We identified that suppressor of cytokine signaling-3 (SOCS-3) gene was aberrantly methylated in its CpG island in three of 10 human hepatocellular carcinoma (HCC) cell lines. SOCS-3 RNA was undetectable in five of the 10 HCC cell lines including the three methylated cell lines, and a demethylating agent, 5-aza-2 0 -deoxycytidine, reactivated SOCS-3 expression in three cell lines tested. The DNA region where we found aberrant DNA methylation includes a signal transducers and activators of transcription (STAT) binding consensus sequence. When the DNA region was used as a promoter, DNA methylation markedly reduced promoter activity. SOCS-3 was also aberrantly methylated in six of 18 primary HCC samples. SOCS-3 expression was reduced in three of the three methylated and one of the three unmethylated primary samples examined. Restoration of SOCS-3 in cells lacking SOCS-3 expression suppressed STAT3 phosphorylation and cell growth. We found that IL-6 acted as a growth factor in HCC cells. Inhibition of SOCS-3 expression in cells whose growth was induced by IL-6 enhanced STAT3 phosphorylation and cell growth. In addition, AG490, a chemical JAK2 inhibitor, suppressed cell growth and downregulated STAT3 phosphorylation, but not FAK phosphorylation. We also found that SOCS-3 physically interacted with phosphorylated FAK and Elongin B in HCC cells. Restoration of SOCS-3 decreased FAK phosphorylation as well as FAK protein level. Inhibition of SOCS-3 expression increased FAK phosphorylation, resulting in enhancement of cell migration. These data indicate that SOCS-3 negatively regulates cell growth and cell motility by inhibiting Janus kinase (JAK)/STAT and FAK signalings in HCC cells. Thus, loss of SOCS-3 by the associated DNA methylation confers cells advantage in growth and migration.

Taurine effectively improves metabolism in OLETF rats by decreasing serum cholesterol and triacylglycerol, presumably via increased secretion of cholesterol into bile acid and decreased production of cholesterol because of increased nitric oxide production.

ubclinical hypothyroidism (SCH), defined as high serum thyroid-stimulating hormone (TSH) levels and normal levels of serum free-triiodothyronine (fT3) and serum free-thyroxine (fT4), is a common medical problem among the elderly. The prevalence of SCH has been reported to be 4-10% in the general population and up to 20% in women older than 60 years. [1][2][3] The incidence of SCH is 2.1-3.8% per year in thyroid-antibody-positive subjects and 0.3% per year in thyroid-antibody-negative subjects. 4 Serum lipid levels in SCH have been reported as either normal 5 or elevated. 6,7 In the Tromsø study, low-density lipoprotein-cholesterol (LDL-C) levels were significantly higher in subjects with SCH compared with controls 7 and, moreover, they were reduced with thyroxine treatment. In addition, associations between left ventricular function and SCH have been widely investigated, but the findings are controversial. Some studies have shown an association between SCH and poor left ventricular function and others have not. 8 Moreover, the positive association between arterial stiffness and hypothyroidism, even in the subclinical stage, has been reported. 9,10 Subclinical hyperthyroidism has been associated with a higher prevalence of atrial fibrillation (AF) and increased heart rate, 8 but not with elevated serum lipid levels. 6 Circulation Journal Vol.71, February 2007 In the present study we investigated whether subclinical thyroid dysfunction in Japanese individuals is associated with various phenotypes related to cardiovascular disease and metabolic syndromes. Methods Study PopulationThe selection criteria and design of the Suita study have been described previously. 11-13 Serum TSH, fT3, and fT4 levels were measured in 3,607 subjects who were not being treated for thyroid disease. The present study was approved by the Ethics Committee of the National Cardiovascular Center, and all subjects provided written informed consent. We categorized patients into 5 groups: normal (normal levels of serum TSH [0.436-3.78 U/ml], fT3 [2.1-4.1 pg/ml] and fT4 [1.0-1.7 ng/dl]), hyperthyroidism (low levels of TSH and high levels of fT3 and/or fT4), hypothyroidism (high levels of TSH and low levels of fT3 and/or fT4), SCH (high levels of TSH and normal levels of fT3 and fT4), and subclinical hyperthyroidism (low levels of TSH and normal levels of fT3 and fT4). 14 Body mass index (BMI) was calculated as body weight (kg) divided by height in square meters.The intima -media thickness (IMT) was measured on longitudinal scan of the common carotid artery at a point 10 mm proximal from the beginning of the dilation of the bulb. 11 Serum TSH, fT3, and fT4 LevelsFasting serum samples were collected at study entry and stored at -80°C until tests were run. Serum TSH was mea- Characterization of Subclinical Thyroid Dysfunction From Cardiovascular and Metabolic ViewpointsThe Suita Study Naoyuki Takashima, MD; Yasuharu Niwa, PhD; Toshifumi Mannami, MD* , **; Hitonobu Tomoike, MD*; Naoharu Iwai, MDBackground Subclinical hypothyroidism, defined as hi...

JapanInflammatory markers have been associated with increased risk of several cancers, including colon, lung, breast and liver, but the evidence is inconsistent. We conducted a nested case-control study in the longitudinal cohort of atomic-bomb survivors. The study included 224 hepatocellular carcinoma (HCC) cases and 644 controls individually matched to cases on gender, age, city and time and method of serum storage, and countermatched on radiation dose. We measured C-reactive protein (CRP) and interleukin (IL)-6 using stored sera obtained within 6 years before HCC diagnosis from 188 HCC cases and 605 controls with adequate volumes of donated blood. Analyses with adjustment for hepatitis virus infection, alcohol consumption, smoking habit, body mass index (BMI) and radiation dose showed that relative risk (RR) of HCC [95% confidence interval (CI)] in the highest tertile of CRP levels was 1.94 (0.72-5.51) compared to the lowest tertile (p 5 0.20). RR of HCC (95% CI) in the highest tertile of IL-6 levels was 5.12 (1.54-20.1) compared to the lowest tertile (p 5 0.007). Among subjects with BMI > 25.0 kg=m 2 , a stronger association was found between a 1-standard deviation (SD) increase in log IL-6 and HCC risk compared to subjects in the middle quintile of BMI (21.3-22.9 kg=m 2 ), resulting in adjusted RR (95% CI) of 3.09 (1.78-5.81; p 5 0.015). The results indicate that higher serum levels of IL-6 are associated with increased HCC risk, independently of hepatitis virus infection, lifestyle-related factors and radiation exposure. The association is especially pronounced among subjects with obesity.

xposure to particulate matter air pollution has been reported to be associated with death and hospitalization from cardiovascular causes. 1,2 The mechanism by which long-term exposure to fine particulate matter increases the risk of cardiovascular disease remains uncertain. Accelerated atherosclerosis and vulnerability to plaque rupture have been documented in experimental animal models exposed to particulate matter, 3,4 and ambient pollution has been correlated with elevated blood pressure (BP) 5-8 and heart rate (HR) 9 in humans. Moreover, the duration of exhaust exposure in highway toll collectors has been shown to be associated with carotid intima -media thickening. 10 We recently showed that a 10-week intra-tracheal dispersion of carbon black (CB) induced atherosclerosis in low-density lipoprotein receptor knock-out (LDLR/KO) mice and the explanation appeared to be the inflammatory responses against deposited CB in the lungs. 11 It has been postulated that inhalation of fine particulate matter might cause inflammation in the lung, and that this low-grade and prolonged inflammation might accelerate atherothrombotic diseases. 12,13 On the other hand, a more direct role of nanomaterials has been proposed, based on the study by Nemmar et al that showed rapid translocation of inhaled nano-sized carbon particles into the bloodstream of humans. 14 Our in-vitro studies also suggested that nano-sized particulate matter might penetrate alveoli into circulating blood, and might directly damage endothelial cells, activate mononuclear cells, and aggregate platelets to accelerate the formation of atherothrombotic diseases. [15][16][17] In our previous analysis of the effect of CB exposure in LDLR/KO mice, 11 CB was not detected in tissues other than the lungs. Thus, it is unlikely that dispersed CB translocates into the circulating blood and directly damages target tissues or cells. However, the method of CB exposure in the previous study was intratracheal dispersion, which might not mimic the physiological responses elicited by the common route of exposure in humans. It is possible that CB particles administered by intra-tracheal dispersion may more easily aggregate and deposit in alveolar regions than CB particles dispersed in the respiratory air. With whole-body inhalation exposure to nano-sized CB particles, CB might translocate into circulating blood and reach target tissues. To assess this possibility, we examined whether exposure of rats to nano-sized CB particles by inhalation causes translocation of CB particles into the circulation and increases cardiovascular risk by exerting direct adverse effects on extrapulmonary tissues. Inhalation Exposure to Carbon Black Induces Inflammatory Response in RatsYasuharu Niwa, PhD*; Yumiko Hiura, PhD*; Hiromi Sawamura, MS; Naoharu Iwai, MD Background A link between exposure to fine particulate matter and cardiovascular events has been established. Inhaled nanoparticles are thought to pass through the lungs to reach other tissues via systemic circulation and to induce cell or...