Figure 4.

CHRDL2 blocked BMP‐9 and regulated PI3K/AKT pathway. (a) Immunoprecipitation demonstrated the binding between BMP‐9, BMP‐7, BMP‐4, BMP‐2, and CHRDL2. (b,c) Western blot was used to detect the expression of BMP‐9 while CHRDL2 was overexpressed or inhibited. (d) Immunoprecipitation was performed to detect the combination between BMP‐9 and ALK1 while CHRDL2 was inhibited. (e) Immumohistochemical staining was used to detect the expression relationship between CHRDL2 and BMP‐9 in osteosarcoma tissues (magnification ×400). (f) GSEA analysis showed CHRDL2 had potential to regulate PI3K/AKT pathway according to the gene expression profile GSE87624 and GSE99671. (g) Western blot was used to detect the expression of PI3K, p‐PI3K, AKT, p‐AKT, and MMP‐9 while CHRDL2 was inhibited. (h) Western blot was used to detect the expression of PI3K, p‐PI3K, AKT, p‐AKT, and MMP‐9 while CHRDL2 was overexpressed. BMP‐9, bone morphogenetic protein 9; CHRDL2, chordin‐like 2; GSEA, gene set enrichment analysis