if cancer is basically a clump of cells that dont want to die, why/how do things like cigarettes, asbestos, and the literal sun trigger it?
In: Biology
The cells in our body reproduce regularly and based off of a genetic map. That genetic map can naturally become distorted and cause cells to reproduce uncontrollably, becoming cancerous growths known as tumors.
A “carcinogen” is a substance (certain types of radiation, chemicals, etc.) that can basically screw up that genetic map much faster than would naturally occur in an otherwise healthy person. Cigarette smoke has a lot of carcinogens, both from radioactive sources and from certain chemicals. Energy from the sun is also radioactive – a lot of the more harmful light is filtered out in the atmosphere but you can still receive dangerous doses if you’re outside all the time without protection on.
Cancer cells result from mutations that disable the things that keep cell growth in check. Those mutations come from incorrect repairs to cell DNA, and those errors happen more frequently the more repairs take place.
Therefore things that cause damage that requires repairs increase the chances of developing cancer, stuff like cigarettes, asbestos, and sun exposure.
Every time your cells split theres a very small chance that something goes wrong and it becomes a cancerous cell instead of a healthy cell.
Those carcinogens damage cells, and force your body to get rid of them, and for another cell to split to replace it. Since they increase the number of cell splits, they increase your risk of cancer.
Those things damage your DNA. Your DNA is an instruction set on how to build cells.
If the right bits of DNA are damaged, then your body will read the wrong instructions and build heaps of useless cells, and that is called Cancer
Instead of a bunch of cells that don’t want to die, think of it more like a bunch of cells that have had their self-destruct button broken, or the wiring from the self-destruct button to the “reactor” broken. Because that self destruct signal either is not being received or not being carried out properly, the cells keep growing & replicating in an uncontrolled manner.
Carcinogens (or things that cause cancer) like smoking, UV radiation, etc., are the things breaking the self destruct.
A lot of people are saying stuff like carcinogens are the cause and mutations and etc without actually answering the question
Sun releases ionizing radiation which can knock electrons out in the DNA, thus changing it
Chemicals can cause stuff like DNA methylation to happen where the transcription and translation process of the DNA get affected so new cells can get made incorrectly etc
A more recent proposed mental model for understanding cancer comes from observing that cancer cells behave like much more primitive cells, and act in their own interest rather than in the interest of the organism. The idea is that harmful substances injure the cell to the point where instead of booting the cell’s assigned OS and operating accordingly, so to speak, it goes into kernel panic mode, and operates like a bacterium, having forgotten that it is supposed to operate as part of a larger organism. Those ultra primitive functions include proliferation and cell division, but lack the regulatory functions that make it participate in the over-all functioning of the organism. Part of that proper behavior is that certain cells trigger cell suicide when their continued activity harms the organism. There is evidence that supports this interpretation, but as with anything as complicated, it is controversial.
See this: [A New Theory on Cancer: What We Know About How It Starts Could All Be Wrong](https://www.newsweek.com/2017/07/28/cancer-evolution-cells-637632.html)
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In addition to the DNA damage aspect, these things cause irritation and inflammation. Inflammation helps promote cell replication thus allowing cells with damaged DNA to divide more.
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