Knowing how a person's body would allow a toxic effect to occur at the gene and protein level, may someday make it easier for doctors to decide what treatment is more appropriate. Such information also would lead to the development of better biomarkers to detect toxicity earlier during medical treatment, researchers said today at the 2003 American Association for the Advancement of Science (AAAS) Annual Meeting.
Like a wad of gum stuck in a child's hair, a small breast cancer cell from a tissue mass requires delicate unraveling and extraction. Traditionally, researchers have studied the genetics of the whole tumor mass because of the difficulty faced when trying to excise the cell of interest. Now, Emanuel Petricoin of the Food and Drug Administration has been working with a special video-game like microscope that pulls selected cells out, like a tractor beam. When combined with new protein array technologies he and his colleague Lance Liotta (National Cancer Institute) have also been developing, the new microscope technology has allowed him to study toxicity and the cancer-associated "miswiring" of the cellular circuitry in breast cancer patients receiving different kinds of drugs or combination of drugs.
After the cell is isolated from the tumor mass, it is ready to have its proteome (the protein complement encoded by a person's genome) analyzed. To do this, Petricoin has also developed protein array tests to detect subtle changes in protein phosphorylation along many key "nodes" within the cellular circuitry. Phosphorylation occurs when a phosphate group is removed from ATP, a component in many cellular circuits. While it is possible to know of the existence of a ge