The next meeting of the National Mathematics Colloquium will be held on July 30, 2014 (Wednesday) at 16:15 in the Conference Room of the Institute of Mathematics and Informatics, Acad. G. Bonchev Street, Block 8

A talk on:

„BIOLOGICAL CLOCKS AND AGE PREDICTION METHODS“

will be delivered by Prof. Steve Horvath, Human Genetics and Biostatistics University of California, Los Angeles.

Everybody is invited.

Head of the Colloquium: Acad. P. Popivanov

Abstract:

Recently I developed a multi-tissue predictor of age that allows one to estimate the DNA methylation age of most tissues and cell types. The predictor was developed using 8,000 samples from 82 Illumina DNA methylation array datasets, encompassing 51 healthy tissues and cell types. I found that DNA methylation age has the following properties: first, it is close to zero for embryonic and induced pluripotent stem cells; second, it correlates with cell passage number; third, it gives rise to a highly heritable measure of age acceleration; and, fourth, it is applicable to chimpanzee tissues.

Analysis of 6,000 cancer samples from 32 datasets showed that cancer types exhibit significant positive and negative age acceleration. Low age-acceleration of cancer tissue is associated with a high number of somatic mutations and TP53 mutations, while mutations in steroid receptors greatly accelerate DNA methylation age in breast cancer. Finally, I characterize the 353 CpG sites that together form an aging clock in terms of chromatin states and tissue variance.

I propose that DNA methylation age measures the cumulative effect of an epigenetic maintenance system. This novel epigenetic clock can be used to address a host of questions in developmental biology, cancer and aging research.

Relevant references:
Article: Horvath S (2013) DNA methylation age of human tissues and cell types. Genome Biology 2013, 14:R115
http:/genomebiology.com/2013/14/10/R115  
Correction: http://genomebiology.com/2013/14/10/R115/comments
Wikipedia: https://en.wikipedia.org/wiki/Biological_clock_(aging)
Online calculator: http://labs.genetics.ucla.edu/horvath/dnamage/