Mapping the Progression of Therapy-Induced Senescence to Therapy Tolerance: An Evolutionarily Conserved Mechanism for...

Area of Science:

• Oncology
• Cell Biology
• Pharmacology

Background:

• Therapy-induced senescence (TIS) is a reversible cell cycle arrest caused by cancer treatments.
• TIS can lead to long-term therapy resistance in tumor cells.
• Senotherapeutics targeting senescent cells are under clinical investigation.

Purpose of the Study:

• To investigate the transient nature of TIS and its impact on drug tolerance.
• To determine the optimal timing for senolytic intervention in TIS.
• To explore the role of TGF-β signaling in TIS-mediated drug tolerance.

Main Methods:

• Development of a TIS cell line model in triple-negative breast cancer (TNBC) using YM155.
• Assessment of senescence reversibility and drug tolerance in cancer and non-cancerous cells.
• Analysis of TGF-β expression and inhibition of TGF-β signaling.

Main Results:

• YM155-induced TIS in TNBC cells resulted in a transient senescence and a persistent drug-tolerant state.
• This drug tolerance phenomenon was observed in various cell types and in zebrafish larvae.
• Inhibition of TGF-β signaling reversed the tolerant phenotype but was most effective within a specific time window post-TIS induction.

Conclusions:

• TIS is a transient state with potential for rapid adaptation against xenobiotics.
• The effectiveness of senolytics depends on precise timing relative to TIS induction.
• Targeted, timely senotherapeutic intervention may enhance the efficacy of anticancer therapies.