Figure 5. Supernatants of spheroid cells promote proliferation and migration of EPCs.

(A-C) EPCs adhere to FN-coated flask after 72 hr and EPCs clones can be seen after one week (A), and present cobbles-like sign after two weeks (B). EPCs in later stage display a certain expression of CD34 and CD133, but high level expression of VEGFR2 (C). (D, E) Cell proliferation (D) and migration (E) of EPCs treated by supernatants of spheroid cells were higher than their counterpart.