Construction Of ODC Antisense RNA Mammalian Expression Plasmid And The Reversion Of Malignant Phenotypes Of Human Lung Squamous Carcinoma Cells

Ornithine decarboxylase (ODC,EC4.1.1.17) is a rate-limiting enzyme in polyamine biosynthesis. Polyamines including putrescine (Pu), spermidine (Spd), and spermine (Sp) play important regulatory roles in mammalian cell proliferation and differentiaton. The aberrations in ODC expression regulation, and subesquent polyamine accumulation are intimately associated with the genesis and development of cancer. Elevated levels of ODC gene products are consistantly detected in some oncogene transformed cell lines and virtually all animal tumors. Our previous reports and present studies had demonstrated that ODC specific inhibitor difluoromethylornithine (DFMO) could arrest cancer cell proliferation and induce its differentiation.It was indicated that controlling polyamine biosynthesis might be an effective pathway of anticancer.In order to control polyamine biosynthesis at gene level,and further to study the role of ODC gene in maintaining the malignant phenotypes of cancer, The ODC antisense RNA mammalian expression plasmid was constructed. The changes in growth characteristics and tumorigenicity of human lung squamous carcinoma cells transfected with ODC antisense RNA expression plasmid and the molecular mechanism of these changes were studied systematically. The main points of this study were summarized as follows:1. Construction of recombinant plasmids expressing ODC anti-...