miRNAs: The New Addition to the Biomarker BuffetSeptember 16, 2008Human blood serum is cellular buffet of different biological molecules sampled continuously from every tissue of the body. So it’s not surprising that many researchers have attempted to identify biomarkers in serum that reflect a particular physiological or disease state. Most of these potential biomarkers are proteins (important-yes, exciting-not really), but Zvi Bentwich, Ayelet Chajut, […]
The Many Faces of the miRNA-Argonaute ComplexSeptember 16, 2008Some might recall playing with Mr. Potato Head as a child (or maybe earlier this morning). By sticking different noses, mouths, eyes, shoes, or other accessories on the basic potato head module, you could generate a variety of silly-looking spuds. Similarly, the interaction of different accessory proteins with the miRNA-argonaute complex might determine the fate […]
DNA Methylation, miRNAs, and MetastasisSeptember 9, 2008OK this one is a week old, but we love a paper that addresses epigenetic regulation of epigenetic regulators, so we couldn’t resist a recent PNAS report that identified a miRNA DNA methylation signature for human cancer metastasis. Like proteins, miRNAs act as oncogenes, tumor suppressors, and metastatic mediators, and their expression can be influenced […]
miRNAs: From worthless junk to evolutionary slam dunkAugust 17, 2008Gone are the days when microRNAs (miRNAs) were relegated to the unimportant “junk heap” of sequences cluttering up the genome. We now know that these tiny, highly conserved non-coding RNAs play important roles in RNA stability and translation by base-pairing with partially complementary sequences in the 3’ untranslated regions (UTRs) of target mRNAs. Moreover, a […]
Integration now! DNA methylation, genomic imbalance, and gene expression analyses in osteosarcomaAugust 17, 2008No longer can the genetic and epigenetic causes of cancer and the resulting changes in gene expression be analyzed separately, with little regard for their interdependency. In this spirit, Jeremy Squire and coworkers at the Hospital for Sick Children, the Ontario Cancer Institute, and Queen’s University (all in Canada) conducted the first integrative analysis of […]
The Methylation Ultimatum in ImprintingAugust 7, 2008 Last week PLoS Genetics ran a great paper from Anders Lindroth and colleagues illustrating a mutually exclusive relationship between DNA Methylation and methylation of H3K27 in the a differentially methylation domain (DMD) of an imprinting control region (ICR). Now before we drop any more epi-breviations…. The area of focus in the study was a […]
miRNA Retention and EnhancementJuly 21, 2008miRNAs, the small but mighty inhibitors of complementary mRNA sequences, might be accused of having a Napoleon complex, but they don’t start out life itty-bitty—they are transcribed as long primary miRNAs (pri-miRNAs). Cleavage by the RNase III-like enzyme Drosha in the nucleus releases a ~70-nt stem-loop structure (pre-mRNA), which is further processed by Dicer in […]
Mom, Methylation, and ObesityJuly 15, 2008Let the blame game begin. In addition to our lifestyle habits, our mothers could have something to do with those stubborn pounds that dont seem to shed. An interesting obesity studying involving DNA methylation has provided new evidence suggesting that obese moms give birth to kids who have a propensity to become even more obese. […]
Non-Invasive DNA Methylation Assay for Colorectal Cancer Now Available from LabCorpJuly 14, 2008Not even a month after announcing a reagent supply agreement with OncoMethylome Sciences, LabCorp has announced the commercial availability of the Methylation-Specific PCR Assay for monitoring the methylation status of Vimentin DNA. Marketed as ColoSure(TM) by LabCorp, the MSP Assay is being positioned for assessing any stage colorectal cancer in asymptomatic average risk patients who […]
That Stinks…Pollution Demethylating DNAJanuary 15, 2008As if making the air stink and harder to breathe wasn’t enough, researchers in Italy and Boston have found that when certain particulates from traffic exhaust increase, epigenetic effects can increase. They looked at the percent of methylated cytosines in Long Interspersed Nucleotide Elements (LINE-1) repeats, in leukocytes of elderly men taking part in a longitudinal study. […]