Definition cancer cell
Cancer cells are cells that divide uncontrollably and can form solid tumors or spread to other parts of the body through the blood or lymphatic system. They differ from normal cells in various ways, including their growth and division patterns, DNA mutations, and characteristics.
How Does a Normal Cell Become a Cancer Cell?
Cancer cells are normal cells that have undergone genetic mutations that cause them to grow and divide uncontrollably. These mutations can be inherited, develop over time as we age, or occur due to exposure to environmental factors such as chemicals, viruses, tobacco smoke, or UV radiation from the sun.
When DNA becomes damaged in a normal cell, it either dies or repairs itself. However, in cancer cells, the damaged DNA is not repaired.
Cancer starts with changes in one cell or a small group of cells in the body. Mutations can happen by chance when a cell is dividing. Some mutations mean that the cell no longer understands its instructions and can start to grow out of control. There have to be about six different mutations before a normal cell turns into a cancer cell.
Not all tumors are cancerous. Benign tumors are not cancerous and are rarely life-threatening. They do not invade surrounding tissues or spread to other parts of the body like cancerous tumors do.
Metastasis is one of the terminal stages of cancer where cancerous cells enter the bloodstream or lymphatic system and travel to other parts of the body where they begin to divide and form secondary tumors.
Gene Variant Causes
Cancer is a genetic disease caused by changes in genes that control the way cells grow and multiply. There are two basic types of genetic mutations: acquired mutations and inherited mutations.
Acquired mutations are the most common cause of cancer, occurring from damage to genes in a particular cell during a person’s life. Inherited mutations, on the other hand, are present in the very first cell that eventually becomes a person and are passed down from parents to their children.
Some gene variants can increase a person’s risk of developing certain types of cancer. For example, BRCA1 and BRCA2 gene mutations increase a woman’s risk of developing hereditary breast or ovarian cancers.
Germline p53 mutations are rare but patients who carry them are at higher risk of developing many different types of cancer. Mutations in the KRAS gene have been linked to around 5% of people with cancer.
It typically takes more than one gene mutation for a cell to become a cancer cell. However, when someone inherits an abnormal copy of a gene, their risk of getting cancer is increased.
A single mutation will likely not cause cancer; usually, cancer occurs from multiple mutations over a lifetime. That is why cancer occurs more often in older people who have had more opportunities for mutations to build up.
Cancer Cell Cycle
Cancer is a disease of uncontrolled cell division. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as tumor suppressor genes. In normal cells, hundreds of genes intricately control the process of cell division.
Normal growth requires a balance between the activity of those genes that promote cell proliferation and those that suppress it. Tumor suppressor genes prevent the formation of cancerous tumors when they are working correctly, and tumors may form when they mutate so they no longer work.
Cancer cells can utilize telomerase to add many telomeric sections to the ends of DNA during DNA replication, allowing the cells to live much longer than other somatic cells. With this mechanism, cancer cells that usually die simply continue to divide.
Cancer Cell Vs Normal Cell
Cancer cells and normal cells differ in several ways. Normal cells follow a typical cycle of growth, division, and death. In contrast, cancer cells do not follow this cycle. Instead of dying, they multiply and continue to reproduce other abnormal cells.
These cells can invade body parts such as the breast, liver, lungs, and pancreas. Cancer cells ignore the body’s signals to stop dividing. The body has a built-in process called apoptosis or programmed cell death that tells the body to get rid of cells it doesn’t need anymore.
Normal cells are better at listening: They listen to the body’s cues and die when they are supposed to.
Cancer cells may influence normal cells by affecting their behavior, molecules, and blood vessels near a tumor. For example, cancer cells may recruit normal cells to develop new blood vessels that keep the tumor alive and give it a chance to grow.
Cancer is a group of about 100 diseases involving abnormal cell growth. Although most individuals facing a cancer diagnosis want to know what caused their cancer, the answer is not that simple.
Cancer cells don’t stop growing and dividing when there are enough of them, unlike normal cells that obey signals telling them when they have reached their limit and will cause damage if they grow any further.
Unlike healthy cells that carry on maturing or become so specialized, cancer cells don’t specialize because they often reproduce very quickly and don’t have a chance to mature.
Cancer therapies prevent blood vessels from growing toward tumors by targeting the abnormal features of cancerous behaviors such as relying on different kinds of nutrients than normal ones or making energy from nutrients in a different way than most normal ones.