with dysplasia in cirrhotic livers. Therefore, GPC3 may serve as a precancerous biomarker in cirrhotic livers.

MicroRNA-362-5p promotes tumor growth and metastasis by targeting CYLD in hepatocellular carcinoma

MicroRNAs are increasingly recognized as playing important roles in hepatocellular carcinoma (HCC) tumorigenesis. Here we identified an essential role for miR-362-5p in the regulation of HCC development. We found that miR-362-5p was significantly up-regulated in HCCs and associated with HCC progression. Inhibition of miR-362-5p in HCC cells dramatically decreased cell proliferation, clonogenicity, migration and invasion in vitro as well as tumor growth and metastasis in vivo. We subsequently identified that CYLD was a target gene of miR-362-5p. Furthermore, knockdown of CYLD expression partially counteracted the tumor suppressive effects of miR-362-5p inhibitors. Finally, we have shown that miR-362-5p acts through CYLD to activate the NF-κB signaling pathway, which contributes to HCC progression. Taken together, our findings indicate that miR-362-5p belongs to a new class of oncomiR that regulates HCC cell aggressiveness, thus providing new insight into the molecular mechanisms underlying HCC development. This study also suggests that miR-362-5p may serve as a novel therapeutic target for miRNA based HCC therapy.

MicroRNA-331-3p promotes proliferation and metastasis of hepatocellular carcinoma by targeting PH domain and leucine-rich repeat protein phosphatase

Hepatocellular carcinoma (HCC) is a highly invasive tumor with frequent intrahepatic or pulmonary metastasis, which is the main reason for high recurrence and poor survival of HCC after liver resection. However, the mechanisms for metastasis remain incompletely clear. Given that microRNAs (miRNAs) are implicated in HCC progression, we explored a potential role of miRNAs in metastasis by performing miRNA expression profiling in three subtypes of HCC with different metastatic potentials. We discovered miR-331-3p as one of most significantly overexpressed miRNAs and highly associated with metastasis of HCC. Increased expression of miR-331-3p was correlated with poor long-term survival of HCC. We provided both in vivo and in vitro evidence demonstrating that miR-331-3p promoted proliferation and metastasis of HCC cells. Using an integrated approach, we uncovered that PH domain and leucine-rich repeat protein phosphatase (PHLPP) was a novel target of miR-331-3p. Indeed, the miR-331-3p-mediated effects were antagonized by reexpression of PHLPP or mimicked by silencing of PHLPP. We further showed that miR-331-3p-mediated inhibition of PHLPP resulted in stimulation of protein kinase B (AKT) and subsequent epithelial mesenchymal transition (EMT). Finally, inhibition of miR-331-3p through a jetPEI-mediated delivery of anti-miR-331-3p vector resulted in marked inhibition of proliferation and metastasis of HCC in xenograft mice.

CONCLUSION

miR-331-3p promotes proliferation and EMT-mediated metastasis of HCC through suppression of PHLPP-mediated dephosphorylation of AKT. Our work implicates miR-331-3p as a potential prognostic biomarker and a novel therapeutic target.

The long noncoding RNA expression profile of hepatocellular carcinoma identified by microarray analysis

Background

Thousands of long noncoding RNAs (lncRNAs) have been reported in mammalian genomes. These RNAs represent an important subset of pervasive genes involved in a broad range of biological functions. Aberrant expression of lncRNAs is associated with many types of cancers. Here, in order to explore the potential lncRNAs involved in hepatocellular carcinoma (HCC) oncogenesis, we performed lncRNA gene expression profile analysis in 3 pairs of human HCC and adjacent non-tumor (NT) tissues by microarray.

Methodology

Differentially expressed lncRNAs and mRNAs were detected by human lncRNA microarray containing 33,045 lncRNAs and 30,215 coding transcripts. Bioinformatic analyses (gene ontology, pathway and network analysis) were applied for further study of these differentially expressed mRNAs. By qRT-PCR analysis in nineteen pairs of HCC and adjacent normal tissues, we found that eight lncRNAs were aberrantly expressed in HCC compared with adjacent NT tissues, which is consistent with microarray data.

Conclusions

We identified 214 lncRNAs and 338 mRNAs abnormally expressed in all three HCC tissues (Fold Change ≥2.0, P<0.05 and FDR <0.05) with the genome-wide lncRNAs and mRNAs expression profile analysis. The lncRNA-mRNA co-expression network was constructed, which may be used for predicting target genes of lncRNAs. Furthermore, we demonstrated for the first time that BC017743, ENST00000395084, NR_026591, NR_015378 and NR_024284 were up-regulated, whereas NR_027151, AK056988 and uc003yqb.1 were down-regulated in nineteen pairs of HCC samples compared with adjacent NT samples. Expression of seven lncRNAs was significantly correlated to their nearby coding genes. In conclusion, our results indicated that the lncRNA expression profile in HCC was significantly changed, and we identified a series of new hepatocarcinoma associated lncRNAs. These results provide important insights about the lncRNAs in HCC pathogenesis.

Single nucleotide polymorphism-specific regulation of matrix metalloproteinase-9 by multiple miRNAs targeting the coding exon

Microribonucleic acids (miRNAs) work with exquisite specificity and are able to distinguish a target from a non-target based on a single nucleotide mismatch in the core nucleotide domain. We questioned whether miRNA regulation of gene expression could occur in a single nucleotide polymorphism (SNP)-specific manner, manifesting as a post-transcriptional control of expression of genetic polymorphisms. In our recent study of the functional consequences of matrix metalloproteinase (MMP)-9 SNPs, we discovered that expression of a coding exon SNP in the pro-domain of the protein resulted in a profound decrease in the secreted protein. This missense SNP results in the N38S amino acid change and a loss of an N-glycosylation site. A systematic study demonstrated that the loss of secreted protein was due not to the loss of an N-glycosylation site, but rather an SNP-specific targeting by miR-671-3p and miR-657. Bioinformatics analysis identified 41 SNP-specific miRNA targeting MMP-9 SNPs, mostly in the coding exon and an extension of the analysis to chromosome 20, where the MMP-9 gene is located, suggesting that SNP-specific miRNAs targeting the coding exon are prevalent. This selective post-transcriptional regulation of a target messenger RNA harboring genetic polymorphisms by miRNAs offers an SNP-dependent post-transcriptional regulatory mechanism, allowing for polymorphic-specific differential gene regulation.

Hepatitis B virus X upregulates HuR protein level to stabilize HER2 expression in hepatocellular carcinoma cells

Hepatitis B virus- (HBV-) associated hepatocellular carcinoma (HCC) is the most common type of liver cancer. However, the underlying mechanism of HCC tumorigenesis is very complicated and HBV-encoded X protein (HBx) has been reported to play the most important role in this process. Activation of downstream signal pathways of epidermal growth factor receptor (EGFR) family is known to mediate HBx-dependent HCC tumor progression. Interestingly, HER2 (also known as ErbB2/Neu/EGFR2) is frequently overexpressed in HBx-expressing HCC patients and is associated with their poor prognosis. However, it remains unclear whether and how HBx regulates HER2 expression. In this study, our data showed that HBx expression increased HER2 protein level via enhancing its mRNA stability. The induction of RNA-binding protein HuR expression by HBx mediated the HER2 mRNA stabilization. Finally, the upregulated HER2 expression promoted the migration ability of HBx-expressing HCC cells. These findings deciphered the molecular mechanism of HBx-mediated HER2 upregulation in HBV-associated HCC.

The role of microRNAs in hepatocarcinogenesis: current knowledge and future prospects

MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate gene expression post-transcriptionally through complementary base pairing with thousands of messenger RNAs. Although the precise biological functions of individual miRNAs are still unknown, miRNAs are speculated to play important roles in diverse biological processes through fine regulation of their target gene expression. A growing body of data indicates the deregulation of miRNAs during hepatocarcinogenesis. In this review, we summarize recent findings regarding deregulated miRNA expression and their possible target genes in hepatocarcinogenesis, with emphasis on inflammation-related hepatocarcinogenesis. Because miRNA-based strategies are being applied to clinical therapeutics, precise knowledge of miRNA functions is crucial both scientifically and clinically. We discuss the current open questions from these points of view, which must be clarified in the near future.

MicroRNA-452 promotes tumorigenesis in hepatocellular carcinoma by targeting cyclin-dependent kinase inhibitor 1B

Dysregulation of miR-452 has been observed in many tumors, but its biological function in hepatocellular carcinoma (HCC) is still unknown. Our results showed that miR-452 expression is significantly increased in HCC tissues and HCC cell lines. We also found that overexpression of miR-452 dramatically accelerated proliferation, induced cell cycle from G1 to S transition, and blocked apoptosis of HCC cells. Migration and matrigel invasion assays indicated that miR-452 significantly promotes HepG2 and QGY-7703 cells migration and invasion in vitro. Further studies showed that miR-452 directly targets the 3'-untranslated region of cyclin-dependent kinase inhibitor 1B (CDKN1B), ectopic miR-452 expression suppressed CDKN1B expression on mRNA and protein level. Silencing CDKN1B by small interfering RNA resembled the phenotype resulting from ectopic miR-452 expression. This study provides new insights into the potential molecular mechanisms that miRNA-452 contributed to HCC.

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

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

Identification of predictive biomarkers for early diagnosis of larynx carcinoma based on microRNA expression data

The abnormal expression of microRNAs (miRNAs) plays a key role in tumorigenesis. In order to identify potential miRNA biomarkers for early diagnosis of larynx carcinoma, we employed a miRNA microarray technique and applied bioinformatic algorithms to characterize miRNA classifiers in early larynx carcinoma and normal esophageal mucosa tissue samples from 69 patients who were selected retrospectively for this study. We identified 47 miRNAs that were significantly differentially expressed in primary larynx tumor tissues compared to normal tissues using a SAM algorithm. Of these, 30 were up-regulated and 17 down-regulated in early larynx cancer, including hsa-miR-657, which was overexpressed, and hsa-miR-1287, which was underexpressed. These two candidate miRNA biomarkers were combined as a single classifier to recognize the biological characteristics in early larynx carcinoma. Real-time quantitative reverse-transcription PCR validated the microarray results in both trial and test samples. The hsa-miR-657-hsa-miR-1287 classifier displayed high sensitivity and specificity for discriminating between early larynx carcinoma and normal mucosa tissues, suggesting they may be suitable as potential predictive biomarkers for the early diagnosis of larynx carcinoma.

Hepatitis B virus inhibits apoptosis of hepatoma cells by sponging the MicroRNA 15a/16 cluster

Hepatitis B virus (HBV) causes chronic hepatitis in hundreds of millions of people worldwide, which can eventually lead to hepatocellular carcinoma (HCC). The molecular mechanisms underlying HBV persistence are not well understood. In this study, we found that HBV inhibited the chemotherapy drug etoposide-induced apoptosis of hepatoma cells. Further analysis revealed that HBV mRNAs possess a microRNA 15a/16 (miR-15a/16)-complementary site (HBV nucleotides [nt] 1362 to 1383) that acts as a sponge to bind and sequester endogenous miR-15a/16. Consequently, Bcl-2, known as the target of miR-15a/16, was upregulated in HBV-infected cells. The data from HBV-transgenic mice further confirmed that HBV transcripts cause the reduction of miR-15a/16 and increase of Bcl-2. More importantly, we examined the levels of HBV transcripts and miR-15a/16 in HBV-infected HCC from patients and found that the amount of HBV mRNA and the level of miR-15a/16 were negatively correlated. Consistently, the level of Bcl-2 mRNA was upregulated in HBV-infected patients. In conclusion, we identified a novel HBV mRNA-miR-15a/16-Bcl-2 regulatory pathway that is involved in inhibiting etoposide-induced apoptosis of hepatoma cells, which may contribute to facilitating chronic HBV infection and hepatoma development.

Clinical implications of microRNAs in liver cancer stem cells

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