9 things (you might not know) about cancer
See how many of these scientific facts about cancer you already know.
Photo credit Dr Ellen De Leon, GBM cells in gel.
1. Cancer is a genetic disease.
However, unlike many other genetic diseases, only around 1% of cancers are inherited! This means that almost all cancers start from mature cells, through mutations to DNA, which may damage the DNA, accelerate cell division, halt cell death or changes to cells’ ability to migrate through the body.
2. One mutation is not enough to cause cancer.
Mutations to our DNA happen all the time as our cells divide and replicate. In most cases these mistakes are taken care of by built-in repair and ‘proofreading’ mechanisms that fix mutations or instruct the cell to die if it is damaged beyond repair. Cancer, it is believed, is a multistep process requiring several cancer-related genes to be mutated for cancer to occur. Mutations can sometimes build up over time, which is why many cases of cancer happen to older people.
3. Environmental factors affect our epigenetics which can cause cancer.
Epigenetics is the process by which our DNA changes in regards to the environment, affecting the regulation and transcription (copying) of particular genes. The main environmental causes of cancer are cigarette smoke, viruses, diet and ionising radiation.
4. An oncogene is a gene that has the potential to turn a cell cancerous.
This can happen when these genes are mutated or expressed at high levels.
5. The p53 tumour-suppressor gene
This is mutated in more than 50% of cancers and is involved in the regulation or stimulation of more than 50 other genes! Tumour-suppressor genes normally regulate cell lifecycle functions and cell death. Mutations in these genes result in DNA damage or mutations that, if not corrected, can accumulate and lead to cancer.
6. Cancer cells make connections
Cancer cells grow into bigger tumours through actively pulling in healthy cells by extending ‘cables’ out and reeling them into the mass.
7. Chemotherapy targets DNA through different stages of cell division.
Chemotherapy doesn’t specifically target cancer over other cells. However, because cancers grow and divide much more quickly than normal cells they get hit with the chemotherapy first. It does mean that other fast-dividing cells in the body like your hair also feel the effects, which is why people on chemo often lose their hair.
8. There are several different kinds of immunotherapy
These are being developed to rope your immune system into helping your body battle cancer. The main kinds are antibodies, nonspecific immunotherapies that use cytokines and cancer vaccines. Antibodies are used in different ways. They can ‘flag’ the cancer to your immune system, block parts of the cell that enable them to grow, or carry medicines such as radiotherapy or chemotherapy specifically to cancer cells. Cytokines (proteins produced by white blood cells to control immune responses) are used to help the body’s immune system destroy cancer cells and are typically given in combination with chemo and radiotherapy. They can be used to slow the growth of cancer cells, increase production of white blood cells to fight cancer and even counteract some of the effects of chemo. The last kind, cancer vaccines, can be split into two types – preventative and therapeutic vaccines. Preventative vaccines are only useful for cancer that are caused by infections, such as HPV. Therapeutic vaccines are given when someone has cancer and help prompt the immune system to fight the cancer cells.
9. Things are getting personal
Precision medicines are targeted to the individual characteristics of a person’s disease. In the case of cancer that means creating subgroups of people that have the same driving mutations of their cancers.
Sofia Casbolt & Tim Chalmers