Carcinogens, or carcinogens, are external influences that cause changes in the genetic material of a cell, leading to the development of cancer. This term covers chemical substances as well as physical and biological factors. What are they of importance in the development of neoplastic disease? When are we exposed to them? Can we avoid them?
Contents:
- How was it discovered that carcinogens can cause cancer?
- What do we currently know about carcinogens?
- What are chemical carcinogens?
- Who is particularly at risk from chemical carcinogens?
- Carcinogens in cigarette smoke
- Alcohol as a chemical carcinogen
- What are physical carcinogens?
- When are we particularly exposed to physical carcinogens?
- How to protect yourself from UV radiation?
- What are biological carcinogens?
- How do oncogenic viruses cause cancerous mutations?
- How to protect yourself against oncogenic viruses?
- Is it possible to protect against carcinogens?
Carcinogenshave other names -carcinogens ,oncogenic agents , carcinogens ,carcinogens . Carcinogens, through various types of interactions, damage the structure of the DNA molecule. In this way they cause mutations. Most of these changes are harmless. In some cases, however, information relating to the control of cell proliferation or programmed death, i.e. apoptosis, is destroyed. Such changes lead to the formation of dangerous tissue that grows in an uncontrolled way and gradually kills the body.
It should be noted, however, that not all cancers are caused by carcinogens. Mutations of this type can arise spontaneously during cell division or be inherited from DNA obtained from our ancestors.
How was it discovered that carcinogens can cause cancer?
The first reports of doctors and scientists on the influence of carcinogens on the formation of cancer appeared at the beginning of the 20th century. It has been observed that this type of disease is particularly common among workers in the paint industry.These workers were exposed to toxic chemicals at work.
These observations were confirmed in tests on mice. The research showed that animals in which the skin was rubbed with toxic tar suffered from cancer significantly more often.
With the development of research on nuclear radiation, reports appeared about its impact on the human body. People who came into contact with him at work often died as a result of cancer. An example is Maria Skłodowska, who was particularly exposed to this influence because she researched natural radioactive isotopes. The researcher died of leukemia and her disease is now linked to a carcinogenic factor which is nuclear radiation.
What do we currently know about carcinogens?
The knowledge of cell biology and tumorigenesis has developed rapidly over the past century. We now know that various external factors can damage DNA leading to mutations.
Carcinogens are classified into:
- chemical carcinogens
- physical carcinogens
- biological carcinogens
What are chemical carcinogens?
Chemical carcinogens are substances that react with DNA causing permanent changes in it. Such damage is called mutations. Most of them do not lead to a neoplastic lesion. The process of neoplastic growth only begins when the information change relates to the record of the cell's life cycle. With prolonged exposure to a chemical carcinogen, the likelihood of a reaction leading to this type of mutation increases.
Examples of chemical substances that are carcinogens:
- asbestos - a material used in construction
- organic chemicals used in industry: aromatic amines, benzene, vinyl chloride, dioxins
- alcohol
- alkylating drugs - cytostatics used in chemotherapy
- thorotrast - a substance used as a contrast in X-ray analysis
- free radicals
- tar in cigarette smoke: anthracenes, benzopyrene, aromatic amines, nitrosamines
- aflatoxin - mold toxin produced
- heavy metals: arsenic, nickel
Who is particularly at risk from chemical carcinogens?
People working in industries that use toxic substances are particularly exposed to chemical carcinogens. People living in industrial areas or near an incineration plant are also at risk.
For occupations that are prone to factorscarcinogenic also include:
- car mechanics
- boiler manufacturers
- carpenters
- electricians
- steelworkers
- stoczniowcy
- railwaymen
Another risk group is people who are addicted to alcohol or cigarettes. It is currently estimated that these stimulants are one of the most dangerous factors leading to neoplastic diseases in our society.
Carcinogens in cigarette smoke
The substances contained in cigarette smoke easily penetrate the cells of our body. These toxins enter the blood through the alveoli and travel to all organs in our body. In cells, they react with DNA, leading to a number of mutations. These substances are involved in the formation of neoplasms such as:
- lip cancer
- oral cancer
- throat cancer
- bronchial cancer
- esophageal cancer
- stomach cancer
- pancreatic cancer
- kidney cancer
- bladder cancer
Statistics show that 25-30% of deaths as a result of cancer are related to the action of a carcinogenic factor which is cigarette smoke.
Alcohol as a chemical carcinogen
The statistics clearly show a significant share of the chemical factor, which is alcohol. It is estimated that high consumption of this substance increases the risk of neoplasms, such as: cancer of the oral cavity, cancer of the larynx, cancer of the larynx, cancer of the esophagus, cancer, liver cancer
The damage to the body's cells is caused not by ethyl alcohol itself, but by its toxic metabolite - acetaldehyde. This compound reacts with DNA causing permanent changes in it.
What are physical carcinogens?
Physical neoplastic factors include various types of radiation that can damage the structure of DNA. Mutations created in this way, if they concern information containing a record about the cell cycle, may lead to the formation of a neoplastic change.
The most important physical carcinogens:
- ionizing radiation
- UV radiation
When are we particularly exposed to physical carcinogens?
Using a solarium and excessive sunbathing are situations in which we are particularly exposed to harmful physical carcinogens. This is due to UV radiation, which has the ability to cause mutations. This factor also disrupts the biology of the cell, inactivating enzymes, as a result of which the mechanisms protecting against cancer are damaged.
Exposure to the sun or lamp light intanning beds can lead to the development of many types of skin cancer. People with fair complexion are particularly exposed to ultraviolet radiation.
How to protect yourself from UV radiation?
In order to reduce the risk of cancers caused by UV radiation, it is recommended:
- covering the body to avoid sunburn
- avoiding summer sun exposure between 11 and 15 o'clock
- using sunscreen
- resignation from visits to the solarium
What are biological carcinogens?
Biological carcinogens include microorganisms capable of causing genetic mutations.
Examples of biological carcinogens include:
- herpesvirus 8-HHV-8
- human papillomavirus - HPV
- hepatitis B-HBV
- hepatitis C-HCV virus
- Epstein-Barr- EBV virus
There are also microorganisms that do not cause mutations directly, but their presence increases the risk of developing a neoplastic lesion. This group includes:
- HIV virus
- Helicobacter pylori- bacteria responsible for the formation of stomach ulcers
Viruses with the ability to cause neoplastic mutations are called oncogenic.
How do oncogenic viruses cause cancerous mutations?
Viruses are biological creatures that do not have the ability to multiply on their own. In order to reproduce themselves, they use the host cells - that is, in the case of human disease, the cells of our body. For this purpose, they introduce their genetic material into our DNA. In the next step, human cells produce viruses based on information that is implanted in them.
In the case of oncogenic viruses, it happens that when genetic material is introduced into our cells, a neoplastic mutation occurs. It is estimated that 15% of malignant tumors are caused by these microorganisms.
How to protect yourself against oncogenic viruses?
Currently, vaccination is the most effective method of preventing cancer caused by viruses. An example is the vaccine against the human papillomavirus, or HPV. It is used in the prevention of cervical cancer. Research shows that it is an effective and safe method.
Is it possible to protect against carcinogens?
Our organisms are attacked by carcinogens every day. Some of them are produced by our body during metabolic changes. We are not inable to completely exclude their impact on our body.
Mutations appear in our cells quite often, but a he althy organism has repair mechanisms preventing the development of neoplastic changes. If the action of the carcinogen is prolonged and intense, this protection may fail. As a result, cancer cells are formed.
We have to accept that carcinogens are part of our daily life. Knowing the safety rules and avoiding carcinogens is the way to reduce the risk of cancer.
About the author
Sara Janowska, MA in pharmacyPhD student of interdisciplinary doctoral studies in the field of pharmaceutical and biomedical sciences at the Medical University of Lublin and the Institute of Biotechnology in Białystok. A graduate of pharmaceutical studies at the Medical University of Lublin with a specialization in Plant Medicine. She obtained a master's degree defending a thesis in the field of pharmaceutical botany on the antioxidant properties of extracts obtained from twenty species of mosses. Currently, in his research work, he deals with the synthesis of new anti-cancer substances and the study of their properties on cancer cell lines. For two years she worked as a master of pharmacy in an open pharmacy.