Microbiota-shaped neutrophil senescence regulates sexual dimorphism in bladder cancer.

Sex disparities have been epidemiologically demonstrated in non-reproductive cancers, yet how the sex-specific intrinsic microbiome orchestrates the immune system to affect these disparities is unclear. Here we identify a subpopulation of RETNLG+LCN2+ senescence-like neutrophils (RLSNs) that preferentially accumulate in the male tumor microenvironment and exert a strong immunosuppressive effect to limit antitumor immunity, resulting in poor prognosis for patients with bladder cancer. This difference in enrichment of RLSNs between sexes can be attributed to intestinal bacterium Alistipes shahii, which preferentially populates in females rather than males. A. shahii-associated metabolite lurasidone directly targets iron sequestrator LCN2 in RLSNs. By freeing Fe2+, lurasidone induces ferroptosis, thereby eliminating RLSNs and promoting antitumor immunity in females. In males lacking A. shahii and lurasidone, RLSNs have a survival advantage. Together, these findings demonstrate that a microbiota-lurasidone-LCN2 circuit regulates sexual disparity in bladder cancer and indicates the therapeutic potential of lurasidone for male cancer patients.