*Cancer is a disease caused by uncontrolled growth of abnormal cells that can spread throughout the body*
What makes cancer cells abnormal?
What makes cancer cells abnormal?
- Shape - cancer cells are usually larger with unclear, jagged edges. Their nuclei are significantly larger, as seen in the image below (figure 2).
- Chromosomes - cancer cells are often missing or have extra chromosomes. The chromosomes that are present can often be broken or damaged. This leads to further mutations when dividing.
- Damaged DNA - cells have genes to regulate growth and allow the cell to undergo apoptosis. In cancer, a deadly combination of mutations causes unregulated growth and division. The cell is unable to trigger apoptosis to stop itself from continuing to spread.
- Surface proteins - one change that allows tumors to grow is an altered surface protein. These are used to identify itself to other cells. Usually, dysfunctional cells can be identified and killed by the immune system, but cancer cells hide from the body's defense by imitating normal surface proteins.
- Angiogenesis - tumors signal for blood vessels to grow towards them, providing the tumor with extra nutrients to grow faster. It also gives the cancerous cells easier access to the rest of the body.
- Metastatic capabilities - while normal cells bond with their surrounding tissue, cancer cells are not bond, allowing them to break away from their original growth site and spread around the body. This process is called metastasis (figure 1).