Abstract: PTEN/MMAC1/TEP1: (hereafter PTEN) is a tumor suppressor gene (located at 10q23) that is frequently mutated or deleted in sporadic human tumors. PTEN encodes a multifunctional phosphatase, which negatively regulates cell growth, migration and survival via the phosphatidylinositol 3'-kinase/AKT signalling pathway. Accordingly, Pten+/- mice develop various types of tumors including teratocarcinomas and teratomas. We have investigated PTEN expression in 60 bioptic specimens of germ cell tumors (32 seminomas, 22 embryonal carcinomas and six teratomas) and 22 intratubular germ cell neoplasias (ITGCN) adjacent to the tumors for PTEN protein and mRNA expression. In total, 10 testicular biopsies were used as controls. In the testis, PTEN was abundantly expressed in germ cells whereas it was virtually absent from 56% of seminomas as well as from 86% of embryonal carcinomas and virtually all teratomas. On the contrary, ITGCN intensely expressed PTEN, indicating that loss of PTEN expression is not an early event in testicular tumor development. The loss of PTEN expression occurs mainly at the RNA level as determined by in situ hybridization of cellular mRNA (17/22) but also it may involve some kind of post-transcriptional mechanisms in the remaining 25% of cases. Analysis of microsatellites D10S551, D10S541 and D10S1765 in GCTs (n=22) showed LOH at the PTEN locus at 10q23 in at least 36% of GCTs (three embryonal carcinoma, three seminoma, two teratoma); one seminoma and one embryonal (9%) carcinoma presented an inactivating mutation in the PTEN gene (2/22). Finally, we demonstrated that the phosphatidylinositol 3'-kinase/AKT pathway, which is regulated by the PTEN phosphatase, is crucial in regulating the proliferation of the NT2/D1 embryonal carcinoma cells, and that the cyclin-dependent kinase inhibitor p27(kip1) is a key downstream target of this pathway.

Abstract: Multicenter randomized trials have shown that once-weekly pegylated interferon (peginterferon) alfa-2a is more efficacious than conventional interferon alfa-2a (IFN) in patients with chronic hepatitis C. We performed a meta-analysis of 1,013 previously untreated patients (from 3 randomized trials) with pretreatment and post-treatment liver biopsies to assess the differences between peginterferon alfa-2a and IFN in terms of their effects on liver histology. Reported values were standardized mean differences (SMD) between patients receiving peginterferon alfa-2a and those receiving IFN (post-treatment value minus baseline value for each group). We used a random-effects model to quantify the average effect of peginterferon alfa-2a on liver histology. Peginterferon alfa-2a significantly reduced fibrosis compared with IFN (SMD, -0.14; 95% CI: -0.27, -0.01; P =.04). A reduction in fibrosis was observed among sustained virologic responders (SMD, -0.59; 95% CI: -0.89, -0.30; P <.0001) and patients with recurrent disease (SMD, -0.34; 95% CI: -0.54, -0.14; P =.0007), whereas no significant reduction was observed among nonresponders (SMD, -0.13; 95% CI: -0.32, 0.05; P =.15). Logistic regression analysis indicated that patients with sustained virologic responses (SVRs) had an odds ratio (OR) of 1.61 (95% CI: 1.14, 2.29) for reduction in fibrosis compared with patients without SVRs, whereas obese patients (body mass index [BMI] > 30 kg/m(2)) had an OR of 0.56 (95% CI: 0.35, 0.90) compared with normal-weight (BMI < 25 kg/m(2)) and overweight patients (BMI, 25-30 kg/m(2)). In conclusion, in patients with chronic hepatitis C with or without cirrhosis, peginterferon alfa-2a (relative to IFN) significantly reduced fibrosis. The beneficial effects of peginterferon on liver histology are closely related to virologic response.

Abstract: BACKGROUND: The benefit of neoadjuvant chemoradiotherapy in oesophageal cancer has been extensively studied but data on survival are still equivocal. OBJECTIVE: To assess the effectiveness of chemoradiotherapy followed by surgery in the reduction of mortality in patients with resectable oesophageal cancer. METHODS: Computerised bibliographic searches of MEDLINE and CANCERLIT (1970-2002) were supplemented with hand searches of reference lists. STUDY SELECTION: Studies were included if they were randomised controlled trials (RCTs) comparing preoperative chemoradiotherapy plus surgery with surgery alone, and if they included patients with resectable histologically proven oesophageal cancer without metastatic disease. Six eligible RCTs were identified and included in the meta-analysis. DATA EXTRACTION: Data on study populations, interventions, and outcomes were extracted from each RCT according to the intention to treat method by three independent observers and combined using the DerSimonian and Laird method. RESULTS: Chemoradiotherapy plus surgery compared with surgery alone significantly reduced the three year mortality rate (odds ratio (OR) 0.53 (95% confidence interval (CI) 0.31-0.93); p = 0.03) (number needed to treat = 10). Pathological examination showed that preoperative chemoradiotherapy downstaged the tumour (that is, less advanced stage at pathological examination at the time of surgery) compared with surgery alone (OR 0.43 (95% CI 0.26-0.72); p = 0.001). The risk for postoperative mortality was higher in the chemoradiotherapy plus surgery group (OR 2.10 (95% CI 1.18-3.73); p = 0.01). CONCLUSIONS: In patients with resectable oesophageal cancer, chemoradiotherapy plus surgery significantly reduces three year mortality compared with surgery alone. However, postoperative mortality was significantly increased by neoadjuvant chemoradiotherapy. Further large scale multicentre RCTs may prove useful to substantiate the benefit on overall survival.

Abstract: BACKGROUND & AIMS: Increased morbidity and mortality from liver disease have been reported in chronic hepatitis B surface antigen (HBsAg) carriers, but data on survival are equivocal. To assess the impact of hepatitis B virus (HBV) infection on survival and liver-related complications, we re-evaluated, after a mean follow-up of 30 years, a cohort of 296 blood donors excluded from donation 30 years ago when HBsAg screening became mandatory. METHODS: Clinical and ultrasound examination and biochemical and virologic tests were performed. The cause of death was recorded and survival was compared with a control population of 157 HBV-negative blood donors selected at baseline. RESULTS: Thirty-two (10.8%) cases and 14 controls (8.9%) ( P = 0.625) had died; 3 of 32 (9.3%) and 1 of 14 (7.1%) deaths were liver-related. Hepatocellular carcinoma (HCC) caused death in 2 of 296 and 1 of 157 subjects (0.6% in each group). Alcohol-induced cirrhosis occured in the remaining subject. By Cox regression analysis, survival was independently predicted by older age, abnormal gamma-glutamyl transpeptidase (GGT) levels, and presence of medical comorbidities at baseline. Unequivocal liver disease was found in 4 carriers only. No disease decompensation occurred during follow-up. Fifty-nine (32.2%) carriers cleared HBsAg (yearly incidence, 1.0%). Full-length serum HBV DNA was present in 32.2% of persistently HBsAg-positive individuals (average titer always <10 5 copies/mL). CONCLUSIONS: Over a 30-year period, chronic HBV carrier blood donors from Northern Italy did not develop clinically significant liver disease, hepatocellular cancer, or other liver-related morbidity or mortality at a higher rate than uninfected controls. The presence of medical comorbidities, older age at diagnosis, and abnormal GGT levels were independent predictors of death among chronic HBV carriers.

Abstract: Expression of the adenovirus E1A gene in the rat thyroid differentiated cell line PC Cl 3 induces thyrotropin-independent cell growth and impairs differentiation. However, the malignant phenotype is achieved only when the PC E1A cells are infected with other murine retroviruses carrying the v-abl, v-raf or polyoma middle-T genes. To determine through which genes E1A affects thyroid cells, we differentially screened PC Cl 3 and PC E1A cells. Here we report a new gene, named CL2, that is upregulated in PC E1A cells. The CL2 transcript is 4.4 kb long and encodes a 949 amino-acid protein. Conceptual translation of the open reading frame showed one product with a signal peptide, multiple nuclear localization signals and three newly described domains. Furthermore, in vivo, this protein was located juxtanuclear, which is suggestive of Golgian localization, and also in cytoplasm and nucleus/nucleolus. Finally, CL2 gene expression was drastically downregulated in human thyroid neoplastic cell lines and tissues.

Abstract: We demonstrated previously that rat tyrosine phosphatase r-PTPeta expression was suppressed in rat and human thyroid neoplastic cells, and that restoration of r-PTPeta expression reverted the malignant phenotype. To investigate the potential of this gene for cancer therapy, we generated an adenovirus carrying the r-PTPeta cDNA (Ad-r-PTPeta). This virus infected human thyroid carcinoma cells and overexpressed the r-PTPeta protein. Overexpression of r-PTPeta significantly inhibited the growth of four thyroid carcinoma cell lines. Cell growth inhibition was associated with down-regulation of extracellular signal-regulated kinase 1/2 activity, with increased levels of the cell-cycle inhibitor p27(kip1) protein and with dephosphorylation of PLCgamma1, a substrate of DEP-1, the human homologue of r-PTPeta. Finally, the growth of xenograft tumors induced in athymic mice by anaplastic thyroid carcinoma ARO cells transduced with the Ad-r-PTPeta virus was drastically reduced. These data suggest that gene therapy based on restoration of PTPeta function has potential in the treatment of human thyroid malignant neoplasias.

Abstract: Cytotoxicity of methylating agents is caused mostly by methylation of the O6 position of guanine in DNA to form O6-methylguanine (O6-meG). O6-meG can direct misincorporation of thymine during replication, generating O6-meG:T mismatches. Recognition of these mispairs by the mismatch repair (MMR) system leads to cell cycle arrest and apoptosis. MMR also modulates sensitivity to other antitumor drugs. The base excision repair (BER) enzyme MED1 (also known as MBD4) interacts with the MMR protein MLH1. MED1 was found to exhibit thymine glycosylase activity on O6-meG:T mismatches. To examine the biological significance of this activity, we generated mice with targeted inactivation of the Med1 gene and prepared mouse embryonic fibroblasts (MEF) with different Med1 genotype. Unlike wild-type and heterozygous cultures, Med1-/- MEF failed to undergo G2-M cell cycle arrest and apoptosis upon treatment with the methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Similar results were obtained with platinum compounds' 5-fluorouracil and irinotecan. As is the case with MMR-defective cells, resistance of Med1-/- MEF to MNNG was due to a tolerance mechanism because DNA damage accumulated but did not elicit checkpoint activation. Interestingly, steady state amounts of several MMR proteins are reduced in Med1-/- MEF, in comparison with Med1+/+ and Med1+/- MEF. We conclude that MED1 has an additional role in DNA damage response to antitumor agents and is associated with integrity of the MMR system. MED1 defects (much like MMR defects) may impair cell cycle arrest and apoptosis induced by DNA damage.

Abstract: BACKGROUND: Appropriate treatment of acute hepatitis C is still a matter of controversy due to the lack of large controlled trials. AIM: To assess the effectiveness of interferon as treatment for acute hepatitis C by meta-analysis. METHODS: MEDLINE search (1985-2002) was supplemented with manual searches of reference lists. Studies were included if they were controlled trials comparing interferon to no treatment and if they included patients with either post-transfusion or sporadic acute hepatitis C. Twelve trials were analyzed (414 patients). The outcome assessed was the sustained virological response (SVR) rate (undetectable hepatitis C virus RNA in serum at least 6 months after cessation of therapy). RESULTS: Interferon significantly increased the SVR (risk difference 49%; 95% confidence interval 32.9-65%) in comparison to no treatment. The risk difference of SVR increased from 5 to 90% when trials were ordered by increasing interferon weekly dose. Delaying therapy by 8-12 weeks after the onset of disease does not compromise the SVR rate. CONCLUSIONS: Current evidence is sufficient to recommend interferon treatment of patients with acute hepatitis C. A later initiation of therapy yields the same likelihood of response as early treatment. A daily induction dose during the 1st month is the best option of treatment.

Abstract: PURPOSE: To review the available evidence of chemoembolization for unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Computerized bibliographic searches with MEDLINE and CANCERLIT databases from 1980 through 2000 were supplemented with manual searches, with the keywords "hepatocellular carcinoma," "liver cell carcinoma," "randomized controlled trial [RCT]," and "chemoembolization." Studies were included if patients with unresectable HCC were enrolled and if they were RCTs in which chemoembolization was compared with nonactive treatment (five RCTs) or if different transarterial modalities of therapy (13 RCTs) were compared. Data were extracted from each RCT according to the intention-to-treat method. Five of the RCTs with a nonactive treatment arm were combined by using the random-effects model, whereas all 18 RCTs were pooled from meta-regression analysis. RESULTS: Chemoembolization significantly reduced the overall 2-year mortality rate (odds ratio, 0.54; 95% CI: 0.33, 0.89; P =.015) compared with nonactive treatment. Analysis of comparative RCTs helped to predict that overall mortality was significantly lower in patients treated with transarterial embolization (TAE) than in those treated with transarterial chemotherapy (odds ratio, 0.72; 95% CI: 0.53, 0.98; P =.039) and that there is no evidence that transarterial chemoembolization is more effective than TAE (odds ratio, 1.007; 95% CI: 0.79, 1.27; P =.95), which suggests that the addition of an anticancer drug did not improve the therapeutic benefit. CONCLUSION: In patients with unresectable HCC, chemoembolization significantly improved the overall 2-year survival compared with nonactive treatment, but the magnitude of the benefit is relatively small.

Abstract: BACKGROUND: Reactive oxygen species play a critical role in inducing apoptosis. The small GTPase p21 Ras and the ERK1/2 MAPK have been proposed as key regulators of the signaling cascade triggered by oxidative stress (H2O2). Harvey-Ras (Ha-Ras) and Kirsten-Ras (Ki-Ras) isoforms are so far functionally indistinguishable, because they activate the same downstream effectors, including ERK1/2. Moreover, ERK1/2 signaling has been involved in both protection and induction of apoptosis. METHODS AND RESULTS: Human umbilical vein endothelial cells (HUVECs) were subjected to H2O2, and apoptosis was detected by fluorescence-activated cell sorting analysis, fluorescence microscopy, and caspase-3 activation. Transfection of Ha-Ras and Ki-Ras genes in HUVECs was performed to evaluate the response to H2O2. We have found that, whereas Ha-Ras decreases tolerance to oxidative stress, Ki-Ras has a potent antiapoptotic activity. Both effects are mediated by ERK1/2. Tolerance to H2O2 is encoded by a unique stretch of lysines at the COOH terminus of the Ki-Ras, lacking in Ha-Ras, and it is relatively independent of the farnesylated anchor. Inhibition of p21 Ras signaling by farnesylation inhibitors increased the resistance to apoptosis in Ha-Ras-expressing cells. CONCLUSIONS: These findings explain the opposite effects of ERK1/2 stimulation on apoptosis found in different cell types and suggest that local activation of ERK1/2 signaling may account for the opposing response to oxidative stress by Ha-Ras or Ki-Ras-expressing cells. Modulation of cell reactivity to oxidative stress by p21 Ras points to the specific and predictive effects of Ras inhibitors in vivo as potential therapeutic drugs in disorders produced by increase of reactive oxygen species inside the cells.

Abstract: BACKGROUND AND AIMS: Retreatment with a combination of alpha interferon (IFN) plus ribavirin of patients with chronic hepatitis C who did not respond to IFN monotherapy has not been assessed in large controlled studies. METHODS: To assess the effectiveness and tolerability of IFN/ribavirin retreatment of non-responders to IFN and to identify predictors of complete (biochemical and virological) sustained response, we performed a meta-analysis of individual data on 581 patients from 10 centres. Retreatment with various IFN schedules (mean total dose 544 mega units) and a fixed ribavirin dose (1000-1200 mg/daily depending on body weight) was given for 24-60 (mean 39.5) weeks. RESULTS: Biochemical end of treatment and sustained responses were observed in 271/581 (46.6%; 95% confidence interval (CI) 42.6-50.7%) and in 109/581 (18.7%; 95% CI 15.6-22.0%) cases, respectively. Two hundred and six of 532 patients (38.7%; 95% CI 34.6-42.9%) had an end of treatment complete response to retreatment while a complete sustained response occurred in 88 of 559 (15.7%; 95% CI 12.8-18.8%). Fifty four of 581 patients (9.2%; 95% CI 7.0-11.7%) stopped retreatment due to adverse effects. By logistic regression, complete sustained response was predicted independently by age <45 years (p=0.04), by normal pretreatment gamma-glutamyltransferase levels (p=0.01), and by a second course total IFN dose of at least 432 mega units (p=0.008). CONCLUSIONS: The overall low probability of effectiveness argues against indiscriminate retreatment of all IFN monotherapy non-responders with IFN/ribavirin. Patients less than 45 years old with normal gamma-glutamyltransferase levels who were retreated with high dose long course combination therapy had a complete sustained response rate of 30%.

Abstract: Our aims were to develop a noninvasive predictive tool to identify cirrhotic patients with esophageal varices and to evaluate whether portal Doppler ultrasonographic parameters may improve the value of other predictors. One hundred forty-three consecutive compensated cirrhotic patients underwent upper gastrointestinal endoscopy. Fourteen clinical, biochemical, ultrasonographic, and Doppler ultrasonographic parameters of each patient were also recorded. Esophageal varices were detected in 63 of the 143 patients examined (44%; 95% confidence interval [CI] 36.2-52.6). Medium and large esophageal varices were observed in 28 subjects (44%; 95% CI 31.4-58.4). Using stepwise logistic regression, presence of esophageal varices was independently predicted by prothrombin activity less than 70% (odds ratio [OR]: 5.83; 95% CI: 2.6-12.8), ultrasonographic portal vein diameter greater than 13 mm (OR: 2.92; 95% CI: 1.3-6.4), and platelet count less than 100 x 10(9)/L (OR: 2.83; 95% CI: 1.27-6.28). Variables included in the model were used to generate a simple incremental rule to evaluate each individual patient. The discriminating ability of the prediction rule was relevant (area under the curve: 0.80) and did not change by replacing ultrasonographic portal vein diameter with congestion index of portal vein. We concluded that compensated cirrhotic patients should be screened by upper gastrointestinal endoscopy when prothrombin activity less than 70%, platelet count less than 100 x 10(9)/L, and ultrasonographic portal vein diameter greater than 13 mm are observed, whereas those without any of these predictors should not undergo endoscopy. The contribution provided by portal Doppler ultrasonographic parameters does not appear of practical utility.

Abstract: This study was performed to determine whether the levels of soluble intercellular adhesion molecule-1 (sICAM-l) and soluble endothelial molecule-1 (sE-selectin) were elevated in subjects with hypercholesterolemia who presented with no other risk factors or evidence of atherosclerosis. The effects of administration of an HMG-CoA reductase inhibitor on the serum levels of these molecules were also examined. Forty hypercholesterolemic subjects (HCh) (19 males and 21 females), without hypertension or cardiovascular disease, received placebo for 4 weeks. The patients were then randomized in two groups; 20 of them (simvastatin group) were treated with simvastatin (20 mg/day) and the other 20 (placebo group) continued placebo administration. After 12 and 24 weeks of either simvastatin or placebo treatment, sICAM-1 and sE-selectin levels were measured. The same parameters were measured in 20 control subjects (C) with normal cholesterol levels, matched for sex and age. HCh had sICAM-1 basal values higher than C (352.4+/-57.9 ng/ml versus 114.9+/-89.6 ng/ml; P<0.001); however, sE-selectin basal values were not different in the two groups. No correlation was observed between HCh sICAM-1 levels and cholesterol levels (total and low-density lipoprotein). Furthermore, cholesterol-lowering treatment with simvastatin did not significantly diminish sICAM-1 levels. Our findings would support the hypothesis that patients with isolated hypercholesterolemia and without clinical atherosclerosis may be silent carriers of arterial subendothelial inflammation, expressed as an increase of sICAM-1.

Abstract: The DNA mismatch repair (MMR) is a specialized system, highly conserved throughout evolution, involved in the maintenance of genomic integrity. To identify novel human genes that may function in MMR, we employed the yeast interaction trap. Using the MMR protein MLH1 as bait, we cloned MED1. The MED1 protein forms a complex with MLH1, binds to methyl-CpG-containing DNA, has homology to bacterial DNA repair glycosylases/lyases, and displays endonuclease activity. Transfection of a MED1 mutant lacking the methyl-CpG-binding domain (MBD) is associated with microsatellite instability (MSI). These findings suggest that MED1 is a novel human DNA repair protein that may be involved in MMR and, as such, may be a candidate eukaryotic homologue of the bacterial MMR endonuclease, MutH. In addition, these results suggest that cytosine methylation may play a role in human DNA repair.

Abstract: Prolonged Q-T interval predicts severe arrhythmias and sudden death, and has been shown to occur in alcoholic liver disease and cirrhotic patients who are candidates for liver transplantation. This study first evaluated the prevalence of prolonged Q-T interval in a large population of unselected patients with cirrhosis, and assessed the relationship between abnormal Q-T, etiology, and severity of liver disease and mortality of patients. Possible causes of Q-T abnormality were also explored. Ninety-four patients with cirrhosis without overt heart disease and 37 control subjects with mild chronic active hepatitis were enrolled. Rate-corrected Q-T interval (Q-Tc) was assessed along with routine liver tests, Child-Pugh score, serum bile salts, electrolytes and creatinine, plasma renin activity, aldosterone, norepinephrine, atrial natriuretic factor and, gonadal hormones. Q-Tc was longer in patients with cirrhosis than in controls (440.3 +/- 3.2 vs. 393.6 +/- 3.7 ms; P < .001) and prolonged (> 440 ms) in 44 patients (46.8%) and 2 controls (5.4%; P < .001). Q-Tc length was not influenced by the etiology of cirrhosis and correlated with Child-Pugh score (r = .53; P < .001), liver tests such as prothrombin activity, and serum concentrations of albumin and bilirubin, plasma bile salts, and plasma norepinephrine. Multivariate analysis showed that only Child-Pugh score and plasma norepinephrine were independently correlated with Q-Tc duration. Over a median follow-up period of 19 months (range, 2-33 months), patients with Q-Tc longer than 440 ms had a significantly lower survival rate than those with normal Q-Tc. Q-T interval is frequently prolonged in patients with cirrhosis, regardless the etiology of the disease, worsens in parallel with the severity of the disease, and may have an important prognostic meaning. In addition to other undefined factors related to the severity of cirrhosis, sympathoadrenergic hyperactivity may play a pathogenetic role.

Abstract: BACKGROUND/AIMS: Hepatitis B virus (HBV) core gene heterogeneity may influence the outcome of liver disease and the response to interferon (IFN) therapy in adult HBV carriers. The aim of this study was to evaluate the possible association between HBV core gene variability and evolution of chronic hepatitis in children. METHODS: We examined serum samples from 25 children with HBV chronic hepatitis and HBe antigen (HBeAg) positivity who were followed-up for a mean of 7.4 years. Seven cases spontaneously seroconverted to anti-HBe, becoming HBV healthy carriers; nine cases were successfully treated with IFN; nine cases were non-responders to IFN therapy. HBV-DNA was extracted from one serum sample ("I") collected during the HBeAg positive phase, and from a second sample ("II") collected after the anti-HBe seroconversion or, in non-responders, after stopping therapy. The entire core gene of the HBV isolates was amplified and sequenced. RESULTS: Each isolate showed single or no missense mutation independently of the clinical behavior of the patients. HBeAg-defective viruses were detected in one case in both samples and in two cases only in sample "II". CONCLUSIONS: Core gene variability does not seem to be involved either in the outcome of infection or in the response to IFN treatment in children with HBV chronic hepatitis. Considering that most of the HBV carriers in our area acquire the infection in childhood, our data suggest that core gene heterogeneity is not a major cause of progression to chronicity.