Tumor cells recruit macrophage bodyguards to outlast chemotherapy.

Tumor-macrophage niches in bladder cancer promote chemoresistance, with PARP14 inhibition transforming these niches into cisplatin-sensitive environments.

• Why it matters: Understanding how tumor cells evade chemotherapy is crucial for improving treatment outcomes in bladder cancer. These protective niches may be key to overcoming resistance.
• What they did: Carvalho et al. used spatial analysis to identify tumor-macrophage niches, specifically EMT-like CD44 high cancer cells paired with SPP1/PARP14 high macrophages, which drive chemoresistance.
• The result: Inhibiting PARP14 can convert these niches into an inflammatory state that enhances cisplatin sensitivity, suggesting a potential strategy to counteract chemoresistance.