iPod and Probiotic Giveaway

What Causes Cancer?

The cause of cancer is mutation (sudden change in DNA) within cells. This is the reason cancer is commonly seen in tissues (group of cells) where cell division occurs frequently (e.g. skin, where normally all cells of dermis are replaced in every four weeks, intestine where the intestinal mucosa cells divide rapidly) and cancer is almost nonexistent in tissues where cell division occurs very rarely or absent, such as heart muscles, skeletal muscles etc. Because sudden and unpredicted change in DNA (mutation) occurs only if cells divide frequently.id-100204117

DNA contain genes and each individual gene contain instruction that tells a cell what function to perform, how to grow and divide. Errors in instruction (mutation) can lead the cell to stop performing its normal functions and allow a cell to be cancerous by changing instructions how to grow.

Gene mutation can give a healthy cell to do following and thereby make it cancerous:

  • Instruct the cell to grow rapidly. Rapid division of cells produce similar kind of cells that themselves have instruction to grow rapidly, instead of normal rate of growth, because they all have same mutated genes.
  • Mutated cells fail to stop growing, unlike normal cells. Normal cells know when to stop growing (done by tumor suppressor gene) and dividing and have just the number of cells that are required by the body. But mutated cells do not know this and keep growing and accumulating. Cancer develops when tumor suppressor gene cannot perform its function normally and the opposing gene start over functioning. In normal cells there is a balance between tumor suppressor gene and tumor causing gene, i.e. There is disbalance in these two opposing genes.
  • Normally when there is an error in DNA, the DNA repair genes look for error and correct the error. However, if there is mutation in the DNA repair gene itself it leads to failure to repair errors in DNA and lead to cancerous cells. These cancerous cells multiply rapidly and develop full blown cancer in short time. In fact gene mutation occur frequently during normal cell growth and cell division. However, cell recognize this mutation/error quickly and repair done quickly too. But, sometimes the cell may miss the error/mutation and that may cause cancerous cell to start.

DNA/gene mutation can occur in two ways.

  • Mutation that is genetical, i.e. You inherit this mutation and you are born with such mutations. However, only a small fraction of cancers occur due to this type of mutation.
  • Mutation that occur after birth. This is the common form of mutation and cause of cancer. Gene mutation may occur due to radiation, smoking, exposure to cancer causing chemicals known as carcinogens, environmental exposure etc. Various other factors also contribute in causation of mutation and cancer such as obesity, lack of physical exercise, hormonal problems, chronic inflammation etc.

 

Image courtesy of [Mister GC] at FreeDigitalPhotos.net

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