MutationCancer is a result of the breakdown of the controls that regulate cells. The causes of the the breakdown always include changes in important genes. The changes are often the result of mutations, changes in the sequence of chromosomes. Mutations can be very small changes, affecting only a few nucleotides or they can be very large, leading to major changes in the structure of chromosomes.
Both small and large mutations can affect the behavior of cells. Combinations of mutations in important genes can lead to the development of cancer. The material covered in these sections describes the relationship between mutation and cancer, the different kinds of mutations and what causes them.
Cancer GenesThe cell division process is dependent on a tightly controlled sequence of events. These events are dependent on the proper levels of and of certain genes. When this process does not occur properly, unregulated cell growth may be the end result. Of the 30,000 or so genes that are currently thought to exist in the human , there is a small subset that seems to be particularly important in the prevention, development, and progression of cancer. These genes have been found to be either malfunctioning or non-functioning in many different kinds of cancer.
The genes that have been identified to date have been categorized into two broad categories, depending on their normal functions in the cell.
- Genes whose products stimulate or enhance the division and viability of cells. This first category also includes genes that contribute to tumor growth by inhibiting cell death.
- Genes whose protein products can directly or indirectly prevent cell division or lead to cell death.
The genes in the second group are called tumor suppressors.
All Information from: http://www.cancerquest.org/tumor-host-interface-overview.html
(What I have been reading)