Gene therapy of gastric cancer using LIGHT-secreting human umbilical cord blood-derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) have the ability to migrate into tumors and therefore are potential vehicles for the therapy of malignant diseases. In this study, we investigated the use of umbilical cord blood mesenchymal stem cells (UCB-MSCs) as carriers for a constant source of transgenic LIGHT (TNFSF14) to target tumor cells in vivo. Lentiviral vectors carrying LIGHT genes were constructed, producing viral particles with a titer of 2 x 10(8) TU/L. Fourteen days after UCB-MSCs transfected by LIGHT gene packaged lentivirus had been injected into mouse gastric cancer models, the expression levels of LIGHT mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Then the tumors' approximate volumes were measured. The treatment with MSC-LIGHT demonstrated a strong suppressive effect on tumor growth compared to treatment with MSC and NaCl (p < 0.001). Examination of pathological sections of the tumor tissues showed that the areas of tumor necrocis in the MSC-LIGHT group were larger than those in the MSC group. Moreover, we found that MSCs with LIGHT were able to significantly induce apoptosis of tumor cells. The expression levels of LIGHT mRNA and protein were significantly higher in the UCB-MSCs with the LIGHT gene than the levels in UCB-MSCs (p < 0.001). These results suggest that UCB-MSCs carrying the LIGHT gene have the potential to be used as effective delivery vehicles in the treatment of gastric cancers.