Figure 4. miR-200a promoted tumor growth by up-regulating the expression of PD-L1 in vivo. (A) miR-200a promoted the growth of osteosarcoma through up-regulating PD-L1. (B) Quantification of tumor volume. (C–D) Immunohistochemical staining analysis of ki-67 expression in tumor tissues. Scale bar represents 50μm. (E) Immunohistochemical staining analysis of PD-L1 expression in tumor tissues. Scale bar represents 100μm. (F–G) Flow cytometry analysis of PD-L1 expression in tumor tissues. *P<0.05, **P<0.01, ***P<0.001.