Expression and Selection of Human Foxm1c Binding Peptides and Their Inhibitions on MCF7 Cancer Cells

Elevated expression of forkhead/winged helix transcription factor FOXM1 are closely involved in cancer initiation, invasion and metastasis. It is a potentially suitable target for anticancer drug discovery and therapy. In this study, we investigated the expression and selection of human Foxm1c binding peptides and their inhibitions on MCF7 cancer cells. The protein of DNA binding domain of human FoxM1c(DBDFoxM1c) was expressed in prokaryotic system and then purified and later used as the target for binding peptide selection based on the phage random dodecapeptide library. The phages were enriched after four rounds of selection and 18 different peptide sequences were obtained. seven possible consensus peptide sequences WHL/Q/ D / N , DL/ H L/ N Y, SSLWN/ E ; HLD/ Y Y/ E ; YH/ L E/ D /E/ D ; YPH/ L / S and F/ N Y/ F N/ Y L were identified and they were found to dock well to the 3D structure model of DBDFoxM1c by molecular docking. One representative peptide was designed and in vitro study revealed that the viability of MCF7 cancer cells could be reduced to 34.30 % at the concentration of 100 µg/ml of the peptide. In conclusion, the consensus peptide sequences identified in our study were newly reported and it is the first report of the screening of binding peptides targeting DBDFoxM1c. We expect that the results of these studies will result in future development of FoxM1c based lead peptide drug as well as the further understanding of DBDFoxM1c.