An adenovirus expressing mutant p27 showed more potent antitumor effects than adenovirus-p27 wild type

• Published in: Cancer research (Chicago, Ill.) Ill.), 2001-08, Vol.61 (16), p.6163-6169
• Main Authors: PARK, Kyung-Ho, SEOL, Ja Young, KIM, Tae-You, YOO, Chul-Gyu, YOUNG WHAN KIM, SUNG KOO HAN, SHIM, Young-Soo, LEE, Choon-Taek
• Format: Article
• Language: English
• Subjects: Adenoviridae - genetics; Animals; Antineoplastic agents; Apoptosis - physiology; Biological and medical sciences; Carcinoma, Non-Small-Cell Lung - genetics; Carcinoma, Non-Small-Cell Lung - pathology; Carcinoma, Non-Small-Cell Lung - therapy; CDC2-CDC28 Kinases; Cell Cycle Proteins - biosynthesis; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Division - physiology; Chemotherapy; Cyclin E - metabolism; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases - metabolism; DNA Fragmentation; Female; Flow Cytometry; G1 Phase - physiology; Genetic Therapy - methods; Humans; Lung Neoplasms - genetics; Lung Neoplasms - pathology; Lung Neoplasms - therapy; Medical sciences; Mice; Mice, Inbred BALB C; Mice, Nude; Pharmacology. Drug treatments; Phosphorylation; Poly(ADP-ribose) Polymerases - metabolism; Protein-Serine-Threonine Kinases - metabolism; Retinoblastoma Protein - metabolism; S Phase - physiology; Transduction, Genetic; Tumor Cells, Cultured; Tumor Suppressor Proteins; Xenograft Model Antitumor Assays
• ISSN: 0008-5472; 1538-7445

The main inhibitory action of p27, a cyclin-dependent kinase inhibitor (CDKI), arises from its binding with the cyclin E/cyclin-dependent kinase 2 (Cdk2) complex that results in G(1)-S arrest. Degradation of p27 is mediated by phosphorylation of Thr-187 of p27, which follows ubiquitination. In this study, we generated two adenoviruses expressing wild-type p27 (ad-p27wt) and mutant p27 (ad-p27mt), with mutation of Thr-187/Pro-188 (ACGCCC) to Met-187/Ile-188 (ATGATC), which was produced with the belief that mutant p27 would bind cyclin E/CDK2 more stably and show more potent antitumor effects. Ad-p27wt and ad-p27mt expressed p27 proteins that were indistinguishable by anti-p27 antibody. A pulse chase experiment showed that p27mt was more resistant to degradation than p27wt. In human lung cancer cell lines, ad-p27mt showed stronger growth inhibition than ad-p27wt. Both types of ad-p27 induced G(1)-S arrest and apoptosis; however, ad-p27mt induced stronger G(1)-S arrest and apoptosis. Intratumoral injection of ad-p27mt induced partial regression of established tumors and inhibited the growth of human lung cancer xenografts more strongly than ad-p27wt. From these results, we conclude that ad-p27mt has the potential to become a novel and powerful gene therapy tool.