Cancer, as the definition goes, is uncontrolled cell growth. In order for these cancer cells to continue growing, they must have signals from inside or the environment to tell the cell to grow. Usually, these signals come from normal signals that have become mutated and cannot be turned on or turned off.
These signals are in form of proteins that turn on and off certain cell functions. Here is one of them.
Ras. Ras is a protein that turns on the cell cycle, or the process that cells undergo when dividing. Normally, Ras is turned off after its function is complete. But, a mutated Ras cannot be turned off. Therefore, it’ll continue to tell the cell to proliferate.
Before Ras is mutated, it is a proto-oncogene. This is a gene that once mutated becomes an oncogene. An oncogene is a gene who codes for a mutated protein that pushes the cell cycle forward without being able to be turned off.
Sources: Figure 11.30 The Biology of Cancer (© Garland Science 2007)
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