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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Adenosylmethionine Decarboxylase, Animals, Animals, Newborn, Cell Proliferation, Colorectal Neoplasms, Cytomegalovirus, Dependovirus, Evaluation Studies as Topic, Factor IX, Female, Gene Transfer Techniques, Genetic Therapy, Genetic Vectors, Humans, In Vitro Techniques, Injections, Intraperitoneal, Injections, Intravenous, Luciferases, Luminescent Measurements, Male, Mice, Mice, Inbred C57BL, Neoplasm Invasiveness, Oligonucleotides, Antisense, Ornithine Decarboxylase, Polyamines, Serotyping, Sex Factors, Time Factors, Tissue Distribution, Transgenes, beta-Galactosidase.
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Does polyamine depletion by ODC-AdoMetDC antisense adenovirus impair human colorectal cancer growth and invasion in vitro and in vivo? Context: Polyamine biosynthesis is controlled primarily by ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC). Polyamine concentrations are elevated in colorectal cancer. Depletion of polyamine content in colorectal cancer by chemotherapy is related to tumor regression and impaired tumorigenicity. The current study evaluates the therapeutic effects of antisense ODC and AdoMetDC sequences on colorectal cancer in vitro and in vivo. Antisense ODC and AdoMetDC sequences were cloned into an adenoviral vector (Ad-ODC-AdoMetDCas). The human colon cancer cell lines, HT-29 and Caco-2, were infected with Ad-ODC-AdoMetDCas as well as with control vector. Viable cell counting, determination of polyamine concentrations, cell cycle analysis, and Matrigel invasion assays were performed in order to assess properties of tumor growth and invasiveness. Furthermore, the antitumor effects of Ad-ODC-AdoMetDCas were also evaluated in vivo in a nude mouse tumor model. Our study demonstrated that adenovirus-mediated ODC and AdoMetDC antisense expression inhibits tumor cell growth through a blockade of the polyamine synthesis pathway. This inhibitory effect cannot be reversed by the administration of putrescine. Tumor cells were arrested at the G1 phase of the cell cycle after gene transfer and had reduced invasiveness. The adenovirus also induced tumor regression in established tumors in nude mice.
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Our study suggests that Ad-ODC-AdoMetDCas has antitumor activity and therapeutic potential for the treatment of colorectal cancer. Final Decision: yes