PARP1 and osteosarcoma: In line with this, a doxorubicin28 and trabectedin resistant leiomyosarcoma cell line restored its sensitivity to these DNA damage agents by adding PARP inhibitors.66 Also, in osteosarcoma cells, the doxorubicin plus olaparib combined treatment incremented the apoptotic rate.68 Furthermore, recent clinical results have shown that combining trabectedin with olaparib allowed a partial response in sarcoma patients.27