Antitumoral gene-based strategy involving nitric oxide synthase type III overexpression in hepatocellular carcinoma.

Hepatocellular carcinoma develops in cirrhotic liver. The nitric oxide (NO) synthase type III (NOS-3) overexpression induces cell death in hepatoblastoma cells. The study developed gene therapy designed to specifically overexpress NOS-3 in cultured hepatoma cells, and in tumors derived from orthotopically implanted tumor cells in fibrotic livers. Liver fibrosis was induced by CCl4 administration in mice. The first-generation adenoviruses were designed to overexpress NOS-3 or green fluorescent protein, and luciferase complementary DNA under the regulation of murine alpha-fetoprotein (AFP) and Rous Sarcoma Virus (RSV) promoters, respectively. Both adenovirus and Hepa 1-6 cells were used for in vitro and in vivo experiments. Adenoviruses were administered through the tail vein 2 weeks after orthotopic tumor cell implantation. AFP-NOS-3/RSV-luciferase increased oxidative-related DNA damage, p53, CD95/CD95L expression and caspase-8, -9 and -3 activities in cultured Hepa 1-6 cells. The increased expression of CD95/CD95L and caspase-8 activity was abolished by Nω-nitro-l-arginine methyl ester hydrochloride, p53 and CD95 small interfering RNA. AFP-NOS-3/RSV-luciferase adenovirus increased cell death markers, and reduced cell proliferation of established tumors in fibrotic livers. The increase of oxidative/nitrosative stress induced by NOS-3 overexpression induced DNA damage, p53, CD95/CD95L expression and cell death in hepatocellular carcinoma cells. The effectiveness of the gene therapy has been demonstrated in vitro and in vivo.

Obesity-dependent metabolic signatures associated with nonalcoholic fatty liver disease progression.

Our understanding of the mechanisms by which nonalcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH) is still very limited. Despite the growing number of studies linking the disease with altered serum metabolite levels, an obstacle to the development of metabolome-based NAFLD predictors has been the lack of large cohort data from biopsy-proven patients matched for key metabolic features such as obesity. We studied 467 biopsied individuals with normal liver histology (n=90) or diagnosed with NAFLD (steatosis, n=246; NASH, n=131), randomly divided into estimation (80% of all patients) and validation (20% of all patients) groups. Qualitative determinations of 540 serum metabolite variables were performed using ultraperformance liquid chromatography coupled to mass spectrometry (UPLC-MS). The metabolic profile was dependent on patient body-mass index (BMI), suggesting that the NAFLD pathogenesis mechanism may be quite different depending on an individual's level of obesity. A BMI-stratified multivariate model based on the NAFLD serum metabolic profile was used to separate patients with and without NASH. The area under the receiver operating characteristic curve was 0.87 in the estimation and 0.85 in the validation group. The cutoff (0.54) corresponding to maximum average diagnostic accuracy (0.82) predicted NASH with a sensitivity of 0.71 and a specificity of 0.92 (negative/positive predictive values=0.82/0.84). The present data, indicating that a BMI-dependent serum metabolic profile may be able to reliably distinguish NASH from steatosis patients, have significant implications for the development of NASH biomarkers and potential novel targets for therapeutic intervention.

Neuroprotective effect of carvedilol and melatonin on 3-nitropropionic acid-induced neurotoxicity in neuroblastoma.

In neurodegenerative diseases, progressive oxidative stress is a major event that precedes neuronal death. Oxidative stress is characterized by an imbalance between oxidants and antioxidants. This imbalance induced oxidative molecular and cell damage, reducing cellular viability. 3-Nitropropionic acid (3NP) causes oxidative stress and other molecular and cellular changes similar to those observed in neurons of patients with Huntington's disease. Since carvedilol and melatonin act as free-radical scavengers, this study examined the effect of carvedilol (10(-5) M) and melatonin (10(-5) M) on oxidative and cell damage induced by 3NP in N1E-115 neuroblastoma cells. Carvedilol and melatonin prevented the increases in lipid peroxidation and total LDH activity, as well as the depletion of reduced glutathione (GSH) and the reduction of antioxidative enzymes activities in N1E-115 cells incubated with 100 mM 3NP. All these carvedilol and melatonin effects were more intense when the drugs were added before rather than after inducing the damage by 3NP. These results also provided evidence supporting the hypothesis that carvedilol and melatonin can be useful for treating neurodegenerative diseases, such as Huntington's disease.

Alteration of the renal regulatory hormonal pattern during experimental obstructive jaundice.

OBJECTIVE: The alteration of hormones regulating sodium and water status is related to renal failure in obstructive jaundice (OJ). EXPERIMENTAL DESIGN: OJ was induced by common bile duct ligation. Samples were obtained from the control (SO) and OJ groups at 24 and 72 hours, and at 7 days. Different parameters related to biliary obstruction, liver and renal injury, and vasoactive mediators such as renin, aldosterone, endothelin-1 (ET-1) and prostaglandin E2 (PGE2) were studied. RESULTS: Bile duct ligation caused an increase in total bilirubin (p < 0.001) and alkaline phosphatase (AP) (p < 0.001). The SO and OJ groups had the same values for diuresis, renin, and creatinine clearance at 24 h. However, animals with OJ had a lower sodium concentration in urine than SO animals (p < 0.01), as well as an increase in aldosterone levels (p < 0.03). ANP levels were moderately increased during OJ but did not reach statistical significance when compared to the SO group. In contrast, OJ animals showed a rise in serum ET-1 concentration (p < 0.001) and increased PGE2 in urine (p < 0.001). CONCLUSIONS: Biliary obstruction induced an increase in ET-1 release and PGE2 urine excretion. These hormones might play a role during the renal complications associated with renal disturbances that occur during OJ.

Effect of melatonin on myocardial oxidative stress induced by experimental obstructive jaundice.

OBJECTIVE: melatonin has been demonstrated to have active antioxidant properties in different tissues during experimental cholestasis. The aim of this research was to study myocardial oxidative stress on obstructive jaundice, and to analyze the effect of melatonin on myocardial oxidative lesions. MATERIAL AND METHODS: we achieved cholestasis by ligature and sectioning of the main bile duct. Melatonin was administered intraperitoneally (500 microg/kg/day). We measured malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxydase (GPx) antioxidant enzyme levels in the heart tissue. RESULTS: obstructive cholestasis increased MDA and decreased GSH as well as all antioxidant enzymes. Melatonin administration significantly decreased MDA values, and increased GSH and antioxidant enzymes on the icteric animal myocardium. CONCLUSIONS: melatonin treatment prevents oxidative stress in the cardiac tissue as induced by experimental cholestasis.

Thioredoxin and glutaredoxin regulate metabolism through different multiplex thiol switches.

The aim of the present study was to define the role of Trx and Grx on metabolic thiol redox regulation and identify their protein and metabolite targets. The hepatocarcinoma-derived HepG2 cell line under both normal and oxidative/nitrosative conditions by overexpression of NO synthase (NOS3) was used as experimental model. Grx1 or Trx1 silencing caused conspicuous changes in the redox proteome reflected by significant changes in the reduced/oxidized ratios of specific Cys's including several glycolytic enzymes. Cys91 of peroxiredoxin-6 (PRDX6) and Cys153 of phosphoglycerate mutase-1 (PGAM1), that are known to be involved in progression of tumor growth, are reported here for the first time as specific targets of Grx1. A group of proteins increased their CysRED/CysOX ratio upon Trx1 and/or Grx1 silencing, including caspase-3 Cys163, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Cys247 and triose-phosphate isomerase (TPI) Cys255 likely by enhancement of NOS3 auto-oxidation. The activities of several glycolytic enzymes were also significantly affected. Glycolysis metabolic flux increased upon Trx1 silencing, whereas silencing of Grx1 had the opposite effect. Diversion of metabolic fluxes toward synthesis of fatty acids and phospholipids was observed in siRNA-Grx1 treated cells, while siRNA-Trx1 treated cells showed elevated levels of various sphingomyelins and ceramides and signs of increased protein degradation. Glutathione synthesis was stimulated by both treatments. These data indicate that Trx and Grx have both, common and specific protein Cys redox targets and that down regulation of either redoxin has markedly different metabolic outcomes. They reflect the delicate sensitivity of redox equilibrium to changes in any of the elements involved and the difficulty of forecasting metabolic responses to redox environmental changes.

[Prognostic factors associated with postoperative complications in liver transplant]. / Factores pronósticos de complicaciones postoperatorias en el transplante hepático.

OBJECTIVES: the postoperative evolution of patients submitted to orthotopic liver transplant (OLT) is frequently associated with the appearance of different types of complications such as renal failure, graft rejection, infections, and neurological disorders. These complications are the most significant causes of early morbidity and mortality in patients undergoing OLT. The purpose of the present study was the identification of factors related to the different postoperative complications after OLT. EXPERIMENTAL DESIGN: a prospective study was carried out. PATIENTS: seventy-eight variables were analyzed in 32 consecutive patients undergoing OLT. The factors independently associated with the appearance of postoperative complications were identified using a stepwise logistic regression analysis. RESULTS: the multivariate analysis showed that malondialdehyde and creatinine pretransplant serum levels were associated with the development of renal dysfunction. The pretransplant levels of haemoglobin and the units of platelets administered during surgery were prognostic factors of infections. Acute graft rejection was predicted by ?-glutamyl transpeptidase and total bilirubin serum levels. The pretransplant sodium and glutaredoxin levels in serum were associated with neurological complications. CONCLUSIONS: we propose these markers for the identification of high-risk patients allowing an early surveillance and/or treatment to improve morbidity and survival in patients submitted to OLT.

Anti-TNF-alpha treatment and bile duct drainage restore cellular immunity and prevent tissue injury in experimental obstructive jaundice.

Several experimental studies of obstructive jaundice (OJ) have shown the presence of immunosuppressive state associated with the rise of tumor necrosis factor-alpha (TNF-alpha) concentration in plasma. The present study evaluates the impact of anti-TNF- alpha administration or bile duct drainage on the inflammatory response, liver injury and renal insufficiency in obstructed rats. OJ was induced by the ligation of bile duct in Wistar rats. The parameters were determined at 14 and 21 days after OJ. Two additional groups of animals were treated with anti-TNF-alpha antibodies or submitted to bile duct drainage at 14 days, and sacrificed 21 days after OJ. Cholestasis decreased glucose, and enhanced urea, creatinin, bilirubin and transaminases. Cholestasis increased the number of different inflammatory cells (T and B lymphocytes, and monocytes-macrophages) but reduced the expression of the corresponding cellular activation markers. This low responsiveness of the inflammatory cells was related to a decreased free radical production and phagocytic activity of cells. Anti-TNF-alpha and bile duct drainage reduced tissue injury, and prevented the reduction of the number and activity of T lymphocytes and phagocytic cells observed at the advanced stages of cholestasis. In conclusion, anti-TNF- alpha and bile duct drainage improved cell immunodeficiency, and reduced liver injury, cholestasis and renal insufficiency in experimental OJ.

Treatment of peritoneal carcinomatosis from ovarian cancer. Present, future directions and proposals.

Peritoneal carcinomatosis, considered years ago as a final stage of unresectable cancer, can now be managed with curative intention by means of a radical cytoreductive surgical procedure with associated peritonectomy and intraperitoneal chemotherapy, as described by Sugarbaker. Malignant neoplasms such as mesothelioma and pseudomyxoma peritonei, ovarian and colon cancer nowadays are experiencing some new therapeutical approaches. Higher survival rates can be reached in ovarian cancer, which is commonly diagnosed in the presence of peritoneal carcinomatosis, using an optimal cytoreductive radical surgery with intraperitoneal chemotherapy. An actualised review of the treatment of advanced ovarian cancer and a proposal of a national multicentre protocol for the treatment of peritoneal carcinomatosis from ovarian cancer has been performed by a group of Spanish surgeons and oncologists dedicated to a therapeutical approach to this pathology.

Adjuvant chemotherapy for prevention of recurrence of invasive hepatocellular carcinoma after orthotopic liver transplantation.

UNLABELLED: Orthotopic liver transplantation (OLT) is the best treatment for nonresectable hepatocellular carcinoma (HCC), but tumor recurrence reduces long-term and medium-term survival. The effectiveness of adjuvant chemotherapy to prevent tumor recurrence has not been fully established. METHODS: Three hundred eighty-seven consecutive patients, including 43 with HCC superimposed on liver cirrhosis, underwent OLT. Twelve patients with one or more prognostic criteria for HCC recurrence were entered into a prospective prophylaxis protocol with monthly cycles of cisplatin (60 mg/m(2)) and adriamycin (30 mg/m(2)), beginning the fourth week post-OLT for a maximum of seven sessions. RESULTS: The 5-year survival of the non-HCC patients was 65.7% and that of the HCC patients was 60.46% (P = NS). Chemotherapy was reasonably well tolerated, but the 9 patients with hepatitis C- or B-associated cirrhosis showed viral and histological recurrence of the primary disease. A high proportion of patients (7 of 12) developed tumor recurrence during the first year after OLT. Six of these patients died, all but one due to HCC relapse. Five patients remain healthy and tumor free at 58 to 130 months. Post-OLT adjuvant chemotherapy does not avoid tumor recurrence and its fatal consequences but may contribute to prolonged tumor-free survival among a significant proportion of patients with high-risk HCC. However, the uncertain implications on viral recurrence and the lack of control groups do not allow post-OLT chemotherapy to be recommended outside controlled clinical trials, which are clearly warranted.

Treatment of refractory cholestatic pruritus with molecular adsorbent recirculating system (MARS).

UNLABELLED: Pruritus is a common complication of cholestatic liver diseases or liver graft dysfunction. Current medical therapies lack efficacy. The molecular adsorbent recirculating system (MARS) represents an interesting therapeutic option. Our objective was to report our experience in the management of four patients with intractable pruritus with MARS. PATIENTS AND METHODS: The MARS treatment cycle included three consecutive treatments, each of 8 hours duration. The four patients with intractable pruritus who were treated had primary biliary cirrhosis/autoimmune hepatitis overlap syndrome (n = 1), ductopenic allograft rejection (n = 2), or posttransplant cholestatic HCV recurrence (n = 1). Intensity of pruritus was documented 24 hours before as well as 24 hours, 7 and 30 days after MARS therapy, and at the end of follow-up. We measured complete blood cell counts, glucose, BUN, creatinine, sodium, potassium, AST, ALT, GGT, alkaline phosphatase, bilirubin, prothrombin activity, and activated partial thromboplastin time. RESULTS: MARS therapy was well tolerated. Patient 1 experienced temporal relief of pruritus, but needed another MARS cycle because of relapse. Patient 2 experienced partial and temporary relief of pruritus, was listed for retransplantation, and received a liver graft 2 months later. Patient 3 showed a dramatic reduction in the degree of pruritus with MARS. Pruritus in patient 4 decreased promptly with MARS therapy and conversion of immunosuppression to tacrolimus, thereby avoiding retransplantation. CONCLUSION: MARS therapy is a promising, safe therapeutic option to treat refractory pruritus caused by cholestatic liver disorders.

cdc25 cell cycle-activating phosphatases and c-myc expression in human non-Hodgkin's lymphomas.

cdc25A, cdc25B, and cdc25C are a family of human phosphatases that activate the cyclin-dependent kinases at different points of the cell cycle. cdc25A and cdc25B have been shown to have oncogenic potential, and they have been identified as transcriptional targets of c-myc. To determine the role of cdc25 genes in the pathogenesis of human lymphomas and their possible correlation with c-myc deregulation, we have analyzed the expression of cdc25A, cdc25B, and cdc25C and c-myc genes in a series of 63 non-Hodgkin's lymphomas and 8 nonneoplastic lymphoid tissues. The mRNA levels of the three phosphatases in the nonneoplastic tissues were negative or negligible. cdc25B overexpression was detected in 35 tumors (56%). This overexpression was more frequently found in aggressive (81%) than in indolent lymphomas (36%; P < 0.01). cdc25B overexpression was also significantly associated with a higher proliferative activity of the tumors. No cdc25B gene amplification or rearrangements were detected by Southern blot analysis. A biallelic EcoRI polymorphism of cdc25B gene was identified with a similar distribution in patients with lymphoma and in a normal population. cdc25A was overexpressed in three aggressive lymphomas. No detectable cdc25C mRNA levels were seen in any of the tumors. c-myc was overexpressed in 43% of tumors, and it correlated significantly with the presence of cdc25B up-regulation. Twenty-six of 35 (74%) lymphomas with high levels of cdc25B mRNA also showed c-myc overexpression, whereas 27 of 28 (96%) tumors without detectable or with very low cdc25B expression also had undetectable c-myc levels (P < 0.0001). In addition, a significant linear correlation was found between the cdc25B and c-myc mRNA levels (r = 0.575, P < 0.001). These findings suggest that cdc25B overexpression in non-Hodkin's lymphoma may participate in the pathogenesis of aggressive variants, and it may cooperate with c-myc oncogene in the development of these tumors.

Watching Subtitled Films Can Help Learning Foreign Languages.

Watching English-spoken films with subtitles is becoming increasingly popular throughout the world. One reason for this trend is the assumption that perceptual learning of the sounds of a foreign language, English, will improve perception skills in non-English speakers. Yet, solid proof for this is scarce. In order to test the potential learning effects derived from watching subtitled media, a group of intermediate Spanish students of English as a foreign language watched a 1h-long episode of a TV drama in its original English version, with English, Spanish or no subtitles overlaid. Before and after the viewing, participants took a listening and vocabulary test to evaluate their speech perception and vocabulary acquisition in English, plus a final plot comprehension test. The results of the listening skills tests revealed that after watching the English subtitled version, participants improved these skills significantly more than after watching the Spanish subtitled or no-subtitles versions. The vocabulary test showed no reliable differences between subtitled conditions. Finally, as one could expect, plot comprehension was best under native, Spanish subtitles. These learning effects with just 1 hour exposure might have major implications with longer exposure times.

An Experimental Study on the Use of Calcium Alginate to Heal Colonic Anastomoses.

BACKGROUND: Anastomotic leak is considered the major complication following abdominal surgery. In recent years, the use of a variety of sealing materials for the prevention of leaks has been analyzed. Different biomaterials have been employed as scaffolds to favour tissue repair and regeneration. Among these materials we must mention alginate, a natural polymer with different applications as temporary supporting matrix. The aim of the present study is to evaluate the behavior of both alginate-impregnated sutures and lyophilized alginate sponges in the healing process of colonic anastomes using an experimental animal model. MATERIAL AND METHODS: A preliminary study was undertaken to select the adequate scaffold. Animals (n = 45) were distributed into three groups: control (colonic anastomosis using non-continuous 5-0 Polyglactin 910 suture), suture (colonic anastomosis using suture impregnated with alginate gel at 4%) and sponge (colonic anastomosis using suture reinforced with lyophilized alginate sponge). The macroscopic and histological variables were assessed at 4, 8 and 12 days after surgical intervention. RESULTS: No statistically significant differences have been observed between the groups during the analysis of macroscopic variables. Animals with sponge implantation showed a greater degree of epithelial reepithalization, less acute and chronic inflammation and greater collagen deposit. CONCLUSIONS: The use of lyophilized alginate sponges to reinforce colonic anastomoses in an animal model reduces inflammation and promotes the earlier formation of greater collagen deposits without increasing the number of adhesions or the incidence of stenosis.

Splicing regulator SLU7 preserves survival of hepatocellular carcinoma cells and other solid tumors via oncogenic miR-17-92 cluster expression.

Resisting death is a central hallmark of cancer cells. Tumors rely on a number of genetic mechanisms to avoid apoptosis, and alterations in mRNA alternative splicing are increasingly recognized to have a role in tumorigenesis. In this study, we identify the splicing regulator SLU7 as an essential factor for the preservation of hepatocellular carcinoma (HCC) cells viability. Compared with hepatocytes, SLU7 expression is reduced in HCC cells; however, further SLU7 depletion triggered autophagy-related cellular apoptosis in association with the overproduction of reactive oxygen species. Remarkably, these responses were not observed in primary human hepatocytes or in the well-differentiated HepaRG cell line. Mechanistically, we demonstrate that SLU7 binds the C13orf25 primary transcript in which the polycistronic oncomir miR-17-92 cluster is encompassed, and is necessary for its processing and expression. SLU7 knockdown altered the splicing of the C13orf25 primary transcript, and markedly reduced the expression of its miR-17, miR-20 and miR-92a constituents. This led to the upregulation of CDKN1A (P21) and BCL2L11 (BIM) expression, two bona fide targets of the miR-17-92 cluster and recognized mediators of its pro-survival and tumorigenic activity. Interestingly, altered splicing of miR-17-92 and downregulation of miR-17 and miR-20 were not observed upon SLU7 knockdown in non-transformed hepatocytes, but was found in other (HeLa, H358) but not in all (Caco2) non-hepatic tumor cells. The functional relevance of miR-17-92 dysregulation upon SLU7 knockdown was established when oxidative stress, autophagy and apoptosis were reversed by co-transfection of HCC cells with a miR-17 mimic. Together, these findings indicate that SLU7 is co-opted by HCC cells and other tumor cell types to maintain survival, and identify this splicing regulator as a new determinant for the expression of the oncogenic miR-17-92 cluster. This novel mechanism may be exploited for the development of antitumoral strategies in cancers displaying such SLU7-miR-17-92 crosstalk.

Effect of catecholestrogen administration during adriamycin-induced cardiomyopathy in ovariectomized rat.

The therapeutical beneficial effect of estrogen-derived metabolites or catecholestrogens is controversial. These molecules are produced during estrogen therapy based on 17-beta-estradiol treatment. The metabolization of 17-beta-estradiol is carried out in brain, kidney or liver, and triggers different products such as 2- and 4- hydroxyestradiol (2OH and 4OH). These products have shown antioxidant properties against oxidative stress (OS) in several experimental models. Different noxious side effects related to those metabolites have also been observed upon estrogen therapy. In this sense, catecholestrogens seem to be implicated in tumoral and mutagenic process after long treatment with estrogens substitutive therapy. In our study, we have verified that 2OH and 4OH have antioxidant and cardioprotective effects against adriamycin (AD)-induced cardiomyopathy in ovariectomized (OVX) rats. Catecholestrogens diminished the lipid peroxides and carbonyl protein (CO) content, and different enzymes related to cell injury (creatinine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase) in cardiac tissue from OVX-, AD-, and OVX+AD-treated rats. All these changes were correlated to a recovery on reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) in heart tissue. The present study showed that 2OH and 4OH reduced all the parameters related to OS, antioxidant depletion and cardiac injury in OVX rats treated or not with AD.

Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells.

Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.