Aging-like Spontaneous Epigenetic Silencing Facilitates Wnt Activation, Stemness, and Braf-Induced Tumorigenesis.

We addressed the precursor role of aging-like spontaneous promoter DNA hypermethylation in initiating tumorigenesis. Using mouse colon-derived organoids, we show that promoter hypermethylation spontaneously arises in cells mimicking the human aging-like phenotype. The silenced genes activate the Wnt pathway, causing a stem-like state and differentiation defects.

Interplay between post-translational cyclooxygenase-2 modifications and the metabolic and proteomic profile in a colorectal cancer cohort.

Background: Colorectal cancer (CRC) is the second most common cause of cancer death worldwide. It is broadly described that cyclooxygenase-2 (COX-2) is mainly overexpressed in CRC but less is known regarding post-translational modifications of this enzyme that may regulate its activity, intracellular localization and stability. Since metabolic and proteomic profile analysis is essential for cancer prognosis and diagnosis, our hypothesis is that the analysis of correlations between these specific parameters and COX-2 state in tumors of a high number of CRC patients could be useful for the understanding of the basis of this cancer in humans.

Survivin, a key player in cancer progression, increases in obesity and protects adipose tissue stem cells from apoptosis.

Adipose tissue (AT) has a central role in obesity-related metabolic imbalance through the dysregulated production of cytokines and adipokines. In addition to its known risk for cardiovascular disease and diabetes, obesity is also a major risk for cancer. We investigated the impact of obesity for the expression of survivin, an antiapoptotic protein upregulated by adipokines and a diagnostic biomarker of tumor onset and recurrence.

DNA methylation profiling of well-differentiated thyroid cancer uncovers markers of recurrence free survival.

Thyroid cancer is a heterogeneous disease with several subtypes characterized by cytological, histological and genetic alterations, but the involvement of epigenetics is not well understood. Here, we investigated the role of aberrant DNA methylation in the development of well-differentiated thyroid tumors. We performed genome-wide DNA methylation profiling in the largest well-differentiated thyroid tumor series reported to date, comprising 83 primary tumors as well as 8 samples of adjacent normal tissue.

Epigenetics of host-pathogen interactions: the road ahead and the road behind.

A growing body of evidence points towards epigenetic mechanisms being responsible for a wide range of biological phenomena, from the plasticity of plant growth and development to the nutritional control of caste determination in honeybees and the etiology of human disease (e.g., cancer).

Novel methylation panel for the early detection of colorectal tumors in stool DNA.

Background: Previous studies showed that the assessment of promoter hypermethylation of a limited number of genes in tumor biopsies may identify the majority of colorectal tumors. This study aimed to assess the clinical usefulness of a panel of methylation biomarkers in stool DNA in the identification of colorectal tumors, using methylation-specific melting curve analysis (MS-MCA), a technique that simultaneously analyzes all cytosine-phosphate-guanine (CpG) residues within a promoter.

Materials And Methods: The promoter methylation status of 4 tumor-related genes (RARB2, p16INK4a, MGMT, and APC) was analyzed in DNA stool samples and corresponding tissues in an initial set of 12 patients with newly diagnosed primary colorectal carcinomas and 20 patients with newly diagnosed colorectal adenomas, using methylation-specific polymerase chain reaction.

Tumour selection advantage of non-dominant negative P53 mutations in homozygotic MDM2-SNP309 colorectal cancer cells.

Background: Mdm2 is a natural inhibitor of p53 function and its overexpression impairs p53 transcriptional activity. T-->G single-nucleotide polymorphism at position 309 (SNP309) of mdm2 induces overexpression of mdm2, but inhibits p53.

Objectives: To determine whether SNP309 is a risk-modifier polymorphism in colorectal cancer (CRC) and whether tumour selection of P53 mutations are influenced by SNP309.

Determination of genomic damage in neuroblastic tumors by arbitrarily primed PCR: MYCN amplification as a marker for genomic instability in neuroblastomas.

The aim of this study is to establish an estimation of the global genomic alteration in neuroblastic tumors (ganglioneuromas, ganglioneuroblastomas and neuroblastomas) and correlate them with different clinical parameters (age, sex, diagnosis, Shimada index, proliferation index, tumor location, and 1p and v-myc avian myelocitomatosis viral-related (MYCN) status) in order to find new molecular and/or prognostic markers for neuroblastoma. To assess the genomic damage in neuroblastic tumors, we used an arbitrarily primed PCR approach, a technique based on the reproducibility of band profiles obtained by a PCR with a low annealing temperature in its first cycles. Genomic damage was assessed by comparing band profiles of tumors and normal paired samples.

Standardized approach for microsatellite instability detection in gastric carcinomas.

Microsatellite instability (MSI) defines a specific type of genetic instability. Although consensus diagnostic criteria for MSI definition in colorectal cancer have been established, their utility in other tumor types remain to be proven. Previously we developed a mathematical model for MSI definition in colorectal cancer.

A TP53 polymorphism is associated with increased risk of colorectal cancer and with reduced levels of TP53 mRNA.

We undertook a case-control study to examine the possible associations of the TP53 variants Arg > Pro at codon 72 and p53PIN3, a 16 bp insertion/duplication in intron 3, with the risk of colorectal cancer (CRC). The p53PIN3 A2 allele (16 bp duplication) was associated with an increased risk (OR 1.55, 95% CI 1.

Common genetic evolutionary pathways in familial adenomatous polyposis tumors.

Cancer cells progress through the accumulation of genetic alterations. Familial adenomatous polyposis (FAP) tumors provide an excellent model to unravel the molecular steps underlying malignant transformation. Global genomic damage was assessed in 56 adenomas and 3 carcinomas from six FAP patients and compared with that of sporadic adenomas and carcinomas.