Nucleic acids in therapy.

Human diseases have been dissected at the molecular level, and most have been found to have their bases in genetic malfunctioning. Following the age-old principle of 'set a thief to catch a thief', nucleic acids have been awarded the role of rectifying these genetic defects. Through intensive research, nucleic acids have begun to earn their rightful place as therapeutic tools, as adjuncts to traditional therapies or as definitive therapies on their own. The commercial potential of these developments in the rapidly expanding global economy is also immense. However, careful consideration of the appropriate target cells, delivery vectors, timing and dosage is essential. The ethical and social impact of the technology must also be taken into account. Besides genetic therapy (delivering 'corrective' nucleic acid sequences into the target cells), genetic medicine will have two major auxiliary impacts on human health. First, the nucleic acid sequences will increasingly provide 'tracking devices' for disease progression in response to therapy, thus serving as an adjunct to other therapeutic modalities such as radiotherapy, chemotherapy and immunotherapy. Second, the same technologies that are being developed to 'vector' the nucleic acid sequences into the target cells will become methods of delivery into these cells for novel drug molecules, which themselves will be products of genetic medicine.