Targeting the complexity of ERBB2 biology in gastroesophageal carcinoma.

ERBB2 is the most prominent therapeutic target in gastroesophageal adenocarcinoma (GEA). For two decades, trastuzumab was the only treatment available for GEA overexpressing ERBB2. Several drugs showing evidence of efficacy over or in complement to trastuzumab in breast cancer failed to show clinical benefit in GEA. This resistance to anti-ERBB2 therapy is peculiarly recurrent in GEA and is mostly due to tumor heterogeneity with the existence of low expressing ERBB2 tumor clones and loss of ERBB2 over time. The development of new ERBB2 testing strategies and the use of antibody-drug conjugates having a bystander effect are providing new tools to fight heterogeneity in ERBB2-positive GEA. Co-amplifications of tyrosine kinase receptors, alterations in mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways and in proteins controlling cell cycle are well known to contribute resistance to anti-ERBB2 therapy, and they can be targeted by dual therapy. Recently described, NF1 mutations are responsible for Ras phosphorylation and activation and can also be targeted by MEK/ERK inhibition along with anti-ERBB2 therapy. Multiple lines of evidence suggest that immune mechanisms involving antibody-dependent cell-mediated cytotoxicity are preponderant over intracellular signaling in anti-ERBB2 therapy action. A better comprehension of these mechanisms could leverage immune action of anti-ERBB2 therapy and elucidate efficacy of combinations associating immunotherapy and anti-ERBB2 therapy, as suggested by the recent intermediate positive results of the KEYNOTE-811 trial.

Liver stiffness values in HIV-infected patients with isolated anti-hepatitis B core antibodies.

BACKGROUND: Hepatitis B reactivation has been observed in HIV-infected patients with isolated anti-HBc. However, the impact of isolated anti-HBc on liver fibrosis is not known in this population. METHODS: We investigated liver stiffness values (LSV) in a population of HIV-infected patients with isolated anti-HBc, and attempted to identify risk factors for high values. RESULTS: Fifty-one out of 69 patients (74%) had low LSV (≤7.1 kPa). In univariate analysis, high LSV (>7.1 kPa) were associated with HCV coinfection, the duration of HIV infection, the duration of antiretroviral therapy and lipodystrophy. In age-adjusted multivariate analysis, HCV coinfection (OR 11.5; 95% CI, 3.0-62.9; P=0.001) and lipodystrophy (OR 4.6; 95% CI, 1.1-20.7; P=0.031) remained associated with high liver stiffness values. CONCLUSIONS: Lipodystrophy was the only factor associated with high liver stiffness values in our population of HIV-infected patients with isolated anti-Hbc and extensive exposure to antiretroviral drugs active on HBV, apart from HCV coinfection Our study correlates to recent studies the results of which have shown that lipodystrophy, and more generally mitochondrial toxicity, was associated with advanced liver fibrosis in HIV/HCV co-infected patients.

T-cell responses to hepatitis B splice-generated protein of hepatitis B virus and inflammatory cytokines/chemokines in chronic hepatitis B patients. ANRS study: HB EP 02 HBSP-FIBRO.

A new hepatitis B virus (HBV) protein, hepatitis B splice-generated protein (HBSP), has been detected in liver biopsy specimens from patients with chronic active hepatitis. The aim of this study was to characterize the phenotype and functions of peripheral HBSP-specific T cells and to determine whether these T-cell responses may be implicated in liver damage or viral control. Two groups of patients were studied: HBV-infected patients with chronic active hepatitis and HBV-infected patients who were inactive carriers of hepatitis B surface antigen. HBSP-specific T-cell responses were analysed ex vivo and after in vitro stimulation of peripheral blood mononuclear cells. Soluble cytokines and chemokines were analysed in sera and in cell culture supernatants. Few HBSP- or capsid-specific T-cell responses were detected in patients with chronic active hepatitis whereas frequency of HBV-specific T cells was significantly higher in inactive carrier patients. HBSP activated CD8+ and CD4+ T cells that recognized multiple epitopes and secreted inflammatory cytokines. The IL-12 level was significantly lower in sera from asymptomatic carrier patients compared to patients with chronic active hepatitis. IL-12 and IP-10 levels in the sera were significantly and independently correlated with both alanine amino transferase and HBV DNA levels. Our results show that the HBSP protein activates cellular immune responses in HBV-infected patients but has probably no prominent role in liver damage. The pattern of cytokines and chemokines in sera was linked to HBV viral load and was consistent with the level of inflammation during chronic hepatitis.

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC): molecular mechanisms and novel paradigms.

Chronic hepatitis B (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Most HCCs complicate the evolution of an active or inactive cirrhosis. However, some tumors occur on livers with minimal histological changes; the prevalence of such cases varies from one geographical region to the other, being much higher in the Southern half of Africa (around 40% of HCCs) than in Asia, America and Europe, where at least 90% of HCCs are associated in the cirrhosis. This heterogeneity is probably a reflection of different environmental and genetic factors. This review will summarise the current knowledge on the mechanisms involved in HBV-related liver carcinogenesis. It will show in particular how viruses can be viewed as tools to discover and dissect new cellular pathways involved in cancer development and emphasize the potential synergistic effects between HBV and hepatitis C virus (HCV), as well as between viral infections and other environmental factors, such as alcohol.

[Management of cytomegalovirus infections in patients treated with immunosuppressive drugs for chronic inflammatory diseases]. / Prise en charge de l'infection à cytomégalovirus symptomatique chez les patients traités par immunosuppresseurs pour une maladie inflammatoire chronique.

INTRODUCTION: For patients with chronic inflammatory disease treated by immunosuppressive agents (for example: rheumatoid arthritis or systemic lupus erythematosus), there are no available guidelines in medical literature on the use of antiviral agents for the management of symptomatic cytomegalovirus (CMV) infection. EXEGESIS: A patient treated by methotrexate for a spondylarthritis presented a CMV infection manifested with persistent fever and pneumonia. CMV pp65 antigenemia was of 120 positive nuclei for 100,000 cells. Treatment with valganciclovir allowed a prompt recovery, while treatment by methotrexate was maintained. CONCLUSION: Symptomatic CMV infection evolution is unpredictable and potentially severe in patients with chronic inflammatory diseases receiving immunosuppressive agents. Although there is no data issued from clinical trials, the observation reported in this article and the publications of similar cases in the medical literature indicate that treatment with valganciclovir seems worth to be used in this context. Stopping immunosuppressive therapy does not seem mandatory.

Hepatitis B virus-related hepatocellular carcinoma: paradigms for viral-related human carcinogenesis.

As discussed in detail in other chapters of this review, chronic hepatitis B (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Most HCCs complicate the evolution of an active or inactive cirrhosis. However, some tumors occur on livers with minimal histological changes; the prevalence of such cases varies from one geographical region to the other, being much higher in the southern half of Africa (around 40% of HCCs) than in Asia, America and Europe, where at least 90% of HCCs are associated with the cirrhosis. This heterogeneity is probably a reflection of different environmental and genetic factors. This review will summarize the current knowledge on the mechanisms involved in HBV-related liver carcinogenesis. It will show in particular how viruses can be viewed as tools to discover and dissect new cellular pathways involved in cancer development and emphasize the potential synergistic effects between HBV and hepatitis C virus, as well as between viral infections and other environmental factors, such as alcohol.

Biological impact of natural COOH-terminal deletions of hepatitis B virus X protein in hepatocellular carcinoma tissues.

The hepatitis B virus (HBV) X protein (HBx) is a transcriptional transactivator that has been implicated in the development of HBV-related hepatocellular carcinoma. Mutations in the HBx open reading frame have been reported, but their general impact on the biological function of HBx remains unknown. To address this issue, we comparatively analyzed the structures and biological functions of HBx sequences isolated from sera and from tumor and nontumor tissues of patients with a HBV-related hepatocellular carcinoma. In addition to the HBx sequences derived from free HBV genomes, HBx from HBV integrants was also obtained from the tumor tissues by use of a HBx-Alu PCR-based approach. Sequence analysis showed that the HBx sequences derived from tumor tissues (6 of 7), particularly those isolated from HBV integrants (4 of 4), contained a deletion in the distal COOH-terminal region. Interestingly, most of the COOH-terminally truncated HBx sequences obtained from tumor tissues, in contrast to the full-length HBx isolated from the sera and nontumor tissues, lost their transcriptional activity and their inhibitory effects on cell proliferation and transformation. Importantly, although full-length HBx suppressed the focus formation induced by the cooperation of ras and myc oncogenes in primary rat embryo fibroblasts, COOH-terminally truncated HBx enhanced the transforming ability of ras and myc. Finally, by analyzing the artificial mutants, we were able to more precisely map the functional domains located at the COOH-terminal of HBx. Taken together, our results suggest a key role for the HBx COOH-terminal end in controlling cell proliferation, viability, and transformation. This study further supports the hypothesis that natural HBx mutants might be selected in tumor tissues and play a role in hepatocarcinogenesis by modifying the biological functions of HBx.

In vivo expression of a new hepatitis B virus protein encoded by a spliced RNA.

Hepatitis B virus (HBV) is a small DNA virus with a compact genomic organization. All HBV proteins identified to date have been encoded by unspliced HBV RNAs. Spliced HBV RNAs have been described, but their functions are unknown. We show here that a singly spliced HBV RNA encodes a novel HBV protein in vivo. This HBV splice-generated protein (HBSP) corresponds to the fusion of a part of the viral polymerase and a new open reading frame that is created by the splicing event. In vivo, HBSP protein was found in HBV-infected liver samples, and anti-HBSP antibodies occurred in one-third of sera samples collected from chronic HBV carriers. In vitro, the ectopic expression of HBSP had no effect on viral DNA replication or transcription but induced cell apoptosis without a cell-cycle block. Overall, our results suggest that HBV has evolved a mechanism that directly modulates virus-cell interaction through RNA splicing.

Bulimia nervosa and autoimmunity.

The autoantibodies that react with dopamine and serotonin are of interest in the study of bulimia nervosa. These neurotransmitters play an important role in appetite control, sexual and social behavior, and stress responses, all of which form a part of the clinical picture of bulimia nervosa. Are these autoantibodies involved in the serotoninergic hypofunctioning present in bulimia nervosa? Are they a part of an immunity regulation system essential for the cerebral system's homeostasis? To address these questions, 31 bulimic females (diagnosed according to DSM-III-R criteria) were compared with 10 control subjects (matched to the patients for sex, age, and demographic/psychosocial features). Measurement of the activity of natural autoantibodies reacting with dopamine, dopamine-beta-hydroxylase and serotonin was performed by an enzyme-linked immunosorbent assay (ELISA) for typical immunoglobulins (IgG, IgM, IgA). All of the autoantibodies of the IgG type were lower in the bulimic group than in the control group, a difference that was statistically significant for IgG anti-serotonin and IgG anti-dopamine. There was a trend for the amount of IgM anti-dopamine to be lower in patients than in controls. Dopamine and serotonin are specific components of brain cells. It can therefore be hypothesized that these antigens acting with autoantibodies could be the antigenic cerebral targets reacting with 'anti-brain' antibodies. The study of these specific autoantibodies provides information about the immunological characteristics that may be related to brain disturbances.

Inhibition of interferon-inducible MxA protein expression by hepatitis B virus capsid protein.

Chronic hepatitis B treatment has been significantly improved by interferon (IFN) treatment. However, some studies have suggested that hepatitis B virus (HBV) might have a direct effect on the resistance to IFN. Defective particles, generated by spliced HBV RNA and associated with chronic hepatitis B, have been previously characterized; expression of these particles leads to cytoplasmic accumulation of the capsid protein. The aim of this study was to investigate the role of these defective genomes in IFN resistance. The global antiviral activity of IFN was studied by virus yield reduction assays, the expression of three IFN-induced antiviral proteins was analysed by Western blotting and confocal microscopy, and the regulation of MxA gene expression was studied by Northern blotting and the luciferase assay, in Huh7 cells transfected with a complete or the defective HBV genome. Results showed that the expression of the defective genome reduces the antiviral activity of IFN and that this modulation involves a selective inhibition of MxA protein induction by the HBV capsid protein. Our results also show the trans-suppressive effect of the HBV capsid on the MxA promoter, which might participate in this phenomenon. In conclusion, this study shows a direct interplay between the IFN-sensitive pathway and the capsid protein and might implicate this defective HBV genome in virus persistence.

[Bulimia and autoimmunity]. / Boulimie et auto-immunité.

In the first part of this study, we investigated the rate of natural autoantibodies, in a sample of 31 female inpatients with bulimia nervosa according to DSM III-R criteria. The control (age and sex matched) group consisted in high school students including 10 females without eating disorders, depressive disorder or immunological disease. We investigated especially natural autoantibodies reacting with compounds of the central nervous system (Dopamine, Dopamine beta Hydroxylase, Serotonin). Our first conclusion is that there is a lower level of these natural auto-antibodies among female patients with bulimia nervosa. In the second part of the study, we have especially investigated the correlation between impulsivity in bulimia nervosa and the rate of natural autoantibodies against serotonin.

Differences in the natural autoantibody patterns of patients with schizophrenia and normal individuals.

The expression of IgG and IgM autoantibodies directed against various autoantigens, either part of the central nervous system or not, was investigated in the sera of inpatients with schizophrenia (n = 10). An enzyme immunoassay was used to measure the levels of these autoantibodies in whole sera, IgG-depleted sera, and isolated IgG fractions. IgG and IgM antibodies, reacting with all the antigens tested, were present in the sera of patients with schizophrenia as well as in the sera of normal individuals. Among patients suffering from schizophrenia, IgM natural autoantibody reactivities could be higher (myoglobin, serotonin, tubulin), lower (dopamine), or even identical to those of normal individuals, depending on whether whole or fractionated sera were assayed and on the group of patients with schizophrenia (responders and nonresponders) considered. The isolated IgG fractions of patients suffering from schizophrenia had higher anti-DNA and antiserotonin reactivities than those detected in normal individuals.

New antipsychotics in schizophrenia: the French experience.

Since the beginning of the neuroleptics in 1952, French psychiatrists have proposed a classification of neuroleptics, taking into account the pharmacological and therapeutic differences between these drugs. They distinguished 3 different clinical effects of neuroleptics: sedative effects, effects on the positive symptoms of schizophrenia and effects on the negative symptoms. The effect of some neuroleptics on negative symptoms is recognized by the international community, which considers clozapine to be effective. In France, in most cases, the indication of clozapine is still refractory paranoid schizophrenia. The effect of this atypical neuroleptic on other types of schizophrenic patient is not well known. Remoxipride appears to be as effective in treating psychotic symptoms and to have fewer side effects than haloperidol. Remoxipride is effective for both positive and negative symptoms. Loxapine has been prescribed in France since 1980. Its pharmacological profile is close to that of clozapine: it has dopamine (D2), histamine (H1), serotonin (5-HT2) and adrenergic (alpha 1)-blocking activities. Its best indication seems to be paranoid schizophrenia, although some data suggest bipolar action. The bipolar action of some new neuroleptics is illustrated by amisulpride, a substitute benzamide derivative. The originality of this molecule lies in its two opposite actions at two distinct doses. Doses of 600-1200 mg/day are effective against positive symptoms; 50-150 mg/day improves negative symptoms. This latter effect could be mediated by activation of the dopamine system.(ABSTRACT TRUNCATED AT 250 WORDS)

[Automatic actions with amnesia induced by taking hypnotic drugs. Association with personal and familial history of somnambulism and epilepsy]. / Activités automatiques avec amnésie induites par la prise de médicaments hypnotiques. Association à un passé personnel et familial de somnambulisme et d'épilepsie.

A family which combined sleep-walking drug-induced sleep-walking and epilepsy is reported. This co-morbidity suggest various mechanisms which could explain drug induced sleep-walking. We stated the hypothesis that these behaviors were epileptic states due to a mini-withdrawal syndrome. This mini-withdrawal including of course a rebound of anxiety and insomnia during the day, but also a pro-convulsivant effect.

[Schizophrenia and immunity]. / Schizophrénie et immunité.

In schizophrenia, various modifications of the immune system have been reported. A decrease of interleukin-2 production by T lymphocytes and an increase of IL-2 receptors were observed by several authors. Not only cellular but humoral immunity seems to be modified: apart from the viral hypothesis, an auto-immune hypothesis holds that auto-antibodies may play a role in the biology of schizophrenia. Natural auto-antibodies, preexisting any antigenic stimulation, may also be involved, particularly in the response to neuroleptic drugs.