Anti-Trop2-Guided Liposomes Restore Methotrexate Sensitivity in Chemoresistant Gestational Trophoblastic Neoplasia

Methotrexate (MTX) resistance limits its clinical efficacy in gestational trophoblastic neoplasia (GTN). To develop safer treatment strategies for patients of reproductive age, this study aims to investigate whether anti-trophoblast cell surface antigen 2 (Anti-Trop2) facilitates the tumor-targeted delivery of MTX-loaded liposomes, thereby enhancing drug sensitivity in chemoresistant GTN.

Clinical samples were collected to detect trophoblast cell surface antigen 2 (Trop2) in MTX-resistant GTN. A methotrexate-loaded targeted liposome (A-Lipo@MTX) was designed and fully characterized. In vitro experiments were performed to evaluate the cellular uptake efficiency and cytotoxicity of the liposomes in MTX-resistant JEG3 cells (JEG3R), and to explore the underlying mechanism. The antitumor efficacy against drug-resistant tumors and initial biosafety of A-Lipo@MTX were further assessed in animal models.

Clinical specimens revealed that Trop2 was significantly upregulated in chemoresistant GTN tissues. Trop2 could serve as a potential therapeutic target for drug-resistant tumors. The designed A-Lipo@MTX exhibited a uniform nanoscale size (~210 nm), high encapsulation efficiency (~85%), and favorable stability. In vitro, Anti-Trop2 functionalization significantly increased liposomal endocytosis within MTX-resistant GTN cells; the resulting intracellular MTX accumulation inhibited PI3K-AKT-mTOR signaling and triggered tumor cell apoptosis. In vivo imaging results confirmed its increased tumor accumulation, which translated into superior antitumor efficacy. Importantly, A-Lipo@MTX improved biosafety during medication, as indicated by stable body weight, normal serum biochemical parameters, and minimal organ damage.

This study identifies Trop2 as an effective target to promote liposome specific uptake, elevates intratumoral MTX accumulation at tumor sites, and suppress the activation of drug-resistant signaling pathways. This strategy provides a clinically relevant and safer approach for overcoming chemoresistance in GTN.