Doxorubicin-Induced Cancer Cell Senescence Shows a Time Delay Effect and Is Inhibited by Epithelial-Mesenchymal Transition (EMT)

Abstract

Background Senescence is a natural barrier for the body to resist the malignant transformation of its own cells. This work investigated the senescence characteristics of cancer cells in vitro . Material/Methods Human cervical cancer HeLa cells were treated with different concentrations of doxorubicin for 3 days, with or without subsequent extended culture in drug-free medium for 6 days. Senescent cell ratios between these 2 culture schemes were calculated. Expression of 2 senescence-associated secretory factors, IL-6 and IL-8, were detected by RT-PCR and ELISA. Doxorubicin treatment induced epithelial-mesenchymal transition in cancer cells. The proportions of senescent cells in epithelial-like and mesenchymal-like sub-groups were calculated. Doxorubicin-treated HeLa cells were stained with Vimentin antibody and sorted by flow cytometry. Senescent cell marker p16 INK4a and IL-8 expression in Vimentin-high and Vimentin-low cells were detected by Western blot. Results We found that less than 1% of HeLa cells showed senescence phenotype after treatment with doxorubicin for 3 days. However, the proportion of senescent cells was significantly increased when the doxorubicin-treated cells were subsequently cultured in drug-free medium for another 6d. RT-PCR and ELISA results showed that this prolonged culture method could further improve the expression of IL-6 and IL-8. We also found that the senescent cells were mainly epithelial-like type and few presented mesenchymal-like shape. p16 INK4a and IL-8 expression were decreased in cell fraction with higher Vimentin expression. Conclusions Our results suggested the existence of time delay effect in doxorubicin-induced senescence of HeLa cells, and epithelial-mesenchymal transition may resist doxorubicin-induced cell senescence.

In Vitro Characterization of Doxorubicin-Mediated Stress-Induced Premature Senescence in Human Chondrocytes

“…Although it has been shown that Doxo treatment can induce DNA damage and apoptosis in rapidly dividing cells in vivo and in vitro, the cellular response to Doxo can differ within a population of cells. Accordingly, a recent study demonstrated that proliferative epithelial cells either underwent apoptosis or became senescent, as confirmed by the expression of the characteristic SA marker and an increase in cell size [ 32 ]. Molecular mechanisms, which are involved in Doxo-induced senescence comprise p53 upregulation, oxidative stress, and concurrent caspase inhibition [ 29 ].…”

Hypoxia-inducible factor-2α mediates senescence-associated intrinsic mechanisms of age-related bone loss

“…To overexpress Hif-2α in vitro, primary calvarial preosteoblasts were infected with adenovirus expressing Hif-2α at the indicated multiplicity of infection (MOI) on differentiation day 2. Doxorubicin is a commonly used chemotherapy drug that can induce DNA cross-linking and lead to cell apoptosis, autophagy, and/or senescence 28 . The concentration of doxorubicin used in this experiment did not cause cell apoptosis.…”

Metastatic suppression by DOC2B is mediated by inhibition of epithelial-mesenchymal transition and induction of senescence

“…These results indicate that DOC2B is associated with induction of senescence. Doxorubicin is well known inducer of senescence and is used as a positive control in senescence experiments (Hu and Zhang 2019;Saleh et al 2020).…”