Objective      To investigate the ability of CD133

+

ovarian cancer stem-like cells (OCSLCs) differentiating into vascular endothelial cells.       Methods      Ovarian cancer A2780 cells were cultured in serum-free medium to induce CD133

+

OCSLCs. Matrigel tube-forming assay was used to test the ability of CD133

+

OCSLCs differentiating into vascular endothelial cells

which was validated by CD31 expression with RT-PCR and Western blotting. The CD133

+

OCSLCs were subcutaneously injected to

nude mice and then immuno-fluorescence staining of human specific endothelial markers was done to investigate the differentiation ability of CD133

+

OCSLCs in vivo.       Results      CD133

+

OCSLCs formed vessel-like tubes in Matrigel tube-forming assay

with the most obvious tube formation at 6 h. Immunofluorescence

RT-PCR and Western blot results showed that human specific CD31 was significantly up-regulated in Matrigel tube-forming assay (P0.01). Immunofluorescence staining of xenografts in nude mice showed the formation of human vessels

suggesting the ability of CD133

+

OCSLCs differentiating to tumor vascular endothelial cells in vivo．      Conclusion      CD133

+

OCSLCs have the potential of vascular endothelial cell differentiation

uncovering a novel mechanism of ovarian cancer angiogenesis and a novel way in anti-angiogenesis therapy of ovarian cancer．