Cancer begins in our DNA, the material that stores our genetic information. This material is made of molecules called nucleotides that are partially made up of nitrogenous bases (one nucleotide has one base). The order of these bases that are attached to the rest of their respective nucleotides and represented by A’s, T’s, C’s, and G’s are what create the sequence of our DNA. When changed and not repaired by DNA repair mechanisms, these sequences that are vital to the function of our bodies’ physiological processes can lead to a cancer diagnosis.
Not All Changes Create Cancer
Fortunately, the vast majority of our DNA is non-coding, meaning that it does not result in a protein and, therefore, does not have a direct role in body processes. Changes, also known as mutations, in these areas of our DNA very rarely result in cancer. It is mutations in coding regions of our genome, also known as protein-coding genes, that typically result in the disease. More specifically, mutations in tumor suppressor genes and other genes that control cell growth are common causes. These genes are like signals that tell a cell when it should grow or not. When they become mutated and the “green light” is always on, cells grow out of control. This is when cancer occurs.
Survival of the Fittest
The mutated DNA has given the cell where it is contained an advantage over the other cells in its environment. It allows the cell to grow and divide whether or not it is healthy for the body and without behaving cooperatively with the other cells nearby. If we view the collection of cells as a group of animals and the cell with the mutated DNA as an animal with a particularly advantageous trait, it makes sense that the cell with the mutated DNA would be more likely to reproduce and to do so more frequently.
