ATO prevents osteosarcoma growth in vivo.

<p>143B cells (1 × 10⁶) were subcutaneously inoculated into nude mice. Tumor volume was calculated weekly using the formula LW² /2 (where L and W represent the length and width of tumors). Seven days after inoculation, the tumor volume was set as 1 and was evaluated at different time points. (A) ATO treatment inhibited tumor growth as compared with control (<b>*</b>P < 0.05 or **P < 0.01) (error bars represent mean [SD]). Kaplan-Meier analysis revealed that ATO treatment provided a significant survival benefit (**P < 0.01). (B) Apoptotic cell death in the tumors was analyzed by TUNEL staining, which showed that ATO treatment increased apoptotic cell death in vivo (<b>*</b>P < 0.05 or **P < 0.05) (error bar indicates SD).