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Supplementary Fig. S3. Doxycyline-induced overexpression of Dicer in HCC cells. HepG2 (A) and Huh-7 (B) cells stably transfected with the inducible Dicer construct were incubated with or without doxycycline (Dox) for 24 h. C: HepG2 cells with the inducible Dicer construct were incubated for the indicated duration with or without doxycycline. A-C: The lysates were analyzed by immunoblotting using anti-Dicer and anti-β-actin antibodies. D: Western blot analysis of Dicer protein expression in Dicer-transgenic HepG2 xenografts from mice treated for 7 days with doxycycline (n = 3) or vehicle (n = 4), that were used for the experiment displayed in Fig. 5F. A-D: β-actin was used as endogenous control.

Table S1. Clinicopathological parameters of the patients with HCC. HBV, hepatitis B virus; HCV, hepatitis C virus

Purpose: A role of Dicer, which converts precursor miRNAs to mature miRNAs, in the tumor-promoting effect of hypoxia is currently emerging in some tumor entities. Its role in hepatocellular carcinoma (HCC) is unknown.Experimental Design: HepG2 and Huh-7 cells were stably transfected with an inducible Dicer expression vector and were exposed to hypoxia/normoxia. HepG2-Dicer xenografts were established in nude mice; hypoxic areas and Dicer were detected in HCC xenografts and HCCs from mice with endogenous hepatocarcinogenesis; and epithelial–mesenchymal transition (EMT) markers were analyzed by immunohistochemistry or by immunoblotting. The correlation between Dicer and carbonic anhydrase 9 (CA9), a marker of hypoxia, was investigated in resected human HCCs.Results: Hypoxia increased EMT markers in vitro and in vivo and led to a downregulation of Dicer in HCC cells. The levels of Dicer were downregulated in hypoxic tumor regions in mice with endogenous hepatocarcinogenesis and in HepG2 xenografts. In human HCCs, the levels of Dicer correlated inversely with those of CA9, indicating that the negative regulation of Dicer by hypoxia also applies to HCC patients. Forced expression of Dicer prevented the hypoxia-induced increase in hypoxia-inducible factor 1α (HIF1α), HIF2α, hypoxia-inducible genes (CA9, glucose transporter 1), EMT markers, and cell migration.Conclusions: We here identify downmodulation of Dicer as novel essential process in hypoxia-induced EMT in HCC and demonstrate that induced expression of Dicer counteracted hypoxia-induced EMT. Thus, targeting hypoxia-induced downmodulation of Dicer is a promising novel strategy to reduce HCC progression. Clin Cancer Res; 23(14); 3896–905. ©2017 AACR.

Supplementary Information

Supplementary Figure S3: Body weight of HepG2 (A) and Huh-7 (B) xenograft-bearing mice treated with iRGD, control (Ctl.) peptide, PBS and sorafenib (Sora).

Purpose: A role of Dicer, which converts precursor miRNAs to mature miRNAs, in the tumor-promoting effect of hypoxia is currently emerging in some tumor entities. Its role in hepatocellular carcinoma (HCC) is unknown. Experimental Design: HepG2 and Huh-7 cells were stably transfected with an inducible Dicer expression vector and were exposed to hypoxia/normoxia. HepG2-Dicer xenografts were established in nude mice; hypoxic areas and Dicer were detected in HCC xenografts and HCCs from mice with endogenous hepatocarcinogenesis; and epithelial–mesenchymal transition (EMT) markers were analyzed by immunohistochemistry or by immunoblotting. The correlation between Dicer and carbonic anhydrase 9 (CA9), a marker of hypoxia, was investigated in resected human HCCs. Results: Hypoxia increased EMT markers in vitro and in vivo and led to a downregulation of Dicer in HCC cells. The levels of Dicer were downregulated in hypoxic tumor regions in mice with endogenous hepatocarcinogenesis and in HepG2 xenografts. In human HCCs, the levels of Dicer correlated inversely with those of CA9, indicating that the negative regulation of Dicer by hypoxia also applies to HCC patients. Forced expression of Dicer prevented the hypoxia-induced increase in hypoxia-inducible factor 1α (HIF1α), HIF2α, hypoxia-inducible genes (CA9, glucose transporter 1), EMT markers, and cell migration. Conclusions: We here identify downmodulation of Dicer as novel essential process in hypoxia-induced EMT in HCC and demonstrate that induced expression of Dicer counteracted hypoxia-induced EMT. Thus, targeting hypoxia-induced downmodulation of Dicer is a promising novel strategy to reduce HCC progression. Clin Cancer Res; 23(14); 3896–905. ©2017 AACR.

Background: Efficient delivery of the poorly water-soluble compound sorafenib still poses a challenge to current formulation strategies. To incorporate the lipophilic molecule into biocompatible and biodegradable theranostic nanoparticles has great potential for improving efficacy and safety of cancer therapy. Results: In this study, sorafenib nanoencapsulation was optimized using poly(D,L-lactide-co-glycolide) and polyethylene glycol-poly(D,L-lactide-co-glycolide) copolymers comparing three different technologies. The particles ranged in size between 220 and 240 nm with encapsulation efficiencies from 76.1 ± 1.7 % to 69.1 ± 10.1 %. A remarkable maximum drug load of 9.0 % was achieved. Finally, a gadolinium complex was covalently attached to the nanoparticle surface transforming the nanospheres into theranostic devices allowing the localization using magnetic resonance imaging. Conclusion: The manufacture of sorafenib-loaded nanoparticles and the functionalization of the particle surface with a gadolinium complex resulted in a high drug loading, a strong MRI signal, optimal stability features and a sustained release profile.

MicroRNAs (miRNAs) circulating extracellularly in the blood are currently intensively studied as novel disease markers. However, the preanalytical factors influencing the levels of the extracellular miRNAs are still incompletely explored. In particular, it is unknown, whether the incubation of blood samples as occurring in clinical routine can lead to a release of miRNAs from blood cells and thus alter the extracellular miRNA levels before the preparation of serum or plasma from the blood cells. Using a set of marker miRNAs and quantitative RT-PCR, we found that the levels of extracellular miRNA-1, miRNA-16, and miRNA-21 were increased in EDTA and serum collection tubes incubated for 1-3 hours at room temperature and declined thereafter; the levels of the liver-specific miRNA-122 declined monophasically. These events occurred in the absence of significant hemolysis. When the blood was supplemented with Ribonuclease A inhibitor, the levels of miRNA-1, miRNA-16, and miRNA-21 increased substantially during the initial 3 hours of incubation and those of miRNA-122 remained unchanged, indicating that the release of blood cell-derived miRNAs occurred during the initial 3 hours of incubation of the blood tubes, but not at later time points. Separation of 5-hour preincubated blood into vesicle and nonvesicle fractions revealed a selective increase in the portion of vesicle-associated miRNAs. Together, these data indicate that the release of vesicle-associated miRNAs from blood cells can occur in blood samples within the time elapsing in normal clinical practice until their processing without significant hemolysis. This becomes particularly visible on the inhibition of miRNA degradation by Ribonuclease A inhibitor.

BACKGROUND/AIMS:Signaling of Gs protein-coupled receptors (GsPCRs) is accomplished by stimulation of adenylyl cyclase, causing an increase of the intracellular cAMP concentration, activation of the intracellular cAMP effectors protein kinase A (PKA) and Epac, and an efflux of cAMP, the function of which is still unclear.METHODS:Activation of adenylyl cyclase by GsPCR agonists or cholera toxin was monitored by measurement of the intracellular cAMP concentration by ELISA, anti-phospho-PKA substrate motif phosphorylation by immunoblotting, and an Epac-FRET assay in the presence and absence of adenosine receptor antagonists or ecto-nucleotide phosphodiesterase/pyrophosphatase2 (eNPP2) inhibitors. The production of AMP from cAMP by recombinant eNPP2 was measured by HPLC. Extracellular adenosine was determined by LC-MS/MS, extracellular ATP by luciferase and LC-MS/MS. The expression of eNPP isoenzymes 1-3 was examined by RT-PCR. The expression of multidrug resistance protein 4 was suppressed by siRNA.RESULTS:Here we show that the activation of GsPCRs and the GsPCRs-independent activation of Gs proteins and adenylyl cyclase by cholera toxin induce stimulation of cell surface adenosine receptors (A2A or A2B adenosine receptors). In PC12 cells stimulation of adenylyl cyclase by GsPCR or cholera toxin caused activation of A2A adenosine receptors by an autocrine signaling pathway involving cAMP efflux through multidrug resistance protein 4 and hydrolysis of released cAMP to AMP by eNPP2. In contrast, in PC3 cells cholera toxin- and GsPCR-induced stimulation of adenylyl cyclase resulted in the activation of A2B adenosine receptors.CONCLUSION:Our findings show that stimulation of adenylyl cyclase causes a remarkable activation of cell surface adenosine receptors. Fil: Pleli, Thomas. Goethe Universitat Frankfurt; Alemania Fil: Mondorf, Antonia. Goethe Universitat Frankfurt; Alemania Fil: Ferreiros, Nerea. Goethe Universitat Frankfurt; Alemania Fil: Thomas, Dominique. Goethe Universitat Frankfurt; Alemania Fil: Dvorak, Karel. Goethe Universitat Frankfurt; Alemania Fil: Biondi, Ricardo Miguel. Goethe Universitat Frankfurt; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biomedicina de Buenos Aires - Instituto Partner de la Sociedad Max Planck; Argentina Fil: Heringdorf, Dagmar Meyer zu. Goethe Universitat Frankfurt; Alemania Fil: Zeuzem, Stefan. Goethe Universitat Frankfurt; Alemania Fil: Geisslinger, Gerd. Goethe Universitat Frankfurt; Alemania Fil: Zimmermann, Herbert. Goethe Universitat Frankfurt; Alemania Fil: Waidmann, Oliver. Goethe Universitat Frankfurt; Alemania Fil: Piiper, Albrecht. Goethe Universitat Frankfurt; Alemania

iRGD is a derivative of the integrin-binding peptide RGD, which selectively increases the penetrability of tumor tissue to various coadministered substances in several preclinical models. In this study, we investigated the ability of iRGD to improve the delivery of sorafenib and doxorubicin therapy in hepatocellular carcinoma (HCC) using established mouse models of the disease. A contrast-enhanced MRI method was developed in parallel to assess the in vivo effects of iRGD in this setting. We found that iRGD improved the delivery of marker substances to the tumors of HCC-bearing mice about three-fold without a parallel increase in normal tissues. Control peptides lacking the critical CendR motif had no effect. Similarly, iRGD also selectively increased the signal intensity from tumors in Gd-DTPA–enhanced MRI. In terms of antitumor efficacy, iRGD coadministration significantly augmented the individual inhibitory effects of sorafenib and doxorubicin without increasing systemic toxicity. Overall, our results offered a preclinical proof of concept for the use of iRGD coadministration as a strategy to widen the therapeutic window for HCC chemotherapy, as monitored by Gd-DTPA–enhanced MRI as a noninvasive, clinically applicable method to identify iRGD-reactive tumors. Cancer Res; 75(15); 3147–54. ©2015 AACR.

Nanoparticle (NP)-based contrast agents that enable high resolution anatomic T1-weighted magnetic resonance imaging (MRI) offer the prospect of improving differential diagnosis of liver tumors such as hepatocellular carcinoma (HCC). In the present study, we investigated the possibility of employing novel non-toxic human serum albumin nanoparticles conjugated with Gd-DTPA and rhodamine 123 (Gd-Rho-HSA-NPs) for the detection of HCC by T1-weighted MRI. In addition, the influence of surface coating of the NPs with poloxamine 908, which alters the absorptive behavior of NPs and changes their distribution between the liver and tumor was examined. MRI of transgenic mice with endogenously formed HCCs following intravenous injection of Gd-Rho-HSA-NPs revealed a strong negative contrast of the tumors. Contrasting of the HCCs by NP-enhanced MRI required less Gd as compared to gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced MRI, which currently provides the most sensitive detection of HCC in patients. Immunohistochemical analyses revealed that the Gd-Rho-HSA-NPs were localized to macrophages, which were - similar to HCC in patients - fewer in number in HCC as compared to the liver tissue, which is in agreement with the negative contrasting of HCC in Gd-Rho-HSA-NP-enhanced MRI. Poloxamine-coated NPs showed lower accumulation in the tumor macrophages and caused a longer lasting enhancement of the MRI signal. These data indicate that Gd-Rho-HSA-NPs enable sensitive detection of HCC by T1-weighted MRI in mice with endogenous HCC through their uptake by macrophages. Poloxamine coating of the NPs delayed the tumor localization of the NPs.

The impact of the RNA-binding protein HuR for the post-transcriptional deregulation of tumor-relevant genes is well established. Despite of elevations in HuR expression levels, an increase in cytoplasmic HuR abundance in many cases correlates with a high grade of malignancy. Here, we demonstrated that administration of the actin-depolymerizing macrolide latrunculin A, or blebbistatin, an inhibitor of myosin II ATPase activity, caused a dose- and time-dependent reduction in the high cytoplasmic HuR content of HepG2 and Huh7 hepatocellular carcinoma (HCC) cells. Subcellular fractionation revealed that in addition, both inhibitors strongly attenuated cytoskeletal and membrane-bound HuR abundance and conversely increased the HuR amount in nuclear cell fractions. Concomitant with changes in intracellular HuR localization, both cytoskeletal inhibitors markedly decreased the half-lives of cyclooxygenase-2 (COX-2), cyclin A and cyclin D1 encoding mRNAs resulting in a significant reduction in their expression levels in HepG2 cells. Importantly, a similar reduction in the expression of these HuR targets was achieved by a RNA interference (RNAi)-mediated knockdown of either HuR or nonmuscle myoin IIA. Using polysomal fractionation, we further demonstrate that the decrease in cytoplasmic HuR by latrunculin A or blebbistatin is accompanied by a marked change in the allocation of HuR and its mRNA cargo from polysomes to ribonucleoprotein (RNP) particles. Functionally, the basal migration and prostaglandin E2 synthesis are similarly impaired in inhibitor-treated and stable HuR-knockdown HepG2 cells. Our data demonstrate that interfering with the actomyosin-dependent HuR trafficking may comprise a valid therapeutic option for antagonizing pathologic posttranscriptional gene expression by HuR and furthermore emphasize the potential benefit of HuR inhibitory strategies for treatment of HCC.

Soluble CD163 (sCD163), a marker for macrophage activation, was found to be associated with the severity of liver cirrhosis. The aim of the current study was to investigate whether serum sCD163 levels correlate with liver inflammation and fibrosis in patients with chronic hepatitis B virus (HBV) infection. In a retrospective cohort study, serum sCD163 levels were assessed by ELISA together with clinical and laboratory data in 186 patients with chronic HBV infection and 15 healthy controls. The relation between parameters for liver fibrosis and necroinflammation and sCD163 levels was analysed. Additionally, sCD163 was quantified in a subset of follow-up serum samples after initiation of antiviral treatment. sCD163 levels differed among phases of chronic HBV infection (P < 0.0001), and sCD163 concentrations were associated with inflammatory activity and fibrosis in the liver. sCD163 levels ≥ 1961 ng/l had a high specificity in the identification of subjects with substantial fibrosis (F ≥ 2). sCD163 concentrations decreased significantly after initiation of antiviral treatment. The correlation of sCD163 levels with necroinflammation and fibrosis and the sCD163 decline under treatment indicates that macrophage activation plays a role in HBV-related liver pathogenesis.

Tumor visualization by magnetic resonance imaging (MRI) and nanoparticle-based contrast agents may improve the imaging of solid tumors such as hepatocellular carcinoma (HCC). In particular, human serum albumin (HSA) nanoparticles appear to be a suitable carrier due to their safety and feasibility of functionalization. In the present study HSA nanoparticles were conjugated with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) using carbodiimide chemistry. The nanoparticles had a uniform spherical shape and a diameter of 235 ± 19 nm. For better optical visualization in vitro and in vivo, the HSA-Gd nanoparticles were additionally labeled with rhodamine 123. As shown by confocal microscopy and flow cytometry analysis, the fluorescent nanoparticles were readily taken up by Huh-7 hepatocellular carcinoma cells. After 24 h incubation in blood serum, less than 5% of the Gd(III) was released from the particles, which suggests that this nanoparticulate system may be stable in vivo and, therefore, may serve as potentially safe T1 MRI contrast agent for MRI of hepatocellular carcinoma.

Today, efficient delivery of sorafenib to hepatocellular carcinoma remains a challenge for current drug formulation strategies. Incorporating the lipophilic molecule into biocompatible and biodegradable theranostic nanocarriers has great potential for improving the efficacy and safety of cancer therapy. In the present study, three different technologies for the encapsulation of sorafenib into poly(d,l-lactide-co-glycolide) and polyethylene glycol-poly(d,l-lactide-co-glycolide) copolymers were compared. The particles ranged in size between 220 and 240 nm, with encapsulation efficiencies from 76.1 &plusmn, 1.7% to 69.1 &plusmn, 10.1%. A remarkable maximum drug load of approximately 9.0% was achieved. Finally, a gadolinium complex was covalently attached to the nanoparticle surface, transforming the nanospheres into theranostic devices, allowing their localization using magnetic resonance imaging. The manufacture of sorafenib-loaded nanoparticles alongside the functionalization of the particle surface with gadolinium complexes resulted in a highly efficacious nanodelivery system which exhibited a strong magnetic resonance imaging signal, optimal stability features, and a sustained release profile.

Immunotherapy in cancer is a recent and very promising approach, namely the inhibition of the PD/programmed death-ligand 1 (PD-L1) axis. Here we aimed to investigate the prognostic value of a soluble form of PD-L1 in hepatocellular carcinoma (HCC) patients.HCC patients were prospectively recruited and soluble programmed death-ligand 1 (sPD-L1) levels were determined. sPD-L1 levels were compared to stages of cirrhosis and HCC. The association of the sPD-L1 levels and overall survival (OS) was assessed.Two hundred fifteen patients with HCC were prospectively included. The median serum sPD-L1 concentration in patients with HCC was 0.5 ng/ml (range 0.03-6.04). Soluble PD-L1 levels positively correlated with the stage of cirrhosis and with stages of HCC. Furthermore, sPD-L1 correlated positively with a marker of macrophage activation (sCD163) and inflammation (C-reactive protein). The cut-off for high-level sPD-L1 (0.8 ng/ml) was defined by sPD-L1 levels determined in a healthy control cohort. Patients with high serum sPD-L1 concentrations had an increased mortality risk (hazard ratio 3.340, 95 % confidence interval 1.609-6.934, P0.001), while very low PD-L1 levels seem to come along with better prognosis. High sPD-L1 levels were associated with mortality independently from cirrhosis stage, alpha-fetoprotein and sCD163 levels in a multivariate Cox regression model.We conclude that a high sPD-L1 level is a possible prognostic indicator for a poor outcome in HCC patients. The predictive value of sPD-L1 levels for a successful anti-PD1/PD-L1 therapy should be investigated in the future.

Highly promising preclinical data obtained in cultured cells and in nude mice bearing xenografts contrast with the rather modest clinical efficacy of Polo-like kinase 1 (Plk1) inhibitors. In the present study, we investigated if Plk1 might be a suitable target in hepatocellular carcinoma (HCC) and if a genetically engineered mouse tumor model that well reflects the tumor cell and micro-environmental features of naturally occurring cancers might be suitable to study anti-Plk1 therapy. Analysis of Plk1 expression in human HCC samples confirmed that HCC express much higher Plk1 levels than the adjacent normal liver tissue. Inhibition of Plk1 by an adenovirus encoding for a short hairpin RNA against Plk1 or by the small-molecule inhibitor BI 2536 reduced the viability of HCC cell lines and inhibited HCC xenograft progression in nude mice. Treatment of transforming growth factor (TGF) α/c-myc bitransgenic mice with BI 2536 during hepatocarcinogenesis reduced the number of dysplastic foci and of Ki-67-positive cells within the foci, indicating diminished tumorigenesis. In contrast, BI 2536 had no significant effect on HCC progression in the transgenic mouse HCC model as revealed by magnetic resonance imaging. Measurement of BI 2536 by mass spectrometry revealed considerably lower BI 2536 levels in HCC compared with the adjacent normal liver tissue. In conclusion, low intratumoral levels are a novel mechanism of resistance to the Plk1 inhibitor BI 2536. Plk1 inhibitors achieving sufficient intratumoral levels are highly promising in HCC treatment.

miR-122 is a liver-specific microRNA, which also circulates in the blood. The levels of miR-122 in serum and plasma correlate with hepatic necroinflammation in patients with hepatitis B virus (HBV) infection. Here, we investigated whether miR-122 levels correlate with surrogate markers for viral replication and translation. Furthermore, we examined whether miR-122 levels differ in the different groups of HBV-infected patients and whether miR-122 levels may be useful to identify patients with higher or lower risk for liver disease progression. Therefore, RNA was extracted from sera of therapy-naive patients with HBV infection (n = 89) and from healthy volunteers (n = 19). The concentration of miR-122 was assessed by quantitative real-time reverse-transcription PCR. HBs antigen and HBV DNA levels were quantified as surrogate parameters for HBV replication and translation. Liver biopsies were examined according to the histological activity index and the degree of fibrosis was assessed. We found that the miR-122 serum concentration correlated with the level of ALT, HBV DNA and HBs antigen (r = 0.259, P 3500 IU/mL) or low (

Overdosing of the analgesic acetaminophen (APAP, paracetamol) is a major cause of acute liver injury. Whereas toxicity is initiated by hepatocyte necrosis, course of disease is regulated by mechanisms of innate immunity having the potential to serve in complex manner pathogenic or pro-regenerative functions. Interleukin (IL)-36γ has been identified as novel IL-1-like cytokine produced by and targeting epithelial (-like) tissues. Herein, we investigated IL-36γ in acute liver disease focusing on murine APAP-induced hepatotoxicity. Enhanced expression of hepatic IL-36γ and its prime downstream chemokine target CCL20 was detected upon liver injury. CCL20 expression coincided with the later regeneration phase of intoxication. Primary murine hepatocytes and human Huh7 hepatocellular carcinoma cells indeed displayed enhanced IL-36γ expression when exposed to inflammatory cytokines. Administration of IL-36 receptor antagonist (IL-36Ra) decreased hepatic CCL20 in APAP-treated mice. Unexpectedly, IL-36Ra likewise increased late phase hepatic injury as detected by augmented serum alanine aminotransferase activity and histological necrosis which suggests disturbed tissue recovery upon IL-36 blockage. Finally, we demonstrate induction of IL-36γ in inflamed livers of endotoxemic mice. Observations presented introduce IL-36γ as novel parameter in acute liver injury which may contribute to the decision between unleashed tissue damage and initiation of liver regeneration during late APAP toxicity.

BackgroundAutotaxin (ATX) and its product lysophosphatidic acid (LPA) are considered to be involved in the development of liver fibrosis and elevated levels of serum ATX have been found in patients with hepatitis C virus associated liver fibrosis. However, the clinical role of systemic ATX in the stages of liver cirrhosis was unknown. Here we investigated the relation of ATX serum levels and severity of cirrhosis as well as prognosis of cirrhotic patients.MethodsPatients with liver cirrhosis were prospectively enrolled and followed until death, liver transplantation or last contact. Blood samples drawn at the day of inclusion in the study were assessed for ATX content by an enzyme-linked immunosorbent assay. ATX levels were correlated with the stage as well as complications of cirrhosis. The prognostic value of ATX was investigated by uni- and multivariate Cox regression analyses. LPA concentration was determined by liquid chromatography-tandem mass spectrometry.Results270 patients were enrolled. Subjects with liver cirrhosis showed elevated serum levels of ATX as compared to healthy subjects (0.814±0.42 mg/l vs. 0.258±0.40 mg/l, PConclusionSerum ATX is an indicator for the severity of liver disease and the prognosis of cirrhotic patients.

Background The identification of new biomarkers to predict the aggressiveness of hepatocellular carcinoma (HCC) and supplement the current set of prognosis and treatment algorithms is an important clinical need. Extracellular microRNAs (miRNAs) circulating in the blood are a new class of highly promising disease markers. Aim Here we investigated the prognostic potential of miR-1 and miR-122 in sera from patients with HCC. Methods RNA was extracted from 195 sera of HCC patients and 54 patients with liver cirrhosis, obtained at the time of study enrolment. miR-1 and miR-122 levels were correlated with overall survival (OS), Cancer of the Liver Italian Program (CLIP) score, Barcelona Clinic Liver Cancer stage, clinical chemistry parameters and tumor specific treatment. Results Patients with higher miR-1 and miR-122 serum levels showed longer OS than individuals with lower miR-1 and miR-122 serum concentrations (hazard ratio [HR] 0.440, 95% confidence interval [CI] 0.233–0.831, P = 0.011 for miR-1 and HR 0.493, 95% CI 0.254–0.956, P = 0.036 for miR-122, respectively). Serum miR-1 and miR-122 concentrations did not differ significantly between patients with HCC and liver cirrhosis. An age-, sex-, tumor stage and treatment-adjusted multivariate Cox regression analysis revealed that miR-1 serum levels (HR 0.451, 95% CI 0.228–0.856, P = 0.015) were independently associated with OS, whereas serum miR-122 was not. miR-1 serum levels showed no relevant correlation with clinical chemistry liver parameters, whereas serum miR-122 correlated with clinical chemistry parameters of hepatic necroinflammation, liver function and synthetic capacity. Conclusion Our data indicate that serum miR-1 is a new independent parameter of OS in HCC patients and may therefore improve the predictive value of classical HCC staging scores.

Cyclic AMP analogs containing hydrophobic modification of C(8) at the adenine ring such as 8-(4-chlorophenylthio)-cAMP (8-pCPT-cAMP) and 8-(4-chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-methyl-cAMP) can penetrate membranes due to their high lipophilicity and directly activate intracellular cAMP effectors. Therefore, these cAMP analogs have been used in numerous studies, assuming that their effects reflect the consequences of direct activation of cAMP effectors. The present study provides evidence that 8-pCPT-modified cAMP analogs and their corresponding putative hydrolysis products (8-(4-chlorophenylthio)-adenosine (8-pCPT-ado) and 8-(4-chlorophenylthio)-2'-O-methyl-adenosine (8-pCPT-2'-O-methyl-ado)) inhibit the equilibrative nucleoside transporter 1 (ENT1). In PC12 cells, in which nucleoside transport strongly depended on ENT1, 8-pCPT-ado, 8-pCPT-2'-O-methyl-ado, and, to a smaller extent, 8-pCPT-2'-O-methyl-cAMP caused an increase of protein kinase A substrate motif phosphorylation and anti-apoptotic effect by an A(2A) adenosine receptor (A(2A)R)-dependent mechanism. In contrast, the effects of 8-pCPT-cAMP were mainly A(2A)R-independent. In HEK 293 showing little endogenous ENT1-dependent nucleoside transport, transfection of ENT1 conferred A(2A)R-dependent increase in protein kinase A substrate motif phosphorylation. Together, the data of the present study indicate that inhibition of ENT1 and activation of adenosine receptors have to be considered when interpreting the effects of 8-pCPT-substituted cAMP/adenosine analogs.