¡¾Abstract¡¿ AIM: To investigate RNA expression of dendritic cells(DC) pulsed with totol RNA from Ewing sarcoma cells. METHODS: DC was generated from the peripheral blood mononuclear cells(PBMC) of Ewing sarcoma patients. Surface markers of matured DCs was detected by flow cytometer(FCM). Total RNA was isolated from Ewing sarcoma by Trizol. DC were transfected with total tumor cell RNA. The expression of DC tansfected with total RNA was measured by RTª²PCR method. RESULTS: Surface markers of DC pulsed with total RNA changed apparently. CD40 increased from 32.24% to 72.32%. CD83 increased from 17.39% to 30.97%, while monocyte CD14 declined from 26.37% to 10.46% .This indicated the significant reinforcement of antigen presentation of DC. RTª²PCR showed the specific sequence EWSª²FLI1 of Ewing sarcoma can be combined with the primer specifically at the best temperature of 54¡æ. CONCLUSION: DC pulsed with total RNA of Ewing sarcoma cells can present tumor specific antigen and express its characteristic sequence EWSª²FLI1 specifically. ......