It is not yet known whether DNA methylation levels can be used to accurately predict age across a broad spectrum of human tissues and cell types, nor whether the resulting age prediction is a biologically meaningful measure. 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, which is freely available, 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 all of the considered 20 cancer types exhibit significant age acceleration, with an average of 36 years. 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.

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DNA methylation age of human tissues and cell types

AACR Centennial Conference: Translational Cancer Medicine-- Nov 4-8, 2007; Singapore

PL02-05 

All cancers are due to abnormalities in DNA. The availability of the human genome sequence has led to the proposal that resequencing of cancer genomes will reveal the full complement of somatic mutations and hence all the cancer genes. To explore the nature of the information that will be derived from cancer genome sequencing we have sequenced the coding exons of the family of 518 protein kinases, ~1.3Mb DNA per cancer sample, in 210 cancers of diverse histological types. Despite the screen being directed toward the coding regions of a gene family that has previously been strongly implicated in oncogenesis, the results indicate that the majority of somatic mutations detected are “passengers”. There is considerable variation in the number and pattern of these mutations between individual cancers, indicating substantial diversity of processes of molecular evolution between cancers. The imprints of exogenous mutagenic exposures, mutagenic treatment regimes and DNA repair defects can all be seen in the distinctive mutational signatures of individual cancers. This systematic mutation screen and others have previously yielded a number of cancer genes that are frequently mutated in one or more cancer types and which are now anticancer drug targets (for example BRAF , PIK3CA , and EGFR ). However, detailed analyses of the data from our screen additionally suggest that there exist a large number of additional “driver” mutations which are distributed across a substantial number of genes. It therefore appears that cells may be able to utilise mutations in a large repertoire of potential cancer genes to acquire the neoplastic phenotype. However, many of these genes are employed only infrequently. These findings may have implications for future anticancer drug development.

Patterns of Somatic Mutation in Human Cancer Genomes

WHO laboratory manual for the examination and processing of human semen

Numerous reports have recently focused on various aspects of adverse trends in male reproductive health, such as the rising incidence of testicular cancer; low and probably declining semen quality; high and possibly increasing frequencies of undescended testis and hypospadias; and an apparently growing demand for assisted reproduction. Due to specialization in medicine and different ages at presentation of symptoms, reproductive problems used to be analysed separately by various professional groups, e.g. paediatric endocrinologists, urologists, andrologists and oncologists. This article summarizes existing evidence supporting a new concept that poor semen quality, testis cancer, undescended testis and hypospadias are symptoms of one underlying entity, the testicular dysgenesis syndrome (TDS), which may be increasingly common due to adverse environmental influences. Experimental and epidemiological studies suggest that TDS is a result of disruption of embryonal programming and gonadal development during fetal life. Therefore, we recommend that future epidemiological studies on trends in male reproductive health should not focus on one symptom only, but be more comprehensive and take all aspects of TDS into account. Otherwise, important biological information may be lost.

Testicular dysgenesis syndrome ; an increasingly common developmental disorder with environmental aspects

Human mitochondrial DNA is widely used as tool in many fields including evolutionary anthropology and population history, medical genetics, genetic genealogy, and forensic science. Many applications require detailed knowledge about the phylogenetic relationship of mtDNA variants. Although the phylogenetic resolution of global human mtDNA diversity has greatly improved as a result of increasing sequencing efforts of complete mtDNA genomes, an updated overall mtDNA tree is currently not available. In order to facilitate a better use of known mtDNA variation, we have constructed an updated comprehensive phylogeny of global human mtDNA variation, based on both coding- and control region mutations. This complete mtDNA tree includes previously published as well as newly identified haplogroups, is easily navigable, will be continuously and regularly updated in the future, and is online available at http://www.phylotree.org. © 2008 Wiley-Liss, Inc.

/pdf/updated-comprehensive-phylogenetic-tree-of-global-human-448qrnrzdo.pdf

Updated Comprehensive Phylogenetic Tree of Global Human Mitochondrial DNA Variation

Chromosome Abnormalities and the Infertile Male

Paternal Influences on Human Reproductive Success: The role of aging on fecundity in the male

What are the benefits of empiric nutritional and medical therapy on the semen parameters, pregnancy rates and live birth rates in couples with idiopathic infertility? A systematic review and meta-analysis

Andrology, a multidisciplinary field of biomedicine devoted to male health, has long been fragmented and not well supported by research grant institutions and a poorly informed public. One of the reasons was the lack of a network through which researchers and clinicians could interact towards the strengthening of research collaboration, andrology education and public awareness of growing problems in male health. These objectives largely overlap with the priorities of the European Academy of Andrology (EAA); therefore the establishment of such a network has been strongly promoted by the EAA, which during the last 2 years reached out to numerous groups and organizations across Europe and beyond. The project was submitted to the European Cooperation in Science and Technology (COST) funding organization at the end of 2020 by a team of 45 proposers from 26 countries, and the funding was approved in May 2021. The network has the acronym ANDRONET: European andrology network—research coordination, education and public awareness (CA20119). As the project’s title stipulates, ANDRONET has three main objectives: (1) to improve coordination of research, (2) to improve education in andrology and (3) to increase public awareness of male health-related issues. Each objective has short-and longterm goals, which form the basis of the main working groups (WGs) (Figure 1). The need for such a network was urgent due to the increasing incidence of infertility and testicular cancer, worrying reports of an association of poor reproductive function with poor general health and greater male predisposition to several serious diseases leading to

ANDRONET: A new European network to boost research coordination, education and public awareness in andrology

ABSTRACT
Sex hormone concentrations, particularly testosterone, are primary determinants of sex-based differences in athletic and sports performance, and this relationship may inform fair competition and participation for athletes. This article describes the sex-based dichotomy in testosterone and the implications for sex-based differences in individual sports performance, including factors that relate to athletic performance for transgender individuals, and areas of future investigation.

Csilla Krausz

Papers

Chromosome Abnormalities and the Infertile Male

Paternal Influences on Human Reproductive Success: The role of aging on fecundity in the male

What are the benefits of empiric nutritional and medical therapy on the semen parameters, pregnancy rates and live birth rates in couples with idiopathic infertility? A systematic review and meta-analysis

ANDRONET: A new European network to boost research coordination, education and public awareness in andrology

Sex Differences in Athletic Performance: Perspectives on Transgender Athletes.