Construction of an Ewing's sarcoma specific expression vector of diphtheria toxin and observation of the killing effect on cultured Ewing's sarcoma cell line / 第三军医大学学报

ABSTRACT

Objective To construct an expression vector containing Ewing's sarcoma EWS FLI 1 specific binding sequence and diphtheria toxin A chain (DTA) gene sequence to investigate the killing effect of DTA on cultured Ewing's sarcoma cells so as to provide proof for the exploration of new methods for gene therapy for cancer. Methods Expression vector (pS2 DTA) containing EWS FLI 1 specific binding sequence and DTA gene sequence was constructed by replacing the luciferase gene in pS2 with DTA gene at the points of Nco Ⅰ and Xba Ⅰ by molecular technique. After transfection of pS2 DTA into Ewing's sarcoma cells and the control cells, DTA expression and its killing effect on cells were detected. Results pS2 DTA was highly expressed in Ewing's sarcoma cell line, and the killing effect of DTA was much higher than that in the control cells. Conclusion pS2 DTA has selective killing effect on Ewing's sarcoma cells and can inhibit the growth of Ewing's sarcoma cells. So pS2-DTA has potential value in the treatment of Ewing's sarcoma.