TP53 and osteosarcoma: Its potential anti-tumor effect against osteosarcoma has been also investigated by Lima et al. They reported that CH-5 exerts its anti-tumor activity by stabilization of p53 and downregulation of sp1 protein leading to activation of apoptosis via modulation of DNA methyltransferase 1 (DNMT1) and damage-inducible 45 alpha gene (Gadd45a) expression.