摘要

The aim of the present study was to investigate the efficacy of using human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) as gene delivery vectors in the treatment of ovarian cancer. Lentivectors overexpressing cytosine deaminase (CD) and herpes simplex virus thymidine kinase (HSV-tk) (pGC-FU-CD-TK) were constructed, and confirmed by enzyme digestion, DNA sequence and western blotting. Quantitative PCR (PCR) was used to verify the overexpression of the fusion gene (CD and HSV-tk). SKOV3 cells were co-cultured with MSCs/tk(+)CD(+) at a 1:1 ratio, and were then treated with the prodrugs (GCV) and/or 5-fluorocytosine (5-FC) at different concentrations, and the cytotoxic effects were evaluated using MTT assay and flow cytometry. DNA sequencing demonstrated that the sequence of HSV-tk and CD genes were consistent with the objective sequence and western blotting verified that the constructed lentivector could produce the HSV-tk/CD gene. The packed titer was 2.00e+8 TU/ml. The pGC-FU-CD-TK could be stably transferred to hUCB-MSCs, and the infection efficiency was almost 80%. RT-PCR demonstrated that the expression levels of the HSV-tk/CD fusion gene in MSCs/tk(+)CD(+) group was 75 times that in the negative control (P<0.05). Compared with GCV or 5-FC alone, the growth inhibition rate (GIR) was significantly higher in the combined treatment (F=85.35, P<0.05). The reconstructed MSCs/tk(+)CD(+) vectors were capable of slowing down the growth of human SKOV3 cells in the presence of prodrugs in vitro. The use of combination chemotherapy exhibited a more significant inhibitory effect than using a single prodrug.

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