Gene Therapy

Gene Therapy is a technique for correcting defective genes responsible for disease development. It involves replacing, removing, inserting, or altering genes in order to prevent or treat a disease. This can occur in several ways. Researchers can correct defective genes by adding normal genes to the genome (the total set of genes carried by the cell), replacing abnormal genes, selectively mutating abnormal genes, or by altering the degree to which a gene is turned ‘on’ or ‘off.’

A carrier called a ‘vector’ is used to deliver the therapeutic gene. The most common ‘vectors’ are viruses (there are also non-viral vectors), because they already have the unique ability to get into the cell. Viral vectors are altered so they do not create new viruses in the cell, but just deliver their cargo, the new gene. Viruses are very effective at targeting specific cells.

For several years now, scientists in many labs in several countries have been looking for ‘suicide genes’ that would attack cancer cells, leaving normal cells untouched. A viral vector would introduce cells to a ‘suicide’ gene to rapidly dividing cells to raise intracellular protein levels associated with this gene. An inactive drug would then be administered to the cancer patient. The protein created by the suicide gene would convert the drug to its active form, which in turn would kill the cell. Since only tumor cells expressed the gene/protein, only tumor cells would be targeted and killed. Gene therapy is a relatively new treatment approach, very much in the experimental stages, and requires participation in a clinical trial to access.