OBJECTIVETo investigate the potentiality of herpes simplex virus thymidine kinase transduced endothelial progenitor cells (EPC-TK) as angiogenesis-targeting vector in the glioma treatment in vitro and in vivo.

METHODSEPC-TK were mixed with human umbilical vein endothelial cells (HUVECs), U87 or U251 cells at various ratios for ganciclovir (GCV) treatment. The bystander effect was observed by counting the survival cells using MTT assay, and the apoptotic cells were determined by annexin-V and propidium iodide (PI) staining. EPC-TK, EPCs, or phosphate buffered saline (PBS) were injected into the nude mice model of glioma xenograft by tail vein, for the EPC-TK group, EPC group, and PBS group, respectively. And then the changes of tumor volume and tumor vasculature were observed.

RESULTSGCV killed most EPC-TK and reduced the number of other viable cells in a cell:cell ratio-dependent and time-dependent manner. EPC-TK obviously inhibited tumor growth. The tumor volumes on day 21 were 1741.20+/- 576.10 mm(3), 3275.52 +/- 710.86 mm(3) and 3033.09+/-1134.86 mm(3) in the EPC-TK, EPC and PBS group, respectively. EPC-TK also displayed a significant effect on the inhibition of tumor angiogenesis.

CONCLUSIONEPC-TK can exert a potent antiglioma effect via inhibiting angiogenesis.