Identification of liver cancer progenitors whose malignant progression depends on autocrine IL-6 signaling.

Hepatocellular carcinoma (HCC) is a slowly developing malignancy postulated to evolve from premalignant lesions in chronically damaged livers. However, it was never established that premalignant lesions actually contain tumor progenitors that give rise to cancer. Here, we describe isolation and characterization of HCC progenitor cells (HcPCs) from different mouse HCC models. Unlike fully malignant HCC, HcPCs give rise to cancer only when introduced into a liver undergoing chronic damage and compensatory proliferation. Although HcPCs exhibit a similar transcriptomic profile to bipotential hepatobiliary progenitors, the latter do not give rise to tumors. Cells resembling HcPCs reside within dysplastic lesions that appear several months before HCC nodules. Unlike early hepatocarcinogenesis, which depends on paracrine IL-6 production by inflammatory cells, due to upregulation of LIN28 expression, HcPCs had acquired autocrine IL-6 signaling that stimulates their in vivo growth and malignant progression. This may be a general mechanism that drives other IL-6-producing malignancies.

Dietary and genetic obesity promote liver inflammation and tumorigenesis by enhancing IL-6 and TNF expression.

Epidemiological studies indicate that overweight and obesity are associated with increased cancer risk. To study how obesity augments cancer risk and development, we focused on hepatocellular carcinoma (HCC), the common form of liver cancer whose occurrence and progression are the most strongly affected by obesity among all cancers. We now demonstrate that either dietary or genetic obesity is a potent bona fide liver tumor promoter in mice. Obesity-promoted HCC development was dependent on enhanced production of the tumor-promoting cytokines IL-6 and TNF, which cause hepatic inflammation and activation of the oncogenic transcription factor STAT3. The chronic inflammatory response caused by obesity and enhanced production of IL-6 and TNF may also increase the risk of other cancers.

Developing the modified 4-item version of perceived stress scale for functional dyspepsia.

BACKGROUND: To develop the modified 4-item version of Perceived Stress Scale (PSS) with a better reliability and validity than the 4-item version of PSS (PSS-4) in evaluating psychological stress in patients with functional dyspepsia (FD). The present study also aimed to explore the correlation between dyspepsia symptoms severity (DSS), anxiety, depression, somatization, quality of life (QoL), and psychological stress assessed by two approaches in FD. METHODS: A total of 389 FD patients who met the Roman IV criteria completed the 10-item version of the PSS (PSS-10), and 4/10 items were selected by five methods, such as Cronbach's coefficient, exploratory factor analysis (EFA), correlation coefficient, discrete degree, and item analysis, to develop the modified PSS-4. The reliability and validity of the modified PSS-4 and the PSS-4 were compared by internal consistency, EFA, and confirmatory factor analysis (CFA). The correlation between psychological stress assessed by two approaches and DSS, anxiety, depression, somatization, and QoL was explored by Pearson's correlation coefficient and multiple linear regression analysis. RESULTS: Cronbach's α coefficient of the modified PSS-4 and the PSS-4 was 0.855 and 0.848, respectively, and a common factor was extracted. The cumulative contribution rate of one factor to the overall variance for the modified PSS-4 and the PSS-4 was 70.194% and 68.698%, respectively. The model used for the modified PSS-4 showed that the values of the goodness-of-fit index (GFI) and the adjusted GFI (AGFI) were 0.987 and 0.933, respectively, indicating that the model fitted well. Psychological stress was correlated to DSS, anxiety, depression, somatization, and QoL as assessed by the modified PSS-4 and PSS-4. Multiple linear regression analysis revealed that psychological stress was correlated to somatization, as assessed by the modified PSS-4 (ß = 0.251, P < 0.001) and PSS-4 (ß = 0.247, P < 0.001). Psychological stress, DSS, and somatization were correlated to QoL, as assessed by the modified PSS-4 (ß = 0.173, P < 0.001) and the PSS-4 (ß = 0.167, P < 0.001). CONCLUSIONS: The modified PSS-4 showed better reliability and validity, and psychological stress had a greater effect on the somatization and QoL of FD patients assessed by the modified PSS-4 than PSS-4. These findings were helpful for further investigation of the clinical application of the modified PSS-4 in FD.

Developing the Patient Health Questionnaire-8 for a greater impact on the quality of life of patients with functional dyspepsia compared to Somatic Symptom Scale-8.

BACKGROUND: To develop the Patient Health Questionnaire-8 (PHQ-8) as a more reliable approach than the Somatic Symptom Scale-8 (SSS-8), evaluating somatization which might be a critical factor influencing the quality of life (QoL) in patients with functional dyspepsia (FD). Also, the effects of somatization on QoL of FD patients were assessed by these two approaches. METHODS: Herein, 612 FD patients completed a questionnaire involving 25 items. 8/25 items were selected to develop the PHQ-8 by four methods of discrete degree, correlation coefficient, factor analysis, and Cronbach's α coefficient. Reliability and validity of the PHQ-8 and the SSS-8 were compared by principal component and confirmatory factor analyses. The effects of somatization, depression, and anxiety on the Nepean Dyspepsia Index (NDI) for QoL were explored by Pearson's correlation coefficient and linear regression analysis. RESULTS: The Cronbach's α coefficient for the PHQ-8 and the SSS-8 was 0.601 and 0.553, respectively, and the cumulative contribution rate of three extracted factors for the developed PHQ-8 and SSS-8 was 55.103% and 51.666%, respectively. Somatization evaluated by the PHQ-8 (r = 0.309, P < 0.001) and the SSS-8 (r = 0.281, P < 0.001) was found to be correlated to NDI. The model used for the PHQ-8 showed that the values of goodness-of-fit index (GFI) and adjusted GFI (AGFI) were 0.984 and 0.967, respectively, which indicated that the model fitted well. Linear regression analysis unveiled that somatization (ß = 0.270, P < 0.001), anxiety (ß = 0.163, P < 0.001), and depression (ß = 0.136, P = 0.003) assessed by the PHQ-8 were correlated to NDI. In addition, somatization (ß = 0.250, P < 0.001), anxiety (ß = 0.156, P < 0.001), and depression (ß = 0.155, P = 0.001) evaluated by the SSS-8 were correlated to NDI. CONCLUSIONS: PHQ-8 showed a superior reliability and validity, and somatization assessed by the developed PHQ-8 showed a greater influence on the QoL of FD patients as compared to the SSS-8. Our findings suggested that the developed PHQ-8 may show improvement in a reliable assessment of the effects of somatization on FD patients in lieu of the SSS-8.

Hepatic expression of HCV RNA-dependent RNA polymerase triggers innate immune signaling and cytokine production.

Innate immunity controls pathogen replication and spread. Yet, certain pathogens, such as Hepatitis C Virus (HCV), escape immune elimination and establish persistent infections that promote chronic inflammation and related diseases. Whereas HCV regulatory proteins that attenuate antiviral responses are known, those that promote inflammation and liver injury remain to be identified. Here, we show that transient expression of HCV RNA-dependent RNA polymerase (RdRp), NS5B, in mouse liver and human hepatocytes results in production of small RNA species that activate innate immune signaling via TBK1-IRF3 and NF-κB and induce cytokine production, including type I interferons (IFN) and IL-6. NS5B-expression also results in liver damage.

Synergy of 5-aminolevulinate supplement and CX3CR1 suppression promotes liver regeneration via elevated IGF-1 signaling.

Inadequate remnant volume and regenerative ability of the liver pose life-threatening risks to patients after partial liver transplantation (PLT) or partial hepatectomy (PHx), while few clinical treatments focus on safely accelerating regeneration. Recently, we discovered that supplementing 5-aminolevulinate (5-ALA) improves liver cold adaptation and functional recovery, leading us to uncover a correlation between 5-ALA metabolic activities and post-PLT recovery. In a mouse 2/3 PHx model, 5-ALA supplements enhanced liver regeneration, promoting infiltration and polarization of anti-inflammatory macrophages via P53 signaling. Intriguingly, chemokine receptor CX3CR1 functions to counterbalance these effects. Genetic ablation or pharmacological inhibition of CX3CR1 (AZD8797; phase II trial candidate) augmented the macrophagic production of insulin-like growth factor 1 (IGF-1) and subsequent hepatocyte growth factor (HGF) production by hepatic stellate cells. Thus, short-term treatments with both 5-ALA and AZD8797 demonstrated pro-regeneration outcomes superior to 5-ALA-only treatments in mice after PHx. Overall, our findings may inspire safe and effective strategies to better treat PLT and PHx patients.

Targeted deletion of hepatocyte Ikkbeta confers growth advantages.

Mice lacking hepatocyte IKKbeta (Ikkbeta(Delta hep)) are defective in TNFalpha-activation of hepatocellular transcription factor NF-kappaB, and highly susceptible to hepatotoxicity. Following diethylnitrosamine (DEN) exposure, Ikkbeta(Delta hep) mice develop more hepatocellular carcinoma (HCC) than control mice due partly to enhanced DEN-induced hepatocyte death. Here we show that Ikkbeta(Delta hep) hepatocytes display growth advantages over normal hepatocytes consisting of precocious PCNA and cyclin D1 expression during liver regeneration (shortened hepatocyte G(0)-->G(1) transitions), and enhanced recovery efficiency, cyclin D1 expression and cell proliferation after plating. Ex vivo deletion of Ikkbeta also accelerates hepatocyte growth. Ikkbeta(Delta hep) hepatocyte proliferative responses show heightened sensitivity to TGFalpha and TNFalpha, and heightened expression of fibronectin, collagens I/III, nidogen, beta-actin and integrin beta1 mRNAs. These findings suggest that altered mitogen signaling and expression of extracellular matrix and its associated components underlie growth advantages. Increased HCC development in Ikkbeta(Delta hep) mice may also be caused by growth advantages of surviving Ikkbeta-deleted hepatocytes.

Thiazolidinediones inhibit insulin-like growth factor-i-induced activation of p70S6 kinase and suppress insulin-like growth factor-I tumor-promoting activity.

Thiazolidinediones are a novel class of antidiabetic drugs that improve insulin sensitivity in type 2 diabetic patients. Recently, these compounds have also been shown to suppress tumor development in several animal models. The molecular basis for their antitumor action, however, is largely unknown. We report here that oral administration of thiazolidinediones (rosiglitazone and troglitazone) remarkably inhibited insulin-like growth factor-I (IGF-I)-promoted skin tumor development by 73% in BK5.IGF-1 transgenic mice, although they were previously found to be ineffective in inhibiting UV- or chemically induced mouse skin tumorigenesis. The anti-IGF-I effect of troglitazone in mouse skin keratinocytes was due to, at least partially, inhibition of IGF-I-induced phosphorylation of p70S6 kinase (p70S6K) at Thr(389), a site specifically phosphorylated by mammalian target of rapamycin (mTOR). Troglitazone did not directly inhibit mTOR kinase activity as shown by mTOR in vitro kinase assay but rapidly activated AMP-activated protein kinase (AMPK) through a yet undefined peroxisome proliferator-activated receptor gamma-independent mechanism. Expression of a dominant-negative AMPK reversed the inhibitory effect of troglitazone on IGF-I-induced phosphorylation of p70S6K, suggesting that troglitazone inhibited IGF-I and p70S6K signaling through activation of AMPK. Collectively, these data suggest that thiazolidinediones specifically inhibit IGF-I tumor-promoting activity in mouse skin through activation of AMPK and subsequent inhibition of p70S6K.

Association of Antenatal Micronutrient Supplementation With Adolescent Intellectual Development in Rural Western China: 14-Year Follow-up From a Randomized Clinical Trial.

Importance: The association of micronutrient supplementation during pregnancy with the intellectual development of adolescent offspring is unknown. Objective: To assess the long-term association of antenatal micronutrient supplementation with adolescent intellectual development. Design, Setting, and Participants: This 14-year follow-up study of a randomized clinical trial of micronutrient supplementation in pregnancy was conducted in 2 counties in rural western China in 2118 adolescent offspring (aged 10 to 14 years) of mothers who were randomized to take a daily capsule of either folic acid, folic acid plus iron, or multiple micronutrients from August 1, 2002, through February 28, 2006. Follow-up was conducted from June 1, 2016, through December 31, 2016. Data analyses took place from April 1, 2017, to June 20, 2017. Main Outcomes and Measures: Adolescent full-scale intelligence quotient and aspects of verbal comprehension, working memory, perceptual reasoning, and processing speed indexes were assessed by the Wechsler Intelligence Scale for Children. Results: Of 2118 adolescent offspring, 1252 (59.1%) were boys and 866 (40.9%) were girls, with a mean (SD) age of 11.7 (0.87) years, representing 47.2% of the 4488 single live births that were eligible to participate. Compared with folic acid supplementation, multiple micronutrient supplementation was associated with a 1.13-point higher full-scale intelligence quotient (95% CI, 0.15-2.10) and a 2.03-point higher verbal comprehension index (95% CI, 0.61-3.45); similar results were found in comparison with folic acid plus iron. When mothers initiated supplementation early (<12 weeks of gestation) and had an adequate dose (≥180 capsules), multiple micronutrient capsules were associated with a 2.16-point higher full-scale intelligence quotient (95% CI, 0.41-3.90) and 4.29-point higher verbal comprehension index (95% CI, 1.33-7.24) compared with folic acid capsules. The mean test scores were lower in the substratum of supplementation initiated late (≥12 weeks of gestation) and with an inadequate dose (<180 capsules). The multiple micronutrient group had higher scores than the other 2 treatment groups, and significant differences were observed for full-scale intelligence quotient (adjusted mean difference, 2.46; 95% CI, 0.98-3.94) when compared with the folic acid plus iron group. Conclusions and Relevance: Compared with folic acid plus iron or folic acid capsules supplementation, antenatal multiple micronutrient supplementation appeared to be associated with increased adolescent intellectual development; initiating supplementation in the first trimester and then continuing for at least 180 days were associated with the greatest rewards. Trial Registration: isrctn.org Identifier: ISRCTN08850194.

Prostaglandin receptor EP2 is responsible for cyclooxygenase-2 induction by prostaglandin E2 in mouse skin.

The EP2 prostanoid receptor is one of the four subtypes of receptors for prostaglandin E2 (PGE2). We previously reported that deletion of EP2 led to resistance to chemically induced mouse skin carcinogenesis, whereas overexpression of EP2 resulted in enhanced tumor development. The purpose of this study was to investigate the underlying molecular mechanisms. We found that EP2 knockout mice had reduced cyclooxygenase-2 (COX-2) expression after 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment compared with wild-type (WT) mice. Further, primary keratinocytes from EP2 transgenic mice had increased COX-2 expression after either TPA or PGE2 treatment and COX-2 expression was blocked by 10 microM SQ 22,536, an adenylate cyclase inhibitor. EP2 knockout mice had significantly decreased, whereas EP2 transgenic mice had significantly increased PGE2 production in response to a single treatment of TPA. Cyclic AMP response element-binding protein (CREB) phosphorylation was elevated to a greater extent in keratinocytes from EP2 transgenic mice compared with those of WT mice following PGE2 treatment. A protein kinase A (PKA) inhibitor reduced PGE2-mediated CREB phosphorylation in keratinocytes from EP2 transgenic mice. Furthermore, we found that there was no CREB phosphorylation in EP2 knockout mice following PGE2 treatment. PGE2-induced DNA synthesis (cell proliferation) was significantly decreased in keratinocytes from EP2 knockout mice following pretreatment with 10 microM SQ 22,536. Taken together, EP2 activation of the PKA/CREB-signaling pathway is responsible for keratinocyte proliferation and our findings reveal a positive feedback loop between COX-2 and PGE2 that is mediated by the EP2 receptor.

Lack of expression of the EP2 but not EP3 receptor for prostaglandin E2 results in suppression of skin tumor development.

The EP2 receptor for prostaglandin E2 (PGE2) is a membrane receptor that mediates at least part of the action of PGE2. It has been shown that EP2 plays a critical role in tumorigenesis in mouse mammary gland and colon. However, the possibility that the EP2 receptor is involved in the development of skin tumors was unknown. The purpose of this study was to investigate the role of the EP2 receptor in mouse skin carcinogenesis. Unlike EP3 knockout mice, the EP2 knockout mice produced significantly fewer tumors and reduced tumor incidence compared with wild type (WT) mice in a 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) two-stage carcinogenesis protocol. EP2 knockout mice had significantly reduced cellular proliferation of mouse skin keratinocytes in vivo and in vitro compared with that in WT mice. In addition, the epidermis of EP2 knockout mice 48 hours after topical TPA treatment was significantly thinner compared with that of WT mice. The inflammatory response to TPA was reduced in EP2 knockout mice, based on a reduced number of macrophages in the dermis and a reduced level of interleukin-1alpha mRNA expression, compared with WT mice. EP2 knockout mice also had significantly reduced epidermal cyclic AMP levels after PGE2 treatment compared with WT mice. Tumors from WT mice produced more blood vessels and fewer apoptotic cells than those of EP2 knockout mice as determined by immunohistochemical staining. Our data suggest that the EP2 receptor plays a significant role in the protumorigenic action of PGE2 in skin tumor development.

Troglitazone induction of COX-2 expression is dependent on ERK activation in keratinocytes.

Cyclooxygenase-2 (COX-2) plays an important role in tumorigenesis of several tissues, including skin. We report here that troglitazone, a thiazolidinedione class of antidiabetic drug, induced COX-2 expression at both the protein and mRNA levels and increased production of prostaglandin E2 (PGE2) in cultured keratinocytes. Troglitazone-induced COX-2 expression in keratinocytes was likely peroxisome proliferator-activated receptor gamma (PPARgamma)-independent. Troglitazone treatment of these cells also resulted in a sustained increase in phosphorylation of ERK. We show that induction of COX-2 by troglitazone was almost completely inhibited by specific inhibitors of ERK activation. These data suggest that troglitazone is capable of inducing COX-2 expression through an ERK-dependent mechanism in mouse skin keratinocytes.

Troglitazone inhibits cyclin D1 expression and cell cycling independently of PPARgamma in normal mouse skin keratinocytes.

Troglitazone is one of the thiazolidinedione (TZD) class of anti-diabetic drugs and a ligand for peroxisome proliferator-activated receptor gamma (PPARgamma). Troglitazone and other PPARgamma ligands have been shown to inhibit cell proliferation and induce cell cycle arrest in a variety of cancer cells, and have been considered as potential tumor preventive and tumor therapeutic agents. Little is known, however, about how normal or initiated cells respond to these agents during mouse skin carcinogenesis. We report here that troglitazone and another TZD, ciglitazone, dramatically inhibited mitogen-induced cellular proliferation in normal mouse skin primary keratinocytes and in the C50 keratinocyte cell line. This was accompanied by induction of cell cycle G1 phase arrest and suppression of cyclin D1, cdk4, and cdk2 expression. Troglitazone suppressed cyclin D1 expression at multiple levels. In addition, we demonstrated that PPARgamma was not expressed at functional levels in cultured mouse skin keratinocytes, and that the inhibitory effects of troglitazone on cellular proliferation and cyclin D1 expression in these cells were PPARgamma-independent. Given the important role of keratinocyte proliferation in skin carcinogenesis, our data suggest that TZD may be useful tumor preventive agents in skin.

[The preventive and therapeutic effects of low molecular weight heparin on DSS-induced colitis in mice].

OBJECTIVE: To evaluate the preventive and therapeutic effects of low molecular weight heparin (LMWH) on dextran sulphate sodium (DSS)-induced colitis in mice. METHODS: Twenty normal mice were randomized into two groups: 10 mice of the prevention group received DSS per os and LMWH by sub-cutaneous injection for 7 days; 10 mice as controls received DSS per os and sub-cutaneous normal saline for 7 days. Another 20 mice with DSS-induced colitis were randomized into two groups: the treatment group received sub-cutaneous injection of LMWH and the control group received subcutaneous injection of normal saline for 7 days. The preventive and therapeutic effects of LMWH were assessed by disease activity index (DAI), histologic score and MSB fibrin staining to identify microvascular thrombus. RESULTS: The DAI, rectal and transverse histological scores of the prevention group compared with those of the control group were 2.40 vs 2.52 (P > 0.05), 1.65 vs 1.85 (P > 0.05), 1.55 vs 1.72 (P > 0.05), respectively. Microvascular thrombi in the prevention group decrease significantly as compared with the control; microvascular thrombi were positive in 6 of 10 controls, but only one was positive in the prevention group, P = 0.029. The DAI, rectal and transverse histological scores in the treatment group compared with those of the control were 0.42 vs 0.44 (P > 0.05), 1.36 vs 1.75(P < 0.05), 1.30 vs 1.65(P < 0.05), respectively. Microvascular thrombi were positive in 3 of 10 controls, and one microvascular thromous was positive in the treatment group, P = 0.291. CONCLUSION: LMWH could effectively prevent microvascular thrombosis and inhibit colonic and rectal inflammation in the mice with DSS-induced colitis. These animal experimental results suggested that LMWH might also be used effectively in ulcerative colitis.

p38α inhibits liver fibrogenesis and consequent hepatocarcinogenesis by curtailing accumulation of reactive oxygen species.

Most hepatocellular carcinomas (HCC) develop in the context of severe liver fibrosis and cirrhosis caused by chronic liver inflammation, which also results in accumulation of reactive oxygen species (ROS). In this study, we examined whether the stress-activated protein kinase p38α (Mapk14) controls ROS metabolism and development of fibrosis and cancer in mice given thioacetamide to induce chronic liver injury. Liver-specific p38α ablation was found to enhance ROS accumulation, which appears to be exerted through the reduced expression of antioxidant protein HSP25 (Hspb1), a mouse homolog of HSP27. Its reexpression in p38α-deficient liver prevents ROS accumulation and thioacetamide-induced fibrosis. p38α deficiency increased expression of SOX2, a marker for cancer stem cells and the liver oncoproteins c-Jun (Jun) and Gankyrin (Psmd10) and led to enhanced thioacetamide-induced hepatocarcinogenesis. The upregulation of SOX2 and c-Jun was prevented by administration of the antioxidant butylated hydroxyanisole. Intriguingly, the risk of human HCC recurrence is positively correlated with ROS accumulation in liver. Thus, p38α and its target HSP25/HSP27 appear to play a conserved and critical hepatoprotective function by curtailing ROS accumulation in liver parenchymal cells engaged in oxidative metabolism of exogenous chemicals. Augmented oxidative stress of liver parenchymal cells may explain the close relationship between liver fibrosis and hepatocarcinogenesis.

Preclinical evaluation of the toxicological effects of a novel constrained ethyl modified antisense compound targeting signal transducer and activator of transcription 3 in mice and cynomolgus monkeys.

ISIS 481464 is a constrained ethyl (cEt) modified phosphorothioate antisense oligonucleotide (ASO) targeting signal transducer and activator of transcription 3 (STAT3) studied in mice and monkey to support oncology clinical trials. Six-week toxicology studies were performed in mice and cynomolgus monkey (up to 70 and 30 mg/kg/week respectively). Reduction in STAT3 protein up to 90% of control was observed in monkey. Cynomolgus monkey was considered the most relevant species to human with respect to pharmacokinetic properties, but mice are useful in their relative sensitivity to the potential proinflammatory and hepatic effects of oligonucleotides. In monkeys, there was no impact on organ function at doses up to 30 mg/kg/week for 6 weeks. Minimal to slight proximal tubular epithelial cell degeneration and regeneration within the kidney was observed, which had no impact on renal function and showed reversibility at the end of the treatment-free period. Additionally, mild and transient activated partial thromboplastin time elevations and mild increases in complement Bb were observed at the higher doses by intravenous dosing only. In mice, the alterations at 70 mg/kg/week included spleen weight increase up to 1.4-fold relative to control, increases in alanine aminotransferase and aspartate aminotransferase up to 1.8-fold over control, interleukin-10 increases up to 3.7-fold, and monocyte chemoattractant protein-1 increase up to 1.9-fold over control. No significant clinical pathology or histopathology changes were seen in mice at 20 mg/kg/week or less. The toxicity profile of ISIS 481464 is consistent with effects observed with phosphorothioate ASOs containing 2'-O-methoxyethylribose modifications instead of cEt.

NF-κB and STAT3 - key players in liver inflammation and cancer.

Hepatocellular carcinoma (HCC), the major form of primary liver cancer, is one of the most deadly human cancers. The pathogenesis of HCC is frequently linked with continuous hepatocyte death, inflammatory cell infiltration and compensatory liver regeneration. Understanding the molecular signaling pathways driving or mediating these processes during liver tumorigenesis is important for the identification of novel therapeutic targets for this dreadful disease. The classical IKKß-dependent NF-κB signaling pathway has been shown to promote hepatocyte survival in both developing and adult livers. In addition, it also plays a crucial role in liver inflammatory responses by controlling the expression of an array of growth factors and cytokines. One of these cytokines is IL-6, which is best known for its role in the liver acute phase response. IL-6 exerts many of its functions via activation of STAT3, a transcription factor found to be important for HCC development. This review will focus on recent studies on the roles of NF-κB and STAT3 in liver cancer. Interactions between the two pathways and their potential as therapeutic targets will also be discussed.

Hepatocyte IKKbeta/NF-kappaB inhibits tumor promotion and progression by preventing oxidative stress-driven STAT3 activation.

The NF-kappaB activating kinase IKKbeta suppresses early chemically induced liver tumorigenesis by inhibiting hepatocyte death and compensatory proliferation. To study IKKbeta's role in late tumor promotion and progression, we developed a transplant system that allows initiated mouse hepatocytes to form hepatocellular carcinomas (HCC) in host liver after a long latency. Deletion of IKKbeta long after initiation accelerated HCC development and enhanced proliferation of tumor initiating cells. These effects of IKKbeta/NF-kappaB were cell autonomous and correlated with increased accumulation of reactive oxygen species that led to JNK and STAT3 activation. Hepatocyte-specific STAT3 ablation prevented HCC development. The negative crosstalk between NF-kappaB and STAT3, which is also evident in human HCC, is a critical regulator of liver cancer development and progression.

Hepatocyte necrosis induced by oxidative stress and IL-1 alpha release mediate carcinogen-induced compensatory proliferation and liver tumorigenesis.

Hepatocyte I kappaB kinase beta (IKK beta) inhibits hepatocarcinogenesis by suppressing accumulation of reactive oxygen species (ROS) and liver damage, whereas JNK1 activation promotes ROS accumulation, liver damage, and carcinogenesis. We examined whether hepatocyte p38 alpha, found to inhibit liver carcinogenesis, acts similarly to IKK beta in control of ROS metabolism and cell death. Hepatocyte-specific p38 alpha ablation enhanced ROS accumulation and liver damage, which were prevented upon administration of an antioxidant. In addition to elevated ROS accumulation, hepatocyte death, augmented by loss of either IKK beta or p38 alpha, was associated with release of IL-1 alpha. Inhibition of IL-1 alpha action or ablation of its receptor inhibited carcinogen-induced compensatory proliferation and liver tumorigenesis. IL-1 alpha release by necrotic hepatocytes is therefore an important mediator of liver tumorigenesis.

The microvascular thrombi of colonic tissue in ulcerative colitis.

Mucosal microvascular thrombi in rectal biopsies were observed in some ulcerative colitis (UC). Heparin may be effective in steroid resistant UC in some studies, however, the new results of meta-analysis demonstrated a non-significant effect of heparin in controlled clinical trials, differing markedly from observational studies. The objective of this study was to identify colonic microvascular thrombi in larger cases with UC, and analyse its possible risk factors: age, gender, histologic score, extent of lesions and operation or biopsy specimens, and assess the significance of microvascular thrombosis in patients with UC. The microvascular thrombi were identified by immunohistochemical staining with anti-CD61 monoclonal antibody and Martius scarlet blue (MSB) staining in 40 colonic tissue samples of UC (31 biopsy specimens and nine operated cases) and 12 cases of normal colon tissue from operated colonic carcinoma. Logistic regression analysis was used to assess the relationship of age, gender, degree of histology, origin of the specimens, extent of lesions and microvascular thrombi examined. Microvascular thrombi were positive in 14 of 40 UC cases, and none in the controls. The presence of microvascular thrombi was related to operation specimens with odds ratio 11.667, P=0.0179, it might be also related to histologic score (OR=1.350) and extent of lesions (OR=1.619). These results suggest that microvascular thrombosis may be one of the important pathogenesis in some UC, and that the effect of anticoagulant treatment still needs to be assessed.