In addition, inhibition of miR-655 could effectively antagonize the effect of BMSCs derived exosomes XIST on the level of XIST in osteosarcoma cells (Fig. 4A, B), suggesting that XIST and miR-655 in osteosarcoma cells could bind and regulate the level of each other, that is, there was a ceRNA mechanism. Here, XIST is linked to osteosarcoma.