Cancer as a Genetic Disease Summary
Presented by: Charles Sawyers MD
Cancer research has been transformed into a disease-focused examination, which allows medical investigators to find the causes for a specific cancer and treat the cancer in a more targeted way. This transformation into a disease oriented research was made a reality by advances in DNA sequencing technologies, which allow scientists to understand the underlying causes of cancer and develop cancer-specific drugs. These technologies can sequence the DNA of the tumors in cancer patients, and will enable scientists to discover and chart the DNA mutations which lead to cancer. Thus, cancer research has entered a new phase, in ...view middle of the document...
On the cellular level, cancer disrupts normal homeostasis of cell birth and cell death. That is, cancer increases the rate of cellular division, to the point that it is uncontrollable, and inhibits cell death, resulting in a rapid increase of cell numbers. This imbalance of normal cell division and death negatively affects healthy tissue functioning. Thus, the basis of cancer research now is to better understand cancer at the molecular level and how to prevent the disruption of homeostasis.
Traditional cancer treatments include surgery, radiation and chemotherapy. Surgery removes tumor cells, and is highly effective. However, this can sometimes be difficult and even impossible when the cancer cells are located in highly vital and sensitive organs of the body, such as the brain. Surgery also does not ensure that all cancerous cells are removed, as even sophisticated technologies cannot detect all the cancer cells. This is why surgeons often use radiation and chemotherapy to supplement surgical removal of cancer cells, as these treatments can target microscopic cancer cell deposits.
Radiation and chemotherapy damage the DNA of the cancer cells with radiation and drugs respectively. This damage to the DNA prevents the cell from entering mitosis, and instead induces apoptosis. However, radiation has negative side effects such as hair loss, fatigue and skin changes. This occurs because radiation kills normal body cells along with cancerous cells. Similarly, chemotherapy drugs also damage normal healthy body cells. While these traditional cancer treatments are highly effective, their negative side effects and risks often diminish their advantages. Thus, researchers started to look for other solutions and found a possible answer in genomics.
Originally, cancer was thought to be spread and caused by infectious agent- viruses. This conjecture was a result of a discovery made by Dr. Francis Peyton Rous in 1901. When a farmer came and told Rous that tumors were spreading to all his chickens, Rous hypothesized that cancer was caused by an infection. He conducted an experiment to test his hypothesis, in which he injected a filtrate of the cancer without its cells into a healthy chicken, which soon developed cancer. This led him to conclude that cancer is caused by something smaller than a cell, a virus called Rous sarcoma virus (RSV). However, this later was proved to be false, as scientists discovered that the cancer causing...