Objective   Tumor vessels were foundation of tumors’ formation

growth and metastasis

and the destruction of a spot of them would lead to wide avascular necrosis of tumor cells

so the specific killing effect on tumor vasculature endothelial cells had become one of the most important strategies for tumor therapy. Endostar

a novel recombinant human endostatin expressed and purified with an additional nine-amino acid sequence

is a new anti-  drug. This study aimed to determine how endostar to affect the behavior of endothelial cells and tumor endothelial cells in vitro and in vivo.   Methods   Human umbilical vein

endothelial cells (HUVEC) was isolated and cultured followed by identification with Ⅷ factor related antigens. The cells differentiated into tumor-derived endothelial cells (Td-ECs) by co-culturing with supernatants of A549 cells. The anti- effect of endostar on Td-ECs was detected with MTT assay

cell migration assay

flow cytometry and TUNEL assay.   Results   Endostar had a significant effect on the proliferation of Td-EC in a time- and concentration-dependent manner. At the same time

though Endostar at a certain concentration inhibited cell migration process significantly

arrested the cells at G

0

/G

1

and S phases and induced cell apoptosis (P0.01)

however

under the same conditions

Endostar had little impact on HUVEC (P0.05).   Conclusion   Our study indicates a novel function of endostar

to inhibit   and Td-ECs proliferation in vitro. So

using endostar for cancer therapy is worthwhile for further study in clinical trials.