How do oncogenes cause cancer? What are proto oncogenes?
What are oncogenes? Oncogenes, which are genes that can cause cancer, have become a hot topic in cancer research. The word comes from the Greek term onco, meaning tumor. Most cancer researchers believe that somehow, usually over a period of years, cancer causing agents ( carcinogens ) repeatedly brought into the body, finally damage a critical piece of a cell's genetic code. The damage causes the cell to send out abnormal messages related to some aspect of cell growth. As new cells spring from old, the misled cell leads an onslaught of others that result in runaway growth. The altered ones oncogenes take charge. More than twenty cancer genes have been identified in experiments in animals or in normal cells grown in the laboratory. How do oncogenes work? The oncogenes start dominating the way the cells behave. They disrupt the usual schedule and direct the cell to continue to grow. Most researchers believe that at least two cancer genes must be created, by random error, be...