Aging is one of the prime risk factors for the development of cancer. Expression patterns of epigenetic regulators, including histone modification levels, are altered during aging of normal cells, a phenomenon referred to as epigenetic drift. Furthermore, it is known that epigenetic mechanisms are involved in the development of cancer.
View Article and Find Full Text PDFAims: Epigenetic changes are of crucial importance in cancer development and are potentially reversible; they are therefore targets of interest for anti-cancer therapy. The aim of this study was to investigate the clinical prognostic value of the histone deacetylases SIRT1, HDAC1 and HDAC2 and the histone modifications H4K16Ac and H3K56Ac in colorectal cancer.
Methods And Results: The epigenetic markers were immunohistochemically stained on tissue microarrays containing colorectal tumours (n = 254) and normal colorectal tissues (n = 50).
The apoptosis pathway of programmed cell death is frequently deregulated in cancer. An intact apoptosis pathway is required for proper response to anti-cancer treatment. We investigated the chromatin status of key apoptosis genes in the apoptosis pathway in colorectal cancer cell lines in relation to apoptosis induced by chemo-, immune- or radiation therapy.
View Article and Find Full Text PDFNumerous changes in epigenetic mechanisms have been described in various types of tumors. In search for new biomarkers, we investigated the expression of Polycomb-group (PcG) proteins EZH2, BMI1 and SUZ12 and associated histone modification H3K27me3 in colorectal cancer. Nuclear expression of PcG proteins and histone modification H3K27me3 were immunohistochemically (IHC) stained on a tissue microarray (TMA), including 247 tumor tissues and 47 normal tissues, and scored using the semi-automated Ariol system.
View Article and Find Full Text PDFBackground: Breast cancer is a heterogeneous disease with a highly variable clinical outcome in which both genetic and epigenetic changes have critical roles. We investigated tumor expression levels of histone-modifying enzymes LSD1, HDAC2 and SIRT1 in relation with patient survival and tumor relapse in a retrospective cohort of 460 breast cancer patients. Additionally, we correlated expression levels with tumor differentiation and tumor cell proliferation.
View Article and Find Full Text PDFDeregulation of the apoptotic pathway, one of the hallmarks of tumor growth and -progression, has been shown to have prognostic value for tumor recurrence in rectal cancer. In order to develop clinically relevant biomarkers, we studied the methylation status of promoter regions of key apoptosis genes in rectal cancer patients, using methylation-sensitive restriction enzymes. DNA was extracted from fresh-frozen tumor tissues of 49 stage I-III rectal cancer patients and 10 normal rectal tissues.
View Article and Find Full Text PDFBackground: Post-translational modification of histone tails by methylation plays an important role in tumorigenesis. In this study, we investigated the nuclear expression of H3K4me3, H3K9me3 and H4K20me3 in early-stage colon cancer in relation to clinical outcome.
Methods: Tumor tissue cores of 254 TNM stage I-III colorectal cancer patients were immunohistochemically stained for H3K4me3, H3K9me3 and H4K20me3 and scored using the semi-automated Ariol system.
Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients.
View Article and Find Full Text PDFPreviously, we have shown that CCR5 transcription is regulated by CREB-1. However, the ubiquitous pattern of CREB-1 expression suggests the involvement of an additional level of transcriptional control in the cell type-specific expression of CCR5. In this study, we show that epigenetic changes (i.
View Article and Find Full Text PDFMicrosatellite instability (MSI) and genomic hypermethylation of methylated-in-tumor (MINT) loci are both strong prognostic indicators in a subgroup of patients with sporadic colorectal cancer (CRC). The present study was designed to determine whether the methylation of MINT loci during the progression of adenoma to CRC is related to MSI in CRC cases. Methylation index (MI) was measured by absolute quantitative assessment of methylated alleles at seven MINT loci in primary CRC with contiguous adenomatous and normal tissues of 79 patients.
View Article and Find Full Text PDFPurpose: Risk assessment for locoregional disease recurrence would be highly valuable in preoperative treatment planning for patients undergoing primary rectal tumor resection. Epigenetic aberrations such as DNA methylation have been shown to be significant prognostic biomarkers of disease outcome. In this study, we evaluated the significance of a quantitative epigenetic multimarker panel analysis of primary tumors to predict local recurrence in rectal cancer patients from a retrospective multicenter clinical trial.
View Article and Find Full Text PDFX-ray spectromicroscopy has been successfully applied to determine the evolution of the Cr oxidation state in Portland cement during leaching experiments. To our knowledge, this is the first study that demonstrates the possibility to study the chromium oxidoreduction phenomena in cement materials at natural Cr concentration (approximately 60 ppm) and at the micron scale. Line scans of Cr for Cr(VI) doped (2000 ppm) and undoped samples indicate that the altered layer (0-1000 microm from the surface) is characterized by a lower amount of Cr as compared to the core part, whereas an accumulation appears in the intermediate region (1000-1300 microm).
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