From gene networks to drugs: systems pharmacology approaches for AUD

The alcohol research field has amassed an impressive number of gene expression datasets spanning key brain areas for addiction, species (humans as well as multiple animal models), and stages in the addiction cycle (binge/intoxication, withdrawal/negative effect, and preoccupation/anticipation). These data have improved our understanding of the molecular adaptations that eventually lead to dysregulation of brain function and the chronic, relapsing disorder of addiction. Identification of new medications to treat alcohol use disorder (AUD) will likely benefit from the integration of genetic, genomic, and behavioral information included in these important datasets. Systems pharmacology considers drug effects as the outcome of the complex network of interactions a drug has rather than a single drug-molecule interaction. Computational strategies based on this principle that integrate gene expression signatures of pharmaceuticals and disease states have shown promise for identifying treatments that ameliorate disease symptoms (called in silico gene mapping or connectivity mapping). In this review, we suggest that gene expression profiling for in silico mapping is critical to improve drug repurposing and discovery for AUD and other psychiatric illnesses. We highlight studies that successfully apply gene mapping computational approaches to identify or repurpose pharmaceutical treatments for psychiatric illnesses. Furthermore, we address important challenges that must be overcome to maximize the potential of these strategies to translate to the clinic and improve healthcare outcomes.

Niclosamide, an oral antihelmintic drug, exhibits antimetastatic activity in hepatocellular carcinoma cells through downregulating twist-mediated CD10 expression

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, especially, in eastern Asia, and its prognosis is poor once metastasis occurs. Niclosamide, a US Food and Drug Administration-approved antihelmintic drug, was shown to inhibit the growth of various cancers including HCC, but the effect of niclosamide on cell motility and the underlying mechanism have not yet been completely defined. The present study demonstrated that niclosamide, at 0-40 nM, concentration-dependently inhibited wound closure and the migratory/invasive capacities of human Huh7 and SK-Hep-1 HCC cells without exhibiting cytotoxicity. A protease array analysis showed that CD10 was dramatically downregulated in Huh7 cells after niclosamide treatment. Western blot and flow cytometric assays further demonstrated that CD10 expression was concentration-dependently downregulated in Huh7 and SK-Hep-1 cells after niclosamide treatment. Mechanistic investigations found that niclosamide suppressed Twist-mediated CD10 transactivation. Moreover, knockdown of CD10 expression by CD10 small interfering RNA in HCC cells suppressed cell migratory/invasive abilities and overexpression of CD10 relieved the migration inhibition induced by niclosamide. Taken together, our results indicated that niclosamide could be a potential agent for inhibiting metastasis of HCC, and CD10 is an important target of niclosamide for suppressing the motility of HCC cells.

EZH2 inhibition promotes methyl jasmonate-induced apoptosis of human colorectal cancer through the Wnt/β-catenin pathway

Methyl jasmonate potentially induces the differentiation of human myeloid leukemia cells and inhibits their proliferation; it may induce the differentiation and apoptosis of human lymphocytic leukemia cells, but does not exert a damaging effect on normal lymphocytes. In the present study, the anticancer effect of methyl jasmonate on human colorectal cancer cells was investigated. Cell viability and apoptosis was assessed using a Cell Counting kit-8 assay and flow cytometry, respectively. Methyl jasmonate suppressed cell viability and induced apoptosis in human colorectal cancer cells. Additionally, methyl jasmonate increased the activation of caspase-3, inhibited the expression levels of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) and the Wnt/β-catenin pathway in human colorectal cancer. Downregulation of EZH2 expression enhanced the anticancer effect of methyl jasmonate on human colorectal cancer cells through suppression of the Wnt/β-catenin pathway. Thus, EZH2 downregulation promotes the anticancer effect of methyl jasmonate by inducing apoptosis in human colorectal cancer cells through the Wnt/β-catenin pathway.

Microenvironment and tumor cells: two targets for new molecular therapies of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), is one of the most frequent human cancer and is characterized by a high mortality rate. The aggressiveness appears strictly related to the liver pathological background on which cancer develops. Inflammation and the consequent fibro/cirrhosis, derived from chronic injuries of several origins (viral, toxic and metabolic) and observable in almost all oncological patients, represents the most powerful risk factor for HCC and, at the same time, an important obstacle to the efficacy of systemic therapy. Multiple microenvironmental cues, indeed, play a pivotal role in the pathogenesis, evolution and recurrence of HCC as well as in the resistance to standard therapies observed in most of patients. The identification of altered pathways in cancer cells and of microenvironmental changes, strictly connected in pathogenic feedback loop, may permit to plan new therapeutic approaches targeting tumor cells and their permissive microenvironment, simultaneously.

Genome-Wide Expression Profiles Drive Discovery of Novel Compounds that Reduce Binge Drinking in Mice

Transcriptome-based drug discovery has identified new treatments for some complex diseases, but has not been applied to alcohol use disorder (AUD) or other psychiatric diseases, where there is a critical need for improved pharmacotherapies. High Drinking in the Dark (HDID-1) mice are a genetic model of AUD risk that have been selectively bred (from the HS/Npt line) to achieve intoxicating blood alcohol levels (BALs) after binge-like drinking. We compared brain gene expression of HDID-1 and HS/Npt mice, to determine a molecular signature for genetic risk for high intensity, binge-like drinking. Using multiple computational methods, we queried LINCS-L1000 (Library of Integrated Network-Based Cellular Signatures), a database containing gene expression signatures of thousands of compounds, to predict candidate drugs with the greatest potential to decrease alcohol consumption. Our analyses predicted novel compounds for testing, many with anti-inflammatory properties, providing further support for a neuroimmune mechanism of excessive alcohol drinking. We validated the top 2 candidates in vivo as a proof-of-concept. Terreic acid (a Bruton's tyrosine kinase inhibitor) and pergolide (a dopamine and serotonin receptor agonist) robustly reduced alcohol intake and BALs in HDID-1 mice, providing the first evidence for transcriptome-based drug discovery to target an addiction trait. Effective drug treatments for many psychiatric diseases are lacking, and the emerging tools and approaches outlined here offer researchers studying complex diseases renewed opportunities to discover new or repurpose existing compounds and expedite treatment options.

The diverse origins of circulating cell-free DNA in the human body: a critical re-evaluation of the literature

Since the detection of cell-free DNA (cfDNA) in human plasma in 1948, it has been investigated as a non-invasive screening tool for many diseases, especially solid tumours and foetal genetic abnormalities. However, to date our lack of knowledge regarding the origin and purpose of cfDNA in a physiological environment has limited its use to more obvious diagnostics, neglecting, for example, its potential utility in the identification of predisposition to disease, earlier detection of cancers, and lifestyle-induced epigenetic changes. Moreover, the concept or mechanism of cfDNA could also have potential therapeutic uses such as in immuno- or gene therapy. This review presents an extensive compilation of the putative origins of cfDNA and then contrasts the contributions of cellular breakdown processes with active mechanisms for the release of cfDNA into the extracellular environment. The involvement of cfDNA derived from both cellular breakdown and active release in lateral information transfer is also discussed. We hope to encourage researchers to adopt a more holistic view of cfDNA research, taking into account all the biological pathways in which cfDNA is involved, and to give serious consideration to the integration of in vitro and in vivo research. We also wish to encourage researchers not to limit their focus to the apoptotic or necrotic fraction of cfDNA, but to investigate the intercellular messaging capabilities of the actively released fraction of cfDNA and to study the role of cfDNA in pathogenesis.

LGR5 and BMI1 Increase Pig Intestinal Epithelial Cell Proliferation by Stimulating WNT/β-Catenin Signaling

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) and B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI1) are markers of fast-cycling and quiescent intestinal stem cells, respectively. To determine the functions of these proteins in large animals, we investigated their effects on the proliferation of intestinal epithelial cells from pigs. Our results indicated that LGR5 and BMI1 are highly conserved proteins and that the pig proteins have greater homology with the human proteins than do mouse proteins. Overexpression of either LGR5 or BMI1 promoted cell proliferation and WNT/β-catenin signaling in pig intestinal epithelial cells (IPEC-J2). Moreover, the activation of WNT/β-catenin signaling by recombinant human WNT3A protein increased cell proliferation and LGR5 and BMI1 protein levels. Conversely, inhibition of WNT/β-catenin signaling using XAV939 reduced cell proliferation and LGR5 and BMI1 protein levels. This is the first report that LGR5 and BMI1 can increase proliferation of pig intestinal epithelial cells by activating WNT/β-catenin signaling.

Current and Future Treatment of Hepatocellular Carcinoma: An Updated Comprehensive Review

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related mortality. The principal treatment is surgical resection or liver transplantation, depending on whether the patient is a suitable transplant candidate. However, in most patients with HCC the diagnosis is often late, thereby excluding the patients from definitive surgical resection. Medical treatment includes sorafenib, which is the most commonly used systemic therapy; although, it has been shown to only minimally impact patient survival by several months. Chemotherapy and radiotherapy are generally ineffective. Due to the poor prognosis of patients with HCC, newer treatments are needed with several being in development, either in pre-clinical or clinical studies. In this review article, we provide an update on the current and future medical and surgical management of HCC.

Personalised drug repositioning for Clear Cell Renal Cell Carcinoma using gene expression

Reversal of cancer gene expression is predictive of therapeutic potential and can be used to find new indications for existing drugs (drug repositioning). Gene expression reversal potential is currently calculated, in almost all studies, by pre-aggregating all tumour samples into a single group signature or a limited number of molecular subtype signatures. Here, we investigate whether drug repositioning based on individual tumour sample gene expression signatures outperforms the use of tumour group and subtype signatures. The tumour signatures were created using 534 tumour samples and 72 matched normal samples from 530 clear cell renal cell carcinoma (ccRCC) patients. More than 20,000 drug signatures were extracted from the CMAP and LINCS databases. We show that negative enrichment of individual tumour samples correlated (Spearman's rho = 0.15) much better with the amount of differentially expressed genes in drug signatures than with the tumour group signature (Rho = 0.08) and the 4 tumour subtype signatures (Rho 0.036-0.11). Targeted drugs used against ccRCC, such as sirolimus and temsirolimus, which could not be identified with the pre-aggregated tumour signatures could be recovered using individual sample analysis. Thus, drug repositioning can be personalized by taking into account the gene expression profile of the individual's tumour sample.

Reduced hydroxymethylation characterizes medulloblastoma while TET and IDH genes are differentially expressed within molecular subgroups

INTRODUCTION

Medulloblastoma (MB) is an embryonal tumour that originates from genetic deregulation of cerebellar developmental pathways and is classified into 4 molecular subgroups: SHH, WNT, group 3, and group 4. Hydroxymethylation levels progressively increases during cerebellum development suggesting a possibility of deregulation in MB pathogenesis. The aim of this study was to investigate global hydroxymethylation levels and changes in TET and IDH gene expression in MB samples compared to control cerebellum samples.

METHODS

The methods utilized were qRT-PCR for gene expression, dot-blot and immunohistochemistry for global hydroxymethylation levels and sequencing for the investigation of IDH mutations.

RESULTS

Our results show that global hydroxymethylation level was decreased in MB, and low 5hmC level was associated with the presence of metastasis. TET1 expression levels were decreased in the WNT subgroup, while TET3 expression levels were decreased in the SHH subgroup. Reduced TET3 expression levels were associated with the presence of events such as relapse and death. Higher expression of IDH1 was observed in MB group 3 samples, whereas no mutations were detected in exon 4 of IDH1 and IDH2.

CONCLUSION

These findings suggest that reduction of global hydroxymethylation levels, an epigenetic event, may be important for MB development and/or maintenance, representing a possible target in this tumour and indicating a possible interaction of TET and IDH genes with the developmental pathways specifically activated in the MB subgroups. These genes could be specific targets and markers for each subgroup.

The role of enhancer of zeste homolog 2: From viral epigenetics to the carcinogenesis of hepatocellular carcinoma

Nowadays, epigenetics covers a crucial role in different fields of science. The enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2), is a big proponent of how epigenetic changes can affect the initiation and progression of several diseases. Through its catalytic activity, responsible for the tri-methylation of lysine 27 of the histone H3 (H3K27me3), EZH2 is a good target for both diagnosis and therapy of different pathologies. A large number of studies have demonstrated its crucial role in cancer initiation and progression. Nevertheless, only recently its function in virus diseases has been uncovered; therefore, EZH2 can be an important promoter of viral carcinogenesis. This review explores the role of EZH2 in viral epigenetics based on recent progress that demonstrated the role of this protein in virus environment. In particular, the review focuses on EZH2 behavior in Hepatitis B Virus, analyzing its role in the rise of Hepatocellular Carcinoma.

Liquid biopsies: DNA methylation analyses in circulating cell-free DNA

Analysis of patient's materials like cells or nucleic acids obtained in a minimally invasive or noninvasive manner through the sampling of blood or other body fluids serves as liquid biopsies, which has huge potential for numerous diagnostic applications. Circulating cell-free DNA (cfDNA) is explored as a prognostic or predictive marker of liquid biopsies with the improvements in genomic and molecular methods. DNA methylation is an important epigenetic marker known to affect gene expression. cfDNA methylation detection is a very promising approach as abnormal distribution of DNA methylation is one of the hallmarks of many cancers and methylation changes occur early during carcinogenesis. This review summarizes the various investigational applications of cfDNA methylation and its oxidized derivatives as biomarkers for cancer diagnosis, prenatal diagnosis and organ transplantation monitoring. The review also provides a brief overview of the technologies for cfDNA methylation analysis based on next generation sequencing.

DNA methylation as a genomic marker of exposure to chemical and environmental agents

Recent progress in interpreting comprehensive genetic and epigenetic profiles for human cellular states has contributed new insights into the developmental origins of disease, elucidated novel signalling pathways and enhanced drug discovery programs. A similar comprehensive approach to decoding the epigenetic readouts from chemical challenges in vivo would yield new paradigms for monitoring and assessing environmental exposure in model systems and humans.

Nrf2-p62 autophagy pathway and its response to oxidative stress in hepatocellular carcinoma

Deregulation of autophagy is proposed to play a key pathogenic role in hepatocellular carcinoma (HCC), the most common primary malignancy of the liver and the third leading cause of cancer death. Autophagy is an evolutionarily conserved catabolic process activated to degrade and recycle cell's components. Under stress conditions, such as oxidative stress and nutrient deprivation, autophagy is an essential survival pathway that operates in harmony with other stress response pathways. These include the redox-sensitive transcription complex Nrf2-Keap1 that controls groups of genes with roles in detoxification and antioxidant processes, intermediary metabolism, and cell cycle regulation. Recently, a functional association between a dysfunctional autophagy and Nrf2 pathway activation has been identified in HCC. This appears to occur through the physical interaction of the autophagy adaptor p62 with the Nrf2 inhibitor Keap1, thus leading to increased stabilization and transcriptional activity of Nrf2, a key event in reprogramming metabolic and stress response pathways of proliferating hepatocarcinoma cells. These emerging molecular mechanisms and the therapeutic perspective of targeting Nrf2-p62 interaction in HCC are discussed in this paper along with the prognostic value of autophagy in this type of cancer.

DNA methylation in human diseases

Even though the importance of epigenetics was first recognized in light of its role in tissue development, an increasing amount of evidence has shown that it also plays an important role in the development and progression of many common diseases. We discuss some recent findings on one representative epigenetic modification, DNA methylation, in some common diseases. While many new risk factors have been identified through the population-based epigenetic epidemiologic studies on the role of epigenetics in common diseases, this relatively new field still faces many unique challenges. Here, we describe those promises and unique challenges of epigenetic epidemiological studies and propose some potential solutions.

Kanglaite reverses multidrug resistance of HCC by inducing apoptosis and cell cycle arrest via PI3K/AKT pathway

BACKGROUND

Multidrug resistance (MDR) frequently contributes to the failure of chemotherapeutic treatments in patients diagnosed with hepatocellular carcinoma (HCC). Revealing the molecular mechanism of MDR is indispensable for the development of effective chemotherapeutic drugs.

PURPOSE

Due to the low-toxicity modulators to inhibit MDR, we considered that Kanglaite (KLT) is a potential agent for reversing MDR in HCC.

MATERIALS AND METHODS

BEL-7402/5-fluorouracil (5-FU) and HepG2/adriamycin (ADM) were analyzed for cell viability, colony formation assay, cell scratch assay, and cell cycle analysis and apoptosis assay by flow cytometry. The expression of PARP, caspase-3, Bax, Bcl-2, CDC25C, Cyclin B1 and phosphorylation of PTEN, PI3K, and AKT in HepG2/ADM cells were detected by western blotting.

RESULTS

The proliferation of drug-resistant cell lines BEL-7402/5-FU and HepG2/ADM pretreated with KLT was significantly inhibited when compared with drug alone. KLT could increase the accumulation of ADM in HepG2/ADM cells. In this study, we found that KLT treatment notably reduced cell viability, induced apoptosis and cell cycle arrest in human HepG2/ADM and BEL-7402/5-FU cells, and effectively reversed the MDR by p-glycoprotein (P-gp) inhibition. Moreover, KLT decreased the phosphorylation of AKT and PI3K in KLT-treated HepG2/ADM cells. These data together implied that KLT might reverse drug resistance in HCC by blocking the PI3K/AKT signaling.

CONCLUSION

We demonstrated that KLT reversed MDR of human HCC by inducing apoptosis and cell cycle arrest via the PI3K/AKT signaling pathway.

Developing DNA methylation-based diagnostic biomarkers

An emerging paradigm shift for disease diagnosis is to rely on molecular characterization beyond traditional clinical and symptom-based examinations. Although genetic alterations and transcription signature were first introduced as potential biomarkers, clinical implementations of these markers are limited due to low reproducibility and accuracy. Instead, epigenetic changes are considered as an alternative approach to disease diagnosis. Complex epigenetic regulation is required for normal biological functions and it has been shown that distinctive epigenetic disruptions could contribute to disease pathogenesis. Disease-specific epigenetic changes, especially DNA methylation, have been observed, suggesting its potential as disease biomarkers for diagnosis. In addition to specificity, the feasibility of detecting disease-associated methylation marks in the biological specimens collected noninvasively, such as blood samples, has driven the clinical studies to validate disease-specific DNA methylation changes as a diagnostic biomarker. Here, we highlight the advantages of DNA methylation signature for diagnosis in different diseases and discuss the statistical and technical challenges to be overcome before clinical implementation.

Effect of mitochondrial uncouplers niclosamide ethanolamine (NEN) and oxyclozanide on hepatic metastasis of colon cancer

Metabolism of cancer cells is characterized by aerobic glycolysis, or the Warburg effect. Aerobic glycolysis reduces pyruvate flux into mitochondria, preventing a complete oxidation of glucose and shunting glucose to anabolic pathways essential for cell proliferation. Here we tested a new strategy, mitochondrial uncoupling, for its potential of antagonizing the anabolic effect of aerobic glycolysis and for its potential anticancer activities. Mitochondrial uncoupling is a process that facilitates proton influx across the mitochondrial inner membrane without generating ATP, stimulating a futile cycle of acetyl- CoA oxidation. We tested two safe mitochondrial uncouplers, NEN (niclosamide ethanolamine) and oxyclozanide, on their metabolic effects and anti-cancer activities. We used metabolomic NMR to examine the effect of mitochondrial uncoupling on glucose metabolism in colon cancer MC38 cells. We further tested the anti-cancer effect of NEN and oxyclozanide in cultured cell models, APCmin/+ mouse model, and a metastatic colon cancer mouse model. Using a metabolomic NMR approach, we demonstrated that mitochondrial uncoupling promotes pyruvate influx to mitochondria and reduces various anabolic pathway activities. Moreover, mitochondrial uncoupling inhibits cell proliferation and reduces clonogenicity of cultured colon cancer cells. Furthermore, oral treatment with mitochondrial uncouplers reduces intestinal polyp formation in APCmin/+ mice, and diminishes hepatic metastasis of colon cancer cells transplanted intrasplenically. Our data highlight a unique approach for targeting cancer cell metabolism for cancer prevention and treatment, identified two prototype compounds, and shed light on the anti-cancer mechanism of niclosamide.

Behind the curtain of non-coding RNAs; long non-coding RNAs regulating hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most common and aggressive cancers worldwide. HCC is the fifth common malignancy in the world and the second leading cause of cancer death in Asia. Long non-coding RNAs (lncRNAs) are RNAs with a length greater than 200 nucleotides that do not encode proteins. lncRNAs can regulate gene expression and protein synthesis in several ways by interacting with DNA, RNA and proteins in a sequence specific manner. They could regulate cellular and developmental processes through either gene inhibition or gene activation. Many studies have shown that dysregulation of lncRNAs is related to many human diseases such as cardiovascular diseases, genetic disorders, neurological diseases, immune mediated disorders and cancers. However, the study of lncRNAs is challenging as they are poorly conserved between species, their expression levels aren’t as high as that of mRNAs and have great interpatient variations. The study of lncRNAs expression in cancers have been a breakthrough as it unveils potential biomarkers and drug targets for cancer therapy and helps understand the mechanism of pathogenesis. This review discusses many long non-coding RNAs and their contribution in HCC, their role in development, metastasis, and prognosis of HCC and how to regulate and target these lncRNAs as a therapeutic tool in HCC treatment in the future.

Epigenetic basis of hepatocellular carcinoma: A network-based integrative meta-analysis

AIM

To identify the key epigenetically modulated genes and pathways in HCC by performing an integrative meta-analysis of all major, well-annotated and publicly available methylation datasets using tools of network analysis.

METHODS

PubMed and Gene Expression Omnibus were searched for genome-wide DNA methylation datasets. Patient clinical and demographic characteristics were obtained. DNA methylation data were integrated using the Ingenuity Pathway Analysis, a software package for visualizing and analyzing biological networks. Pathway enrichment analysis was performed using IPA, which also provides literature-driven and computationally-predicted annotations for significant association of genes to curated molecular pathways.

RESULTS

From an initial 928 potential abstracts, we identified and analyzed 11 eligible high-throughput methylation datasets representing 354 patients. A significant proportion of studies did not provide concomitant clinical data. In the promoter region, HIST1H2AJ and SPDYA were the most commonly methylated, whereas HRNBP3 gene was the most commonly hypomethylated. ESR1 and ERK were central genes in the principal networks. The pathways most associated with the frequently methylated genes were G-protein coupled receptor and cAMP-mediated signalling.

CONCLUSION

Using an integrative network-based analysis approach of genome-wide DNA methylation data of both the promoter and body of genes, we identified G-protein coupled receptor signalling as the most highly associated with HCC. This encompasses a diverse range of cancer pathways, such as the PI3K/Akt/mTOR and Ras/Raf/MAPK pathways, and is therefore supportive of previous literature on gene expression in HCC. However, there are novel targetable genes such as HIST1H2AJ that are epigenetically modified, suggesting their potential as biomarkers and for therapeutic targeting of the HCC epigenome.

2-Phenylquinazolinones as dual-activity tankyrase-kinase inhibitors

Tankyrases (TNKSs) are enzymes specialized in catalyzing poly-ADP-ribosylation of target proteins. Several studies have validated TNKSs as anti-cancer drug targets due to their regulatory role in Wnt/β-catenin pathway. Recently a lot of effort has been put into developing more potent and selective TNKS inhibitors and optimizing them towards anti-cancer agents. We noticed that some 2-phenylquinazolinones (2-PQs) reported as CDK9 inhibitors were similar to previously published TNKS inhibitors. In this study, we profiled this series of 2-PQs against TNKS and selected kinases that are involved in the Wnt/β-catenin pathway. We found that they were much more potent TNKS inhibitors than they were CDK9/kinase inhibitors. We evaluated the compound selectivity to tankyrases over the ARTD enzyme family and solved co-crystal structures of the compounds with TNKS2. Comparative structure-based studies of the catalytic domain of TNKS2 with selected CDK9 inhibitors and docking studies of the inhibitors with two kinases (CDK9 and Akt) revealed important structural features, which could explain the selectivity of the compounds towards either tankyrases or kinases. We also discovered a compound, which was able to inhibit tankyrases, CDK9 and Akt kinases with equal µM potency.

Down-regulation of Krüppel-like factor-4 by microRNA-135a-5p promotes proliferation and metastasis in hepatocellular carcinoma by transforming growth factor-β1

Krüppel-like Factor-4 (KLF4) is a zinc finger transcription factor which plays an important role in cell cycle, proliferation and apoptosis. In Hepatocellular Carcinoma (HCC), the function of KLF4 has been characterized as tumor suppressor. However, the mechanism remains largely unknown. In this study, we demonstrated that TGF-β1 down-regulated KLF4 by activating miR-135a-5p. MiR-135a-5p promoted proliferation and metastasis in HCC cells by direct targeting KLF4 both in vitro and in vivo. In addition, miR-135a-5p expression was up-regulated in clinical HCC tissues, and was inversely correlated with the expression of KLF4. Taken together, our data indicated that TGF-β1 down-regulated KLF4 by activating miR-135a-5p, promoting proliferation and metastasis in HCC.

Organic Solute Transporter α-β Protects Ileal Enterocytes From Bile Acid-Induced Injury

BACKGROUND & AIMS

Ileal bile acid absorption is mediated by uptake via the apical sodium-dependent bile acid transporter (ASBT), and export via the basolateral heteromeric organic solute transporter α-β (OSTα-OSTβ). In this study, we investigated the cytotoxic effects of enterocyte bile acid stasis in Ostα-/- mice, including the temporal relationship between intestinal injury and initiation of the enterohepatic circulation of bile acids.

METHODS

Ileal tissue morphometry, histology, markers of cell proliferation, gene, and protein expression were analyzed in male and female wild-type and Ostα-/- mice at postnatal days 5, 10, 15, 20, and 30. Ostα-/-Asbt-/- mice were generated and analyzed. Bile acid activation of intestinal Nrf2-activated pathways was investigated in Drosophila.

RESULTS

As early as day 5, Ostα-/- mice showed significantly increased ileal weight per length, decreased villus height, and increased epithelial cell proliferation. This correlated with premature expression of the Asbt and induction of bile acid-activated farnesoid X receptor target genes in neonatal Ostα-/- mice. Expression of reduced nicotinamide adenine dinucleotide phosphate oxidase-1 and Nrf2-anti-oxidant responsive genes were increased significantly in neonatal Ostα-/- mice at these postnatal time points. Bile acids also activated Nrf2 in Drosophila enterocytes and enterocyte-specific knockdown of Nrf2 increased sensitivity of flies to bile acid-induced toxicity. Inactivation of the Asbt prevented the changes in ileal morphology and induction of anti-oxidant response genes in Ostα-/- mice.

CONCLUSIONS

Early in postnatal development, loss of Ostα leads to bile acid accumulation, oxidative stress, and a restitution response in ileum. In addition to its essential role in maintaining bile acid homeostasis, Ostα-Ostβ functions to protect the ileal epithelium against bile acid-induced injury. NCBI Gene Expression Omnibus: GSE99579.

WNT Signaling in Cardiac and Vascular Disease

WNT signaling is an elaborate and complex collection of signal transduction pathways mediated by multiple signaling molecules. WNT signaling is critically important for developmental processes, including cell proliferation, differentiation and tissue patterning. Little WNT signaling activity is present in the cardiovascular system of healthy adults, but reactivation of the pathway is observed in many pathologies of heart and blood vessels. The high prevalence of these pathologies and their significant contribution to human disease burden has raised interest in WNT signaling as a potential target for therapeutic intervention. In this review, we first will focus on the constituents of the pathway and their regulation and the different signaling routes. Subsequently, the role of WNT signaling in cardiovascular development is addressed, followed by a detailed discussion of its involvement in vascular and cardiac disease. After highlighting the crosstalk between WNT, transforming growth factor-β and angiotensin II signaling, and the emerging role of WNT signaling in the regulation of stem cells, we provide an overview of drugs targeting the pathway at different levels. From the combined studies we conclude that, despite the sometimes conflicting experimental data, a general picture is emerging that excessive stimulation of WNT signaling adversely affects cardiovascular pathology. The rapidly increasing collection of drugs interfering at different levels of WNT signaling will allow the evaluation of therapeutic interventions in the pathway in relevant animal models of cardiovascular diseases and eventually in patients in the near future, translating the outcomes of the many preclinical studies into a clinically relevant context.

Targeting the Wnt/beta-catenin pathway in cancer: Update on effectors and inhibitors

The Wnt/beta-catenin pathway is a family of proteins that is implicated in many vital cellular functions such as stem cell regeneration and organogenesis. Several intra-cellular signal transduction pathways are induced by Wnt, notably the Wnt/beta-catenin dependent pathway or canonical pathway and the non-canonical or beta-catenin-independent pathway; the latter includes the Wnt/Ca2+ and Planar Cell Polarity pathway (PCP). Wnt activation occurs at the intestinal crypt floor, and is critical to optimal maintenance of stem cells. Colorectal cancers show evidence of Wnt signaling pathway activation and this is associated with loss of function of the tumor regulator APC. Wnt activation has been observed in breast, lung, and hematopoietic malignancies and contributes to tumor recurrence. The Wnt pathway cross talks with the Notch and Sonic Hedgehog pathways, which has implications for therapeutic interventions in cancers. There are significant challenges in targeting the Wnt pathway, including finding agents that are efficacious without damaging the system of normal somatic stem cell function in cellular repair and tissue homeostasis. Here, we comprehensively review the Wnt pathway and its interactions with the Notch and Sonic Hedgehog pathways. We present the state of the field in effectors and inhibitors of Wnt signaling, including updates on clinical trials in various cancers with inhibitors of Wnt, Notch, and Sonic Hedgehog.

Molecular basis of hepatocellular carcinoma induced by hepatitis C virus infection

Present study outlines a comprehensive view of published information about the underlying mechanisms operational for progression of chronic hepatitis C virus (HCV) infection to development of hepatocellular carcinoma (HCC). These reports are based on the results of animal experiments and human based studies. Although, the exact delineated mechanism is not yet established, there are evidences available to emphasize the involvement of HCV induced chronic inflammation, oxidative stress, insulin resistance, endoplasmic reticulum stress, hepato steatosis and liver fibrosis in the progression of HCV chronic disease to HCC. Persistent infection with replicating HCV not only initiates several liver alterations but also creates an environment for development of liver cancer. Various studies have reported that HCV acts both directly as well as indirectly in promoting this process. Whereas HCV related proteins, like HCV core, E1, E2, NS3 and NS5A, modulate signal pathways dysregulating cell cycle and cell metabolism, the chronic infection produces similar changes in an indirect way. HCV is an RNA virus and does not integrate with host genome and therefore, HCV induced hepatocarcinogenesis pursues a totally different mechanism causing imbalance between suppressors and proto-oncogenes and genomic integrity. However, the exact mechanism of HCC inducement still needs a full understanding of various steps involved in this process.

SMAD7 loci contribute to risk of hepatocellular carcinoma and clinicopathologic development among Chinese Han population

Genome-wide association studies (GWAS) have identified three loci at 18q21 (rs4939827, rs7240004, and rs7229639), which maps to SMAD7 loci, were associated with risk of diseases of the digestive system. However, their associations with hepatocellular carcinoma (HCC) risk remain unknown. A case-control study was conducted to assess genetic associations with HCC risk and clinicopathologic development among Chinese Han population. Three SNPs were genotyped among 1,000 HCC cases and 1,000 controls using Sequenom Mass-ARRAY technology. We observed statistically significant associations for the three SMAD7 loci and HCC risk. Each copy of minor allele was associated with a 1.24–1.36 fold increased risk of HCC. We also found that significant differences were observed between rs4939827 and clinical TNM stage and vascular invasion, as well as rs7240004 and vascular invasion. We also established a genetic risk score (GRS) by summing the risk alleles. The GRS was significantly associated with increased risk of HCC and vascular invasion. Our data revealed the SMAD7 loci is associated with HCC susceptibility and its clinicopathologic development.

Inhibition of WNT signaling reduces differentiation and induces sensitivity to doxorubicin in human malignant neuroblastoma SH-SY5Y cells

Neuroblastoma is one of the most common cancers in infancy, arising from the neuroblasts during embryonic development. This cancer is difficult to treat and resistance to chemotherapy is often found; therefore, clinical trials of novel therapeutic approaches, such as targeted-cancer signaling, could be an alternative for a better treatment. WNT signaling plays significant roles in the survival, proliferation, and differentiation of human neuroblastoma. In this report, WNT signaling of a malignant human neuroblastoma cell line, SH-SY5Y cells, was inhibited by XAV939, a specific inhibitor of the Tankyrase enzyme. XAV939 treatment led to the reduction of β-catenin within the cells, confirming its inhibitory effect of WNT. The inhibition of WNT signaling by XAV939 did not affect cell morphology, survival, and proliferation; however, the differentiation and sensitivity to anticancer drugs of human neuroblastoma cells were altered. The treatment of XAV939 resulted in the downregulation of mature neuronal markers, including β-tubulin III, PHOX2A, and PHOX2B, whereas neural progenitor markers (PAX6, TFAP2α, and SLUG) were upregulated. In addition, the combination of XAV939 significantly enhanced the sensitivity of SH-SY5Y and IMR-32 cells to doxorubicin in both 2D and 3D culture systems. Microarray gene expression profiling suggested numbers of candidate target genes of WNT inhibition by XAV939, in particular, p21, p53, ubiquitin C, ZBED8, MDM2, CASP3, and FZD1, and this explained the enhanced sensitivity of SH-SY5Y cells to doxorubicin. Altogether, these results proposed that the altered differentiation of human malignant neuroblastoma cells by inhibiting WNT signaling sensitized the cells to anticancer drugs. This approach could thus serve as an effective treatment option for aggressive brain malignancy.

Towards natural mimetics of metformin and rapamycin

Aging is now at the forefront of major challenges faced globally, creating an immediate need for safe, widescale interventions to reduce the burden of chronic disease and extend human healthspan. Metformin and rapamycin are two FDA-approved mTOR inhibitors proposed for this purpose, exhibiting significant anti-cancer and anti-aging properties beyond their current clinical applications. However, each faces issues with approval for off-label, prophylactic use due to adverse effects. Here, we initiate an effort to identify nutraceuticals-safer, naturally-occurring compounds-that mimic the anti-aging effects of metformin and rapamycin without adverse effects. We applied several bioinformatic approaches and deep learning methods to the Library of Integrated Network-based Cellular Signatures (LINCS) dataset to map the gene- and pathway-level signatures of metformin and rapamycin and screen for matches among over 800 natural compounds. We then predicted the safety of each compound with an ensemble of deep neural network classifiers. The analysis revealed many novel candidate metformin and rapamycin mimetics, including allantoin and ginsenoside (metformin), epigallocatechin gallate and isoliquiritigenin (rapamycin), and withaferin A (both). Four relatively unexplored compounds also scored well with rapamycin. This work revealed promising candidates for future experimental validation while demonstrating the applications of powerful screening methods for this and similar endeavors.

Gankyrin: a novel promising therapeutic target for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as fifth common malignancies and third common cause of cancer-related death worldwide. The identification of various mechanisms which are involved in hepatocarcinogenesis contributes in finding a variety of cellular and molecular targets for HCC diagnosis, prevention and therapy. Among various identified targets in HCC pathogenesis, Gankyrin is a crucial oncoprotein that is up-regulated in HCC and plays a pivotal role in the initiation and progression of the HCC. Oncogenic role of Gankyrin has been found to stem from inhibition of two ubiquitous tumour suppressor proteins, retinoblastoma protein (pRb) and P53, and also modulation of several vital cellular signalling pathways including Wnt/β-Catenin, NF-κB, STAT3/Akt, IL-1β/IRAK-1 and RhoA/ROCK. As a result, Gankyrin can be considered as a potential candidate for diagnosis and treatment of HCC. In this review, we summarized the physiological function and the significant role of Gankyrin as an important therapeutic target in HCC.

Circulating cell-free high mobility group AT-hook 2 mRNA as a detection marker in the serum of colorectal cancer patients

BACKGROUND

Detection of circulating cell-free mRNA serves as noninvasive tools for cancer diagnosis. As an oncofetal protein, HMGA2 (high mobility group AT-hook 2) is upregulated in colorectal cancer (CRC) tissues. However, it is not clear whether the increased levels of circulating cell-free HMGA2 mRNA functions as potential biomarkers for improved diagnosis of CRC.

METHODS

To assess its clinical significance in diagnosis and prediction, we evaluated serum levels of circulating HMGA2 mRNA in CRC patients and in healthy controls. In this study, 83 CRC patients and 11 normal controls were enrolled in this study. We used real-time quantitative reverse transcription-PCR to evaluate the plasma mRNA levels of HMGA2 and analyze the correlation between their expression and clinicopathologic characteristics.

RESULTS

We found that the levels of HMGA2 mRNA were significantly higher in CRC patients compared with healthy volunteers. The patients with right-sided CRC, colon cancer, positive nerve infiltration, positive vascular invasion, negative microsatellite instability (MSI), and increasing in serum carbohydrate antigen (CA) 199 had higher levels of plasma HMGA2 mRNA. A strong positive correlation between circulating cell-free HMGA2 mRNA and CA199 level in serum was found in our study. Furthermore, statistical analysis revealed that levels of HMGA2 mRNA in plasma and in tumors were strictly correlated.

CONCLUSIONS

Collectively, our data suggested that cell-free HMGA2 mRNA in plasma might function as a novel diagnostic marker for CRC.

MEK inhibitor, PD98059, promotes breast cancer cell migration by inducing β-catenin nuclear accumulation

Abnormal activation of the RAF/MEK/ERK signaling pathway has been observed in breast cancer. Thus, a number of MEK inhibitors have been designed as one treatment option for breast cancer. Although some studies have found that these MEK inhibitors inhibit the growth of a variety of human cancer cells, some trials have shown that the use of MEK inhibitors as a treatment for breast cancer does not adequately improve survival for unknown reasons. In the present study, MEK inhibitor PD98059 was used to evaluate its anticancer effects on human breast cancer MCF-7 and MDA-MB-231 cells and to explore the possible mechanism of action. Our results revealed that MEK inhibitor PD98059 exhibited antiproliferative effects in a dose- and time-dependent manner in MCF-7 and MDA-MB-231 breast cancer cells. Conversely, incubation of MCF-7 and MDA-MB-231 cells with PD98059 promoted their migration. Further investigation disclosed that the enhanced ability of migration promoted by PD98059 was dependent on β-catenin nuclear translocation in the MCF-7 and MDA-MB‑231 cells. Subsequent experiments documented that activation of EGFR signaling induced by PD98059 increased the amount of β-catenin in the nucleus. Taken together, our findings may elucidate a possible mechanism explaining the ineffectiveness of MEK inhibitors in breast cancer treatment and improve our understanding of the role of MEK in cancer.

Tankyrase inhibitors suppress hepatocellular carcinoma cell growth via modulating the Hippo cascade

Previous data indicate that Tankyrase inhibitors exert anti-growth functions in many cancer cell lines due to their ability to inactivate the YAP protooncogene. In the present manuscript, we investigated the effect of Tankyrase inhibitors on the growth of hepatocellular carcinoma (HCC) cell lines and the molecular mechanisms involved. For this purpose, we performed cell proliferation assay by colony-forming ability in seven human HCC cells subjected to XAV-939 and G007-LK Tankyrase inhibitors. Noticeably, the two Tankyrase inhibitors suppressed the HCC cell growth in a dose-dependent manner. Furthermore, we found that Tankyrase inhibitors synergized with MEK and AKT inhibitors to suppress HCC cell proliferation. At the molecular level, Tankyrase inhibitors significantly decreased YAP protein levels, reduced the expression of YAP target genes, and inhibited YAP/TEAD luciferase reporter activity. In addition, Tankyrase inhibitors administration was accompanied by upregulation of Angiomotin-like 1 (AMOTL1) and Angiomotin-like 2 (AMOTL2) proteins, two major negative regulators of YAP. Altogether, the present data indicate that XAV-939 and G007-LK Tankyrase inhibitors could suppress proliferation of hepatocellular carcinoma cells and downregulate YAP/TAZ by stabilizing AMOTL1 and AMOTL2 proteins, thus representing new potential anticancer drugs against hepatocellular carcinoma.

CDX2 upregulates SLC26A3 gene expression in intestinal epithelial cells

SLC26A3 [downregulated in adenoma (DRA)] plays a key role in mammalian intestinal NaCl absorption, in that it mediates apical membrane Cl^-/[Formula: see text] exchange. DRA function and expression are significantly decreased in diarrhea associated with inflammatory bowel disease. DRA is also considered to be a marker of cellular differentiation and is predominantly expressed in differentiated epithelial cells. Caudal-type homeobox protein-2 (CDX2) is known to regulate genes involved in intestinal epithelial differentiation and proliferation. Reduced expression of both DRA and CDX2 in intestinal inflammation prompted us to study whether the DRA gene is directly regulated by CDX2. Our initial studies utilizing CDX2 knockout (CDX2^fV/fV;Cre⁺) mice showed a marked reduction in DRA mRNA and protein levels in proximal and distal colon. In silico analysis of the DRA promoter showed two consensus sites for CDX2 binding. Therefore, we utilized Caco-2 cells as an in vitro model to examine if DRA is a direct target of CDX2 regulation. siRNA-mediated silencing of CDX2 in Caco-2 cells resulted in a marked (~50%) decrease in DRA mRNA and protein levels, whereas ectopic overexpression of CDX2 upregulated DRA expression and also stimulated DRA promoter activity, suggesting transcriptional regulation. Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated direct binding of CDX2 to one of the two putative CDX2 binding sites in the DRA promoter (+645/+663). In summary, our studies, for the first time, demonstrate transcriptional regulation of DRA expression by CDX2, implying that reduced expression of DRA in inflammatory bowel disease-associated diarrhea may, in part, be due to downregulation of CDX2 in the inflamed mucosa.NEW & NOTEWORTHY SLC26A3 [downregulated in adenoma (DRA)] mediates intestinal luminal NaCl absorption and is downregulated in inflammatory bowel disease-associated diarrhea. Since both DRA and caudal-type homeobox protein-2 (CDX2) are reduced in intestinal inflammation and the DRA promoter harbors CDX2 binding sites, we examined whether the DRA gene is regulated by CDX2. Our studies, for the first time, demonstrate transcriptional regulation of DRA expression by CDX2 via direct binding to the DRA promoter, suggesting that reduced expression of DRA in inflammatory bowel disease-associated diarrhea could, in part, be attributed to downregulation of CDX2.

Bidirectional reporter assay using HAL promoter and TOPFLASH improves specificity in high-throughput screening of Wnt inhibitors

Constitutive activation of Wnt signaling plays an important role in colorectal and liver tumorigenesis. Cell-based assays using synthetic TCF/LEF (T-cell factor/lymphoid enhancer factor) reporters, as readouts of β-catenin/TCF-dependent transcriptional activity, have contributed greatly to the discovery of small molecules that modulate Wnt signaling. In the present study, we report a novel screening method, called a bidirectional dual reporter assay. Integrated transcriptome analysis identified a histidine ammonia-lyase gene (HAL) that was negatively regulated by β-catenin/TCF-dependent transcriptional activity. We leveraged a promoter region of the HAL gene as another transcriptional readout of Wnt signaling. Cells stably expressing both an optimized HAL reporter and the TCF/LEF reporter enabled bidirectional reporter activities in response to Wnt signaling. Increased HAL reporter activity and decreased TCF/LEF reporter activity were observed simultaneously in the cells when β-catenin/TCF7L2 was inhibited. Notably, this method could decrease the number of false positives observed when screening an inhibitor library compared with the conventional TCF/LEF assay. We found that Brefeldin A, a disruptor of the Golgi apparatus, inhibited the Wnt/β-catenin signaling pathway. The utility of our system could be expanded to examine other disease-associated pathways beyond the Wnt/β-catenin signaling pathway.

Norcantharidin combined with Coix seed oil synergistically induces apoptosis and inhibits hepatocellular carcinoma growth by downregulating regulatory T cells accumulation

The immune system plays a critical role in exerts effects in the growth and progression of hepatocellular carcinoma (HCC), which needs interacting approaches for effective therapy. In this study, we have found that the Norcantharidin (NCTD) + Coix lacryma-jobi seed oil (CLSO) combination exhibited more potent antitumor effects in an terms of cytotoxicity and apoptotic induction in human HepG2 and HepG2/ADM cells than NCTD or CLSO alone. In vivo, administration of NCTD+CLSO combinations significantly suppressed the formation of tumor in Hepal-1 hepatoma-bearing mice. Furthermore, we found that the in vitro co-cultures of HepG2 or HepG2/ADM cells with PBMCs from healthy donors led to an increase in the number of CD4 + CD25 + T cells. This increase was down-regulated by the combination effectively. Down-regulation of FoxP3 mRNA and protein expression occurred during the combination in the co-cultures. The amount of Tregs of Hepal-1 hepatoma-bearing mice was significantly decreased in the combination treated group. The combination down-regulated the expression of FoxP3, CTLA-4 and Tregs related cytokine (TGF-β and IL-10) in the serum of tumor bearing mice. Taken together, these results suggest that the most valuable aspect of the NCTD+CLSO combined use improves the anti-tumor activity and regulates tumor infiltrating Tregs.

LHX6, An Independent Prognostic Factor, Inhibits Lung Adenocarcinoma Progression through Transcriptional Silencing of β-catenin

Introduction: Our previous study identified LIM homeobox domain 6 (LHX6) as a frequently epigenetically silenced tumor-suppressor gene in lung cancer. However, its clinical value has never been evaluated, and the in-depth anti-tumor mechanism remains unclear.

Methods: Public database was used for lung cancer, lung adenocarcinoma and lung squamous carcinoma patients and tissue microarray data was used for lung adenocarcinoma patients to study prognostic outcome of LHX6 expression by Kaplan-Meier and Cox-regression analysis. In vitro proliferation, metastasis and in vivo nude mice model were used to evaluate the anti-tumor effect of LHX6 on lung adenocarcinoma cell lines. The mechanisms were explored using western blot, TOP/FOP flash assays and luciferase reporter assays. LHX6 expression and clinical stages data were collected from The Cancer Genome Atlas database (TCGA).

Results: Expression of LHX6 was found to be a favorable independent prognostic factor for overall survival (OS) of total lung adenocarcinoma patients (P=0.014) and patients with negative lymph nodes status (P=0.014) but not related the prognostic outcome of lung squamous cell carcinoma patients. The expression status of LHX6 significantly correlated to histological grade (P<0.01), tumor size (P=0.026), lymph node status (P=0.039) and clinical stages (P<0.01) of lung adenocarcinoma patients. Functionally, LHX6 inhibited the proliferation and metastasis of lung adenocarcinoma cells in vitro and in vivo. Furthermore, LHX6 suppressed the Wnt/β-catenin pathway through transcriptionally silencing the expression of β-catenin, and the promoter region (-1161 bp to +27 bp) was crucial for its inhibitory activity.

Conclusions: Our data indicate that the expression of LHX6 may serve as a favorable prognostic biomarker for lung adenocarcinoma patients and provide a novel mechanism of LHX6 involving in the tumorigenesis of lung adenocarcinoma.

Identification and validation of soluble carrier family expression signature for predicting poor outcome of renal cell carcinoma

The soluble carrier (SLC) family plays an important role in cell metabolism. The purpose of the current study was to screen SLCs as potential prognostic factors in clear cell renal cell carcinoma (ccRCC). A total of 509 patients with ccRCC from The Cancer Genome Atlas (TCGA) cohort were enrolled in this study. The expression profile of SLCs was obtained from the TCGA RNAseq database. Metadata of the TCGA cohort, including age, sex, TNM stage, tumor grade, American Joint Committee on Cancer stage, laterality, and overall survival, were collected. Univariate and multivariate Cox proportional hazards regression models were used to analyze the relative factors. Prognosis-associated genes were further validated in a Fudan University Shanghai Cancer Center (FUSCC) cohort consisting of 178 patients. Among a total of 364 SLC transporters, 61 were independent predictors of ccRCC patient overall survival. Among the 61 SLC transporters, 26 were significantly downregulated and 23 were significantly upregulated in tumor tissues compared with non-malignant kidney tissues. Analyses of two open source, RNA expression data sets on sunitinib response revealed that SLC10A2 was downregulated in tyrosine kinase inhibitor-resistant samples. We validated SLC10A2 expression in the FUSCC cohort and showed that SLC10A2 expression was an independent prognostic predictor of overall survival of ccRCC (hazard ratio=0.432, 95% CI: 0.204-0.915). Our results identified a number of associations of SLC gene expression with prognosis of ccRCC patients, indicating that these genes may represent possible oncogenes that could serve as therapeutic targets of ccRCC.

Bioinformatics prediction and experimental validation of microRNA-20a targeting Cyclin D1 in hepatocellular carcinoma

Hepatocellular carcinoma is the major form of primary liver cancer, which is the second and sixth leading cause of cancer-related death in men and women, respectively. Extensive research indicates that Wnt/β-catenin signaling pathway, which plays a pivotal role in growth, development, and differentiation of hepatocellular carcinoma, is one of the major signaling pathways that is dysregulated in hepatocellular carcinoma. Cyclin D1 is a proto-oncogene and is one of the major regulators of Wnt signaling pathway, and its overexpression has been detected in various types of cancers including hepatocellular carcinoma. Using several validated bioinformatic databases, we predicted that the microRNAs are capable of targeting 3′-untranslated region of Cyclin D1 messenger RNA. According to the results, miR-20a was selected as the highest ranking microRNA targeting Cyclin D1 messenger RNA. Luciferase assay was recruited to confirm bioinformatic prediction results. Cyclin D1 expression was first assessed by quantitative real-time polymerase chain reaction in HepG2 cell line. Afterward, HepG2 cells were transduced by lentiviruses containing miR-20a. Then, the expression of miR-20a and Cyclin D1 was evaluated. The results of luciferase assay demonstrated targeting of 3′-untranslated region of Cyclin D1 messenger RNA by miR-20a. Furthermore, 238-fold decline in Cyclin D1 expression was observed after lentiviral induction of miR-20a in HepG2 cells. The results highlighted a considerable effect of miRNA-20a induction on the down-regulation of Cyclin D1 gene. Our results suggest that miR-20a can be used as a novel candidate for therapeutic purposes and a biomarker for hepatocellular carcinoma diagnosis.

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.

Integrated analysis of microRNA and mRNA expression profiles in HBx-expressing hepatic cells

AIM

To identify the miRNA-mRNA regulatory network in hepatitis B virus X (HBx)-expressing hepatic cells.

METHODS

A stable HBx-expressing human liver cell line L02 was established. The mRNA and miRNA expression profiles of L02/HBx and L02/pcDNA liver cells were identified by RNA-sequencing analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed to investigate the function of candidate biomarkers, and the relationship between miRNA and mRNA was studied by network analysis.

RESULTS

Compared with L02/pcDNA cells, 742 unregulated genes and 501 downregulated genes were determined as differentially expressed in L02/HBx cells. Gene ontology analysis suggested that the differentially expressed genes were relevant to different biological processes. Concurrently, 22 differential miRNAs were also determined in L02/HBx cells. Furthermore, integrated analysis of miRNA and mRNA expression profiles identified a core miRNA-mRNA regulatory network that is correlated with the carcinogenic role of HBx.

CONCLUSION

Collectively, the miRNA-mRNA network-based analysis could be useful to elucidate the potential role of HBx in liver cell malignant transformation and shed light on the underlying molecular mechanism and novel therapy targets for hepatocellular carcinoma.

MiR-30b-5p acts as a tumor suppressor, repressing cell proliferation and cell cycle in human hepatocellular carcinoma

MicroRNAs have been verified to participate in various biological behaviors of different tumors, via multiple signaling pathways. Many kinds of microRNAs in hepatocellular carcinoma have been researched. However, miR-30b-5p hasn't been included. Our study aim at the impacts of miR-30b-5p on HCC and the pathway it mediating. The results showed miR-30b-5p was significant downregulated in HCC tissues and cell lines. With clinical data, we've discovered miR-30b-5p was correlated with several clinical pathological characteristics, such as survival time, tumor size, HBV infected, pathological stage, differentiation and intrahepatic metastasis. Also we illustrated miR-30b-5p repressed cell proliferation and cell cycle of HCC cell lines. For a further study, we figured out that miR-30b-5p mediated DNMT3A to repress proliferation, meanwhile it targeted USP37 for decelerating cell cycle. This discovery inferred miR-30b-5p a potential favorable biomarker and therapeutic target for HCC diagnosis and treatment.

High expression of miR-105-1 positively correlates with clinical prognosis of hepatocellular carcinoma by targeting oncogene NCOA1

Increasing evidence supports that microRNA (miRNA) plays a significant functional role in cancer progression by directly regulating respective targets. In this study, the expression levels of miR-105-1 and its target gene were analyzed using genes microarray and hierarchical clustering analysis followed by validation with quantitative RT-PCR in hepatocellular carcinoma (HCC) and normal liver tissues. We examined the expression of nuclear receptor coactivator 1 (NCOA1), the potential target gene of miR-105-1, following the transfection of miR-105-1 mimics or inhibitors. Our results showed that miR-105-1 was downregulated in HCC tissues when compared with normal liver tissues and patients with lower miR-105-1 expression had shorter overall survival (OS) and progression free survival (PFS). Moreover, NCOA1 was confirmed to be a direct target of miR-105-1. Furthermore, concomitant high expression of NCOA1 and low expression of miR-105-1 correlated with a shorter median OS and PFS in HCC patients. In conclusion, our results provide the first evidence that NCOA1 is a direct target of miR-105-1 suggesting that NCOA1 and miR-105-1 may have potential prognostic value and may be useful as tumor biomarkers for the diagnosis of HCC patients.

Scutellaria barbata D. Don extract inhibits the tumor growth through down-regulating of Treg cells and manipulating Th1/Th17 immune response in hepatoma H22-bearing mice

BACKGROUND

Previous studies showed Scutellaria barbata D. Don extract (SBE) is a potent inhibitor in hepatoma and could improve immune function of hepatoma H22-bearing mice. However, the immunomodulatory function of SBE on the tumor growth of hepatoma remains unclear. This study aimed to investigate the anti-tumor effects of SBE on hepatoma H22-bearing mice and explore the underlying immunomodulatory function.

METHODS

The hepatoma H22-bearing mice were treated by SBE for 30 days. The effect of SBE on the proliferation of HepG2 cells in vitro, the growth of transplanted tumor, the cytotoxicity of natural killer (NK) cells in spleen, the amount of CD4⁺CD25⁺Foxp3⁺ Treg cells and Th17 cells in tumor tissue, and the levels of IL-10, TGF-β, IL-17A, IL-2, and IFN-γ in serum of the hepatoma H22-bearing mice was observered. IL-17A was injected to the SBE treated mice from day 9 post H22 inoculation to examine its effect on tumor growth.

RESULTS

SBE treatment inhibited the proliferation of HepG2 cells in vitro with a dose-dependent manner and significantly suppressed the tumor growth of hepatoma H22-bearing mice. Meanwhile, it increased NK cells' cytotoxicity in spleen, down-regulated the amount of CD4⁺CD25⁺Foxp3⁺ Treg cells and Th17 cells in tumor tissue, and decreased IL-10, TGF-β, and IL-17A levels (P < 0.01) whereas increased IL-2 and IFN-γ levels (P < 0.01) in the serum of hepatoma H22-bearing mice. Moreover, administration of recombinant mouse IL-17A reversed the anti-tumor effects of SBE.

CONCLUSION

SBE could inhibit the proliferation of HepG2 cells in vitro. Meanwhile, SBE also could inhibit the growth of H22 implanted tumor in hepatoma H22-bearing mice, and this function might be associated with immunomodulatory activity through down-regulating of Treg cells and manipulating Th1/Th17 immune response.

Developing drugs that target the Wnt pathway: recent approaches in cancer and neurodegenerative diseases

INTRODUCTION

Wnt/β-catenin signaling is an evolutionarily conserved pathway that has a crucial role in embryonic and adult life. Dysregulation of Wnt/β-catenin pathway has been associated with various diseases, including cancer and neurodegenerative disorders, including Parkinson's disease (PD). Several molecular components of the signaling have been proposed as innovative targets for cancer therapy, and very recently, some of them have been also evaluated as potential therapeutic targets for PD. Areas covered: This review focuses on the role of Wnt/β-catenin pathway in the pathogenensis of cancer and PD, examining some recent therapeutic approaches that are ongoing in preclinical and clinical studies. The possibilities that this signaling offers for diagnosis and prognosis of neoplastic diseases, and the concerns of targeting this pathway are also discussed. Expert opinion: Despite the stimulating results obtained in preclinical studies on cancer and other disease models, the clinical experience with Wnt modulators is still in its infancy, and is mainly restricted to anticancer therapy. Even with concerns of the safety of drugs targeting Wnt signaling, the attention of researchers worldwide is increasing to this issue in terms of their therapeutic potential for diseases such as PD, for which no cure exists.

BHX Inhibits the Wnt Signaling Pathway by Suppressing β-catenin Transcription in the Nucleus

BHX (N-(4-hydroxybenzyl)-1,3,4-triphenyl-4,5-dihydro-1H-pyrazole-5-carboxamide), a Wnt signaling pathway inhibitor, effectively inhibits tumor cell growth, but the underlying mechanism is unclear. Thus, we aim to investigate the effects and associated mechanism of BHX action on A549 and MCF-7 cell lines. In our study, MTT(3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide) and xenograft model assay indicated that cell growth was inhibited by BHX at a range of concentrations in vitro and in vivo. The expression of β-catenin and Wnt signaling pathway downstream target genes were decreased evidently under BHX treatment. Flow cytometry also revealed that BHX treatment significantly induced G1 arrest. Further analysis showed that BHX lowered the transcriptional level of β-catenin. In conclusion, BHX inhibited the nuclear synthesis of β-catenin, thereby suppressing the Wnt signaling pathway and further inhibiting tumor growth and proliferation.

UHRF2 decreases H3K9ac expression by interacting with it through the PHD and SRA/YDG domain in HepG2 hepatocellular carcinoma cells

Ubiquitin-like with PHD and ring finger domains 2 (UHRF2) is a multi-domain E3 ubiquitin ligase which is involved in epigenetic regulation and plays an essential role in tumorigenesis. However, the role of UHRF2 in histone H3 acetylation has not yet been fully elucidated and few studies have reported its role in hepatocellular carcinoma (HCC). In this study, we examined the correlation between UHRF2 and acetylated H3 in HCC. Immunohistochemistry and western blot analysis demonstrated that the levels of histone H3 lysine 9 acetylation (H3K9ac) and histone H3 lysine 14 acetylation (H3K14ac) were higher in the HCC tissues and HepG2 HCC cells compared with the adjacent non-tumor tissues and L02 normal cells. The level of UHRF2 was higher in the HCC tissues compared with the adjacent non-tumor tissues, but its expression did not exhibit a significant difference between the HepG2 HCC cells and the L02 normal cells. In addition, when comparing the HCC tissues, a higher expression of UHRF2 correlated with a lower expression of H3K9ac in the HCC tissues. The overexpression of UHRF2 increased the expression of H3K9ac in L02 normal cells (P<0.01), but decreased the expression of H3K9ac in HepG2 cancer cells (P<0.05). Moreover, immunofluorescence staining and co-immunoprecipitation assay indicated that UHRF2 co-localized and interacted with H3K9ac in L02 and HepG2 cells and the plant homeodomain (PHD) finger domain was the key domain for UHRF2 directly binding to H3K9ac. Taken together, these results suggest that UHRF2 decreases the expression of H3K9ac in HepG2 HCC cells and interacts with it through the PHD domain.