Word: suppressor
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...last week researchers had found perhaps 100 cancer genes, at least three dozen of them important in human tumors. Some, known as oncogenes, turn on cell division, whereas others, called tumor-suppressor genes, are responsible for switching the process off. In their normal form, both kinds of genes work as a team, enabling the body to perform such vital tasks as replacing dead cells or repairing defective ones. But mutations in the chemical makeup of these genes, whether inherited or acquired later in life, can disrupt these finely tuned checks and balances. A cell containing a faulty oncogene is often...
...begin with, a cell must accumulate mutations not in just one or two genes but in several. In the case of colon cancer, Dr. Bert Vogelstein and his colleagues at Baltimore's Johns Hopkins Oncology Center have shown that a cell must sustain damage to at least three tumor-suppressor genes and one oncogene. The first mutation spurs the growth of the cell, triggering the formation of a benign polyp. Later changes cause the polyp to expand and become increasingly irregular in shape. By the time a cell in this growing mass suffers a final, fateful...
...ingredients of cigarette smoke. Many carcinogens, it turns out, are not blunderbusses but leave highly individualized fingerprints in the DNA they touch. At the National Cancer Institute, Dr. Curtis Harris, a molecular epidemiologist, has been examining cells from liver- and lung-cancer patients, searching for mutations in a tumor-suppressor gene known as p53 (p stands for the protein the gene makes and 53 for the protein's molecular weight). Smokers who develop lung cancer, Harris has found, show tiny alterations in the p53 gene that differ from those in nonsmokers. They also vary from the changes found in Chinese...
...number one cited scientist in the world, according to Science Watch, is Bert Vogelstein, molecular biologist at Johns Hopkins University who has investigated the activity of a tumor suppressor gene...
While still in the testing stages, Friend hopes the technique, which measures the levels of the product of a genetic tumor suppressor known as p53, will decrease the amount of time necessary to screen patients from weeks to just hours...