Tripartite motif 16 ameliorates nonalcoholic steatohepatitis by promoting the degradation of phospho-TAK1.

Nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma and liver disorders have become the leading causes for the need of liver transplantation in developed countries. Lipotoxicity plays a central role in NASH progression by causing endoplasmic reticulum stress and disrupting protein homeostasis. To identify key molecules that mitigate the detrimental consequences of lipotoxicity, we performed integrative multiomics analysis and identified the E3 ligase tripartite motif 16 (TRIM16) as a candidate molecule. In particular, we found that lipid accumulation and inflammation in a mouse NASH model is mitigated by TRIM16 overexpression but aggravated by its depletion. Multiomics analysis showed that TRIM16 suppressed NASH progression by attenuating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway; specifically, by preferentially interacting with phospho-TAK1 to promote its degradation. Together, these results identify TRIM16 as a promising therapeutic target for the treatment of NASH.

Translationally controlled tumor protein exerts a proinflammatory role in acute rejection after liver transplantation.

BACKGROUND: Translationally controlled tumor protein (TCTP), which has been verified to have a proinflammatory activity, plays an important role in allergy. However, it remains unclear whether TCTP has an impact on the acute rejection (AR) after liver transplantation. METHODS: Three protocols were used to delineate the role of TCTP in AR after liver transplantation. First, in rat orthotopic liver transplantation (OLT), the expression of TCTP was measured by enzyme-linked immunosorbent assay (ELISA), real-time PCR, Western blot and immunofluorescence assays. Second, in mixed lymphocyte reaction (MLR), the role of TCTP in lymphocyte proliferation was measured by carboxyfluorescein succinimidyl ester (CFSE) labeling and the impact of TCTP on inflammatory factor release was detected by cytokine arrays. Third, in human OLT, the level of serum TCTP was detected by ELISA, and the relationship between TCTP and model for early allograft function (MEAF) score was assessed by Spearman's correlation. RESULTS: In rat OLT, AR resulted in great harm to allografts, manifesting as deterioration of liver function, increasing inflammatory factors and infiltrating lymphocytes. Meanwhile, TCTP was overexpressed in serum and allografts. Higher level of TCTP was associated with higher rejection activity index (RAI). In an MLR protocol, TCTP knockdown inhibited the proliferation of mixed inflammatory cells and significantly suppressed the release of 15 cytokines and chemokines. In human OLT, the serum TCTP was up-regulated within a week after operation. Additionally, the increasing speed of serum TCTP positively correlated with MEAF scores (r = 0.449; P = 0.0088). CONCLUSIONS: Up-regulated TCTP positively affects AR after liver transplantation.

NOTCH Signaling via WNT Regulates the Proliferation of Alternative, CCR2-Independent Tumor-Associated Macrophages in Hepatocellular Carcinoma.

Tumor-associated macrophages (TAM) play pivotal roles in tumor progression and metastasis, but the contribution and regulation of different macrophage populations remain unclear. Here we show that Notch signaling plays distinct roles in regulating different TAM subsets in hepatocellular carcinoma (HCC). Myeloid-specific NOTCH blockade by conditional disruption of recombination signal binding protein Jκ (RBPj cKO) significantly delayed the growth of subcutaneously inoculated Lewis lung carcinoma (LLC), but accelerated orthotopically inoculated hepatic Hepa1-6 tumors in mice. In contrast to subcutaneous LLC, RBPj cKO significantly increased the number of TAMs in hepatic Hepa1-6 tumors despite impeded differentiation of monocyte-derived TAMs (moTAM). The dominating TAMs in orthotopic HCC manifested properties of Kupffer cells (KC) and hence are tentatively named KC-like TAMs (kclTAM). The increased proliferation of RBPj cKO kclTAMs was maintained even in Ccr2 -/- mice, in which moTAMs were genetically blocked. NOTCH signaling blockade accelerated proliferation of kclTAMs via enhanced ß-catenin-dependent WNT signaling, which also downregulated IL12 and upregulated IL10 expression by kclTAMs likely through c-MYC. In addition, myeloid-specific RBPj cKO facilitated hepatic metastasis of colorectal cancer but suppressed lung metastasis in mice, suggesting that the phenotype of RBPj cKO in promoting tumor growth was liver-specific. In patient-derived HCC biopsies, NOTCH signaling negatively correlated with WNT activation in CD68+ macrophages, which positively correlated with advanced HCC stages. Therefore, NOTCH blockade impedes the differentiation of moTAMs, but upregulates Wnt/ß-catenin signaling to promote the proliferation and protumor cytokine production of kclTAMs, facilitating HCC progression and hepatic metastasis of colorectal cancer. SIGNIFICANCE: These findings highlight the role of NOTCH and WNT signaling in regulating TAMs in hepatocellular carcinoma.

Preoperative Alfa-Fetoprotein and Fibrinogen Predict Hepatocellular Carcinoma Recurrence After Liver Transplantation Regardless of the Milan Criteria: Model Development with External Validation.

BACKGROUND/AIMS: Patient selection is critically important in improving the outcomes of liver transplantation for hepatocellular carcinoma. The aim of the current study was to identify biochemical measures that could affect patient prognosis after liver transplantation. METHODS: A total of 119 patients receiving liver transplantation for hepatocellular carcinoma were used to construct a model for predicting recurrence. The results were validated using an independent sample of 109 patients from independent hospitals. All subjects in both cohorts met the Hangzhou criteria. RESULTS: Analysis of the discovery cohort revealed an association of recurrence with preoperative fibrinogen and AFP levels. A mathematical model was developed for predicting probability of recurrence within 5 years: Y = logit(P) = -4.595 + 0.824 ×fibrinogen concentration (g/L) + 0.641 × AFP score (1 for AFP<=20ng/ml, 2 for 20 400ng/ml). At a cutoff score of -0.85, the area under the curve (AUC) was 0.819 in predicting recurrence (vs. 0.655 when using the Milan criteria). In the validation cohort, this model had reasonable performance in predicting 5-year overall survival (68.8% vs. 28.1% in using the -0.85 cutoff, p< 0.001) and disease-free survival (65.7% vs. 25.9%, p< 0.001). The sensitivity and specificity were 77.0% and 62.5%, respectively. The AUC of this newly developed model was similar to that with the Milan criteria (0.698 vs. 0.678). Surprisingly, the DFS in patients with score <= -0.85 under this model but not meeting the Milan criteria was similar to that in patients meeting the Milan criteria (53.8% vs. 60.0%, p=0.380). CONCLUSIONS: Preoperative AFP and fibrinogen are useful in predicting recurrence of hepatocellular carcinoma after liver transplantation.

Endothelial Notch activation reshapes the angiocrine of sinusoidal endothelia to aggravate liver fibrosis and blunt regeneration in mice.

Liver sinusoidal endothelial cells (LSECs) critically regulate liver homeostasis and diseases through angiocrine factors. Notch is critical in endothelial cells (ECs). In the current study, Notch signaling was activated by inducible EC-specific expression of the Notch intracellular domain (NIC). We found that endothelial Notch activation damaged liver homeostasis. Notch activation resulted in decreased fenestration and increased basement membrane, and a gene expression profile with decreased LSEC-associated genes and increased continuous EC-associated genes, suggesting LSEC dedifferentiation. Consistently, endothelial Notch activation enhanced hepatic fibrosis (HF) induced by CCl4 . Notch activation attenuated endothelial nitric oxide synthase (eNOS)/soluble guanylate cyclase (sGC) signaling, and activation of sGC by 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) reversed the dedifferentiation phenotype. In addition, Notch activation subverted the hepatocyte-supporting angiocrine profile of LSECs by down-regulating critical hepatocyte mitogens, including Wnt2a, Wnt9b, and hepatocyte growth factor (HGF). This led to compromised hepatocyte proliferation under both quiescent and regenerating conditions. Whereas expression of Wnt2a and Wnt9b was dependent on eNOS-sGC signaling, HGF expression was not rescued by the sGC activator, suggesting heterogeneous mechanisms of LSECs to maintain hepatocyte homeostasis. CONCLUSION: Endothelial Notch activation results in LSEC dedifferentiation and accelerated liver fibrogenesis through eNOS-sGC signaling, and alters the angiocrine profile of LSECs to compromise hepatocyte proliferation and liver regeneration (LR). (Hepatology 2018).

Cytotherapy with M1-polarized macrophages ameliorates liver fibrosis by modulating immune microenvironment in mice.

BACKGROUND & AIMS: Macrophages play vital roles in chronic liver injury, and have been tested as a tool for cytotherapy in liver fibrosis. However, macrophages possess ontogenic and functional heterogeneities. Some subsets are pro-fibrotic, whereas others are anti-fibrotic. This study aimed to clarify which macrophage subset is efficient for cytotherapy in liver fibrosis and to elucidate the underlying mechanisms. METHODS: Liver fibrosis was induced in mice by carbon tetrachloride injection or bile duct ligation. Bone-marrow-derived macrophages (BMDMs) were polarized into M0, M1, or M2 macrophages, respectively. BMDMs were infused into mice through the tail vein at different stages of fibrogenesis. Fibrosis progression, hepatic cell populations, and related molecular changes were evaluated. RESULTS: Both M0 and M1 BMDMs significantly ameliorated liver fibrosis, but M1 exhibited stronger therapeutic effects than M0. M2 macrophages were not effective on liver fibrosis. M1 macrophages reduced the number and activation of hepatic stellate cells (HSCs), which could be attributed at least partly to increased HSC apoptosis. M1 macrophages enhanced the recruitment of endogenous macrophages into fibrotic liver, which displayed the phenotype of Ly6Clo restorative macrophages and produced matrix metalloproteinases (MMPs) and hepatic growth factor (HGF) to enhance collagen degradation and hepatocyte proliferation, respectively. M1 macrophages also increased the number of total and activated natural killer (NK) cells in the fibrotic liver, which released TNF-related apoptosis-inducing ligand (TRAIL), inducing HSC apoptosis. CONCLUSIONS: M1 macrophages, which modulate the immune microenvironment to recruit and modify the activation of endogenous macrophages and NK cells, are effective for cytotherapy in experimental liver fibrosis. Lay summary: M1 Bone marrow-derived macrophages (BMDMs) exhibit a stronger therapeutic effect by modulating the hepatic microenvironment to recruit and modify the activation of endogenous macrophages and natural killer (NK) cells, which likely lead to hepatic stellate cells (HSCs) apoptosis and hampered fibrogenesis.

Blocking Notch signal in myeloid cells alleviates hepatic ischemia reperfusion injury by repressing the activation of NF-κB through CYLD.

Ischemia-reperfusion (I/R) is a major reason of hepatocyte injury during liver surgery and transplantation. Myeloid cells including macrophages and neutrophils play important roles in sustained tissue inflammation and damage, but the mechanisms regulating myeloid cells activity have been elusive. In this study, we investigate the role of Notch signaling in myeloid cells during hepatic I/R injury by using a mouse model of myeloid specific conditional knockout of RBP-J. Myeloid-specific RBP-J deletion alleviated hepatic I/R injury. RBP-J deletion in myeloid cells decreased hepatocytes apoptosis after hepatic I/R injury. Furthermore, myeloid-specific RBP-J deletion led to attenuated inflammation response in liver after I/R injury. Consistently, Notch blockade reduced the production of inflammatory cytokines by macrophages in vitro. We also found that blocking Notch signaling reduced NF-κB activation and increased cylindromatosis (CYLD) expression and knockdown of CYLD rescued reduction of inflammatory cytokines induced by Notch blockade in macrophages during I/R injury in vitro. On the other hand, activation of Notch signaling in macrophages led to increased inflammatory cytokine production and NF-κB activation and decreased CYLD expression in vitro. These data suggest that activation of Notch signaling in myeloid cells aggravates I/R injury, by enhancing the inflammation response by NF-κB through down regulation of CYLD.

Combining Exosomes Derived from Immature DCs with Donor Antigen-Specific Treg Cells Induces Tolerance in a Rat Liver Allograft Model.

Allograft tolerance is the ultimate goal in the field of transplantation immunology. Immature dendritic cells (imDCs) play an important role in establishing tolerance but have limitations, including potential for maturation, short lifespan in vivo and short storage times in vitro. However, exosomes (generally 30-100 nm) from imDCs (imDex) retain many source cell properties and may overcome these limitations. In previous reports, imDex prolonged the survival time of heart or intestine allografts. However, tolerance or long-term survival was not achieved unless immune suppressants were used. Regulatory T cells (Tregs) can protect allografts from immune rejection, and our previous study showed that the effects of imDex were significantly associated with Tregs. Therefore, we incorporated Tregs into the treatment protocol to further reduce or avoid suppressant use. We defined the optimal exosome dose as approximately 20 µg (per treatment before, during and after transplantation) in rat liver transplantation and the antigen-specific role of Tregs in protecting liver allografts. In the co-treatment group, recipients achieved long-term survival, and tolerance was induced. Moreover, imDex amplified Tregs, which required recipient DCs and were enhanced by IL-2. Fortunately, the expanded Tregs retained their regulatory ability and donor-specificity. Thus, imDex and donor-specific Tregs can collaboratively induce graft tolerance.

Pig Liver Xenotransplantation: A Review of Progress Toward the Clinic.

Experience with clinical liver xenotransplantation has largely involved the transplantation of livers from nonhuman primates. Experience with pig livers has been scarce. This brief review will be restricted to assessing the potential therapeutic impact of pig liver xenotransplantation in acute liver failure and the remaining barriers that currently do not justify clinical trials. A relatively new surgical technique of heterotopic pig liver xenotransplantation is described that might play a role in bridging a patient with acute liver failure until either the native liver recovers or a suitable liver allograft is obtained. Other topics discussed include the possible mechanisms for the development of the thrombocytopenis that rapidly occurs after pig liver xenotransplantation in a primate, the impact of pig complement on graft injury, the potential infectious risks, and potential physiologic incompatibilities between pig and human. There is cautious optimism that all of these problems can be overcome by judicious genetic manipulation of the pig. If liver graft survival could be achieved in the absence of thrombocytopenia or rejection for a period of even a few days, there may be a role for pig liver transplantation as a bridge to allotransplantation in carefully selected patients.

Fbxw7 regulates hepatocellular carcinoma migration and invasion via Notch1 signaling pathway.

Hepatocellular carcinoma (HCC) is one of the most common human malignancies and also the leading cause of cancer-related death in the world. The mechanisms underlying the progression and metastasis of HCC remain unclear. The E3 ubiquitin ligase F-box and WD repeat domain-containing 7 (Fbxw7) is broadly considered as a tumor suppressor gene. However, the role of Fbxw7 in HCC is not clear. To investigate the expression and biological functions of Fbxw7 in HCC, we examined Fbxw7 expression level using HCC tissue microarray and immunohistochemistry. Our data showed that Fbxw7 expression is significantly reduced in HCC compared with non-cancerous tissues (P<0.05). Fbxw7 levels were significantly associated with tumor differentiation (P=0.013), the incidence of portal or hepatic venous invasion (P=0.031), metastasis (P=0.027) and AJCC cancer stage (P=0.047). Then, we observed a strong correlation between low Fbxw7 expression and a worse 5-year survival of HCC patients (P<0.001). Furthermore, multivariate Cox regression analyses demonstrated that the Fbxw7 expression (P<0.001) was an independent factor for the prediction of the overall survival of HCC patients. We also found that both Fbxw7 mRNA and protein levels were significantly reduced in HCC cell lines compared with human liver non-tumor cell line. Moreover, our in vitro experiments showed a remarkable increase of cell migration and invasion in Fbxw7-knockdown cells and a decrease in Fbxw7-overexpress cells. In addition, the present study demonstrated that Fbxw7 is involved in the migration and invasion of HCC cells via regulating Notch1 and the downstream molecules of Notch1. Taken together, our findings indicate that Fbxw7 can be used as a prognostic marker; it has an important role in HCC progression and inhibits HCC cell migration and invasion through the Notch1 signaling pathway.

Significance of serum microRNA-21 in diagnosis of hepatocellular carcinoma (HCC): clinical analyses of patients and an HCC rat model.

MicroRNAs (miRNAs) are associated with human carcinogenesis and tumor development. Moreover, serum miRNAs can reflect the level of tissue miRNAs and be potential tumor markers. Serum microRNA-21 (miR-21) is overexpressed in many human cancers including hepatocellular carcinoma (HCC). However, how serum miR-21 changes during the HCC formation and whether miR-21 plays a regulatory role in this whole process are unknown. The current study evaluated the prognostic and diagnostic potential of serum miR-21 in HCC patients. Next, we established a HCC rat model and collected the blood and liver tissues at regular time points. AFP from the serum, RNA from the serum and liver tissues were collected and quantified separately. The results revealed that tissue and serum miR-21 was upregulated significantly in the groups of cirrhosis, early and advanced HCC compared with normal and fibrosis groups. The AFP levels were increased in early and advanced HCC compared with other groups. Then, the changes of miR-21 downstream proteins (i.e., programmed cell death 4 [PDCD4] and phosphatase and tensin homolog [PTEN]) in the liver tissues were measured. PDCD4 and PTEN expression was decreased gradually after tumor induction and negatively correlated with miR-21 expression. All these results suggested that serum miR-21 was associated with the prognosis of HCC; the changes in serum miR-21 were earlier and more accurately reflected the pathogenesis of HCC than AFP; therefore, it could be used as an early diagnostic marker for HCC. Our in vivo experiments further confirmed that miR-21 plays an important role in promoting the occurrence and development of HCC by regulating PDCD4 and PTEN.

Expression of NEDD9 in hepatocellular carcinoma and its clinical significance.

Neural precursor cell expressed, developmentally downregulated 9 (NEDD9) plays an integral role in natural and pathological cell biology. Overexpression of NEDD9 protein has been correlated with poor prognosis in various types of cancer. However, few available data address the precise function of the NEDD9 gene in hepatocellular carcinoma (HCC). In the present study, we investigated NEDD9 expression in 40 primary human HCC tissues compared with matched adjacent non-tumor hepatic tissues using RT-qPCR and western blot analysis. Immunohistochemistry was performed to analyze the correlations between NEDD9 expression and clinicopathological factors. Statistical analyses were applied to derive prognostic values of NEDD9 in HCC. The results showed that the NEDD9 mRNA and protein expression levels in HCC tissues were significantly higher than those in matched adjacent non-tumor hepatic tissues. High NEDD9 expression was correlated with larger tumor size, advanced tumor grade, metastasis, intrahepatic venous invasion and high UICC TNM stages in HCC patients. Patients with high NEDD9 expression levels exhibited poorer recurrence-free and overall survival than those with a low NEDD9 expression. Additionally, NEDD9 expression status was an independent prognostic factor for survival. This correlation remained significant in patients with early-stage HCC or with normal serum AFP levels. The results of this study suggest that NEDD9 may be a valuable prognostic biomarker for HCC, including early-stage and AFP-normal patients.

Myeloid-specific disruption of recombination signal binding protein Jκ ameliorates hepatic fibrosis by attenuating inflammation through cylindromatosis in mice.

UNLABELLED: Macrophages play multidimensional roles in hepatic fibrosis, but their control has not been fully understood. The Notch pathway mediated by recombination signal binding protein Jκ (RBP-J), the transcription factor transactivated by signals from four mammalian Notch receptors, is implicated in macrophage activation and plasticity. In this study, by using mouse hepatic fibrosis models, we show that myeloid-specific disruption of RBP-J resulted in attenuated fibrosis. The activation of hepatic stellate cells and production of profibrotic factors including platelet-derived growth factor (PDGF)-B and transforming growth factor beta1 (TGF-ß1) reduced significantly in myeloid-specific RBP-J deficient mice. The infiltration of inflammatory cells and production of proinflammatory factors were reduced in liver of myeloid-specific RBP-J-deficient mice during fibrosis. In RBP-J-deficient macrophages, the nuclear factor kappa B (NF-κB) activation was remarkably attenuated as compared with the control. This could be attributed to the up-regulation of cylindromatosis (CYLD), a negative regulator of NF-κB, in Notch signal-compromised macrophages, because the knockdown of CYLD in RBP-J-deficient macrophages or overexpression of p65 in RBP-J knockdown cells both restored NF-κB activation and the production of proinflammatory and/or profibrotic factors by macrophages. In human hepatic fibrosis biopsies, stronger Notch activation is correlated with more severe fibrosis, which is accompanied by a lower level of CYLD but irrespective of etiological reasons. CONCLUSION: RBP-J-mediated Notch signaling is required for macrophages to promote hepatic fibrosis by up-regulation of NF-κB activation through CYLD.

MicroRNA-183 is involved in cell proliferation, survival and poor prognosis in pancreatic ductal adenocarcinoma by regulating Bmi-1.

As a highly aggressive malignant disease, the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC) is poor. Yet, the mechanisms underlying the progression of PDAC remain unclear. MicroRNAs (miRNAs) may be involved in various human cancers as cancer suppressors or oncogenes. MicroRNA-183 (miR-183) was recently reported to be dysregulated in various types of cancer and to play an important role in the processes of cancer. However, the effects and potential mechanisms of action of miR-183 in PDAC have not been explored. In the present study, low expression of miR-183 was observed in PDAC tissues and cell lines. Low expression of miR-183 in PDAC was significantly associated with tumor grade, metastasis and TNM stage. Kaplan-Meier survival analysis demonstrated that patients harboring low expression of miR-183 had a significantly reduced overall survival than patients with a high level of miR-183 expression. The present study revealed that B-cell-specific Moloney murine leukemia virus insertion site 1 (Bmi-1) expression was inversely correlated with miR-183. Our findings also demonstrated that a low level of miR-183 expression effectively suppressed the growth of PDAC cells via regulation of Bmi-1. Following Bmi-1 silencing or upregulation of miR-183, the expression levels of cyclin D1, cyclin-dependent kinase (CDK)2 and CDK4 were decreased. It is reasonable to conclude that alteration of miR-183 expression may regulate the function of PDAC cells by the downregulation of Bmi-1 expression.

Long non-coding RNA URHC regulates cell proliferation and apoptosis via ZAK through the ERK/MAPK signaling pathway in hepatocellular carcinoma.

Long non-coding RNAs (lncRNAs) have previously been implicated in human disease states, especially cancer. Although the aberrant expression of lncRNAs has been observed in cancer, the biological functions and molecular mechanisms underlying aberrantly expressed lncRNAs in hepatocellular carcinoma (HCC) have not been widely established. In the present study, we investigated a novel lncRNA, termed URHC (up-regulated in hepatocellular carcinoma), and evaluated its role in the progression of HCC. Expression profiling using a lncRNA microarray revealed that URHC was highly expressed in 3 HCC cell lines compared to normal hepatocytes. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses confirmed that URHC expression was increased in hepatoma cells and HCC tissues. Moreover, using qRT-PCR, we confirmed that URHC expression was up-regulated in 30 HCC cases (57.7%) and that its higher expression was correlated with poor overall survival. We further demonstrated that URHC inhibition reduced cell proliferation and promoted apoptosis. We hypothesize that URHC may function by regulating the sterile alpha motif and leucine zipper containing kinase AZK (ZAK) gene, which is located near URHC on the same chromosome. We found that ZAK mRNA levels were down-regulated in HCC tissues and the expression levels of ZAK were negatively correlated with those of URHC in the above HCC tissues. Next, we confirmed that URHC down-regulated ZAK, which is involved in URHC-mediated cell proliferation and apoptosis. Furthermore, ERK/MAPK pathway inactivation partially accounted for URHC-ZAK-induced cell growth and apoptosis. Thus, we concluded that high URHC expression can promote cell proliferation and inhibit apoptosis by repressing ZAK expression through inactivation of the ERK/MAPK pathway. These findings may provide a novel mechanism and therapeutic targets for the treatment of HCC.

MicroRNA-135a inhibits cell proliferation by targeting Bmi1 in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal solid tumor due to the lack of reliable early detection markers and effective therapies. MicroRNAs (miRNAs), noncoding RNAs that regulate gene expression, are involved in tumorigenesis and have a remarkable potential for the diagnosis and treatment of malignancy. In this study, we investigated aberrantly expressed miRNAs involved in PDAC by comparing miRNA expression profiles in PDAC cell lines with a normal pancreas cell line and found that miR-135a was significantly down-regulated in the PDAC cell lines. The microarray results were validated by qRT-PCR in PDAC tissues, paired adjacent normal pancreatic tissues, PDAC cell lines, and a normal pancreas cell line. We then defined the tumor-suppressing significance and function of miR-135a by constructing a lentiviral vector to express miR-135a. The overexpression of miR-135a in PDAC cells decreased cell proliferation and clonogenicity and also induced G1 arrest and apoptosis. We predicted Bmi1 may be a target of miR-135a using bioinformatics tools and found that Bmi1 expression was markedly up-regulated in PDAC. Its expression was inversely correlated with miR-135a expression in PDAC. Furthermore, a luciferase activity assay revealed that miR-135a could directly target the 3'-untranslated region (3'-UTR) of Bmi1. Taken together, these results demonstrate that miR-135a targets Bmi1 in PDAC and functions as a tumor suppressor. miR-135a may offer a new perspective for the development of effective miRNA-based therapy for PDAC.

PCBP1 is an important mediator of TGF-ß-induced epithelial to mesenchymal transition in gall bladder cancer cell line GBC-SD.

Gall bladder carcinoma (GBC) is the seventh most common cancer across the globe and the most common malignancy of the biliary tract. Most GBC related deaths occur due to secondary progression and metastasis to distant organs. Epithelial-mesenchymal transition (EMT) is an important pre-requisite for tumor metastasis, however its mechanism in GBC has not yet been defined. Using the GBC-SD cell line, we have uncovered an important mediator, poly r(C) binding protein-1 (PCBP1), of transforming growth factor-beta (TGF-ß)-induced EMT in GBC. Our results show that TGF-ß treatment resulted in PCBP1 phosphorylation in accordance with similar observation in other model systems. We further showed through gain- and loss-of-function assays that PCBP1 expression levels regulate the capacity of GBC-SD cells to migrate and invade in vitro. Finally, our results showed that PCBP1 expression levels also regulate generation of CD44(+)CD24(-) progenitor cell population in GBC-SD cells after TGF-ß treatment. Cumulatively, our results indicate, pending further validation, that PCBP1 might be a prognostic marker for GBC metastasis.

Decreased pain threshold and enhanced synaptic transmission in the anterior cingulate cortex of experimental hypothyroidism mice.

BACKGROUND: Thyroid hormones are essential for the maturation and functions of the central nervous system. Pain sensitivity is related to the thyroid status. However, information on how thyroid hormones affect pain processing and synaptic transmission in the anterior cingulate cortex (ACC) is limited. Nociceptive threshold and synaptic transmission in the ACC were detected in the experimental hypothyroidism (HT) mice. RESULTS: HT was induced by methimazole and potassium perchlorate in distilled drinking water for 4 weeks. The threshold of pain perception to hot insults, but not mechanical ones, decreased in hypothyroid mice. After treatment with tri-iodothyronine (T3) or thyroxine (T4) for 2 weeks, thermal pain threshold recovered. Electrophysiological recordings revealed enhanced glutamatergic synaptic transmission and reduced GABAergic synaptic transmission in the ACC. Supplementation with T3 or T4 significantly rescued this synaptic transmission imbalance. In the same model, HT caused the up-regulation of the GluR1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and NR2B-containing N-methyl-D-aspartate receptors, but it down-regulated γ-aminobutyric acid A receptors in the ACC. Supplementation with T3 or T4 notably recovered the levels of above proteins. CONCLUSIONS: These results suggest that HT promotes hypersensitivity to noxious thermal, and that supplementation with T3 or T4 rescues the imbalance between excitatory and inhibitory transmission in the ACC.

c-Myc-mediated epigenetic silencing of MicroRNA-101 contributes to dysregulation of multiple pathways in hepatocellular carcinoma.

UNLABELLED: The MYC oncogene is overexpressed in hepatocellular carcinoma (HCC) and has been associated with widespread microRNA (miRNA) repression; however, the underlying mechanisms are largely unknown. Here, we report that the c-Myc oncogenic transcription factor physically interacts with enhancer of zeste homolog 2 (EZH2), a core enzymatic unit of polycomb repressive complex 2 (PRC2). Furthermore, miR-101, an important tumor-suppressive miRNA in human hepatocarcinomas, is epigenetically repressed by PRC2 complex in a c-Myc-mediated manner. miR-101, in turn, inhibits the expression of two subunits of PRC2 (EZH2 and EED), thus creating a double-negative feedback loop that regulates the process of hepatocarcinogenesis. Restoration of miR-101 expression suppresses multiple malignant phenotypes of HCC cells by coordinate repression of a cohort of oncogenes, including STMN1, JUNB, and CXCR7, and further increases expression of endogenous miR-101 by inhibition of PRC2 activation. In addition, co-overexpression of c-Myc and EZH2 in HCC samples was closely associated with lower expression of miR-101 (P < 0.0001) and poorer prognosis of HCC patients (P < 0.01). CONCLUSIONS: c-Myc collaborates with EZH2-containing PRC2 complex in silencing tumor-suppressive miRNAs during hepatocarcinogenesis and provides promising therapeutic candidates for human HCC.

MicroRNA-34a targets Bcl-2 and sensitizes human hepatocellular carcinoma cells to sorafenib treatment.

MiR-34a, a direct target of p53, has been shown to target several molecules associated with the cell cycle and cell survival pathways, and its dysregulation is implicated in cancer drug resistance or sensitivity in several human cancers. However, the correlation between miR-34a expression and chemoresistance has not been explored in HCC. In this study, we confirmed that miR-34a was significantly down-regulated in HCC tissues and HCC cell lines by qRT-PCR. HCC tissues with lower miR-34a expression displayed higher expression of Bcl-2 protein than those with high expression of miR-34a; therefore, an inverse correlation is evident between the miR-34a level and Bcl-2 expression. Moreover, patients with lower miR-34a expression had significantly poorer overall survival. Bioinformatics and luciferase reporter assays revealed that miR-34a binds the 3'-UTR of the Bcl-2 mRNA and represses its translation. Western blotting analysis and qRT-PCR confirmed that Bcl-2 is inhibited by miR-34a overexpression. Functional analyses indicated that the restoration of miR-34a reduced cell viability, promoted cell apoptosis and potentiated sorafenib-induced apoptosis and toxicity in HCC cell lines by inhibiting Bcl-2 expression. This study is the first to demonstrate that miR-34a induces sensitivity to the anti-tumor effect of sorafenib in human HCC cells, suggesting a potential role of miR-34a in the treatment of HCC.