FIGURE 4.

VEGFR2 inhibition inactivates the RhoA-ROCK-LIMK2 pathway and suppresses PD-L2 expression in osteosarcoma cells by targeting STAT3. (A) Apatinib reduced the expression of PD-L2, STAT3, p-cofilin and p-LIMK, as demonstrated by western blotting. (B) VEGFR2 knockdown reduced the expression of PD-L2, STAT3, p-cofilin and p-LIMK, as indicated by western blotting. (C) STAT3 expression in KHOS cells was downregulated by three STAT3 siRNA sequences (top). STAT3 knockdown decreased the expression of PD-L2, p-LIMK and p-cofilin (bottom). (D) Overexpression of VEGFR2 increased Y-27632 2HCl-induced decline of p-LIMK and p-Cofilin by western blot. (E) A coexistence phenomenon was observed between RhoA and STAT3 by bioinformatics analysis (http://genemania.org/). (F) The change in RhoA activation in U2OS cells was confirmed by the GTPase test. ***P < 0.001.