Philos Trans R Soc Lond B Biol Sci
September 2016
DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species.
View Article and Find Full Text PDFClinical observations and epidemiologic studies suggest that the incidence of head and neck squamous cell carcinoma (HNSCC) correlates with dental hygiene, implying a role for bacteria-induced inflammation in its pathogenesis. Here we begin to explore the pilot hypothesis that specific microbial populations may contribute to HNSCC pathogenesis via epigenetic modifications in inflammatory- and HNSCC-associated genes. Microbiomic profiling by 16S rRNA sequencing of matched tumor and adjacent normal tissue specimens in 42 individuals with HNSCC demonstrate a significant association of specific bacterial subpopulations with HNSCC over normal tissue (P < 0.
View Article and Find Full Text PDFWe recently identified germline methylation of KILLIN, a novel p53-regulated tumor suppressor proximal to PTEN, in >1/3 Cowden or Cowden syndrome-like (CS/CSL) individuals who are PTEN mutation negative. Individuals with germline KILLIN methylation had increased risks of renal cell carcinoma (RCC) over those with PTEN mutations. Therefore, we tested the hypothesis that KILLIN may be a RCC susceptibility gene, silenced by germline methylation.
View Article and Find Full Text PDFContext: Germline loss-of-function phosphatase and tensin homolog gene (PTEN) mutations cause 80% of Cowden syndrome, a rare autosomal-dominant disorder (1 in 200,000 live births), characterized by high risks of breast, thyroid, and other cancers. A large heterogeneous group of individuals with Cowden-like syndrome, who have various combinations of Cowden syndrome features but who do not meet Cowden syndrome diagnostic criteria, have PTEN mutations less than 10% of the time, making molecular diagnosis, prediction, genetic counseling, and risk management challenging. Other mechanisms of loss of function such as hypermethylation, which should result in underexpression of PTEN or of KILLIN, a novel tumor suppressor transcribed in the opposite direction, may account for the remainder of Cowden syndrome and Cowden-like syndrome.
View Article and Find Full Text PDFHead and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with low survival rates in advanced stages. To facilitate timely diagnosis and improve outcome, early detection markers (e.g.
View Article and Find Full Text PDFBackground: Activator protein 2 alpha (AP-2alpha) is involved in a variety of physiological processes. Increased AP-2alpha expression correlates with progression in various squamous cell carcinomas, and a recent publication found AP-2alpha to be overexpressed in approximately 70% of Head and Neck Squamous Cell Carcinoma (HNSCC) patient samples. It was found to repress transcription of the tumor suppressor gene C/CAAT Enhancer Binding Protein alpha (C/EBPalpha), and its binding site correlated with upstream methylation of the C/EBPalpha promoter.
View Article and Find Full Text PDFThe tumor suppressor C/CAAT enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in cell cycle control and cellular differentiation. A recent study showed that C/EBPalpha is frequently downregulated in head and neck squamous cell carcinoma (HNSCC) by DNA methylation in an upstream regulatory region. Here, we investigated how DNA methylation in the upstream regulatory region disrupts the transcriptional regulation of C/EBPalpha in HNSCC.
View Article and Find Full Text PDFHead and neck squamous cell carcinoma (HNSCC) is a very aggressive cancer. In advanced stages, the patient has poor chances of receiving effective treatment, and survival rates are low. To facilitate timely diagnosis and improve treatment, elucidation of early detection markers is crucial.
View Article and Find Full Text PDFFunctional loss of CCAAT/enhancer binding protein alpha (C/EBP alpha), a master regulatory transcription factor in the hematopoietic system, can result in a differentiation block in granulopoiesis and thus contribute to leukemic transformation. Here, we show the effect of epigenetic aberrations in regulating C/EBP alpha expression in acute myeloid leukemia (AML). Comprehensive DNA methylation analyses of the CpG island of C/EBP alpha identified a densely methylated upstream promoter region in 51% of AML patients.
View Article and Find Full Text PDFProgressive multifocal leukoencephalopathy is a rare, highly fatal demyelinating brain infection caused by the JC virus. This infection is associated with immunosuppressive agents and is emerging in the transplant population. There has never been a documented case of progressive multifocal leukoencephalopathy in a transplant recipient receiving sirolimus.
View Article and Find Full Text PDFTumor suppressor CCAAT enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in cell cycle control and cellular differentiation. In a recent study, microarray expression profiling on head and neck squamous cell carcinoma (HNSCC) samples identified significant C/EBPalpha down-regulation, correlating with poor prognosis. However, the mechanisms of C/EBPalpha down-regulation remained elusive.
View Article and Find Full Text PDFPurpose: Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease for which natural history can be predicted based on the presence or absence of immunoglobulin (Ig) variable heavy chain (V(H)) gene mutations. Herein we report selective epigenetic silencing of the transcription factor TWIST2 (DERMO1) in Ig V(H) mutated CLL and describe a semiquantitative assay to study promoter methylation of this gene in primary tumor cells.
Materials And Methods: TWIST2 promoter methylation was identified by restriction landmark genome scanning.
Aberrant promoter methylation and associated chromatin changes are primarily studied in human malignancies. Thus far, mouse models for human cancer have been rarely utilized to study the role of DNA methylation in tumor onset and progression. It would be advantageous to use mouse tumor models to a greater extent to study the role and mechanism of DNA methylation in cancer because mouse models allow manipulation of the genome, study of samples/populations with a homogeneous genetic background, the possibility of modulating gene expression in vivo, the statistical power of using large numbers of tumor samples, access to various tumor stages, and the possibility of preclinical trials.
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