title: Overexpression of adenovirus-mediated p27kip1 lacking the Jab1-binding region enhances cytotoxicity and inhibits xenografted human cholangiocarcinoma growth.
abstract: The cyclin-dependent kinase inhibitor (CDK1) p27(kip1) is a negative regulator of cell cycling and has antitumor effects. In our previous study, the recombinant adenovirus expressing wild-type p27(kip1) (Adp27-wt) induced cell cycle arrest and apoptosis, and proved that p27 is a tumor suppressor gene like p53. Another adenovirus vector expressing mutant p27(kip1) (Adp27-mt), which inhibited degradation by the ubiquitin-proteasome system, showed increased protein stability and caused a stronger induction of apoptosis. Recently, the p27(kip1) protein binding with Jab1 (Jun activating binding protein 1) was found to translocate from the nucleus into the cytosol, and then become degraded by the 26S proteasome system. The inhibition of nuclear-cytoplasmic translocation increases the protein stability of p27(kip1) and p27(kip1) with a deletion of the Jab1-binding region (p27-jab-d) is not translocated and not degraded. Therefore, a new recombinant adenovirus (Adp27-jab-d) expressing p27-jab-d was made which was able to induce greater cytotoxicity. Adp27-jab-d inhibited the growth of human cholangiocarcinoma cell line (TFK-1) cells in vitro at 3.3 times (IC(50)) lower concentration than Adp27-wt. Moreover, in a xenografted severe combined immuno-deficient (SCID) mouse model injected with TFK-1 cells in the subcutaneous tissue, treatment by intratumor injection of Adp27-jab-d once a day for 3 days after the tumor was established, inhibited tumor growth more strongly than Adp27-wt or Adp27-mt and even induced tumor regression. However, the flow cytometric TUNEL assay showed little enhancement of apoptosis. Adp27-jab-d was thought to induce not only apoptosis but also necrosis, which was due to a specific effect of the Adp27-jab-d. Thus, by enhancing the cytotoxicity through inhibiting the translocaton of p27(kip1), p27(kip1) lacking the Jab1-binding region might be useful for cancer therapy. The control protein localization might also be a new target not only for cancer treatment, but also other diseases.
authors.affiliation: Department of Hepato-Billary-Pancreatic Surgery, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Shiraso
authors.forename: Yu
authors.initials: Y
authors.lastname: Katayose
authors.forename: Kuniharu
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masamichi
authors.initials: M
authors.lastname: Mizuma
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yabuuchi
authors.forename: Akira
authors.initials: A
authors.lastname: Oda
authors.forename: Toshiki
authors.initials: T
authors.lastname: Rikiyama
authors.forename: Tohru
authors.initials: T
authors.lastname: Onogawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Hideo
authors.initials: H
authors.lastname: Ohtsuka
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Motoi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Egawa
authors.forename: Junya
authors.initials: J
authors.lastname: Kato
authors.forename: Michiaki
authors.initials: M
authors.lastname: Unno
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis; D001650:Bile Duct Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D001653:Bile Ducts, Intrahepatic; D015153:Blotting, Western; D000075686:COP9 Signalosome Complex; D002453:Cell Cycle; D002467:Cell Nucleus; D018281:Cholangiocarcinoma / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D005260:Female; D005455:Fluorescent Antibody Technique; D015316:Genetic Therapy; D006801:Humans; D020287:In Situ Nick-End Labeling; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D023041:Xenograft Model Antitumor Assays
chemical_list: C436291:CDKN1B protein, human; D047908:Intracellular Signaling Peptides and Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D010447:Peptide Hydrolases; C501488:COPS5 protein, human; D000075686:COP9 Signalosome Complex