I am interested in the oxidative stress response in ECs and I have noticed that after treatment with H2O2, cells are going into cell cycle arrest and are down-regulating DNA replication and repair mechanisms - is this a symptom of senescence? I'm not sure why they would go into arrest if not to repair DNA.
Results could vary depending of many factors.
How was treatment done (concentration, media composition before, during and after treatment, preconditioning etc.). Cycle arrest could lead to survival and to dead as well as, so expression profile of resulted "population" could be mixture of different fates.
If the DNA damage response is persistent and cannot be repaired then cells can become senescent, possibly promoting immune clearance of these damaged cells rather than undergoing apoptosis. Lower levels of H202 would likely promote transient growth arrest because the DNA damage can be repaired.