Doxorubicin-induced senescence in normal fibroblasts promotes in vitro tumour cell growth and invasiveness: The role of Quercetin in modulating these processes

Ageing is a complex biological phenomenon representing the major risk factor for developing age-related dis-eases, such as cardiovascular pathologies, neurodegenerative diseases, and cancer. Geroscience, the new vision of gerontology, identifies cellular senescence as an interconnected biological process that characterises ageing and age-related diseases. Therefore, many strategies have been employed in the last years to reduce the harmful effects of senescence, and among these, the most intriguing ones use nutraceutical compounds. Here we show that a pre-treatment with Quercetin, a bioactive flavonoid present in many fruits and vegetables, increasing cellular antioxidant defence, can alleviate Doxorubicin (Doxo)-induced cellular senescence in human normal WI -38 fibroblasts. Furthermore, our work demonstrates that Quercetin pre-treatment, reducing the number of senescent cells and the production of the senescence-associated secretory phenotype (SASP) factors, can decrease the pro-tumour effects of conditioned medium from Doxo-induced senescent fibroblasts on osteosarcoma cells. Overall, our findings are consistent with the hypothesis that targeting senescent cells can be an emerging strategy for cancer treatment, especially in elderly patients, in which senescent cells are already abundant in several tissues and organs.