OBJECTIVEThe growth and metastasis of solid tumors are dependent on angiogenesis. Endostatin, the C-terminal proteolytic fragment of collagen XVIII, is a potent endogenous angiogenesis inhibitor. The authors designed a topical antiangiogenic gene therapy with recombinant human endostatin adenovirus (Ad-hEndo) and assessed its effects on the inhibition of angiogenesis in vitro, and tumor growth and metastasis in vivo.

METHODSMalignant cells (A549) were infected with Ad-hEndo. The expression of recombinant protein and the inhibition of cultured human umbilical vein endothelial were investigated. Immunodeficient A549 nude mice were treated with intratumoral injection of Ad-hEndo, the empty vector Ad-control or saline (NS). The dose-response, side effects, and serum concentration of endostatin were observed.

RESULTSRecombinant endostatin protein was detected in the infected tumor cells with different MOI Ad-hEndo and its inhibitory effect on endothelial cells growth was shown. In animal study, the volume of tumor and the number of pulmonary metastatic lesions in the Ad-hEndo treatment group were significantly smaller than those in the control groups (P<0.05).

CONCLUSIONThe present findings provide evidence of the anti-tumor effects of the endostatin and may be important for the further use of it in topical antiangiogenic gene therapy of cancer.