Cancer1
Cancer has affected the lives of each and every one of us alive today. Many people have know someone with cancer, yet even those who haven't have been bombarded with constant reminders of its terrible threat. Although cancer is often referred to as a single condition, it actually consists of more than 100 different diseases, all characterized by the uncontrolled growth, reproduction, and spread of abnormal body cells. All of these diseases are individually unique, yet the basic processes that produce cancers are very similar (Ruddon, 1995). The human body consists of over 30 trillion cells, living in a complex, interdependent harmony. They regulate each other's proliferation; normal cells reproduce only when instructed to do so by other cells in their vicinity. This constant collaboration ensures that each tissue maintains a certain size and function that is exactly what the body needs. Cancer cells, on the other hand, violate the entire process. Not only do they ignore the body's controls on proliferation, they possess the ability to invade nearby tissues, and may even metastasize - migrate and form tumors in distant sites of the body. How do cancer cells achieve this? For decades, this qu
Luckily, cancerous tumors are not caused by one little mutation in one cell - they are caused by multiple mutations in a number of the cell's growth-controlling genes. The number of mutations necessary can be as low as two or quite high, depending on the specific type of cancer. Generally, these mutations occur either from mistakes during cell reproduction, or due to DNA damage caused by carcinogens such as tobacco, certain poisons, and UV rays. So, why don't we all get cancer from these things right away? Consider that one of your cells is damaged by poison and becomes mutated. In order for this cell to turn into a cancer cell, the rest of the necessary mutations must also occur in this very same cell. This in itself, is fairly unlikely. It normally takes decades for an incipient tumor to collect all the mutations required for it's malignant growth, which explains why the average age for cancer diagnosis is 67 (Ruddon, 1995). Why, then, do some individuals contract cancer before the typical age of onset? In many cases, this is explained by the inheritance of a mutation in a critical growth controlling gene. Typically, this mutation would be a very rare event. However, in this individual, the mutation is present in ALL the cells of the body,
Some common words found in the essay are:
Cancer Cancer, Cancer Society, ruddon 1995, Genetics Clinician, Cancer Biology, Brock DJH, University Press, Ruddon Raymond, tumor suppressor genes, body cancer cells, body cancer, brock 1993, university press, ed york, cancer cells, suppressor genes, human body, growth reproduction, tumor suppressor,
Approximate Word count = 849
Approximate Pages = 3 (250 words per page double spaced)
|
