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Cancer Basics |
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Cancer occurs in many forms, in almost any tissue throughout the body, but it is important to first understand what cancer is. Cancer is defined as a disease in which cells: · Become functionally abnormal · Fail to respond to normal control mechanisms · Grow and proliferate without moderation
Cancerous cells will outgrow, out-divide and out-live neighboring cells within a tissue, and if there is an accumulation of cancerous cells in a specific tissue a tumor will arise which is the most characteristic physical manifestation of the disease. What makes cancer so deadly is that if cancerous cell over-run the population of normal cells, the tissue in which the disease presides will consequently lose its function. In addition to this, cancerous cells have the ability to metastasize, or spread to other tissues with in the body which is often the cause of cancer-related death.
Specifically, cancerous cells have characteristics which determine if the cell truly is cancerous. Cancer cells: · Fail to undergo Apoptosis—programmed cell death · This means that there is no biological way for the body to inhibit cancer cell growth · Have genetic instability · Due to abnormal chromosome maintenance, failure to recognize cell cycle checkpoints, and/or are unable to undergo DNA repair results in an abnormally high mutation rate · Fail to repair DNA damage · DNA damage leads to the formation of non or miss-functional proteins that are important in sustaining normal cellular life in a tissue cancer cells skip checkpoints which force the cell to repair DNA damage · Lack a built-in-limit to cell proliferation · Normal cells have a replicative cell senescence, meaning they permanently stop dividing after a certain number of divisions. This process is regulated by the progressive shortening of the telomeres (ends of chromosomes), which is not done in cancer cells · Ignore normal cell signaling pathways · There are various pathways within the cell that conduct the cell’s action in a given environment, cancer cells fail to recognize or use these pathways
In summary, cancerous cells fail to be regulated, fixed, or killed when needed. As a result, these cells need to be destroyed or removed from the body. When treating cancer this proves to be a rather daunting task. This is because one wants to specifically kill the cancerous cells and leave the normal cells in tact, and if one cancerous cell is left after treatment it has the ability to spread, proliferate, and regenerate within the body. |
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Understanding Cancer |
