260 research outputs found
Endoscopic screening for precancerous lesions of the esophagus in a high risk area in northern Iran
Background: Esophageal squamous cell carcinoma (ESCC) is a major health problem in many developing countries, including Iran. ESCC has a very poor prognosis, largely due to late diagnosis. As a first step in developing an early detection and treatment program, we conducted a population-based endoscopic screening for ESCC and its precursor lesion, esophageal squamous dysplasia (ESD), in asymptomatic adults from Golestan Province, northern Iran (a high-risk area for ESCC) to evaluate the feasibility of such a program and to document the prevalence and risk factor correlates of ESD. Methods: This cross-sectional study was conducted among participants of the Golestan Cohort Study (GCS), a population-based cohort of 50,000 adults in eastern Golestan Province. Randomly selected GCS participants were invited by telephone. Those who accepted were referred to a central endoscopy clinic. Eligible subjects who consented were asked to complete a brief questionnaire. Detailed information about selected risk factors was obtained from the GCS main database. Endoscopic examination with was performed with Lugol's iodine staining; biopsies were taken from unstained lesions as well as the normally stained mucosa of the esophagus, and the biopsies were diagnosed by expert pathologists according to previously described criteria. Results: In total, 1906 GCS subjects were invited, of whom only 302 (15.8%) were successfully enrolled. Esophagitis (29.5%) and ESD (6.0%) were the most common pathological diagnoses. Turkmen ethnicity (adjusted OR = 8.61; 95%CI: 2.48-29.83), being older than the median age (OR = 7.7; 95% CI: 1.99-29.87), and using deep frying cooking methods (OR = 4.65; 95%CI: 1.19-18.22) were the strongest predictors for ESD. There were significant relationships between esophagitis and smoking (p-value<0.001), drinking hot tea (P value = 0.02) and lack of education (P value = 0.004). Conclusion: We observed a low rate of participation in endoscopic screening. The overall prevalence of ESD was 6.0%. Developing non-endoscopic primary screening methods and screening individuals with one or more risk factors may improve these rates
MAPK and JAK/STAT pathways targeted by miR-23a and miR-23b in prostate cancer: computational and in vitro approaches
The long-lasting inadequacy of existing treatments for prostate cancer has led to increasing efforts for developing novel therapies for this disease. MicroRNAs (miRNAs) are believed to have considerable therapeutic potential due to their role in regulating gene expression and cellular pathways. Identifying miRNAs that efficiently target genes and pathways is a key step in using these molecules for therapeutic purposes. Moreover, computational methods have been devised to help identify candidate miRNAs for each gene/pathway. MAPK and JAK/STAT pathways are known to have essential roles in cell proliferation and neoplastic transformation in different cancers including prostate cancer. Herein, we tried to identify miRNAs that target these pathways in the context of prostate cancer as therapeutic molecules. Genes involved in these pathways were analyzed with various algorithms to identify potentially targeting miRNAs. miR-23a and miR-23b were then selected as the best potential candidates that target a higher number of genes in these pathways with greater predictive scores. We then analyzed the expression of candidate miRNAs in LNCAP and PC3 cell lines as well as prostate cancer clinical samples. miR-23a and miR-23b showed a significant downregulation in cell line and tissue samples, a finding which is consistent with overactivation of these pathways in prostate cancer. In addition, we overexpressed miR-23a and miR-23b in LNCAP and PC3 cell lines, and these two miRNAs decreased IL-6R expression which has a critical role in these pathways. These results suggest the probability of utilizing miR-23a and miR-23b as therapeutic targets for the treatment of prostate cancer. © 2015, International Society of Oncology and BioMarkers (ISOBM)
Biodegradable PEG-poly(ω-pentadecalactone- co - p -dioxanone) nanoparticles for enhanced and sustained drug delivery to treat brain tumors
Intracranial delivery of therapeutic agents is limited by penetration beyond the blood-brain barrier (BBB)
and rapid metabolism of the drugs that are delivered. Convection-enhanced delivery (CED) of drugloaded
nanoparticles (NPs) provides for local administration, control of distribution, and sustained
drug release. While some investigators have shown that repeated CED procedures are possible, longer
periods of sustained release could eliminate the need for repeated infusions, which would enhance
safety and translatability of the approach. Here, we demonstrate that nanoparticles formed from
poly(ethylene glycol)-poly(u-pentadecalactone-co-p-dioxanone) block copolymers [PEG-poly(PDL-co-
DO)] are highly efficient nanocarriers that provide long-term release: small nanoparticles (less than
100 nm in diameter) continuously released a radiosensitizer (VE822) over a period of several weeks
in vitro, provided widespread intracranial drug distribution during CED, and yielded significant drug
retention within the brain for over 1 week. One advantage of PEG-poly(PDL-co-DO) nanoparticles is that
hydrophobicity can be tuned by adjusting the ratio of hydrophobic PDL to hydrophilic DO monomers,
thus making it possible to achieve a wide range of drug release rates and drug distribution profiles. When
administered by CED to rats with intracranial RG2 tumors, and combined with a 5-day course of fractionated
radiation therapy, VE822-loaded PEG-poly(PDL-co-DO) NPs significantly prolonged survival
when compared to free VE822. Thus, PEG-poly(PDL-co-DO) NPs represent a new type of versatile
nanocarrier system with potential for sustained intracranial delivery of therapeutic agents to treat brain
tumors
Prophylactic DNA vaccine targeting Foxp3+regulatory T cells depletes myeloid-derived suppressor cells and improves anti-melanoma immune responses in a murine model
Abstract
Regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) are the two important and interactive immunosuppressive components of the tumor microenvironment that hamper anti-tumor immune responses. Therefore, targeting these two populations together might be beneficial for overcoming immune suppression in the tumor microenvironment. We have recently shown that prophylactic Foxp3 DNA/recombinant protein vaccine (Foxp3 vaccine) promotes immunity against Treg in tumor-free conditions. In the present study, we investigated the immune modulatory effects of a prophylactic regimen of the redesigned Foxp3 vaccine in the B16F10 melanoma model. Our results indicate that Foxp3 vaccination continuously reduces Treg population in both the tumor site and the spleen. Surprisingly, Treg reduction was associated with a significant decrease in the frequency of MDSC, both in the spleen and in the tumor environment. Furthermore, Foxp3 vaccination resulted in a significant reduction of arginase-1(Arg-1)-induced nitric oxide synthase (iNOS), reactive oxygen species (ROS) and suppressed MDSC activity. Moreover, this concurrent depletion restored production of inflammatory cytokine IFN-γ and enhanced tumor-specific CTL response, which subsequently resulted in the reduction of tumor growth and the improved survival rate of vaccinated mice. In conclusion, our results revealed that Foxp3 vaccine promotes an immune response against tumor by targeting both Treg and MDSC, which could be exploited as a potential immunotherapy approach.
Keywords
Regulatory T cells Myeloid-derived suppressor cells Foxp3 Melanom
Prophylactic DNA vaccine targeting Foxp3 + regulatory T cells depletes myeloid-derived suppressor cells and improves anti-melanoma immune responses in a murine model
Regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) are the two important and interactive immunosuppressive components of the tumor microenvironment that hamper anti-tumor immune responses. Therefore, targeting these two populations together might be beneficial for overcoming immune suppression in the tumor microenvironment. We have recently shown that prophylactic Foxp3 DNA/recombinant protein vaccine (Foxp3 vaccine) promotes immunity against Treg in tumor-free conditions. In the present study, we investigated the immune modulatory effects of a prophylactic regimen of the redesigned Foxp3 vaccine in the B16F10 melanoma model. Our results indicate that Foxp3 vaccination continuously reduces Treg population in both the tumor site and the spleen. Surprisingly, Treg reduction was associated with a significant decrease in the frequency of MDSC, both in the spleen and in the tumor environment. Furthermore, Foxp3 vaccination resulted in a significant reduction of arginase-1(Arg-1)-induced nitric oxide synthase (iNOS), reactive oxygen species (ROS) and suppressed MDSC activity. Moreover, this concurrent depletion restored production of inflammatory cytokine IFN-γ and enhanced tumor-specific CTL response, which subsequently resulted in the reduction of tumor growth and the improved survival rate of vaccinated mice. In conclusion, our results revealed that Foxp3 vaccine promotes an immune response against tumor by targeting both Treg and MDSC, which could be exploited as a potential immunotherapy approach.. © 2017, Springer-Verlag GmbH Germany, part of Springer Nature
Kinetic modelling of competition and depletion of shared miRNAs by competing endogenous RNAs
Non-conding RNAs play a key role in the post-transcriptional regulation of
mRNA translation and turnover in eukaryotes. miRNAs, in particular, interact
with their target RNAs through protein-mediated, sequence-specific binding,
giving rise to extended and highly heterogeneous miRNA-RNA interaction
networks. Within such networks, competition to bind miRNAs can generate an
effective positive coupling between their targets. Competing endogenous RNAs
(ceRNAs) can in turn regulate each other through miRNA-mediated crosstalk.
Albeit potentially weak, ceRNA interactions can occur both dynamically,
affecting e.g. the regulatory clock, and at stationarity, in which case ceRNA
networks as a whole can be implicated in the composition of the cell's
proteome. Many features of ceRNA interactions, including the conditions under
which they become significant, can be unraveled by mathematical and in silico
models. We review the understanding of the ceRNA effect obtained within such
frameworks, focusing on the methods employed to quantify it, its role in the
processing of gene expression noise, and how network topology can determine its
reach.Comment: review article, 29 pages, 7 figure
High-Performance Capillary Electrophoresis for Determining HIV-1 Tat Protein in Neurons
The HIV-1 protein, Tat has been implicated in AIDS pathogenesis however, the amount of circulating Tat is believed to be very low and its quantification has been difficult. We performed the quantification of Tat released from infected cells and taken up by neurons using high performance capillary electrophoresis. This is the first report to successfully measure the amount of Tat in neurons and places Tat as a key player involved in HIV-associated neurocognitive disorders
Relationships of PBMC microRNA expression, plasma viral load, and CD4+ T-cell count in HIV-1-infected elite suppressors and viremic patients
<p>Abstract</p> <p>Background</p> <p>HIV-1-infected elite controllers or suppressors (ES) maintain undetectable viral loads (< 50 copies/mL) without antiretroviral therapy. The mechanisms of suppression are incompletely understood. Modulation of HIV-1 replication by miRNAs has been reported, but the role of small RNAs in ES is unknown. Using samples from a well-characterized ES cohort, untreated viremic patients, and uninfected controls, we explored the PBMC miRNA profile and probed the relationships of miRNA expression, CD4+ T-cell counts, and viral load.</p> <p>Results</p> <p>miRNA profiles, obtained using multiple acquisition, data processing, and analysis methods, distinguished ES and uninfected controls from viremic HIV-1-infected patients. For several miRNAs, however, ES and viremic patients shared similar expression patterns. Differentially expressed miRNAs included those with reported roles in HIV-1 latency (miR-29 family members, miRs -125b and -150). Others, such as miR-31 and miR-31*, had no previously reported connection with HIV-1 infection but were found here to differ significantly with uncontrolled HIV-1 replication. Correlations of miRNA expression with CD4+ T-cell count and viral load were found, and we observed that ES with low CD4+ T-cell counts had miRNA profiles more closely related to viremic patients than controls. However, expression patterns indicate that miRNA variability cannot be explained solely by CD4+ T-cell variation.</p> <p>Conclusions</p> <p>The intimate involvement of miRNAs in disease processes is underscored by connections of miRNA expression with the HIV disease clinical parameters of CD4 count and plasma viral load. However, miRNA profile changes are not explained completely by these variables. Significant declines of miRs-125b and -150, among others, in both ES and viremic patients indicate the persistence of host miRNA responses or ongoing effects of infection despite viral suppression by ES. We found no negative correlations with viral load in viremic patients, not even those that have been reported to silence HIV-1 in vitro, suggesting that the effects of these miRNAs are exerted in a focused, cell-type-specific manner. Finally, the observation that some ES with low CD4 counts were consistently related to viremic patients suggests that miRNAs may serve as biomarkers for risk of disease progression even in the presence of viral suppression.</p
Next-generation sequencing reveals broad down-regulation of microRNAs in secondary progressive multiple sclerosis CD4+ T cells
Low percentage of clinically relevant pistachio nut and mango co-sensitisation in cashew nut sensitised children
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