Objective:To establish genetically engineered human umbilical cord mesenchymal stem cells (hUC-MSCs) with overexpression of hTRAIL for cancer therapy.Methods:The entire coding sequence of human tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) was amplified from cDNAs of MDA231 cells.The amplified fragments were purified and digested with Not I and Mlu I, and then inserted into the lentiviral expression vector LentiORF pLEX-MCS.The recombinant was identified with both PCR and restriction digestion.After verification by DNA sequencing, the recombinant (with accurate sequence of hTRAIL cDNA) was nominated as pLEX-hTRAIL.The lentiviral expression vector pLEX-hTRAIL and lentivirus packaging plasmids psPAX2 and pMD2.G were cotransfected into virus packaging cell line HEK293T using PEI to produce lentiviruses.Human umbilical cord mesenchymal stem cells were infected with hTRAIL-expressing lentiviruses and then subjected to selection with puromycin.The integration of exogenous hTRAIL cDNA into the genome of hUC-MSCs was detected with PCR and overexpression of hTRAIL was analyzed with both regular and real-time qRT-PCR.The cancer therapeutic potential of genetically engineered hUC-MSCs was evaluated by MTS assay using MDA231 and SKBR3 as target cells.