A novel SV40-based vector successfully transduces and expresses an alpha 1-antitrypsin ribozyme in a human hepatoma-derived cell line

Open Access
Publisher Website
Google Scholar
Abstract
Alpha 1-antitrypsin (α1AT) deficiency disease is one of the more common hereditary disorders that affects the liver and lung. The liver disease of α1AT deficiency is generally thought to be caused by the accumulation of an abnormal α1AT protein in hepatocytes, whereas the lung disease is thought to be due to a relative lack of the normal protein in the circulation. Therefore, one possible approach to prevent and treat α1AT disease is to both inhibit the expression of the mutated α1AT gene, and to provide a means of synthesizing the normal protein. To do this, we designed specific hammerhead ribozymes that were capable of cleaving the α1AT mRNA at specific sites, and constructed a modified α1AT cDNA not susceptible to ribozyme cleavage. Ribozymes were effective in inhibiting α1AT expression in a human hepatoma cell line using a newly developed simian virus (SV40) vector system. In addition, the hepatoma cell line was stably transduced with a modified α1AT cDNA that was capable of producing wild-type α1AT protein, but was not cleaved by the ribozyme that decreased endogenous α1AT expression. These results suggest that ribozymes can be employed for the specific inhibition for an abnormal α1AT gene product, the first step in designing a gene therapy for the disease. The findings also suggest that the novel SV40-derived vector may represent a fundamental improvement in the gene therapeutic armarmentarium.