Figure 4. Knockdown miR-221-3p inhibits the malignant progression of OS. miR-221-3p-in were transfected into M2-TAMs. The exosomes in the culture medium of M2-TAMs were isolated and then treated with Saos2 cells. (A) qRT-PCR verified the miR-221-3p profile. (B) CCK-8 monitored cell viability. (C) Cell proliferation was monitored by the colony formation experiment. (D) Cell migration and invasion were compared by Transwell. (E) Apoptosis of Saos2 was detected by FCM. (F) Bax, Bcl2 and Cleaved Caspase-3 were examined by WB. *P < 0.05, **P < 0.01, ***P < 0.001 (vs. con group). &P < 0.05, &&P < 0.01, &&&P < 0.001 (vs. EXOTAMs+NC-in group), N = 3.