title: Characterization of a Novel Cytotoxic Cell-penetrating Peptide Derived From p14ARF Protein.
abstract: The tumor suppressor p14ARF is widely deregulated in many types of cancers and is believed to function as a failsafe mechanism, inhibiting proliferation and inducing apoptosis as cellular response to a high oncogene load. We have found that a 22-amino-acid-long peptide derived from the N-terminal part of p14ARF, denoted ARF(1-22), which has previously been shown to mimic the function of p14ARF, has cell-penetrating properties. This peptide is internalized to the same extent as the cell-penetrating peptide (CPP) TP10 and dose-dependently decreases proliferation in MCF-7 and MDA MB 231 cells. Uptake of the ARF(1-22) peptide is associated with low membrane disturbance, measured by deoxyglucose and lactate dehydrogenase (LDH) leakage, as compared to its scrambled peptide. Also, flow cytometric analysis of annexin V/propidium iodide (PI) binding and Hoechst staining of nuclei suggest that ARF(1-22) induces apoptosis, whereas scrambled or inverted peptide sequences have no effect. The ARF(1-22) peptide mainly translocates cells through endocytosis, and is found intact inside cells for at least 3 hours. To our knowledge, this is the first time a CPP having pro-apoptopic activity has been designed from a protein.
authors.affiliation: Department of Neurochemistry, Stockholm University, Stockholm, Sweden. Electronic address: henrik@neurochem.su.se.
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: Johansson
authors.affiliation: Department of Neurochemistry, Stockholm University, Stockholm, Sweden.
authors.forename: Samir
authors.initials: S
authors.lastname: El-Andaloussi
authors.affiliation: Department of Neurochemistry, Stockholm University, Stockholm, Sweden.
authors.forename: Tina
authors.initials: T
authors.lastname: Holm
authors.affiliation: Department of Neurochemistry, Stockholm University, Stockholm, Sweden.
authors.forename: Maarja
authors.initials: M
authors.lastname: Mäe
authors.affiliation: Department of Cell Biology, Institute of Molecular and Cell Biology, Tartu University, Tartu, Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Jänes
authors.affiliation: Department of Cell Biology, Institute of Molecular and Cell Biology, Tartu University, Tartu, Estonia.
authors.forename: Toivo
authors.initials: T
authors.lastname: Maimets
authors.affiliation: Department of Neurochemistry, Stockholm University, Stockholm, Sweden.
authors.forename: Ülo
authors.initials: Ü
authors.lastname: Langel