The phosphorylated form of histone H2AX, gammaH2AX, is a component of the DNA repair system. Most studies have focused on the role of gammaH2AX during cell transformation and human cancer, but little is known about its role in keratinocytes and the skin during UV irradiation. We analyzed the response to UV irradiation focusing on the phosphorylation of histone H2AX both in vitro, in keratinocyte cultures and in artificial epidermis, and then in vivo, in human skin. Acute UVB irradiation of human keratinocytes increased the phosphorylation of H2AX in a dose-dependent manner; two types of gammaH2AX response were observed either in vitro or in vivo. After a low nonapoptotic UVB irradiation, cells contained phosphorylated H2AX and arrested their cell cycle to repair the DNA damages. For a stronger and proapoptotic UVB irradiation, keratinocytes dramatically increased the phosphorylation of H2AX and committed apoptosis. Our results indicate that gammaH2AX constitutes a highly sensitive marker relevant for studying subapoptotic doses as well as proapoptotic doses of UVB in human skin.

ZAC is a zinc finger transcription factor that induces apoptosis and cell cycle arrest in various cell lines. The corresponding gene is maternally imprinted and localized on chromosome 6q24-q25, a region harboring an unidentified tumor suppressor gene for a variety of solid neoplasms. ZAC expression is lost or down-regulated in some breast, ovary, and pituitary tumors and in an in vitro model of ovary epithelial cell transformation. In the present study, we examined ZAC expression in normal skin and found a high expression level in basal keratinocytes and a lower, more heterogeneous, expression in the first suprabasal differentiating layers of epidermis. In vitro, ZAC was up-regulated following induction of keratinocyte differentiation. Conversely, ZAC expression triggered keratinocyte differentiation as indicated by induction of involucrin expression. Interestingly, we found a dramatic loss of ZAC expression in basal cell carcinoma, a neoplasm characterized by a relatively undifferentiated morphology. In contrast, ZAC expression was maintained in squamous cell carcinomas that retain the squamous differentiated phenotype. Altogether, these data suggest a role for ZAC at an early stage of keratinocyte differentiation and further support its role in carcinogenesis. (Mol Cancer Res 2005;3(9):483 -92)

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The existence of an antisense Open Reading Frame (ORF) that encodes a putative AntiSense Protein (ASP) on the proviral genome of Human Immunodeficiency Virus type 1 (HIV-1) was a source of debate for 30 years. During the last years, some progresses have been made to characterize the cellular immune response against ASP in HIV-1 seropositive patients. However, no tools were available for the detection of antibodies to ASP in the plasma of HIV-1-infected patients during the natural course of the infection. The aim of our study was to develop a Luciferase Immuno-Precipitation System (LIPS) to monitor the quantitative detection of ASP-specific antibodies in the plasma of HIV-1-infected patients [antiretroviral therapy (ART) naive-patients, patients under ART and HIV-1 controllers], patients who discontinued antiretroviral drugs (ARV). We further used this approach to delineate the epitopes of ASP targeted by antibodies. Antibodies directed against ASP were detected in 3 out of 19 patients who discontinued ARV (15%) and in 1 out of 10 ART-naive patients (10%), but were neither detected in HIV-1 infected patients under ART nor in HIV-1 controllers. Individual variations in levels of ASP-specific antibodies were detected overtime. Both the conserved prolin-rich motif and the core 60-189 region of ASP were found to be essential for antibody recognition in the four patients tested positive for anti-ASP antibodies, who were all untreated at the time of sampling. Moreover, for two of these patients, increased levels of ASP-specific antibodies were observed concomitantly to viremia declines. Overall, our method may represent a useful tool to detect a humoral response to ASP in HIV-1-infected patients, which allowed us to confirm the expression of ASP during the course of HIV-1 infection. Further studies will be needed to fully characterize the humoral response to ASP in HIV-1-infected patients.

To study the role of ras, p53 genes and HPV virus (16 and 18) in the development of prostate cancer, we analyzed tissue sections from 27 patients affected with carcinomas (stages A to D) and from 24 patients with adenomas. Mutations of H, K and N-ras and p53 (exons 2-9) were studied by SSCP and DNA sequencing. Accumulation of p53 protein was studied by immunohistochemistry on tissue sections. Tumors were also analyzed for the presence of HPV16 and -18 sequences by PCR and DNA hybridization with sequence-specific oligonucleotides. No mutation was found in the three ras genes studied, either in carcinomas or adenomas. By SSCP analysis we identified p53 mutations in only 2 of 19 carcinomas studied, both in exon 7. Immunohistochemical results strongly correlate with the SSCP results: p53 protein was positive in tumors with p53 mutation but not in others; 32% of studied adenomas had detectable HPV16 DNA, while 53% of carcinomas were HPV16+. Among these I presented a p53 mutation. No HPV18 E6 sequence could be detected. Our data show that in prostate tumors from France, mutations of p53 and ras are rare events but that these tumors display detectable HPV16 DNA at a high frequency. The low incidence of p53 mutation, associated to a significant proportion of tumors showing HPV16 DNA, could suggest that in prostate cancer HPV16 infection could participate in p53 inactivation by E6.

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Background The aim of this study was to describe patterns among people who inject drugs (PWID), risk-related behaviours and access to methadone treatment, in order to design a large-scale intervention aiming to end the HIV epidemic in Haiphong, Vietnam. Methods A respondent-driven sampling (RDS) survey was first conducted to identify profiles of drug use and HIV risk-related behaviour among PWID. A sample of PWID was then included in a one-year cohort study to describe access to methadone treatment and associated factors. Results Among the 603 patients enrolled in the RDS survey, 10% were female, all were injecting heroin and 24% were using methamphetamine, including 3 (0.5%) through injection. Different profiles of risk-related behaviours were identified, including one entailing high-risk sexual behaviour (n = 37) and another involving drug-related high-risk practices (n = 22). High-risk sexual activity was related to binge drinking and methamphetamine use. Among subjects with low sexual risk, sexual intercourse with a main partner with unknown serostatus was often unprotected. Among the 250 PWID included in the cohort, 55.2% initiated methadone treatment during the follow-up (versus 4.4% at RDS); methamphetamine use significantly increased. The factors associated with not being treated with methadone after 52 weeks were fewer injections per month and being a methamphetamine user at RDS. Conclusion Heroin is still the main drug injected in Haiphong. Methamphetamine use is increasing markedly and is associated with delay in methadone initiation. Drug-related risks are low but sexual risk behaviours are still present. Comprehensive approaches are needed in the short term.

IntroductionIn Vietnam, people who inject drugs (PWID), who are the major population infected by hepatitis C virus (HCV), remain largely undiagnosed and unlinked to HCV prevention and care despite recommended universal hepatitis C treatment. The data on the outcomes of HCV treatment among PWID also remain limited in resource-limited settings. The DRug use & Infections in ViEtnam–hepatitis C (DRIVE-C) study examines the effectiveness of a model of hepatitis C screening and integrated care targeting PWID that largely uses community-based organisations (CBO) in Hai Phong, Vietnam. In a wider perspective, this model may have the potential to eliminate HCV among PWID in this city.Methods and analysisThe model of care comprises large community-based mass screening, simplified treatment with direct-acting antivirals (DAAs) and major involvement of CBO for PWID reaching out, linkage to care, treatment adherence and prevention of reinfection. The effectiveness of DAA care strategy among PWID, the potential obstacles to widespread implementation and its impact at population level will be assessed. A cost-effectiveness analysis is planned to further inform policy-makers. The enrolment target is 1050 PWID, recruited from the DRIVE study in Hai Phong. After initiation of pan-genotypic treatment consisting of sofosbuvir and daclatasvir administrated for 12 weeks, with ribavirin added in cases of cirrhosis, participants are followed-up for 48 weeks. The primary outcome is the proportion of patients with sustained virological response at week 48, that will be compared with a theoretical expected rate of 70%.Ethics and disseminationThe study was approved by Haiphong University of Medicine and Pharmacy's Ethics Review Board and the Vietnamese Ministry of Health. The sponsor and the investigators are committed to conducting this study in accordance with ethics principles contained in the World Medical Association's Declaration of Helsinki (Ethical Principles for Medical Research Involving Human Subjects). Informed consent is obtained before study enrolment. The data are anonymised and stored in a secure database. The study is ongoing. Results will be presented at international conferences and submitted to international peer-review journals.Trial registration numberNCT03537196.