Gene Therapy of Chronic Lymphocytic Leukemia

The term gene therapy describes a new type of medicine mediated by the transfer of genes into somatic cells. Knowledge of viruses and how they introduce their genetic material into cells has allowed for development of virus-derived “vectors” that can infect cells and thereby introduce a selected gene(s). Through advances in molecular biology we can achieve high-level expression of the transferred genes (or transgene) in almost any type of mammalian cell. The transgene can direct synthesis of an intracellular, cell surface, or secreted protein(s) that complements a genetic defect or that provides for a desired phenotype. Alternatively, the transferred genetic material may mitigate expression of genes encoding unwanted or mutated proteins through “gene interference” or gene complementation. Conceivably, transfer and expression of appropriate genes could be used to correct for genetic deficiencies or allow for expression of a desired characteristic(s) by vector-infected (or transduced) cells. Although we have yet to realize the application of this technology in clinical practice, gene therapy arguably has tremendous potential for altering our approach to the treatment of a variety of genetic and acquired diseases, including cancer.