ABSTRACT
BACKGROUND: HIV testing remains an important tool in identifying people living with HIV/AIDS (PLWHA). An early diagnosis of HIV can lead to a prolonged life expectancy if treatment is initiated promptly. Indicator conditions can be the first sign of an HIV infection and should therefore be recognised and consequently a HIV test should be carried out. Testing should occur in all individuals as sexuality can be experienced by everyone, and stigma can lead to the exclusion of vulnerable groups, leading to a gap in diagnosis and treatment [1, 2]. CASE PRESENTATION: A 63-year-old man, who identifies as bisexual and has had an intellectual disability since birth, presented at our health care centre for HIV testing. A decade ago, the patient was diagnosed with Stage III Diffuse Large B-cell Non-Hodgkin Lymphoma, an AIDS defining cancer. The patient presented at a Haematology and Oncology department 3 months prior, due to a weight loss of 10 kg over the past 5 months. Oral thrush, an HIV-indicator condition, had been diagnosed by the otolaryngologists shortly before. During this medical evaluation, pancytopenia was identified. Despite the presence of indicator conditions, the patient was never tested for HIV in the past. Staff members from the care facility for intellectually disabled suggested conducting a HIV test in our clinic through the public health department, where HIV positivity was revealed. The AIDS-defining diagnosis, along with a CD4 + cell count of 41/µl, suggests a prolonged period of HIV positivity. CONCLUSION: Due to the presence of existing indicator conditions, an earlier HIV diagnosis was possible. We contend that most of the recent illnesses could have been prevented if earlier testing had been carried out. Therefore, patients presenting with AIDS indicator conditions, including those with mental disabilities, should be given the opportunity to be tested for HIV. HIV/AIDS trainings should be made available to health care professionals as well as to personnel interacting with vulnerable groups.
Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , Intellectual Disability , Sexual Health , Humans , Male , Middle Aged , Early Detection of Cancer , HIV Infections/complications , HIV Infections/diagnosis , HIV Testing , Intellectual Disability/diagnosisABSTRACT
BACKGROUND: RNA interference (RNAi) provides a powerful way to investigate the role of genes in disease pathogenesis and modulate gene expression to treat disease. In 2018, the FDA approved patisiran, the first RNAi-based drug, hence paving the way for a novel class of RNAi therapeutics. Harnessing RNAi to inhibit vaginal HIV transmission requires effective gene silencing in immune cells, which remains difficult. Knockdown in accessible mucosal tissues may be easier than systemic gene silencing. Vaginally applied cholesterol-conjugated small interfering RNAs (chol-siRNAs) blocked herpes simplex virus transmission in mice without tissue damage or immunostimulation. OBJECTIVES AND METHODS: To investigate using flow cytometry, confocal microscopy, and quantitative imaging if chol-siRNAs silence gene expression in vaginal immune cells in mice. RESULTS: Although chol-siRNAs and lipoplexed-siRNAs silence gene expression in dendritic cells (DCs) in vitro, most internalized siRNAs concentrate within multivesicular bodies, where they are inaccessible to the cellular RNAi machinery. When applied intravaginally in vivo, chol-siRNAs penetrate the vaginal mucosa, including the lamina propria, and are efficiently internalized by intraepithelial (IE) and lamina propria (LP) DCs, and CD11b+ CD45+ cells, but not by T cells. Chol-siRNAs induce partial gene silencing in IE and LP DCs throughout the genital mucosa in vivo but are inactive in F4/80+ CD11b+ macrophages and T cells. CONCLUSION: As mucosal DCs play an essential role for mucosal viral entry and dissemination, chol-siRNAs could be harnessed to target various host factors that are critical for viral uptake, DC migration and trans-infection of virions to T cells, hence allowing the development of a preventive vaginal HIV microbicide. Furthermore, chol-siRNAs could help elucidate the pathways of HIV transmission and understand the immunologic function of DCs in the genital tract.
Subject(s)
HIV Infections , Female , Mice , Animals , RNA Interference , Dendritic Cells/metabolism , Mucous Membrane , Gene ExpressionABSTRACT
BACKGROUND: Our goal was to develop and evaluate an anonymous self-administrable web-based test to determine risk for HIV/STI. METHODS: The Online HIV/STI Risk Test was developed and hosted since 12/2017. 11,529 participants completed the test and 10,668 were analyzed. The test included multiple choice questions about sociodemographic data, sexuality, sexual risk behavior, HIV/STI testing. Participant data was stratified by gender and sexuality and analyzed. RESULTS: 84.5 % were aged 18-39, 7.5 % < 18 and 8.1 % > 40. Males were 53.1 %, female 46.3 % and trans 0.6 %. 12.5 % were men who have sex with men (MSM). 59.1 % and 66.0 % of participants were vaccinated for hepatitis A and B respectively, but 75.1 % unvaccinated for HPV. Prior and repeated instances of HIV or other STI were higher among MSM. Yet, 61.4 % females, 70 % males and 55.4 % MSM had never tested for an STI. Although prevalence of > 3 sexual partners in the last twelve months was highest among MSM, condomless sex was greater among women. 34.5 % of males, 25.6 % of females, and 75 % of MSM engaged in anal sex respectively. CONCLUSIONS: The online HIV/STI Risk Test is a useful tool to acquire data on STI risk-behavior for strategizing STI prevention, testing, and vaccination, thus improving sexual health.
Subject(s)
HIV Infections , Sexual and Gender Minorities , Sexually Transmitted Diseases , Adolescent , Cross-Sectional Studies , Female , Germany/epidemiology , HIV Infections/diagnosis , HIV Infections/epidemiology , Homosexuality, Male , Humans , Male , Prospective Studies , Sexual Behavior , Sexual Partners , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/epidemiologyABSTRACT
BACKGROUND: Holistic sexual healthcare factors in diversity of social habitat and aims to improvise client outreach for prevention, testing, counseling, and treatment of STIs. Towards this goal, the immunology outpatient clinic, the public health department of Bochum, the AIDS Service Organization Bochum e.â¯v., and other community-driven NGOs mutually cooperate under the umbrella of WIR - Walk In Ruhr, Centre for Sexual Health and Medicine. OBJECTIVES: WIR is an innovative concept for multi-professional in-house ambulatory healthcare with cross-sectoral and cross-legal reach. It has successfully improved accessibility, testing and treatment rates, and HIV/STI self-assessment. We present the results achieved at WIR. METHODS: A mixed-method design of qualitative and quantitative surveys. RESULTS: The WIR reaches more women (27.7%) and heterosexuals (56.4%) than other counseling/test centers. The rate of positive test results at the WIR increased from 9.3% in 2017 to 12.6% in 2018 and progress from prevention to medical care is a significant aspect of WIR. The Federal Ministry of Health has externally evaluated WIR for over three years. DISCUSSION: The integrative care model of WIR allows for early outreach and treatment of individuals with HIV/ST infections. Health advisors remain an important instrument facilitating outreach and psychosocial/psychotherapeutic counseling is administered frequently. Such a multi-layered approach in prevention, testing, and consultation, leads to improvement in both medical outcomes and the self-responsible attitude of patients towards their sexual health. Hence, expansion of integrative care models like WIR on a wider scale could arguably contribute to better health service and sexual health.
Subject(s)
HIV Infections , Sexual Health , Sexually Transmitted Diseases , Female , Germany , Humans , Sexual Behavior , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/prevention & controlABSTRACT
BACKGROUND: Application-based data regarding sexual health and sexual behavior in various sexually active populations are scarce but at the same time relevant with regards to prevention and healthcare supply strategies. Given the structure of its attendees, the Walk In Ruhr (WIR) Center for Sexual Health and Medicine is able to obtain data from diverse living environments. OBJECTIVES: Based on the online HIV/STI risk test, questionnaires, and attendee data from the WIR, this study aims to deduce population-related findings with regards to age, gender, sexual orientation, and sexual and risk behavior as well as the respective needs for prevention. The influence of the SARS-CoV-19 pandemic on sexual behavior is examined by comparing various phases. METHODS: The analyzed data sources are the online HIV/STI risk test, the COWIR, and the PrEP study as well as the immunological outpatient clinic and the public health department at the WIR. RESULTS: Notwithstanding contact restrictions, sexually transmitted infections (STIs) have increased from 2019 to 2020. Apart from men having sex with men and females having sex with females, young people also have an increased risk of STIs based on sexual practices and the number of sexual contacts. A large number of bisexual and transsexual contacts was found. SARS-CoV2 led to a decrease in sexual contacts; sexual practices continued. There was a growing proportion of STI tests and the treatment rate including partner treatment rose. DISCUSSION: Data from the WIR center show that young attendees with an active sexual life are being reached. The results from questionnaires and the online HIV/STI risk test are mirrored in increased positive STI test results. These results vary depending on sexual behavior and sexual preferences such that specific strategies for sexual education, prevention, testing, and therapy are required.
Subject(s)
COVID-19 , HIV Infections , Sexually Transmitted Diseases , Adolescent , Delivery of Health Care , Female , Germany , HIV Infections/epidemiology , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Pandemics/prevention & control , SARS-CoV-2 , Sexual Behavior , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/prevention & controlSubject(s)
HIV Infections , Sexual Health , Sexual and Gender Minorities , Sexually Transmitted Diseases , Transgender Persons , Transsexualism , Humans , Male , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/prevention & control , HIV Infections/diagnosis , HIV Infections/epidemiology , HIV Infections/prevention & control , HIV Testing , Sexual Behavior , Homosexuality, MaleABSTRACT
Soft tissue sarcomas (STS) are characterized by co-participation of several epigenetic and genetic events during tumorigenesis. Having bypassed cellular senescence barriers during oncogenic transformation, the factors further affecting growth rate of STS cells remain poorly understood. Therefore, we investigated the role of gene silencing (DNA promoter methylation of LINE-1, PTEN), genetic aberrations (karyotype, KRAS and BRAF mutations) as well as their contribution to the proliferation rate and migratory potential that underlies "initial" and "final" passage sarcoma cells. Three different cell lines were used, SW982 (synovial sarcoma), U2197 (malignant fibrous histiocytoma (MFH)) and HT1080 (fibrosarcoma). Increased proliferative potential of final passage STS cells was not associated with significant differences in methylation (LINE-1, PTEN) and mutation status (KRAS, BRAF), but it was dependent on the amount of chromosomal aberrations. Collectively, our data demonstrate that these fairly differentiated/advanced cancer cell lines have still the potential to gain an additional spontaneous growth benefit without external influences and that maintenance of increased proliferative potential towards longevity of STS cells (having crossed senescence barriers) may be independent of overt epigenetic alterations.
Subject(s)
Abnormal Karyotype , Cell Proliferation , Gene Silencing , Mutation , Sarcoma/genetics , Cell Line, Tumor , Cell Movement , DNA Methylation , Humans , Long Interspersed Nucleotide Elements , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Promoter Regions, Genetic , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins p21(ras) , Sarcoma/metabolism , Sarcoma/pathology , ras Proteins/geneticsABSTRACT
BACKGROUND: In Germany, oral HIV pre-exposure prophylaxis (PrEP) was licensed in 2016. Health insurances have been covering the costs since 09/2019. This study compares the sociodemographic profiles of PrEP users before and after PrEP re-imbursement. METHODS: Participants were recruited in a cross-sectoral sexual health centre in Germany. baseline data were compared for 139 vs 138 individuals starting PrEP from 10/2017-12/2018 (pre-reimbursement cohort) and 09/2019-3/2020; respectively. The pre-reimbursement cohort was further analysed with respect to sexual behaviour and incident sexually transmitted infections (STIs). RESULTS: There were no significant differences in the sociodemographic characteristics between the two cohorts. Almost all PrEP users were men-who-have-sex-with-men (MSM). Before reimbursement, fewer individuals used PrEP on a daily base, and more had used PrEP prior to enrolment. During follow-up (pre-reimbursement cohort), the number of sexual and condomless intercourse partners increased, so did the proportion engaging in Chemsex. Incidences of infections with C.trachomatis, N.gonorrhoeae, M.genitalium, and T.pallidum were 45.2; 36.8; 30.1; and 9.2, respectively, per 100 person-years. CONCLUSION: The goal to make PrEP available to a broader range of people with the covering of costs was only partially reached. Medically supervised use is important to detect and treat STIs.
Subject(s)
HIV Infections , Pre-Exposure Prophylaxis , Sexual and Gender Minorities , Sexually Transmitted Diseases , Female , HIV Infections/epidemiology , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Pre-Exposure Prophylaxis/methods , Sexual Behavior , Sexually Transmitted Diseases/epidemiologyABSTRACT
MicroRNAs (miRNAs: short non-coding RNAs) are emerging as a class of potential novel tumor markers, as their dysregulation is being increasingly reported in various types of cancers. In the present study, we investigated the transcription status of miRNA-148a (miR-148a) in human pancreatic ductal adenocarcinoma (PDAC) and its role in the regulation of the dual specificity protein phosphatase CDC25B. We observed that miR-148a exhibited a significant 4-fold down-regulation in PDAC as opposed to normal pancreatic ductal cells. In addition, we observed that stable lentiviral-mediated overexpression of miR-148a in the pancreatic cancer cell line IMIM-PC2, inhibited tumor cell growth and colony formation. Furthermore, CDC25B was identified as a potential target of miR-148a by in silico analysis using PicTar, Targetscan and miRanda in conjunction with gene ontology analysis. The proposed interaction between miR-148a and the 3' untranslated region (UTR) of CDC25B was verified by in-vitro luciferase assays. We demonstrate that the activity of a luciferase reporter containing the 3'UTR of CDC25B was repressed in the presence of miR-148a mimics, confirming that miR-148a targets the 3'UTR of CDC25B. Finally, CDC25B was down-regulated at the protein level in miR-148a overexpressing IMIM-PC2-cells, and in transiently transfected pancreatic cell lines (as detected by Western blot analysis), as well as in patient tumor samples (as detected by immunohistochemistry). In summary, we identified CDC25B as a novel miR-148a target which may confer a proliferative advantage in PDAC.
Subject(s)
Carcinoma, Pancreatic Ductal/metabolism , Cell Survival/genetics , Down-Regulation , MicroRNAs/metabolism , Pancreatic Neoplasms/metabolism , 3' Untranslated Regions , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/physiopathology , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation , HEK293 Cells , Humans , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/physiopathology , Transfection , Up-Regulation , cdc25 Phosphatases/genetics , cdc25 Phosphatases/metabolismABSTRACT
DNA microarray technology is a versatile platform that allows rapid genetic analysis to take place on a genome-wide scale and has revolutionized the way cancers are studied. This platform has enabled researchers to characterize mechanisms central to tumorigenesis and understand important molecular events in the multi-step tumor progression model of cutaneous melanoma and other cancers. In melanoma, multiple global gene expression profiling studies using various DNA microarray platforms and various experimental designs have been performed. Each study has been able to capture and characterize either the involvement of a novel pathway or a novel cause-effect-relationship. The use of microarrays to define subclasses, to identify differentially regulated genes within a mutational context to analyze epigenetically regulated genes has resulted in an unprecedented understanding of the biology of cutaneous melanoma that may lead to more accurate diagnosis, more comprehensive prognosis, prediction and more effective therapeutic interventions. Related DNA microarray platforms like array-comparative genomic hybridization (CGH) have also been instrumental to identify many non-random chromosomal alterations; however, studies identifying validated targets as a result of CGH are limited. Thus, there exists significant opportunity to discover novel melanoma genes and translate such discoveries into meaningful clinical endpoints. In this review, we focus on various DNA microarray-based studies performed in cutaneous melanoma and summarize our current understanding of the genetics and biology of melanoma progression derived from accumulating genomic information.
Subject(s)
Gene Expression Profiling , Melanoma/genetics , Oligonucleotide Array Sequence Analysis , Skin Neoplasms/genetics , Animals , Gene Dosage , Gene Silencing , Humans , Loss of HeterozygosityABSTRACT
BACKGROUND: Melanoma is a complex genetic disease, the management of which will require an in-depth understanding of the biology underlying its initiation and progression. Recently, we have reported the differential regulation of a novel gene, namely ASK/Dbf4, in melanoma and suggested upregulation of ASK/Dbf4 as a novel molecular determinant with prognostic relevance that confers a proliferative advantage in cutaneous melanoma. As trans-acting factor binding is fundamental to understand the regulation of gene expression, this study focuses on characterization of the specific transcriptional regulation of ASK/Dbf4 in melanoma. OBJECTIVE: We investigated whether ASK/Dbf4 is a transcriptional target of the important cell cycle regulator E2F1 in melanoma. RESULTS: As evidenced by gel supershift assays on nuclear extracts from various melanoma cell lines (SK-MEL-28, MV3, M13, A375 and BLM), E2F1 bound to the ASK/Dbf4 minimal promoter (MP). In addition, cisplatin-mediated abrogation of E2F1 binding to the ASK/Dbf4 MP resulted in a transcriptional decrease in ASK/Dbf4. Further, the current study also demonstrated that ASK/Dbf4 regulation was refractory to UVB, a well-known risk factor for melanoma. CONCLUSIONS: In summary, our study not only elucidated that ASK/Dbf4, a novel cell survival gene in melanoma was transcriptionally regulated by E2F1, but also that the induction of ASK/Dbf4 was refractory to UVB exposure suggesting that its upregulation was not an early event in melanomagenesis.
Subject(s)
Cell Cycle Proteins/metabolism , E2F1 Transcription Factor/metabolism , Melanoma/pathology , Skin Neoplasms/pathology , Antineoplastic Agents/pharmacology , Cell Cycle Proteins/genetics , Cell Line, Tumor , Cisplatin/pharmacology , E2F1 Transcription Factor/genetics , Electrophoretic Mobility Shift Assay , Gene Expression Regulation, Neoplastic , Humans , Melanocytes/drug effects , Melanocytes/metabolism , Melanocytes/radiation effects , Melanoma/genetics , Melanoma/metabolism , Promoter Regions, Genetic/genetics , Protein Binding/drug effects , Protein Binding/radiation effects , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Ultraviolet RaysABSTRACT
Phosphatase and tensin homologue deleted from chromosome 10 (PTEN) seems to be an important tumor suppressor gene in melanoma. Because the PTEN gene is only infrequently deleted or mutated, and because the PTEN protein is low to absent in a significant number of melanomas, we investigated alternative methods of epigenetic silencing. We did quantitative positional methylation analysis (pyrosequencing) on 37 sera from melanoma patients and on 21 pairs of corresponding sera and melanoma specimens in addition to Taqman reverse transcription-PCR. We report significant positional PTEN promoter methylation in 62% of circulating DNA isolated from sera of patients with metastatic melanoma. The percentage of methylation of a selected CpG island in blood showed a correlation with methylation levels in the corresponding melanoma tissue. Moreover, high percentages of PTEN methylation were associated with low PTEN transcription levels. Using the demethylation agent 5-aza-2'-deoxycytidine, reduced methylation and a corresponding increase in PTEN protein were observed in BLM melanoma cells, leading to reduced AKT activity in an in vitro kinase assay. In summary, epigenetic PTEN silencing seems to be a relevant mechanism of inactivating this tumor suppressor gene in melanoma that may promote melanoma development by derepression of the AKT pathway.
Subject(s)
Melanoma/genetics , PTEN Phosphohydrolase/genetics , Aged , Aged, 80 and over , Base Sequence , Chromosomes, Human, Pair 10/genetics , CpG Islands/genetics , DNA Methylation , DNA, Neoplasm/blood , DNA, Neoplasm/genetics , Female , Gene Expression Regulation, Neoplastic , Gene Silencing , Genes, Tumor Suppressor , Humans , Male , Melanoma/blood , Melanoma/pathology , Melanoma/secondary , Middle Aged , Molecular Sequence Data , PTEN Phosphohydrolase/biosynthesis , Promoter Regions, GeneticABSTRACT
Transmission of human herpesvirus 8 (HHV-8) may occur through various routes including breastfeeding and sexual intercourse. We attempted to detect HHV-8 infection in nine HIV-positive couples discordant for Kaposi's sarcoma who maintained a monogamous sexual relationship for at least one year. By quantitative real-time polymerase chain reaction and HHV-8 genotyping we provide strong evidence for the sexual transmission of HHV-8 in this unique cohort.
Subject(s)
HIV Seropositivity/virology , Herpesvirus 8, Human/isolation & purification , Sarcoma, Kaposi/virology , Adult , Antiretroviral Therapy, Highly Active , Cohort Studies , DNA, Viral/analysis , Female , Genotype , HIV Seropositivity/complications , HIV Seropositivity/drug therapy , Humans , Leukocytes, Mononuclear/virology , Male , Middle Aged , Polymerase Chain Reaction/methods , Sarcoma, Kaposi/complications , Sequence Homology, Amino Acid , Sexual BehaviorABSTRACT
Malignant melanoma is one of the most aggressive and invasive metastatic tumors derived from melanocytes that have undergone malignant transformation by acquisition of genetic and epigenetic alterations. Oligonucleotide microarray-based screening of distinct stages in the tumor progression model of cutaneous melanoma identified ASK/Dbf4, as a novel determinant for melanoma development. Quantitative real-time polymerase chain reaction-based confirmation of ASK/Dbf4 on a series of benign nevi, dysplastic nevi, primary cutaneous melanomas and cutaneous melanoma metastases; and a number of other controls using normal human melanocytes as calibrator not only revealed a melanoma-specific over-expression but also revealed that higher ASK/Dbf4-expressing melanomas were associated with lower relapse-free survival. Additionally, we also confirmed the observed over-expression of ASK/Dbf4 in melanoma using western blot analysis and immunohistochemistry. As ASK/Dbf4 is known to be a cyclin-like regulatory subunit of mammalian Cdc7 from the studies in yeast, the present study investigated its role in melanoma cells. In keeping with its expected role, our data suggest that up-regulated ASK/Dbf4 is localized in the nucleus and binds to human Cdc7 to form Cdc7-ASK/Dbf4 complexes in several analyzed melanoma cell lines. Further, we demonstrate that small interfering RNA-mediated depletion of ASK/Dbf4 retarded melanoma cell survival and proliferation. In summary, we report the differential regulation of a novel gene, namely ASK/Dbf4, in melanoma and suggest that up-regulation of ASK/Dbf4 is a novel molecular determinant with prognostic relevance that confers a proliferative advantage in cutaneous melanoma.
Subject(s)
Biomarkers, Tumor/metabolism , Cell Cycle Proteins/metabolism , Melanoma/metabolism , Skin Neoplasms/metabolism , Cell Cycle Proteins/genetics , Cell Nucleus/metabolism , Cell Proliferation , Cell Survival , Cells, Cultured , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Melanocytes/metabolism , Melanoma/secondary , Nevus/metabolism , Oligonucleotide Array Sequence Analysis , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Skin Neoplasms/pathologyABSTRACT
Astrocytoma is the most common type of brain cancer constituting more than half of all brain tumors. With an aim to identify markers describing astrocytoma progression, we have carried out microarray analysis of astrocytoma samples of different grades using cDNA microarray containing 1152 cancer-specific genes. Data analysis identified several differentially regulated genes between normal brain tissue and astrocytoma as well as between grades II/III astrocytoma and glioblastoma multiforme (GBM; grade IV). We found several genes known to be involved in malignancy including Achaete-scute complex-like 1 (Drosophila) (ASCL1; Hash 1). As ASCL has been implicated in neuroendocrine, medullary thyroid and small-cell lung cancers, we chose to examine the role of ASCL1 in the astrocytoma development. Our data revealed that ASCL1 is overexpressed in progressive astrocytoma as evidenced by increased levels of ASCL1 transcripts in 85.71% (6/7) of grade II diffuse astrocytoma (DA), 90% (9/10) of grade III anaplastic astrocytoma (AA) and 87.5% (7/8) of secondary GBMs, while the majority of primary de novo GBMs expressed similar to or less than normal brain levels (66.67%; 8/12). ASCL1 upregulation in progressive astrocytoma is accompanied by inhibition of Notch signaling as seen by uninduced levels of HES1, a transcriptional target of Notch1, increased levels of HES6, a dominant-negative inhibitor of HES1-mediated repression of ASCL1, and increased levels of Notch ligand Delta1, which is capable of inhibiting Notch signaling by forming intracellular Notch ligand autonomous complexes. Our results imply that inhibition of Notch signaling may be an important early event in the development of grade II DA and subsequent progression to grade III AA and secondary GBM. Furthermore, ASCL1 appears to be a putative marker to distinguish primary GBM from secondary GBM.
Subject(s)
Astrocytoma/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Neoplastic , Glioblastoma/genetics , Membrane Proteins/metabolism , Signal Transduction , Transcription Factors/metabolism , Astrocytoma/metabolism , Astrocytoma/pathology , Basic Helix-Loop-Helix Transcription Factors , Brain/metabolism , Brain/pathology , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , DNA-Binding Proteins/genetics , Disease Progression , Gene Expression Profiling , Glioblastoma/metabolism , Glioblastoma/pathology , Helix-Loop-Helix Motifs , Humans , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/genetics , Oligonucleotide Array Sequence Analysis , RNA, Neoplasm/genetics , RNA, Neoplasm/metabolism , Receptors, Notch , Reverse Transcriptase Polymerase Chain Reaction , Transcription Factors/genetics , Up-RegulationABSTRACT
Small amounts of cell-free DNA circulate in both healthy and diseased human blood, while increased concentrations of DNA are present in the serum of cancer patients. Tumor-specific mutations or epigenetic modifications have predominantly been detected in tissue specimens. The purpose of this study was to investigate methylation of five different genes involved in tumor suppression and DNA repair (suppressors of cytokine signaling 1 and 2 (SOCS1, SOCS2)), Ras-association domain family protein 1A (RASSF1a), D-type p16(INK4a) cyclin-dependent kinase inhibitor (CDKN), and O6-methylguanine DNA-methyltransferase (MGMT)) in the serum of 100 patients using methylation-specific PCR. In all, 41 melanoma patients (stage I = 18; stage II = 10; stage III/IV = 13), 13 healthy controls without nevi, and 10 individuals with more than 15 nevi of >5 mm in size were investigated. For comparison, sera from patients with other skin tumors (nine basal cell cancers, five Kaposi's sarcoma), different metastasized cancers (five breast cancers, five colon cancers), and several chronic inflammatory diseases (n = 12) were also analyzed. In addition, we examined if methylation was involved in silencing transcription of these genes in 12 melanoma specimens. SOCS1, SOCS2, RASSF1a, CDKN2a, and MGMT were methylated in 75, 43, 64, 75, and 64% of melanoma samples, respectively. Of the 41 melanoma patients, 83% had one hypermethylated gene, while 66, 51, and 41% had two, three, or four hypermethylated genes, respectively. Also, 20% of these patients showed hypermethylation for all genes, while only 17% showed no methylation. Importantly, the methylation profile of the selected genes from melanoma patients was distinct from the other analyzed tumors. Transcription of SOCS1, SOCS2, CDKN2a, and RASSF1a genes was significantly reduced in fresh melanoma samples, while MGMT showed a 12-fold upregulation at the messenger ribonucleic acid level (P < 0.001). Our findings suggest that epigenetic silencing of the studied tumor suppressor genes is a common and probably important mechanism for melanoma formation. This convenient method using a simple blood sample may contribute to classification of melanoma and awaits clinical validation.
Subject(s)
DNA Methylation , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , Melanoma/genetics , Skin Neoplasms/genetics , Adult , Aged , DNA, Neoplasm/blood , DNA, Neoplasm/metabolism , Female , Gene Expression , Gene Silencing , Genes, p16 , Humans , Intracellular Signaling Peptides and Proteins/genetics , Male , Middle Aged , O(6)-Methylguanine-DNA Methyltransferase/genetics , Repressor Proteins/genetics , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Tumor Suppressor Proteins/geneticsABSTRACT
Altered signaling pathways are key regulators of cellular functions in tumor cells. Constitutive activation of signal transducer and activator of transcription (STAT)3 and -5 may be involved in tumor formation and progression. We have investigated the role of STAT5 in cutaneous melanoma metastases using various RNA and protein techniques. In melanoma specimens, Stat5b transcripts were upregulated approximately 3.8-fold. In 13 of 21 (62%) human melanoma metastases, STAT5 was phosphorylated in comparison to normal human melanocytes and benign nevi. The STAT5 target gene Bcl-2 was frequently upregulated. The investigation of the underlying mechanism revealed specific STAT5 activation by recombinant human epidermal growth factor (rEGF). rEGF-induced activation of STAT5 occurred in vitro through the non-receptor tyrosine kinases transforming gene (src) of Rous Sarcoma virus and Janus kinase 1. Inhibition of Stat5b expression by small interfering RNA strongly reduced the expression of Bcl-2 and led to decreased cell viability and increased apoptosis in the melanoma cell lines A375 and BLM. Transfection with dominant-negative Stat5b caused enhanced cell death and G1 arrest in A375 cells. Our study identifies phosphorylated STAT5 in melanoma and shows regulation through rEGF; STAT5 may thus act as a survival factor for growth of human melanoma and may represent a potential target for molecular therapy.
Subject(s)
Melanoma/metabolism , Protein-Tyrosine Kinases/physiology , STAT5 Transcription Factor/metabolism , src-Family Kinases/physiology , Aged , Aged, 80 and over , Apoptosis , Cell Line, Tumor , DNA/metabolism , Epidermal Growth Factor/pharmacology , ErbB Receptors/analysis , Female , Humans , Janus Kinase 1 , Male , Melanoma/mortality , Melanoma/secondary , Middle Aged , Phosphorylation , Proto-Oncogene Proteins c-bcl-2/analysis , Signal TransductionABSTRACT
BACKGROUND: Melanoma is a complex multigenic disease, susceptibility to which is determined by several parallel and stepwise progressive pathways affecting growth control, differentiation, cell adhesion, and survival. Melanoma and human cancers in general undergo a continuous development from benign to malignant states, as most thoroughly documented in the multistep mole-to-melanoma transition. OBJECTIVE: To examine how high-throughput microarrays are being used in expression profiling to identify regulated genes, patterns, and pathways that may lead to functional characterization and tumor subclassification. DESIGN: Ten melanoma metastases were analyzed by DNA array technology for important regulated candidate genes, with subsequent confirmation by real-time reverse transcription polymerase chain reaction. RESULTS: Hepatocyte growth factor receptor c-met, growth factor receptor-bound protein 10, B-raf proto-oncogene, and several mitogen-activated protein kinase kinase genes were significantly up-regulated in melanoma metastases and several melanoma cell lines relative to normal human melanocytes (P = .03). Among the up-regulated genes, phosphorylated growth factor receptor-bound protein 10 is known to serve a molecular switch turning on the mitogen-activated protein kinase pathway in response to hepatocyte growth factor receptor binding. CONCLUSIONS: As suggested by the DNA arrays, we found the mitogen-activated protein kinase kinase/extracellular-regulated kinase pathway to be activated in most of the cutaneous melanoma metastasis specimens. These findings are in the context of the current microarray technology in melanoma research. Additional steps are needed to gain insights into the pluralistic signaling milieu of this malignancy as we enter the postgenomic era.