NOTCH-mediated non-cell autonomous regulation of chromatin structure during senescence
Aled J. Parry, Matthew Hoare, Dóra Bihary, Robert Hänsel-Hertsch, Stephen Smith, Kosuke Tomimatsu, Shankar Balasubramanian, Hiroshi Kimura, Shamith A. Samarajiwa, Masashi Narita
Received: 15th October 17
Senescent cells interact with the surrounding microenvironment achieving diverse functional outcomes. In addition to autocrine and paracrine signalling mediated by factors of the senescence-associated secretory phenotype, we have recently identified that NOTCH1 can drive ‘lateral induction’ of a unique form of senescence in adjacent cells through specific induction of the NOTCH ligand JAG1. Here we show that NOTCH signalling can modulate chromatin structure both autonomously and non-autonomously. In addition to senescence-associated heterochromatic foci (SAHF), oncogenic RAS-induced senescent (RIS) cells in culture exhibit a massive increase in nucleosome-free regions (NRFs). NOTCH signalling suppresses both SAHF and NFR formation in this context. Strikingly, NOTCH-induced senescent cells, or cancer cells with high JAG1 expression, also drive similar chromatin architectural changes in adjacent cells through cell-cell contact. Mechanistically, we show that NOTCH signalling represses the chromatin architectural protein HMGA1, an association found in a range of human cancers. Thus, HMGA1 is involved not only in SAHFs, but also RIS-specific NFR formation. In conclusion, this study identifies that the JAG1-NOTCH-HMGA1 axis mediates the juxtacrine regulation of chromatin architecture.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.