Genetically engineered human neural stem cells with rabbit carboxyl esterase can target brain metastasis from breast cancer.

Neural stem cells (NSCs) led to the development of a novel strategy for delivering therapeutic genes to tumors. NSCs expressing rabbit carboxyl esterase (F3.CE), which activates CPT-11, significantly inhibited the growth of MDA-MB-435 cells in the presence of CPT-11. F3.CE cells migrated selectively into the brain metastases located in the opposite hemisphere. The treatment also significantly decreased tumor volume in immune-deficient mice bearing MDA-MB-435 tumors when F3.CE cells were transplanted into the contralateral hemisphere. The survival rate was significantly prolonged with the treatment with F3.CE and CPT-11. This strategy may be considered as an effective treatment regimen for brain metastases.