Data from Mesenchymal Stem Cells Expressing CES1 and Soluble TRAIL Activate CPT-11 and Induce Apoptosis in Lung Cancer Brain Metastatic Lesions

<div>Abstract<p>We aimed to develop a novel therapeutic strategy for lung cancer brain metastases by leveraging the tumor-tropic properties of genetically engineered Wharton’s Jelly–derived mesenchymal stem cells (WJ-MSC) as vehicles for dual-agent gene therapy across the blood–brain barrier. WJ-MSCs were transiently engineered using lipid nanoparticle technology to coexpress soluble TRAIL (sTRAIL) and the prodrug-activating enzyme carboxylesterase 1 (CES1). <i>In vitro</i> analyses assessed transfection efficiency, therapeutic protein expression, apoptosis induction, and maintenance of stemness. Tumor-homing capacity was evaluated via EGFP labeling and intracerebral tracking. Therapeutic efficacy was tested in subcutaneous and intracerebral lung cancer xenograft models using bioluminescent imaging, histopathology, and IHC. <i>In vivo</i> treatment included intraperitoneal CPT-11 administration to assess synergy between CES1-mediated prodrug activation and sTRAIL-induced apoptosis. Modified WJ-MSCs exhibited preserved stem cell characteristics and strong tropism toward brain tumor sites. They secreted high levels of functional sTRAIL and CES1, enabling local activation of CPT-11 into SN-38 and inducing apoptosis through death receptor signaling (DR4/DR5). Combination therapy with WJ-MSCs-CES1.sTRAIL and CPT-11 significantly suppressed tumor growth in lung cancer brain metastasis models compared with control groups. The approach demonstrated selective cytotoxicity, minimal off-target effects, and favorable safety profiles. This study establishes a nonviral, transient gene delivery platform using autologous WJ-MSCs for dual-action gene therapy in lung cancer brain metastases. The combined use of CES1 and sTRAIL and enables precise tumor targeting and drug activation, offering a promising avenue for personalized, stem cell–based treatment strategies to improve outcomes in patients with brain metastatic lung cancer.</p>Significance:<p>This study presents a nonviral, stem cell–based therapy for brain metastatic non–small cell lung cancer using WJ-MSCs expressing sTRAIL and CES1. These engineered cells home to tumors, activate CPT-11, and induce apoptosis. The dual-action strategy significantly reduced brain tumor burden with minimal toxicity, demonstrating strong therapeutic potential.</p></div>