MicroRNA-27a-3p targets FoxO signalling to induce tumour-like phenotypes in bile duct cells.

BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a heterogeneous and lethal malignancy, the molecular origins of which remain poorly understood. MicroRNAs (miRs) target diverse signalling pathways, functioning as potent epigenetic regulators of transcriptional output. We aimed to characterise miRNome dysregulation in CCA, including its impact on transcriptome homeostasis and cell behaviour. METHODS: Small RNA sequencing was performed on 119 resected CCAs, 63 surrounding liver tissues, and 22 normal livers. High-throughput miR mimic screens were performed in three primary human cholangiocyte cultures. Integration of patient transcriptomes and miRseq together with miR screening data identified an oncogenic miR for characterization. MiR-mRNA interactions were investigated by a luciferase assay. MiR-CRISPR knockout cells were generated and phenotypically characterized in vitro (proliferation, migration, colony, mitochondrial function, glycolysis) and in vivo using subcutaneous xenografts. RESULTS: In total, 13% (140/1,049) of detected miRs were differentially expressed between CCA and surrounding liver tissues, including 135 that were upregulated in tumours. CCA tissues were characterised by higher miRNome heterogeneity and miR biogenesis pathway expression. Unsupervised hierarchical clustering of tumour miRNomes identified three subgroups, including distal CCA-enriched and IDH1 mutant-enriched subgroups. High-throughput screening of miR mimics uncovered 71 miRs that consistently increased proliferation of three primary cholangiocyte models and were upregulated in CCA tissues regardless of anatomical location, among which only miR-27a-3p had consistently increased expression and activity in several cohorts. FoxO signalling was predominantly downregulated by miR-27a-3p in CCA, partially through targeting of FOXO1. MiR-27a knockout increased FOXO1 levels in vitro and in vivo, impeding tumour behaviour and growth. CONCLUSIONS: The miRNomes of CCA tissues are highly remodelled, impacting transcriptome homeostasis in part through regulation of transcription factors like FOXO1. MiR-27a-3p arises as an oncogenic vulnerability in CCA. IMPACT AND IMPLICATIONS: Cholangiocarcinogenesis entails extensive cellular reprogramming driven by genetic and non-genetic alterations, but the functional roles of these non-genetic events remain poorly understood. By unveiling global miRNA upregulation in patient tumours and their functional ability to increase proliferation of cholangiocytes, these small non-coding RNAs are implicated as critical non-genetic alterations promoting biliary tumour initiation. These findings identify possible mechanisms for transcriptome rewiring during transformation, with potential implications for patient stratification.

Genomic perturbations reveal distinct regulatory networks in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma remains a highly heterogeneous malignancy that has eluded effective patient stratification to date. The extent to which such heterogeneity can be influenced by individual driver mutations remains to be evaluated. Here, we analyzed genomic (whole-exome sequencing, targeted exome sequencing) and epigenomic data from 496 patients and used the three most recurrently mutated genes to stratify patients (IDH, KRAS, TP53, "undetermined"). Using this molecular dissection approach, each subgroup was determined to possess unique mutational signature preferences, comutation profiles, and enriched pathways. High-throughput drug repositioning in seven patient-matched cell lines, chosen to reflect the genetic alterations specific for each patient group, confirmed in silico predictions of subgroup-specific vulnerabilities linked to enriched pathways. Intriguingly, patients lacking all three mutations ("undetermined") harbored the most extensive structural alterations, while isocitrate dehydrogenase mutant tumors displayed the most extensive DNA methylome dysregulation, consistent with previous findings. CONCLUSION: Stratification of intrahepatic cholangiocarcinoma patients based on occurrence of mutations in three classifier genes (IDH, KRAS, TP53) revealed unique oncogenic programs (mutational, structural, epimutational) that influence pharmacologic response in drug repositioning protocols; this genome dissection approach highlights the potential of individual mutations to induce extensive molecular heterogeneity and could facilitate advancement of therapeutic response in this dismal disease. (Hepatology 2018).

IL-6 deficiency alters spatial memory in 4- and 24-month-old mice.

Significance of interleukin 6 (IL-6) deficiency in cognitive processes was evaluated in 4- and 24-month-old C57BL/6J IL-6-deficient (IL-6 KO) and control (WT) mice in Morris water maze (MWM), holeboard test (HB) and elevated plus maze (EPM). During 3-day learning escape latency time (ELT) was longer in IL-6 KO than in WT mice, however their swimming was slower, floating longer, and path length did not differ. The comparison of ELT and the distance traveled between the first and the third learning day within each group revealed significant decrease of ELT in all groups with the highest difference in 4-month-old WT mice, and significant decrease of distance traveled only in both groups of WT mice. In a single probe trial, performed 24 h after the last learning session, there were no major differences in the absolute values of ELT, but ELT turned out to be significantly shorter in both IL-6 KO groups, when it was compared to the ELT on the last learning day, indicating on better memory retrieval. In HB test only significant increase in number of rearings in aged WT mice, and in EPM significant prolongation of open arm time and higher number of open arm entries in 4-month-old IL-6 KO mice were observed. Results of HB and EPM tests showed that alterations of learning and reference memory observed in MWM were specific to cognition. Attenuation of learning ability in young adult IL-6-deficient mice assessed in MWM suggests that physiological level of IL-6 is involved in mechanisms engaged in proper memory formation, and it may also indicate on the importance of IL-6 signaling in brain development. Maintained on similar level in both 4- and 24-month-old IL-6 KO mice learning ability and its attenuation in 24-month-old vs 4-month-old WT mice indicates on slower age-related memory decline in mice not expressing IL-6. Better performance of IL-6 KO mice in the probe trial points to their reference memory improvement and may also indicate that IL-6 plays a role in mechanism responsible for cognitive flexibility.

Molecular Pathogenesis and Current Therapy in Intrahepatic Cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) comprises one of the most rapidly evolving cancer types. An underlying chronic inflammatory liver disease that precedes liver cancer development for several decades and creates a pro-oncogenic microenvironment frequently impairs progress in therapeutic approaches. Depending on the cellular target of malignant transformation, a large spectrum of molecular and morphological patterns is observed. As such, it is crucial to advance our existing understanding of the molecular pathogenesis of iCCA, particularly its genomic heterogeneity, to improve current clinical strategies and patient outcome. This was achieved for other cancers, such as breast carcinoma, facilitated by the delineation of patient subsets and of precision therapies. In iCCA, many questions persevere as to the evolutionary process and cellular origin of the initial transforming event, the context of tumor plasticity and the causative features driving the disease. Molecular profiling and pathological techniques have begun to underline persistent alterations that may trigger inherited drug resistance (a hallmark of hepatobiliary and pancreatic cancers), metastasis and disease recurrence. In this review, we will focus on the key molecular achievements that are currently advancing the characterization and stratification of iCCA. We will discuss current clinical practice and how genomic achievements may advance diagnosis and therapy as well as ultimately improve patient outcome.

HBeAg-positive hepatitis delta: virological patterns and clinical long-term outcome.

BACKGROUND AND AIMS: The presence of the hepatitis B virus (HBV)-eAg in patients with hepatitis B is associated with higher HBV replication and with an increased risk to develop liver-related clinical endpoints defined as liver related death, liver transplantation, development of hepatocellular carcinoma and hepatic decompensation. The aim of this study was to investigate the role of HBeAg in patients co-infected with the hepatitis D virus (HDV). METHODS: We studied virological markers of HBV and HDV infection and as well as biochemical and clinical features of liver disease in a cohort of 534 anti-HDV-positive patients. In addition, we compared the clinical long-term outcome of HBeAg-positive HDV-infected patients with HBeAg-negative control patients matched for age, gender and baseline-MELD score. RESULTS: HBeAg-positive hepatitis delta was detected in 71 of 534 patients (13.3%). HBeAg positivity was associated with a higher biochemical disease activity and higher HBsAg levels in HDV co-infected patients. Sixty one per cent of the HBeAg-positive HDV-infected patients presented with HBV DNA levels below 2000 IU/ml, at least once during follow-up. Both HBeAg-positive and -negative patients showed a similar severe clinical long-term course with about half of the patients developing a liver-related clinical complication after a median follow-up period of 51 months (range: 9-193 months). CONCLUSIONS: HBV DNA levels are low in both HBeAg-negative and HBeAg-positive patients suggesting suppressive effects of HDV on HBV irrespective of the phase of HBV infection. The clinical long-term outcome of HBeAg-positive patients is not different to HBeAg-negative patients infected with the HDV.

Ancestrally Duplicated Conserved Noncoding Element Suggests Dual Regulatory Roles of HOTAIR in cis and trans.

HOTAIR was proposed to regulate either HoxD cluster genes in trans or HoxC cluster genes in cis, a mechanism that remains unclear. We have identified a 32-nucleotide conserved noncoding element (CNE) as HOTAIR ancient sequence that likely originated at the root of vertebrate. The second round of whole-genome duplication resulted in one copy of the CNE within HOTAIR and another copy embedded in noncoding transcript of HOXD11. Paralogous CNEs underwent compensatory mutations, exhibit sequence complementarity with respect to transcripts directionality, and have high affinity in vitro. The HOTAIR CNE resembled a poised enhancer in stem cells and an active enhancer in HOTAIR-expressing cells. HOTAIR expression is positively correlated with HOXC11 in cis and negatively correlated with HOXD11 in trans. We propose a dual modality of HOTAIR regulation where transcription of HOTAIR and its embedded enhancer regulates HOXC11 in cis and sequence complementarity between paralogous CNEs suggests HOXD11 regulation in trans.

The role of interleukin-6 in intracellular signal transduction after chronic ß-adrenergic stimulation in mouse myocardium.

INTRODUCTION: Inflammatory mediators play an important role in development and progression of cardiovascular disease. Both adrenergic stimulation and high levels of interleukin-6 (IL-6) indicate an unfavorable outcome in patients with myocardial infarction or heart failure. Understanding the interaction between ß-adrenergic stimulation and IL-6 in the myocardium may contribute to developing more effective treatments. The aim of this study was to verify the role of IL-6 in the effects of ß-adrenergic stimulation in activating selected intracellular signaling pathways in mouse myocardium. MATERIAL AND METHODS: Experiments were performed on 12-week-old male mice: 16 C57BL/6JIL6­/­TMKopf (IL-6 KO) and 17 C57BL/6J (WT). Animals received intraperitoneal injections of isoproterenol (ISO, 50 mg/kg) or placebo (0.9% NaCl) once a day for 16 days. The phosphorylation of STAT3 (signal transducer and activator of transcription 3), ERK1/2 (extracellular-regulated kinases 1/2), Akt1/2/3, p-38, c-Raf and expression of SOCS3 (suppressor of cytokine signaling 3), PIAS1/3 (protein inhibitors of activated STAT) was assessed by western blotting in the myocardium 24 h after the last injection. Evaluation of gene expression downstream of these pathways was performed by real-time PCR. RESULTS: Chronic ISO treatment leads to increased fibrosis of the myocardium in mice lacking IL-6, which is accompanied by increased activity of ERK1/2, p38 and reduced expression of SOCS3. Administration of ISO in IL-6 KO animals intensified gene expression of proteins activated by MAPK/ERK (myc; CEBPB; BMP4; Fasn; Tank), while it reduced expression of genes repressed by ERK 1/2 (Wisp1, Wnt1). CONCLUSIONS: IL-6 plays an important role in regulating the activation of MAPK pathways in the mouse myocardium in response to chronic ß-adrenergic stimulation.

Altered effector functions of NK cells in chronic hepatitis C are associated with IFNL3 polymorphism.

Interferon α-mediated effector functions of NK cells may contribute to the control of HCV replication and the pathogenesis of liver disease. The single-nucleotide polymorphism rs12979860 near IFNL3 (previously known as IL28B) is important in response to IFN-α treatment and in spontaneous resolution of acute hepatitis C. The role of the IFNL3 polymorphism in NK cell function is unclear. Thus, we investigated the role of IFNL3 polymorphism in type I IFN-dependent regulation of NK cell functions in patients with cHC and healthy control subjects. We demonstrated a marked polarization of NK cells toward cytotoxicity in response to IFN-α stimulation in patients with hepatitis C. That TRAIL up-regulation was present, particularly in patients with the IFNL3-TT allele, was supported by a shift in the pSTAT-1:pSTAT-4 ratios toward pSTAT-1. In patients bearing the IFNL3-TT allele, NK cell effector function correlated with liver disease activity. In contrast, higher cytokine production of NK cells was observed in healthy individuals with the IFNL3-CC genotype, which may support spontaneous HCV clearance in acute infection. Overall, these findings show that the role of NK cells may differ in chronic infection vs. early antiviral defense and that the IFNL3 genotype differentially influences NK cell function.

Transcriptional and post-transcriptional regulation of CCN genes in failing heart.

BACKGROUND: CCN family of proteins has been implicated in various processes in cardiovascular physiology and pathology, including angiogenesis, regeneration and fibrosis. In this study we assessed long term changes of CCN1 and CCN2 gene products abundance in the failing ventricular myocardium. METHODS: Male, 12-14-weeks-old C57BL6/J and C57BL6/J (IL-6-/-) mice were used. To assess short term changes, a transient reversible ischemia model was utilized. Heart failure was caused by ligation of anterior descending coronary artery. The presence of systolic dysfunction was confirmed by echocardiography and left ventricular ANP RNA expression. Molecular analysis was performed on left ventricular samples from animals sacrificed 12-14 weeks after infarction. Western blotting and QT-PCR were used to investigate abundance of CCN proteins and RNAs, respectively. RESULTS: Short ischemia resulted in marked increase of CCN1 transcript. However, three months after myocardial infarction (MI), remote myocardium showed a markedly increased expression of CCN1 protein, but not RNA. In the case of CCN2, the RNA was distinctly up-regulated, whereas the protein presented only modest, non-significant increase in failing myocardium. Expression of CCN2 RNA closely correlated with expression of ANP. Long-term telmisartan administration after infarction decreased the expression of CCN1 protein. Interleukin 6 (IL-6) deficiency caused increased CCN2 protein abundance in control animals, but the difference was absent after MI. Infarction did not increase CCN1 protein in the hearts of IL-6 deficient mice. CONCLUSION: CCN genes are activated in heart failure. Their regulation is multidimensional both transcriptional and posttranscriptional. The involved pathways include angiotensin II and IL-6.

Hepatitis B virus DNA quantification with the three-in-one (3io) method allows accurate single-step differentiation of total HBV DNA and cccDNA in biopsy-size liver samples.

BACKGROUND: Hepatitis B virus (HBV) replicates via reverse transcription converting its partially double stranded genome into the covalently closed circular DNA (cccDNA). The long-lasting cccDNA serves as a replication intermediate in the nuclei of hepatocytes. It is an excellent, though evasive, parameter for monitoring the course of liver disease and treatment efficiency. OBJECTIVE: To develop and test a new approach for HBV DNA quantification in serum and small-size liver samples. STUDY DESIGN: The p3io plasmid contains an HBV fragment and human ß-actin gene (hACTB) as a standard. Respective TaqMan probes were labeled with different fluorescent dyes. A triplex real-time PCR for simultaneous quantification of total HBV DNA, cccDNA and hACTB could be established. RESULTS: Three-in-one method allows simultaneous analysis of 3 targets with a lower limit of quantification of 48 copies per 20 µl PCR reaction and a wide range of linearity (R(2)>0.99, p<0.0001) for all measured sequences. The method showed a pan-genotypic specificity among genotypes A-F with serum DNA samples from HBV infected patients. Total HBV DNA and cccDNA could be quantified in 32 and 22 of 33 FFPE preserved liver specimens, respectively. Total HBV DNA concentrations quantified by the 3io method remained comparable with Cobas TaqMan HBV Test v2.0. CONCLUSIONS: The three-in-one protocol allows the single step quantification of viral DNA in samples from different sources. Therefore lower sample input, faster data acquisition, a lowered error and significantly lower costs are the advantages of the method.

Analysis of gene expression profiles in tympanic membrane following perforation using PCR Array in rats--preliminary investigation.

OBJECTIVES: The goal of this work was to identify genes, known to be involved in the skin wound healing, that express differentially in the healthy and injured tympanic membrane (TM), and designate the molecules potentially beneficial for treatment of TM perforation. The molecular mechanisms controlling the course of TM regeneration are far from being elucidated. METHODS: Twenty rats had their tympanic membranes perforated, while four served as a control. Animals were sacrificed on either days 1, 2, 3, 5 and 10 post injury, and TMs were immediately dissected and frozen in liquid nitrogen. Total TM RNA was isolated and reversely transcribed. qPCR was performed using Rat Wound Healing RT(2) Profiler PCR Array (QIAGEN) containing primers for 84 genes. RESULTS: Statistically significant changes in the expression of 42 genes were found in various stages of TM healing. The increased expression of genes taking part in the inflammatory reaction (interleukin 6, granulocyte and macrophage chemotactic proteins) was observed from day 2. The expression of several genes of extracellular matrix components and their remodeling enzymes was also changed. Among growth factor genes: Vegfa, Igf1 and Hbegf showed increased expression at the beginning of the healing process, while Hgf expression was highest on day 3. CONCLUSIONS: Several changes in the expression of genes involved in remodeling of extracellular matrix point to important role of connective tissue in TM healing. The molecules accelerating this process, like HbEGF and HGF, seem to be good candidates for further evaluation of their possible use in clinical treatment.

CCN1 expression in interleukin-6 deficient mouse kidney in experimental model of heart failure.

Chronic heart failure often leads to worsening of the renal function. Mediators of this process include inflammatory and neuroendocrine factors. CCN1 (Cyr 61), a member of growth factor-inducible immediate early genes, which modulates inflammation and fibrogenesis, is excreted with urine in the early phase of acute renal injury and may be involved in the pathogenesis of the cardiorenal syndrome. The aim of the study was to evaluate CCN1 protein abundance and localization in the kidney of IL-6-deficient C57BL/6J (IL-6 KO) mice and respective wild-type (WT) animals in basal conditions and in animals with chronic heart failure twelve weeks after myocardial infarction. Age- and sex-matched mice from both strains subjected to sham operation served as controls. One group of WT animals subjected to myocardial infarction was treated with antagonist of AT1 receptor telmisartan over 12 weeks. Abundance and localization of CCN1 protein in kidney were assessed with Western blotting and immunohistochemistry, respectively. In all groups the strongest immunohistochemical reaction for CCN1 was observed in distal convoluted tubules and in smaller arteries, however, the total expression of CCN1 protein was lower in IL-6 KO mice in comparison to WT animals. The main difference in CCN1 distribution between the examined genotypes was lack of reaction in internal renal medulla and very weak reaction in proximal convoluted tubules in IL-6 KO mice. Experimental heart failure only slightly attenuated the expression of CCN1 protein in the kidney of WT mice and had no effect in IL-6 KO mice. Although, blockade of AT1 receptor did not alter CCN1 protein expression in kidneys of WT mice after myocardial infarction, it significantly changed its CCN1 distribution in the renal tubular system.

Role of interleukin-6 on RANKL-RANK/osteoprotegerin system in hypothyroid ovariectomized mice.

Postmenopausal women frequently develop hypothyroidism. Estrogen depletion is accompanied by an increase of IL-6, accelerating bone turnover. The influence of hypothyroidism on bone metabolism in postmenopausal women is poorly understood. The aim of the study was an attempt to clarify the role of interleukin-6 on RANKL-RANK/osteoprotegerin system in hypothyroid ovariectomized mice. The study was performed on 56, 12-13 weeks old, female mice: C57BL/6J (wild-type; WT) and C57BL/6JIL6-/-Kopf (IL-6 knock-out; IL6KO). The mice were randomly divided into 8 groups with 7 mice in each one: 1/ WT controls, 2/ IL6KO controls, 3/ WT hypothyroid mice, 4/ IL6KO hypothyroid mice, 5/ WT ovariectomized, 6/ IL6KO ovariectomized, 7/ WT ovariectomized hypothyroid mice and 8/ IL6KO ovariectomized hypothyroid mice. Experimental model of menopause was produced by bilateral ovariectomy carried out in 8-9 weeks old mice. Experimental model of hypothyroidism was induced by propylthiouracyl administration in driking water. The serum levels of TRACP 5b, osteocalcin, OPG and RANKL were determined by ELISA. Serum RANKL concentrations were elevated significantly in all groups of ovariectomized mice as compared to respective controls, but in a minor degree in IL6KO hypothyroid mice as compared to wild-type animals. Moreover sRANKL values were significantly lower in IL6KO as compared to WT controls and IL6KO PTU injected mice. Osteoprotegerin serum levels were decreased in all IL-6 deficient mice and in a highest degree in sham-operated hypothyroid mice. To sum up, the results of the present study suggest that estrogens deficit is a strong stimulus for RANKL-RANK/OPG pathway that breaks an inhibitory influence of hypothyroidism even in IL-6 deficient mice.