Massumi_2026_Mol.Ther.Oncol_34_201214

Cancer stem-like cells (CSCs) drive ovarian cancer metastasis, therapeutic resistance, and relapse. This study aimed to develop a combination therapeutic strategy capable of eliminating both rapidly proliferating ovarian cancer cells and drug-resistant CSCs, thereby eradicating metastatic disease and preventing relapse. We engineered an adipose-derived mesenchymal stem cell clone (ASC-shCE2:yCD) that homes to tumors and locally converts the prodrugs irinotecan and 5-fluorocytosine (5-FC) into the cytotoxic agents SN38 and 5-fluorouracil (5-FU). This approach was combined with natural killer (NK) cell immunotherapy to eradicate CSCs that survived chemotherapy. Using patient-derived, drug-resistant metastatic ovarian cancer models, we show that exposure to SN38 or 5-FU upregulates NKG2D stress ligands (MICA/B) on CSCs, enhancing their susceptibility to NK-mediated cytotoxicity. Real-time imaging demonstrated rapid homing of engineered adipose-derived stem cells (ASCs) to tumor sites within 3 days. In triple-immunodeficient CIEA NOG mice, ASC-directed enzyme/prodrug therapy followed by NK cell immunotherapy eliminated metastatic ovarian tumors and prevented relapse during the monitoring period. Histopathological and hematological analyses revealed no clinically significant toxicity. Collectively, these findings establish a stem cell-directed chemoimmunotherapy that primes drug-resistant ovarian cancer cells for immune elimination, offering a rationale and effective strategy to safely eradicate metastatic disease and prevent recurrence.