Open AccessIonizing radiation‐induced long‐term expression of senescence markers in mice is independent of p53 and immune status
Author(s) -
Le Oanh N. L.,
Rodier Francis,
Fontaine Francois,
Coppe JeanPhilippe,
Campisi Judith,
DeGregori James,
Laverdière Caroline,
Kokta Victor,
Haddad Elie,
Beauséjour Christian M.
Publication year - 2010
Publication title -
aging cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.103
H-Index - 140
eISSN - 1474-9726
pISSN - 1474-9718
DOI - 10.1111/j.1474-9726.2010.00567.x
Subject(s) - senescence , biology , dna damage , immune system , phenotype , microbiology and biotechnology , in vivo , regeneration (biology) , dna repair , cancer research , immunology , dna , genetics , gene
Summary Exposure to IR has been shown to induce the formation of senescence markers, a phenotype that coincides with lifelong delayed repair and regeneration of irradiated tissues. We hypothesized that IR‐induced senescence markers could persist long‐term in vivo , possibly contributing to the permanent reduction in tissue functionality. Here, we show that mouse tissues exposed to a sublethal dose of IR display persistent (up to 45 weeks, the maximum time analyzed) DNA damage foci and increased p16 INK4a expression, two hallmarks of cellular senescence and aging. BrdU‐labeling experiments revealed that IR‐induced damaged cells are preferentially eliminated, at least partially, in a tissue‐dependent manner. Unexpectedly, the accumulation of damaged cells was found to occur independent from the DNA damage response modulator p53, and from an intact immune system, as their levels were similar in wild‐type and Rag2 −/− γC −/− mice, the latter being deficient in T, B, and NK cells. Together, our results provide compelling evidence that exposure to IR induces long‐term expression of senescence markers in vivo , an effect that may contribute to the reduced tissue functionality observed in cancer survivors.