The Senescent Methylome and its relationship with cancer, ageing, and germline genetic variation in humans (gene expression)

Cellular senescence is a stable arrest of proliferation and is considered a key component of processes associated with carcinogenesis and other ageing-related phenotypes. However, till now, biological markers that define senescence on a genome-wide scale have been limited. Here, we report a DNA methylomic analysis of actively dividing and deeply senescent normal human epithelial cells, identifying 3,852 senescence-associated differentially methylated positions (senDMPs). We find that this human senDMP signature is positively and significantly correlated with both cancer and ageing-associated methylomic dynamics. We also identify germline genetic variants, including those associated with the p16INK4A locus, that are associated with the presence of in vivo senDMP signatures. Importantly, we also demonstrate that the senDMP signature can be effectively reversed in a newly-developed protocol of transient cellular rejuvenation. The senDMP signature has significant potential for understanding some of the key (epi)genetic etiological factors that lead to cancer and age-related diseases in humans. Total RNA obtained from the HMECs at early passage (EP) and deep senescence (DS)