In: Biology
Cells become cancer cells largely because of mutations in their genes. Some of these genes are called tumor suppressor genes. Mutationmay also cause some normal genes to become cancer-causing genes known as oncogenes.A tumor suppressor gene, or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer.
Examples of tumor suppressor genes include BRCA1, BRCA2, and p53 or TP53. Germline mutations in BRCA1 or BRCA2 genes increase a woman's risk of developing hereditary breast or ovarian cancers and a man's risk of developing hereditary prostate or breast cancers.
Most cancers are caused by gene faults that develop during our lifetime. They may happen as we get older due to random mistakes when a cell is dividing. Or they may happen because of something we are exposed to, such as cigarette smoke or sunlight. These things are called carcinogens. These gene changes don’t affect all body cells. They are not inherited and can't be passed on to our children. They are called acquired mutations. Cancers caused by acquired mutations are called sporadic cancers.
Inheriting faulty cancer genes-Some faulty genes that increase the risk of cancer can be passed on from parent to child. These are called inherited cancer genes. This occurs when there is a mistake or a fault in the genes in an egg or sperm cell. Then the gene fault can be passed on to children. Genes that increase the risk of cancer are called cancer susceptibility genes.
Drugs to treat cancer typically focus on the tumor's location in the body. They bombard the cancer along with the healthy cells around it.
The normal cells most commonly affected by chemotherapy are the blood cells, the cells in the mouth, stomach and bowel, and the hair follicles; resulting in low blood counts, mouth sores, nausea, diarrhea, and/or hair loss. Different drugs may affect different parts of the body.Cancer cells tend to form new cells more quickly than normal cells and this makes them a better target for chemotherapy drugs. However, chemo drugs can't tell the difference between healthy cells and cancer cells. This means normal cells are damaged along with the cancer cells, and this causes side effects.
Drugs called “small-molecule drugs”can block the process that helps cancer cells multiply and spread. These drugs are usually taken as pills. Angiogenesis inhibitors are an example of this type of targeted therapy. These drugs keep tissue around the tumor from making blood vessels.