DNA methylation in blood from neonatal screening cards and the association with BMI and insulin sensitivity in early childhood.

BACKGROUND/OBJECTIVES: There is increasing evidence that metabolic diseases originate in early life, and epigenetic changes have been implicated as key drivers of this early life programming. This led to the hypothesis that epigenetic marks present at birth may predict an individual's future risk of obesity and type 2 diabetes. In this study, we assessed whether epigenetic marks in blood of newborn children were associated with body mass index (BMI) and insulin sensitivity later in childhood. SUBJECTS/METHODS: DNA methylation was measured in neonatal blood spot samples of 438 children using the Illumina Infinium 450 k BeadChip. Associations were assessed between DNA methylation at birth and BMI z-scores, body fat mass, fasting plasma glucose, insulin and homeostatic model assessment of insulin resistance (HOMA-IR) at age 5 years, as well as birth weight, maternal BMI and smoking status. RESULTS: No individual methylation sites at birth were associated with obesity or insulin sensitivity measures at 5 years. DNA methylation in 69 genomic regions at birth was associated with BMI z-scores at age 5 years, and in 63 regions with HOMA-IR. The methylation changes were generally small (<5%), except for a region near the non-coding RNA nc886 (VTRNA2-1) where a clear link between methylation status at birth and BMI in childhood was observed (P=0.001). Associations were also found between DNA methylation, maternal smoking and birth weight. CONCLUSIONS: We identified a number of DNA methylation regions at birth that were associated with obesity or insulin sensitivity measurements in childhood. These findings support the mounting evidence on the role of epigenetics in programming of metabolic health. Whether many of these small changes in DNA methylation are causally related to the health outcomes, and of clinical relevance, remains to be determined, but the nc886 region represents a promising obesity risk marker that warrants further investigation.

Epigenetics and human obesity.

BACKGROUND: Recent technological advances in epigenome profiling have led to an increasing number of studies investigating the role of the epigenome in obesity. There is also evidence that environmental exposures during early life can induce persistent alterations in the epigenome, which may lead to an increased risk of obesity later in life. METHOD: This paper provides a systematic review of studies investigating the association between obesity and either global, site-specific or genome-wide methylation of DNA. Studies on the impact of pre- and postnatal interventions on methylation and obesity are also reviewed. We discuss outstanding questions, and introduce EpiSCOPE, a multidisciplinary research program aimed at increasing the understanding of epigenetic changes in emergence of obesity. RESULTS: An electronic search for relevant articles, published between September 2008 and September 2013 was performed. From the 319 articles identified, 46 studies were included and reviewed. The studies provided no consistent evidence for a relationship between global methylation and obesity. The studies did identify multiple obesity-associated differentially methylated sites, mainly in blood cells. Extensive, but small, alterations in methylation at specific sites were observed in weight loss intervention studies, and several associations between methylation marks at birth and later life obesity were found. CONCLUSIONS: Overall, significant progress has been made in the field of epigenetics and obesity and the first potential epigenetic markers for obesity that could be detected at birth have been identified. Eventually this may help in predicting an individual's obesity risk at a young age and opens possibilities for introducing targeted prevention strategies. It has also become clear that several epigenetic marks are modifiable, by changing the exposure in utero, but also by lifestyle changes in adult life, which implies that there is the potential for interventions to be introduced in postnatal life to modify unfavourable epigenomic profiles.

Methylated Glutathione S-transferase 1 (mGSTP1) is a potential plasma free DNA epigenetic marker of prognosis and response to chemotherapy in castrate-resistant prostate cancer.

BACKGROUND: Glutathione S-transferase 1 (GSTP1) inactivation is associated with CpG island promoter hypermethylation in the majority of prostate cancers (PCs). This study assessed whether the level of circulating methylated GSTP1 (mGSTP1) in plasma DNA is associated with chemotherapy response and overall survival (OS). METHODS: Plasma samples were collected prospectively from a Phase I exploratory cohort of 75 men with castrate-resistant PC (CRPC) and a Phase II independent validation cohort (n=51). mGSTP1 levels in free DNA were measured using a sensitive methylation-specific PCR assay. RESULTS: The Phase I cohort identified that detectable baseline mGSTP1 DNA was associated with poorer OS (HR, 4.2 95% CI 2.1-8.2; P<0.0001). A decrease in mGSTP1 DNA levels after cycle 1 was associated with a PSA response (P=0.008). In the Phase II cohort, baseline mGSTP1 DNA was a stronger predictor of OS than PSA change after 3 months (P=0.02). Undetectable plasma mGSTP1 after one cycle of chemotherapy was associated with PSA response (P=0.007). CONCLUSIONS: We identified plasma mGSTP1 DNA as a potential prognostic marker in men with CRPC as well as a potential surrogate therapeutic efficacy marker for chemotherapy and corroborated these findings in an independent Phase II cohort. Prospective Phase III assessment of mGSTP1 levels in plasma DNA is now warranted.

Dynamic modelling of prosthetic chorded mitral valves using the immersed boundary method.

Current artificial heart valves either have limited lifespan or require the recipient to be on permanent anticoagulation therapy. In this paper, effort is made to assess a newly developed bileaflet valve prosthesis made of synthetic flexible leaflet materials, whose geometry and material properties are based on those of the native mitral valve, with a view to providing superior options for mitral valve replacement. Computational analysis is employed to evaluate the geometric and material design of the valve, by investigation of its mechanical behaviour and unsteady flow characteristics. The immersed boundary (IB) method is used for the dynamic modelling of the large deformation of the valve leaflets and the fluid-structure interactions. The IB simulation is first validated for the aortic prosthesis subjected to a hydrostatic loading. The predicted displacement fields by IB are compared with those obtained using ANSYS, as well as with experimental measurements. Good quantitative agreement is obtained. Moreover, known failure regions of aortic prostheses are identified. The dynamic behaviour of the valve designs is then simulated under four physiological pulsatile flows. Experimental pressure gradients for opening and closure of the valves are in good agreement with IB predictions for all flow rates for both aortic and mitral designs. Importantly, the simulations predicted improved physiological haemodynamics for the novel mitral design. Limitation of the current IB model is also discussed. We conclude that the IB model can be developed to be an extremely effective dynamic simulation tool to aid prosthesis design.

Preclinical evaluation of a prostate-targeted gene-directed enzyme prodrug therapy delivered by ovine atadenovirus.

Gene-directed enzyme prodrug therapy (GDEPT) based on the Escherichia coli enzyme, purine nucleoside phosphorylase (PNP), provides a novel strategy for treating slowly growing tumors like prostate cancer (CaP). PNP converts systemically administered prodrug, fludarabine phosphate, to a toxic metabolite, 2-fluoroadenine, that kills PNP-expressing and nearby cells by inhibiting DNA, RNA and protein synthesis. Reporter gene expression directed by a hybrid prostate-directed promoter and enhancer, PSMEPb, was assayed after plasmid transfection or viral transduction of prostate and non-CaP cell lines. Androgen-sensitive (AS) LNCaP-LN3 and androgen-independent (AI) PC3 human CaP xenografts in nude mice were injected intratumorally with an ovine atadenovirus vector, OAdV623, that carries the PNP gene under PSMEPb, formulated with cationic lipid for enhanced infectivity. Fludarabine phosphate was then given intraperitoneally for 5 days at 75 mg/m2/day. PNP expression was evaluated by enzymic conversion of its substrate using reverse phase HPLC. OAdV623 showed excellent in vitro transcriptional specificity for CaP cells. In vivo, expression of PNP persisted for > 6 days after OAdV623 injection and a single treatment provided 100% increase in tumor doubling time and > 50% inhibition of tumor growth for both LNCaP-LN3 and PC3 lines, with increased tumor necrosis and apoptosis and decreased tumor cell proliferation. OAdV623 significantly suppressed the growth of AS and AI human CaP xenografts in mice.

Modelling chorded prosthetic mitral valves using the immersed boundary method.

The Immersed Boundary (IB) Method is an efficient method of modelling fluid structure interactions. However, it has two main limitations: ease of use and ability to model static loading. In this paper, the method is developed, so that it can efficiently and easily model any multileaflet elastic structure. The structure may include chordae, which attach to the leaflets and continue through the leaflet surfaces. In addition, an external surface pressure may be applied to the leaflets, thus enabling the deformations that arise under steady loads to be solved. This method is validated for a model of the native mitral valve under systolic loading and for a prosthetic aortic valve under static loading. It is then applied to a new chorded prosthetic mitral valve, housed in a cylindrical tube, subject to a physiological periodic fluid flow. Results are compared with those obtained by using the commercial package ANSYS as well as with experimental measurements. Qualitative agreements are obtained. There are some discrepancies due to the current IB method being unable to model bending and shear behaviour. In particular, the fibre structures of the new prosthetic valve model developed using the IB method may be prone to crimping. Further development of the IB method is necessary to include bending effects. This will improve the accuracy of both the dynamic and static analysis.

Botulinum toxin type a neuromuscular blockade in the treatment of equinus foot deformity in cerebral palsy: a multicenter, open-label clinical trial.

BACKGROUND: Focal spasticity of the gastrocnemius-soleus muscles causes equinus gait in children with cerebral palsy (CP). Botulinum toxin type A (BTX-A), a neuromuscular blocking agent, reduces muscle tone/overactivity in dystonia, stroke, and CP. OBJECTIVE: A prospective, open-label, multicenter clinical trial evaluated the long-term safety and efficacy of repeated intramuscular injections of BTX-A on equinus gait in CP children. METHODS: Nine centers enrolled 207 children. BTX-A injections (4 U/Kg) were given approximately every 3 months (maximum dose 200 U per treatment). Outcome measures included a Physician Rating Scale of gait, ankle range of motion measurements, and the incidence and profile of adverse events. RESULTS: One hundred fifty-five (75%) of 207 children completed at least 1 year with a total of 302 patient years of BTX-A treatment. The mean duration of BTX-A exposure was 1.46 years per patient. Dynamic gait pattern on the Physician Rating Scale improved in 46% of patients (86/185) at first follow-up. The response was maintained in 41% to 58% of patients for 2 years. Both gait pattern and ankle position improved at every visit. The most common treatment-related adverse events included increased stumbling, leg cramps, leg weakness, and calf atrophy in 1% to 11% of patients. No treatment-related serious adverse events were reported. Only 6% (7/117) of patients with pre- and postantibody samples had both detectable antibodies and a subsequent treatment failure. CONCLUSION: BTX-A proved both safe and effective in the chronic management of focal muscle spasticity in children with equinus gait.

In vivo suicide gene therapy model using a newly discovered prostate-specific membrane antigen promoter/enhancer: a potential alternative approach to androgen deprivation therapy.

Prostate-specific membrane antigen (PSMA) is a type-2 membrane protein expressed in the prostate, and it is highly expressed in metastatic or poorly differentiated adenocarcinomas. Moreover, PSMA expression is upregulated by androgen deprivation. These advantages make PSMA a useful target for prostate cancer therapy, especially in combination with conventional hormonal treatment. We recently reported that a prostate-specific enhancer is present in the third intron of the PSMA gene. In this study, we have further analyzed the activity of PSMA promoter/enhancer in prostate cancer cells and cells of other tissue origins (breast cancer MCF-7, lung cancer H157, and colorectal cancer HCT8 cells), and we have examined whether this construct could be used for efficient expression of the suicide gene, cytosine deaminase (CD), in vivo. The PSMA promoter/enhancer expressed the luciferase reporter gene in the prostate cancer lines LNCaP and C4-2, with 8- to 20-fold higher expression than the simian virus 40 promoter/enhancer, although it was inactive in the other cell lines. This construct efficiently drove the suicide gene CD, sensitizing C4-2 cells to 5-fluorocytosine (5-FC) with the inhibitory concentration (IC(50)) <300 micromol/L in vitro. Athymic male nude mice bearing the transfected C4-2 cells were treated with intraperitoneal injections of either 5-FC (600 mg/kg) twice a day or saline solution for 3 weeks. C4-2 cell tumors were eliminated by 5-FC when they were expressing our therapeutic construct carrying CD under the regulatory control of the PSMA promoter/enhancer. Our results show the in vivo utility of the PSMA promoter/enhancer in a gene therapy situation targeting prostate cancer.

A tissue-specific enhancer of the prostate-specific membrane antigen gene, FOLH1.

Prostate-specific membrane antigen (PSMA) is an integral membrane protein that is highly expressed on the surface of prostate epithelial cells. It is also expressed on the vascular endothelium of a number of tumor types. We have used an enhancer trap approach with randomly cleaved overlapping DNA fragments from an approximately 55-kb P1 cosmid insert encompassing the 5' half and upstream sequences of the PSMA gene (FOLH1) to isolate an enhancer that strongly activates the FOLH1 core promoter region. The enhancer (PSME) is located in the third intron about 12 kb downstream from the start site of transcription and is characterized by a 72-bp direct repeat within a 331-bp core region. The PSME activates transcription from its own and heterologous promoters in prostate cell lines; enhancement is greatest in the PSMA-expressing cell line LNCaP (>250-fold). The PSME shows essentially no activity in five nonprostate cell lines. PSME-enhanced expression is repressed in the presence of androgen, mimicking the repression of the endogenous FOLH1 gene. The data demonstrate that both cell-type specificity and androgen regulation are intrinsic properties of the enhancer. These properties make the PSME an excellent candidate for regulation of gene expression in gene therapy approaches to prostate cancer.

Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging.

PURPOSE: To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging. METHODS: We reviewed the neuro-ophthalmologic records and brain/orbital magnetic resonance imaging scans for 43 consecutive pediatric patients with neurofibromatosis type 1 and optic pathway gliomas who were followed at the Children's Hospital of Philadelphia. The presence of visual loss, defined as abnormal visual acuity for age in one or both eyes, was determined. Optic pathway gliomas were classified by tumor extent and location according to involvement of the optic nerves, chiasm, and postchiasmal structures by magnetic resonance imaging. RESULTS: Involvement of the optic tracts and other postchiasmal structures at tumor diagnosis was associated with a significantly higher probability of visual acuity loss (P =.048, chi-square test). Visual loss was noted in 20 of 43 patients (47%) at a median age of 4 years; however, three patients developed visual acuity loss for the first time during adolescence. CONCLUSIONS: In pediatric patients with neurofibromatosis type 1 and optic pathway gliomas, the likelihood of visual loss is dependent on the extent and location of the tumor by magnetic resonance imaging and is particularly associated with involvement of postchiasmal structures. Furthermore, older age during childhood (adolescence) does not preclude the occurrence of visual loss. Close follow-up beyond the early childhood years, particularly for those with postchiasmal tumor, is recommended.

Overview of evolving strategies incorporating prostate-specific membrane antigen as target for therapy.

Prostate-specific membrane antigen (PSMA) is a potential target in prostate cancer patients because it is very highly expressed and because it has been reported to be upregulated by androgen deprivation. This overview addresses the expression of the PSMA gene in terms of the promoter and enhancer and how that may play a role in gene therapy. We also review PSMA as a target for antibodies for imaging and treatment and the development of a novel hybrid T-cell receptor that combines the specificity of anti-PSMA antibodies with that of T-cell receptor activation when introduced into primary lymphocytes by retroviral-mediated gene transfer. We also discuss our recent findings on the expression of a PSMA-like gene and how that understanding allows specific targeting of PSMA.

High level, tissue-specific expression of a modified calcitonin/calcitonin gene-related peptide promoter in a human medullary thyroid carcinoma cell line.

The efficient and high level expression of therapeutic genes in target cells is critical for effective gene therapy. We have developed a novel promoter by utilizing tandem repeats of a tissue-specific regulatory element from the calcitonin/calcitonin gene-related peptide (CT/CGRP) gene placed in close proximity to a basal promoter, thereby removing interstitial sequences. This promoter drives expression of reporter genes at much higher levels than the natural promoter while significantly improving specificity in thyroid C cells.

Prostate-specific suicide gene therapy using the prostate-specific membrane antigen promoter and enhancer.

BACKGROUND: Prostate-specific membrane antigen (PSMA) is abundantly expressed in virtually 100% of prostate cancers and metastases. In addition, unlike prostate-specific antigen (PSA), PSMA is upregulated under conditions of androgen deprivation. Therefore, PSMA is an attractive therapeutic target for advanced prostate cancer. Recently, both the promoter and the enhancer driving prostate-specific expression of the PSMA gene were cloned. We describe here our analysis of the PSMA enhancer for the most active region(s) and present a way of using the enhancer in combination with the E. coli cytosine deaminase gene for suicide-driven gene therapy that converts the nontoxic prodrug 5-fluorocytosine (5-FC) into the cytotoxic drug 5-fluorouracil (5-FU) in prostate cancer cells. METHODS: Deletion constructs of the full-length PSMA enhancer were subcloned into a luciferase reporter vector containing either the PSMA or SV-40 promoter. The most active portion of the enhancer was then determined via luciferase activity in the C4-2 cell line. We then replaced the luciferase gene with the E. coli cytosine deaminase gene in the subclone that showed the most luciferase activity. The specificity of this technique was examined in vitro, using the prostate cancer cell line LNCaP, its androgen-independent derivative C4-2, and a number of nonprostatic cell lines. The toxicity of 5-FC and 5-FU on transiently transfected cell lines was then compared. RESULTS: The enhancer region originally isolated from the PSMA gene was approximately 2 kb. Deletion constructs revealed that at least two distinct regions seem to contribute to expression of the gene in prostate cancer cells, and therefore the best construct for prostate-specific expression was determined to be 1, 648 bp long. The IC(50) of 5-FC was similar in all cell lines tested (>10 mM). However, transfection with the 1648 nt PSMA enhancer and the PSMA promoter to drive the cytosine deaminase gene enhanced toxicity in a dose-dependent manner more than 50-fold, while cells that did not express the PSMA gene were not significantly sensitized by transfection. CONCLUSIONS: Suicide gene therapy using the PSMA enhancer may be of benefit to patients who have undergone androgen ablation therapy and are suffering a relapse of disease.

Detection of multiple reactive protein species by immunoblotting after recombinant outer surface protein A lyme disease vaccination.

Laboratory confirmation of the diagnosis of Lyme disease is based on the detection of an immune response to Borrelia burgdorferi. The serodiagnosis of B. burgdorferi infection is complex and may be further confounded by the immune response to the recombinant outer surface protein A (OspA) Lyme disease vaccine. To describe how the serological response to the recombinant OspA Lyme disease vaccine affects testing for antibody to B. burgdorferi, 240 specimens from 80 study subjects were obtained at defined intervals after recombinant OspA Lyme disease vaccination. Samples were tested by indirect enzyme-linked immunosorbent assay (ELISA), antibody capture enzyme immunoassay (EIA), and Western blotting (WB). After recombinant OspA Lyme disease vaccination, ELISA for 98% of the study subjects revealed reactivity. WB with use of OspA-containing B. burgdorferi strains as sources of antigens demonstrated multiple bands. Results of testing with a US Food and Drug Administration-approved WB kit showed homogeneous reactivity in the molecular weight region >30 kDa. Testing with OspA-free strains completely eliminated all vaccine-associated reactivity by both antibody capture EIA and WB.

A distinct sequence (ATAAA)n separates methylated and unmethylated domains at the 5'-end of the GSTP1 CpG island.

What defines the boundaries between methylated and unmethylated domains in the genome is unclear. In this study we used bisulfite genomic sequencing to map the boundaries of methylation that flank the 5'- and 3'-ends of the CpG island spanning the promoter region of the glutathione S-transferase (GSTP1) gene. We show that GSTP1 is expressed in a wide range of tissues including brain, lung, skeletal muscle, spleen, pancreas, bone marrow, prostate, heart, and blood and that this expression is associated with the CpG island being unmethylated. In these normal tissues a marked boundary was found to separate the methylated and unmethylated regions of the gene at the 5'-flank of the CpG island, and this boundary correlated with an (ATAAA)(19-24) repeated sequence. In contrast, the 3'-end of the CpG island was not marked by a sharp transition in methylation but by a gradual change in methylation density over about 500 base pairs. In normal tissue the sequences on either side of the 5'-boundary appear to lie in separate domains in which CpG methylation is independently controlled. These separate methylation domains are lost in all prostate cancer where GSTP1 expression is silenced and methylation extends throughout the island and spans across both the 5'- and 3'-boundary regions.

Association of antibiotic treatment-resistant Lyme arthritis with T cell responses to dominant epitopes of outer surface protein A of Borrelia burgdorferi.

OBJECTIVE: To explore further the association of antibiotic treatment-resistant Lyme arthritis and T cell reactivity with outer surface protein A (OspA) of Borrelia burgdorferi, including the identification of T cell epitopes associated with this treatment-resistant course. METHODS: The responses of peripheral blood and, if available, synovial fluid lymphocytes to B burgdorferi proteins, fragments, and synthetic peptides, as determined by proliferation assay and interferon-gamma production, were compared in 16 patients with treatment-responsive and 16 with treatment-resistant Lyme arthritis. RESULTS: The maximum severity of joint swelling correlated directly with the response to OspA. Moreover, the only significant difference between patients with treatment-resistant and treatment-responsive arthritis was in reactivity with N-terminal and C-terminal fragments of OspA, OspA1 (amino acids [aa] 16-106), and OspA3 (aa 168-273). Epitope mapping showed that 14 of the 16 patients with treatment-resistant arthritis had responses to OspA peptides (usually 4 or 5 epitopes), whereas only 5 of the 16 patients with treatment-responsive arthritis had reactivity with these peptides (usually 1 or 2 epitopes) (P = 0.003). Patients with HLA-DRB1 alleles associated with treatment-resistant arthritis were more likely to react with peptide 15 (aa 154-173) and, to a lesser degree, with peptide 21 (aa 214-233) than patients with other alleles, whereas the responses to other epitopes were similar in both groups. CONCLUSION: The maximum severity of joint swelling and the duration of Lyme arthritis after antibiotic treatment are associated with T cell responses to specific epitopes of OspA.

Combined interferon, famciclovir and GM-CSF treatment of HBV infection in an individual with periarteritis nodosa.

Treatment of chronic hepatitis B virus (HBV) infection in an individual with periarteritis nodosum is described. A combination of famciclovir, granulocyte macrophage colony stimulating factor (GM-CSF) and interferon alpha 2b was utilized. The periarteritis, but not the HBV infection, responded to immunosuppressive therapy consisting of cyclophosphamide and glucocorticoids. Moreover, the patient failed to clear this HBV infection, despite a full year of interferon therapy at 5 MU daily. With the addition of famciclovir and GM-CSF, the HBV infection rapidly resolved and he converted from HBsAg and eAg positive to HBsAb and eAb positive. No exacerbation of his periarteritis nodosum occurred during the course of his antiviral therapy.