[Sorting of senescent cells by flow cytometry: Specificities and pitfalls to avoid].

Cells can be reprogrammed into senescence to adapt to a variety of stresses, most often affecting the genome integrity. Senescent cells accumulate with age or upon various insults in almost all tissues, and contribute to the development of several age-associated pathologies. Studying the molecular pathways involved in senescence induction, maintenance, or escape is challenged by the heterogeneity in the level of commitment to senescence, and by the pollution of senescent cell populations by proliferating pre- or post-senescent cells.

Flow Cytometry-based Method for Efficient Sorting of Senescent Cells.

Cellular senescence is a reprogrammed cell state triggered as an adaptative response to a variety of stresses, most often those affecting the genome integrity. Senescent cells accumulate in most tissues with age and contribute to the development of several pathologies. Studying molecular pathways involved in senescence induction and maintenance, or in senescence escape, can be hindered by the heterogeneity of senescent cell populations.

The out-of-field dose in radiation therapy induces delayed tumorigenesis by senescence evasion.

A rare but severe complication of curative-intent radiation therapy is the induction of second primary cancers. These cancers preferentially develop not inside the planning target volume (PTV) but around, over several centimeters, after a latency period of 1-40 years. We show here that normal human or mouse dermal fibroblasts submitted to the out-of-field dose scattering at the margin of a PTV receiving a mimicked patient's treatment do not die but enter in a long-lived senescent state resulting from the accumulation of unrepaired DNA single-strand breaks, in the almost absence of double-strand breaks.

[Senescence and cancer: double-dealing].

When ageing, cells profoundly reprogram to enter a state called senescence. Although the link between senescence and cancer is well established, the nature of this link remains unclear and debated. We will describe in this article the properties of senescent cells and make clear on how they could promote or oppose to cancer initiation and progression.