Identification of heptapeptides interacting with IFN-α-sensitive CML cells

Abstract

Background: Interferon-alpha (IFN-α) is the traditional therapeutic agent for chronic myeloid leukemia (CML). The molecular mechanism of IFN-α efficacy in the treatment of CML is not fully clear.

Objectives: To identify the peptides and/or proteins that bind to the proteins specifically expressed on the surface of IFN-α-sensitive CML cells by using a phage display library.

Design/methods: IFN-α-sensitive KT-1/A3 cells were used as the target, and IFN-α-resistant subline KT-1/A3R was used as absorber for phage display biopanning. The positive phage clones were identified by enzyme-linked immunosorbent assay and flow cytometry. The peptides were deduced from their DNA sequences.

Results: Multiple clones showed high binding efficiency to KT-1/A3 cells compared with that of the other leukemia cells. One of the peptides, KLWVIPQ, has a partial amino acid sequence homology with the C-terminal domain of E3 ubiquitin-protein ligase.

Conclusions: This study presents the identification of specific heptapeptides that bind to IFN-α-sensitive KT-1/A3 cells. The cancer-selective ligands provide novel strategies for early and differential diagnoses, as well as potential targeted drug delivery.

Keywords:

• cell surface marker
• chronic myeloid leukemia
• interferon-alpha
• KT-1 cell line
• phage display peptide library