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Mod Pathol. The role of miRNAs in neuroendocrine tumors such as ileal carcinoids is largely unknown.
Guidance for DNA methylation studies: statistical insights from the Illumina EPIC array
All miRNAs chosen for the QuantiMir System array were based on their potential functions related to cancer biology, cell development, and apoptosis. The expression of miRNAs for the samples was normalized to miRNA, and the matching primary and metastatic tumors were compared. In situ hybridization in normal ileum showed that some of the mucosal endocrine cells expressed miRNAa. Both primary and metastatic ileal carcinoid tumors expressed miRNAa by in situ hybridization.
Departments of Pediatrics and Communicable Diseases C. However, the precise role of GH in regulation of macrophage function is unclear. We hypothesized that soluble factors including cytokines produced by macrophages in a GH-dependent manner regulate adipogenesis. Conditioned medium CM from macrophages inhibited adipogenesis in a 3T3-L1 adipogenesis assay. CM from GH-treated macrophages decreased the inhibitory effect of CM from macrophages on adipogenesis.
This effect on preadipocyte differentiation was active only during the first early phase of adipocyte differentiation. CM from stromal vascular compartment macrophages of mice with macrophage-specific deletion of the GHR exhibited more inhibitory effect on 3T3-L1 preadipocyte differentiation compared with CM from stromal vascular compartment macrophages of control mice, indicating that intact GH action in primary macrophages also increases preadipocyte differentiation.
GH did not increase IGF-1 expression in macrophages. Nuclear factor-kappaB stimulates IL-1beta gene expression, and GH induced a significant decrease in the levels of phosphorylated nuclear factor-kappaB in macrophages. IL-1beta is a known inhibitor of adipogenesis, and these results support GH-dependent down-regulation of macrophage IL-1beta expression as one mechanism for the observed increase in adipogenesis with CM from GH-treated macrophages.
We conclude that GH decreases secretion of IL-1beta by the macrophage and thus in a paracrine manner increases adipocyte differentiation. These results provide a novel mechanism for GH's actions in the control of adipogenesis.
This study has investigated whether matrine could also display anti-tumor action on rat C6 glioma cells. Exposure of C6 cells to matrine resulted in inhibition of proliferation and induction of apoptosis in a dose-dependent manner, as measured by the MTT assay and Flow cytometry. To explore the molecular mechanism, an apoptosis real-time PCR array was performed, which has demonstrated that 57 genes were at least 2-fold upregulated, and 11 genes were at least 2-fold downregulated in matrine-treated C6 cells, compared with untreated cells.
However, the gene expression profiles could only partly and roughly explain molecular mechanisms of apoptosis and autophagy in matrine-treated C6 cells, thus further investigations are required to confirm the specific molecular pathways and related molecules responsible for the programmed. The Xenopus laevis oocyte was selected as model, because of its large size more than 1mm and large amount of total RNA approximately 5mug. Because of the high resolution in sectioning, it was possible to distinguish two subgroups of the vegetal gene patterns: germ plasm determinant pattern and profile of other vegetal genes.
Harfe, Michael T. McManus, M. Our studies unveil the existence of an LPS-dependent post-transcriptional regulation of miR biogenesis. Once induced, miR finely tunes the expression of select inflammation mediators in response to LPS. A real-time PCR array for hierarchical identification of Francisella isolates. A robust, rapid and flexible real-time PCR assay for hierarchical genetic typing of clinical and environmental isolates of Francisella is presented. Typing markers were found by multiple genome and gene comparisons, from which 23 canonical single nucleotide polymorphisms canSNPs and 11 canonical insertion-deletion mutations canINDELs were selected to provide phylogenetic guidelines for classification from genus to isolate level.
The specificity of the developed assay, which uses 68 wells of a well real-time PCR format with a detection limit of pg DNA, was assessed using 62 Francisella isolates of diverse genetic and geographical origins. It was then successfully used for typing 14 F. When applied to human ulcer specimens for direct pathogen detection the results were incomplete due to scarcity of DNA, but sufficient markers were identified to detect fine-resolution differences among F.
Microarray Analysis - Gene Expression and Genotyping
Induction of apoptosis in human bladder cancer cells by green tea catechins. Biomed Res. Cell culture and animal studies have demonstrated strong chemopreventative effects of green tea and its associated polyphenols in multiple cancers, though the exact mechanisms of action are not well understood. Lab Chip. Unique features of this ready-to-use device include arrayed primers that are pre-deposited into open micro-reaction chambers and use of the oil phase as a companion fluid for both sample actuation and compartmentalization.
These technical advantages allow for infusion of minute amounts of sample for arrayed MSP analysis, without the added complexities inherent in microfluidic droplet-based studies. Ease of use of this micro device is exemplified by analysis of two tumor suppressor promoters, p15 and TMS1 using an on-chip methylation assay. These results were consistent with standard MSP protocols, yet the simplicity of the droplet-in-oil microfluidic PCR platform provides an easy and efficient tool for DNA methylation analysis in a large-scale arrayed manner.
Using ILtransgenic mice and hydrodynamics-based gene delivery of IL plasmid DNA into wild-type mice as well as in vitro studies, we demonstrate that although IL induces death of resting B cells, it promotes differentiation of B cells into postswitch and plasma cells. Thus, IL differentially influences B cell fate depending on the signaling context, explaining how IL can be proapoptotic for B cells in vitro yet critical for Ag-specific Ig production in vivo. Moreover, we demonstrate that IL unexpectedly induces expression of both Blimp-1 and Bcl-6, indicating mechanisms as to how IL can serve as a complex regulator of B cell maturation and terminal differentiation.
Finally, BXSB-Yaa mice, which develop a systemic lupus erythematosus-like disease, have greatly elevated IL, suggesting a role for IL in the development of autoimmune disease.
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Periodontal disease is one of the most prevalent chronic inflammatory diseases. There is a genetic component to susceptibility and resistance to this disease. We employed a novel and sensitive quantitative real-time PCR method to compare basal RNA transcription of a gene set in the gingiva and the spleen and the subsequent changes in gene expression due to Porphyromonas gingivalis oral infection. Gingival Il1b gene expression increased further and Stat6 gene expression was turned on after P. These results suggest a molecular phenotype in which discrete sets of differentially expressed genes are associated with genetically determined susceptibility Il1b, Tnf, and Stat6 or resistance Il15 and Selp to alveolar bone loss, providing insight into the genetic etiology of this complex disease.
New techniques are being applied to identify all the genes involved in mammalian gonad development and differentiation. As this list of genes increases, understanding the potential interactions between these genes will become increasingly difficult. Interestingly, in most studies these markers showed a similar or somewhat weaker performance, as compared to our results Table 5.
We have to note that our study used fresh frozen samples and a real time PCR restriction-based method. These differences in methodology may contribute to the better sensitivity as compared to those observed in previous studies. Furthermore, we confirmed that metastatic CRCs have a different DNA methylation fingerprint [ 44 ], as most of the genes hypermethylated in precancerous and cancerous lesions were not methylated in MCRC.
We think that hypermethylated genes characteristic for MCRC might have not been included in our array, however this should be further evaluated in subsequent studies. We showed that 7 genes had decreased mRNA expression in tumorous samples, and this decreased mRNA expression could be partly restored by demethylation treatment. This indicates that DNA hypermethylation might play a role in the regulation of these genes and demethlyation could potentially reverse these changes indicating a yet undiscovered systematic underlying mechanism, however this should be further studied to draw firm conclusions.
Among these, SFRP1 was analyzed also at the protein level and showed decreased protein expression compared to healthy samples.
DNA Methylation Microarrays: Experimental Design and - Ebooks
Concerning SFRP1 our data are consistent with published studies [ 27 , 45 ], which provide evidence for hypermethylation and consequential underexpression of SFRP1, promoting tumor formation. SFRPs are well-known inhibitors of the Wnt pathway. Abnormal activation of the Wnt pathway e. The hypermethylation of this gene may also be an early event that can be harnessed in future studies addressing the potential of hypermethylated SFRP1 in early detection of CRC.
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As we along with others have shown, DNA methylation is a promising blood-based biomarker for early detection of CRC and could potentially substitute routinely used, more invasive screening methods [ 46 — 48 ]. When the frequency of mutations and hypermethylated genes in tumorous samples was compared, methylated genes showed a significantly higher penetrance than mutations.
One aspect of this study was to determine if we could correlate changes in DNA methylation with initial steps in the carcinogenesis pathway, first in terms of field effect, and secondly in chronic inflammation, a condition considered as a CRC risk factor. With respect to field effect, Shen et al observed the DNA repair gene O 6 -methylguanine-DNA methyltransferase MGMT to be hypermethylated and silenced in colorectal tumors, but also in the surrounding mucosa [ 49 ], providing proof of principle for the field effect of methylation in CRC.
This phenomenon was later described for several other genes [ 50 ]. Our samples were taken 1 cm and 10 cm away from the margin of the tumor, from the macroscopically normal colorectal mucosa. These showed a similar pattern to healthy controls, suggesting the lack of a field effect for genes in this study. With respect to chronic inflammation, this condition has been proposed to lead to DNA hypermethylation in non-cancerous tissues, that can be detected and used as a risk factor for cancer [ 8 ]. However, our study did not reveal any DNA methylation markers that were predictive of CRC in ulcerative colitis patients as a model for chronic inflammation of the gut.
In conclusion, our study has confirmed that hypermethylation of certain genes is characteristic for MSS cancer. We have shown for the first time that precursor lesions, especially those with low-grade dysplasia, exhibit more hypermethylated genes. These genes are more densely hypermethylated, than their matched cancer pairs.