Iron metabolism disorder and artesunate inhibiting tumor growth by inducing ferroptosis in Lymphangioleiomyomatosis.

Background: Sirolimus, the therapy choice for lymphangioleiomyomatosis (LAM), displayed cytostatic but not cytocidal action, with disease recurrence after withdrawal. The aim of this study is to identify novel potential biomarkers and therapeutic strategies for LAM patients.

Methods: TMT-labeling proteomics was utilized for screening the differentially expressed proteins (DEPs) in the plasma of 10 LAM patients and 6 controls. Plasma levels of transferrin (TRF), ferritin (FRT) and beta2-microglobulin (B2M) were validated in a cohort of 30 LAM patients and 20 controls. The diagnostic efficacy of TRF with/without VEGF-D was assessed using ROC curve analysis. The therapeutic effects of a ferroptosis inducer artesunate (ART) were evaluated both in vitro Tsc2 - / - MEFs cells and in xenograft LAM models.

Results: Proteomics analysis revealed 132 DEPs between LAM patients and controls, which primarily enriched in the regulation of iron ion transport. LAM patients had decreased TRF, elevated FRT and B2M levels compared with controls in the confirmation cohort (p = 0.0386, p = 0.0327 and p = 0.0155, respectively) which independent with VEGF-D level or rapamycin therapy. TRF positively correlated with both FEV₁% predicted (r = 0.4486, p = 0.0251) and DLCO% predicted (r = 0.4018, p = 0.0516) of LAM patients. The combination of TRF and VEGF-D showed superior diagnostic value compared to individual indicator. ART induced the ferroptosis and inhibited the growth in Tsc2 - / - MEFs cells. In LAM animal models, ART exerted anti-tumor effects without obvious adverse effect.

Conclusions: LAM patients exhibit abnormal iron metabolism independent of VEGF-D level. Ferroptosis inducer ART holds promise as a therapeutic novel approach for treating LAM.