ABSTRACT
The controlled expression of genes is the cornerstone in the regulation of growth and development of cells and organisms. This chapter describes two means of accomplishing this: antisense molecules and ribozymes. Antisense-based inhibition of gene expression occurs following the annealing of either DNA or RNA molecules that are complementary to a messenger RNA (mRNA) molecule. The specificity of the antisense molecule to a single mRNA transcript is dependent on its length and ability to hybridize to its target. Antisense targeting has been found to be highly flexible and has been used to inhibit expression of a variety of cellular genes. Oligodeoxynucleotides may also be used as a component of a therapeutic regime to sensitize the cell to conventional therapies. Initial cellular experiments with targeted ribozymes were conducted on transcripts not endogenous to the cell, such as infectious viral RNA. Ribozyme and antisense-based inhibition of gene expression can be targeted specifically to any mRNA.
