Int-H1-S6A F8 c-myc inhibitor

H1 DNA-binding region of c-Myc containing Ser to Ala, and Phe to Ala substitutions (underlined) to confer an increase in its potency to inhibit c-Myc. The N-terminus of this peptide is the Int peptide sequence derived from the third Antennapedia homeodomain, to confer cell permeability. Control for this peptide is H1-S6A,F8A c-Myc inhibibitor peptide (Prod. No. BML-P606). Inhibited cloning efficiency of MCF-7 human breast cancer cells by 90% at 10 µM (IC₅₀=5.9 µM). In MCF-7 cells, it inhibited cell growth and induced apoptosis. In addition, at 10 µM it strongly inhibited transcription of the c-Myc regulated genes ODC and p53. The non-cell-permeable control for this peptide is H1-S6A, F8A c-Myc inhibitor peptide which lacks the N-terminal internalization sequence.