Carcinogenesis Mary Fairbanks Jadaede Charles Hembly Rivas Amy Worth
Introduction: What is Carcinogenesis? • Carcinogenesis is the development of tumors due to alterations in the cells structure. Most alterations can develop due to facts we face day by day. In our environment we can be exposed to harmful substances that can affect us in the cellular level through food, water, sun exposure, or our neighborhood, pollutions and so on. Everything from your diet to prescribed medications can have cancerous effects on your body.
What are the sources of environmental carcinogenesis? • We chose this question in order to shed light on the sources that have actually been observed as having direct correlations to cancer development. This quashes the complacent belief that, “Everything causes cancer.” • Due to our research, we have realized that though many aspects of life expose us to environmental carcinogens, how much exposure, and the malignancy of the carcinogen affect the likeliness that an individual will develop cancer.
Some identified sources of carcinogenesis in our environment include... • Industrial Waste • Medical Treatments • Natural Sources • Diet
Industrial Wastes • Industrial waste can be products or chemicals introduced to the environment that originally were not there. If chemicals are dumped in a river the long terms affect can alter the river's food chain structure, animal's DNA structure by impairing or changing production of proteins, and or eventually lead to contamination in nearby oceans.
Medical Treatments • Radiation is one of the many treatments of environmental carcinogenesis. It mutates cells as well as sterilizes them. No cancer can arise from cells that have received high doses of radiation. • Hydantoin (glycolylurea) modifies the immune response by reducing the humoral response leaving the cellular response practically intact. This treatment has an inhibitory effect on tumor growth.
Natural Sources • UV! (Or Ultraviolet Radiation) The cause of the most common type of cancer, Nonmelanoma skin cancer, is the solar ultraviolet radiation emitted from the sun naturally to all of us. UV in sunlight can cause 3 different types of skin cancer and can be a tumor promoter as well as initiator. The UV induced DNA damage is attributed to the formation of pyrimidine dimmers in between the adjacent pyrimidine bases of DNA. If the damage due to the dimmers is not immediately repaired, the growth regulatory gene, p53, may mutate and contribute to tumor development. UVB has been known to cause Considerable damage to the DNA in skin but its UVA that has been shown to induce the pyrimidine dimmers and oxygen and nitrogen reactive species which damage DNA.
More Natural Sources • Radon!Radon is a cancer causing radioactive gas that is naturally formed from the breakdown of uranium in soil and rocks. It is the leading cause of lung cancer for non smokers and second leading for smokers. Radon affects so many lives because it seeps into homes through cracks in the basements, foundations and floor drains. The alpha particles emitted by radon bombards a cell, producing chemical radicals that enter the cell and cause DNA damage. The cells are usually killed or sterilized but can sometimes survive as damaged cells. The damaged cell can then reproduce in a cancerous manner.
Yet more Natural Sources… • Nitric oxide!Nitric oxide is a pollutant as well as a natural molecule. It can be produced by combustion of substances in air such as a car’s engine. It can also be created by more natural processes for example lightning’s high temperature can catalyze molecules of oxygen and nitrogen to form it and the human body can also produce it. Because of the different ways it can form, nitric oxide is a natural source of carcinogenesis but not always a source of environmental carcinogenesis. The human body produces it from L-arginine by the catalyst NO syntheses. Nitric oxide is a signaling molecule, that is, it transmits information between cells by interacting with the receptors thus triggering responses.
Diet (Concerning Meat) • Some sources environmental carcinogenesis in relation to diet includes eating cooked meats, and alcohol consumption. Though the protein and nutrients we can often only find in adequate consumption of meat are highly beneficial for our bodies, studies have shown that eating char-broiled foods, or meats, are a major contributor to adduct in the blood, which lead to carcinogenesis of healthy cells into cancerous ones. • The well-done cooking of meats and fish provides increased exposure to heterocyclic amines, compounds formed from the pyrolysis of creatines and amino acids, suspected colon and breast cancer carcinogens. (Pyrolysis is the anaerobic process of thermochemical decomposition of organic material at increased temperatures, it’s a process involved in charring.)
Diet (PAHs) • Polycyclic Aromatic Hydrocarbons (PAHs): They’re atmospheric pollutants that consist of fused aromatic rings, not containing heteroatoms or carrying substituents. (Heteroatoms are any atoms that do not contain carbon or hydrogen. Carrying substituents refers to an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon.) • PAHs occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning (whether fossil fuel or biomass), while also being found in food products and diet. While PAHs are found in vegetables and cooked meats, the larger intake comes from cereals, oils, and fats. They’re especially dangerous due to the fact they’re carcinogenic, mutagenic, and teratogenic. (Mutagenic means that they change genetic material and increase the frequency of mutations while teratogenic refers to the interference of the development of a fetus, they cause birth defects.)
A Question to ponder…? • Will there ever be a total cure for cancer? Since there are carcinogenic elements in many, if not all, facets of everyday life, is there any way to avoid the developing the expensive condition of cancer? We can lessen our exposure, but we have no way to totally protect ourselves. (That we’ve discovered so far anyway…)
Sources! Yayyyy • http://www.ncbi.nlm.nih.gov/pubmed/11902565 • http://cancerres.aacrjournals.org/content/60/14/3738.full • http://content.karger.com/ProdukteDB/produkte.asp?doi=10.1159/000106407 • http://ohsonline.com/articles/2008/01/epa-radon-may-be-most-potent-carcinogen-in-us-homes.aspx • http://carcin.oxfordjournals.org/content/15/10/2263.abstract • http://jn.nutrition.org/cgi/content/full/129/2/552S#SEC4 • http://www.springerlink.com/content/m27369m337v282w8