Fusion proteins of DT390 linking TMTP1 for targeted therapy of ovarian cancer / 中国肿瘤临床

ABSTRACT

Objective:To investigate targeted therapy of ovarian cancer with new fusion proteins that were produced by fusing the first 390 amino acids of diphtheria toxin(DT390)to the TMTP1 peptide.Methods:The cisplatin-resistant cell line,C13*,and cisplatin-sensi-tive cell line,OV2008,were selected as models and divided into control,TMTP1,DT390-TMTP1,DT390-biTMTP1,and DT390-triTMTP1 groups.Laser scanning confocal microscopy was used to observe nuclear morphology.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra-zolium bromide(MTT)and flow cytometry assays were used to detect cell survival and apoptosis,respectively.The formation of subcu-taneous tumors in nude mice following injection of C13*cells was used to observe the formation and growth of ovarian cancer.Apop-tosis of cells in the subcutaneous tumor tissue was detected by the terminal deoxynucleotidyl transferase dUTP nick-end labeling(TU-NEL)assay.Results:Laser scanning confocal microscopy showed that DT390-biTMTP1 and DT390-triTMTP1 induced nuclear shrinkage and fragmentation.The MTT assay showed that cell survival was obviously reduced with increasing concentrations of DT390-biTMTP1 and DT390-triTMTP1. Flow cytometry revealed that DT390-biTMTP1 and DT390-triTMTP1 significantly increased cell apoptosis (P<0.05).The apoptosis rates of the DT390-biTMTP1 and DT390-triTMTP1 groups were 66.0%±12.0% and 72.9%±4.6%,respectively.These were higher than the 55.5%±8.9% and 65.1%±9.8% obvserved in OV2008 cells.DT390-biTMTP1 and DT390-triTMTP1 significantly in-hibited the tumor formation (P<0.01) and growth (P<0.05), and increased apoptosis (P<0.05) of subcutaneous tumors. However, DT390-TMTP1 had insignificant effects on C13*and OV2008 cells.Conclusions:DT390-biTMTP1 and DT390-triTMTP1 preferentially tar-geted and inhibited ovarian cancer cells.These fusion proteins may be a promising strategy for clinical therapy of ovarian cancer.