How do healthy cells
become cancerous?
become cancerous?
A healthy cell does not turn into a cancer cell overnight. Its behavior gradually changes, a result of damage to between three and seven of the hundreds of genes that control cell growth, division and life span. First, the cell starts to grow and multiply. Over time, more changes may take place. The cell and its descendants may eventually become immortal, escape destruction by the body's defences, develop their own blood supply and invade the rest of body.
Why is cell growth a problem in
cancer?
cancer?
A cell is continuously receiving messages, both from its own genes and from other cells. Some tell it to grow and multiply, others tell it to stop growing and rest, or even to die. If there are enough 'grow' messages, the next stage of the cell's life starts. In a cancer cell, the messages to grow may be altered, or the messages to stop growing or to die may be missing. The cell then begins to grow uncontrollably and divide too often.
cells live for?
Every time a normal cell divides, the ends of its chromosomes become shorter. Once they have worn down, the cell dies and is replaced. Cancer cells cheat this system - they retain their long chromosomes by continually adding bits back on. This process allows cancer cells to live forever. Cells from Henrietta Lacks, an American woman who was diagnosed with cervical cancer in 1951, are still growing. They are used in research laboratories all over the world, many years following her death.
Cancer Invading the body?
Most normal cells in your tissues stay put, stuck to each other and their surroundings. Unless they are attached to something, they cannot grow and multiply. If they become detached from their neighbours, they commit suicide, by a process known as apoptosis. But in cancer cells the normal self-destruct instructions do not work, and they can grow and multiply without being attached to anything. This allows them to invade the rest of the body, travelling via the bloodstream to start more tumours elsewhere (metastasis)
Here are some other FAQ about cancer
Missing checkpoints?
Why are cancer cells so powerful?
Why don't cancer cells die normally?
To read the answers to those question visit this link
SOURCE:http://www.sciencemuseum.org.uk/WhoAmI/FindOutMore/Yourbody/Whatiscancer/Whathappensincancer/Howdohealthycellsbecomecancerous.aspx#container
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