Repurposing atorvastatin for uterine leiomyosarcoma: mevalonate pathway inhibition yields preclinical antitumor efficacy.

Uterine leiomyosarcoma (ULMS) is a rare yet aggressive uterine malignancy with high recurrence and poor survival, prompting an urgent search for better treatments. We investigated whether atorvastatin, an HMG-CoA reductase inhibitor, could suppress ULMS growth by targeting mevalonate pathway-dependent prenylation. Human ULMS cell lines received atorvastatin ± isoprenoids to assess proliferation, cell-cycle distribution, and smooth muscle contractility, whereas proteomic profiling (LC-MS/MS) and in vivo xenografts were used to evaluate molecular pathways and antitumor efficacy. Atorvastatin inhibited ULMS proliferation in a dose-dependent manner, induced G₀/G₁ cell-cycle arrest, and diminished the contractile phenotype. Geranylgeranyl pyrophosphate rescued these effects, implicating geranylgeranylation as the key dependency, and Rap1A/Rap1B Western blotting confirmed functional GGPP depletion. In xenografts, atorvastatin suppressed ULMS tumor growth by ~50% with minimal toxicity, as evidenced by normal serum ALT and creatinine levels and preserved organ histology. These findings identify protein geranylgeranylation as a novel therapeutic vulnerability in ULMS and support statin repurposing as a promising treatment strategy.