The World of Nanotechnology

There have been many changes in the science of drug discovery in the past decade. One advance that stands out, for example, is employing a patient's genetic profile to judge whether or not a specific drug will be effective in treating disease. Decoding the human genome spawned "pharmacogenomics. " This term was applied in the late 1950s, first to understand the genetic differences that cause people to metabolize drugs differently, and then to describe the creation of drugs in the 1990s that are individually designed for a person's genetic makeup. Genetic testing is now used to identify breast cancer patients who might benefit from therapy with Herceptin (trastuzumab), a monoclonal antibody. The drug targets cancer cells that overexpress a protein called HER-2, which is found on the surface of cancer cells. In tumor cells, errors in DNA replication may result in multiple copies of a gene on a single chromosome. This alteration, known as gene amplification, leads to an overexpression of the HER-2 protein, resulting in increased cell division and a higher rate of cell growth. Herceptin is used only to treat cancers that overexpress the HER-2 protein.1 The 21st century will no doubt be witness to a number of new discoveries in this field as scientists continue to solve the riddles of human genomics. Precise genetic testing will be pivotal in employing new monoclonal antibodies and other ne