Constricted migration increases DNA damage and independently represses cell cycle

Abstract

Cell migration through dense tissues or small capillaries can elongate the nucleus and even damage it, and any impact on cell cycle has the potential to affect various processes including carcinogenesis. Here, nuclear rupture and DNA damage increase with constricted migration in different phases of cell cycle—which we show is partially repressed. We study several cancer lines that are contact inhibited or not and that exhibit diverse frequencies of nuclear lamina rupture after migration through small pores. DNA repair factors invariably mislocalize after migration, and an excess of DNA damage is evident as pan-­nucleoplasmic foci of phosphoactivated ATM and γH2AX. Foci counts are suppressed in late cell cycle as expected of mitotic checkpoints, and migration of contact-inhibited cells through large pores into sparse microenvironments leads also as expected to cell-cycle reentry and no effect on a basal level of damage foci. Constricting pores delay such reentry while excess foci occur independent of cell-cycle phase. Knockdown of repair factors increases DNA damage independent of cell cycle, consistent with effects of constricted migration. Because such migration causes DNA damage and impedes proliferation, it illustrates a cancer cell fate choice of “go or grow.”

BAF facilitates interphase nuclear membrane repair through recruitment of nuclear transmembrane proteins

“…In both cases, nuclear membrane ruptures are repaired and generally non-lethal (De Vos et al, 2011;Vargas et al, 2012;Denais et al, 2016;Raab et al, 2016). However, recent studies suggest that loss of nuclear compartmentalization can alter transcription (De Vos et al, 2011), cause mislocalization of large organelles (De Vos et al, 2011;Vargas et al, 2012;Houben et al, 2013), and cause DNA damage (Maciejowski et al, 2015;Denais et al, 2016;Raab et al, 2016;Irianto et al, 2017;Takaki et al, 2017;Pfeifer et al, 2018;Stephens et al, 2019). Based on these data, nuclear membrane rupture is now being evaluated as a major mechanism of genome instability and cell death in lamin-associated diseases and cancer (Isermann and Lammerding, 2017;Houthaeve et al, 2018).…”

Rescue of DNA damage in cells after constricted migration reveals bimodal mechano-regulation of cell cycle

“…Lamin-B filaments are stiff, with a persistence length of ~0.5µm (Turgay et al, 2017), and therefore will not bend and bind a nuclear envelope with high Gaussian curvature, but myosin tension is somehow independently important because pores impose constant curvature. Squeezing of dozens of mobile proteins into low density regions of chromatin could also be relevant and likely explains the large intranuclear accumulations of GFP-53BP1 during migration through narrow channels (Denais et al, 2016;Irianto et al, 2017;Raab et al, 2016) independent of DNA damage Pfeifer et al, 2018). DNA damage is nonetheless consistent with simple orthogonal measures of a bimodal cell cycle delay, illustrating mechanical control of cell cycle as one mechanism of "go-or-grow".…”

“…phospho-Histone-2AX). However, parallel quantitation of another DNA damage marker (53BP1) shows no increase Pfeifer et al, 2018), with live-cell imaging of large 'foci' of GFP-53BP1 (Denais et al, 2016;Raab et al, 2016) attributed to generic accumulation of mobile nuclear protein into low density pockets of chromatin (Irianto et al, 2016). Imaging of DNA damage sites indeed remains non-trivial (Britton et al, 2013), and in the particular context of constricted migration γH2AX foci counts appear to increase by only ~50% across cell cycle stages, even when cell cycle is blocked .…”

Lymphocyte mechanotransduction: The regulatory role of cytoskeletal dynamics in signaling cascades and effector functions

“…Under inflammatory conditions, less traction stress is required for diapedesis, facilitating leukocyte extravasation . Because less traction force is required for transendothelial migration during inflammation, this mechanism may also protect nuclear and DNA integrity, both of which were shown to undergo mechanical damage during invasive migration …”

“…9 Because less traction force is required for transendothelial migration during inflammation, this mechanism may also protect nuclear and DNA integrity, both of which were shown to undergo mechanical damage during invasive migration. 65 Accordingly, another recent study demonstrated that T cells can sense 3D environments and density of the collagen matrix. 3D collagen matrices induced methylation of histone 3, lysine 4 residue (H3K4) by methyltransferases, and this methylation increased as a function of collagen density.…”